Dissertations / Theses on the topic 'Polyphenols and flavonoids'
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1
Kavuru, Padmini. "Crystal engineering of flavonoids." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002463.
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Oliveira, Eduardo de Jesus. "Development of methods for profiling flavonoids and their metabolites in biological fluids." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366790.
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BALASUBRAMANIAN, SHREEKRIPA. "DOSE AND VEHICLE EFFECTS ON THE PENETRATION RATE OF SELECTED PLANT POLYPHENOLS THROUGH HUMAN SKIN." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1016481382.
4
Kurzová, Pavlína. "Izolace antibakteriálních sloučenin z kávové sedliny." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433498.
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Coffee grounds are one of the very valuable lignocellulosic wastes that have been able to be processed and used for isolated phenolic substances. Many phenolic substances isolated from lignocellulosic wastes have antimicrobial properties. Aim of this thesis is isolation phenolic substances from spent coffee grounds extract and their available antimicrobial properties. Two isolation ways were applied to receive phenolic substances from spent coffee grounds: 1) solvent extraction (hexane, 75% ethanol, 70% acetone, diethyl ether, and ethyl acetate) and 2) release of active substances by alcoholic fermentation. All isolated materials were characterized by the viewpoint of concentration of reducing sugars, polyphenols and flavonoids. Subsequently, their antimicrobial activity was determined by using agar diffusion and broth dilution methods. Two gram-positive bacteria (Bacillus subtilis and Micrococcus luteus), one gram-negative bacteria (Serratia marcescens) and two yeasts (Candida glabrata and Saccharomyces cerevisiae) were used for antimicrobial testing. High-performance liquid chromatography (HPLC) was used to identify phenolic substances in the extracts. First, the results showed that the isolated sample with the highest antimicrobial activity was 70% acetone extract. This extract contained chlorogenic acid, gallic acid, caffeic acid and coumaric acid according to HPLC. The ethyl acetate extract showed the lowest antimicrobial activity. Second, after lyophilization, the isolated materials also revealed high antimicrobial activity. The highest antimicrobial activity displayed the materials obtained by the extraction with 70% ethanol. This sample contained chlorogenic acid, gallic acid and caffeic acids. Next, samples with phenolic compounds were obtained by the alcoholic fermentation of spent coffee grounds. These samples showed similarly to the previous solution extracts significant antimicrobial activity. Interestingly, the unfiltered samples received directly after alcoholic fermentation also showed antifungal properties. The characterization of phenolic compounds by HPLC showed similarly as in previous examples that chlorogenic, caffeic and gallic acids were present in these samples.
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Ciburová, Alena. "Studium antimikrobiálních látek zázvoru." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401841.
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For thousands of years ginger rhizomes are used in traditional Chinese medicine. Because of his significant pungent flavour is commonly used in foods and beverages all over the world. Nowadays many of the beneficial pharmacological positive effects of ginger rhizomes are identified. Their occurrence is due to the high concentration of bioactive compounds. This thesis is focused on analysing of occurrence of bioactive compounds such as polyphenols and flavonoids and their influence on antioxidation and antimicrobial properties of samples of fresh and dried ginger. The results show that for extraction of bioactive compounds in different ginger samples is more suitable to use different types of extraction solvents. The highest antioxidation activity was measured for macerate of 100% bio ginger tea from Sonnentor company in 96% ethanol. Antimicrobial properties were showed only for 100% bio ginger tea against gram-positive bacteria Microccocus luteus.
6
Rezaee, Nasim. "In vitro assessment to evaluate the potential effects of polyphenol extracts from sorghum on Alzheimer’s disease." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2022. https://ro.ecu.edu.au/theses/2581.
Abstract:
Background: Alzheimer's disease (AD) is a progressive neurodegenerative disorder that accounts for most dementia cases. AD is characterised by extracellular deposition of amyloid-β (Aβ) protein plaques and intracellular neurofibrillary tangles (NFTs), composed of hyper-phosphorylated tau. Other common hallmarks of the disease include neuroinflammation, oxidative stress and mitochondrial dysfunction. AD currently affects more than 55 million people worldwide and this number is increasingly growing. It is the second leading cause of death in Australia and the seventh leading cause of death worldwide. Despite its increasing economic, health and social burden, there are currently no effective treatments that substantially slow or reverse the progression of the disease. Because of the limited success of drug clinical trials, attention has focussed on natural products, particularly polyphenols (PPs) as possible alternative therapies mainly due to their multi-modal neuroprotective actions and fewer side effects. Sorghum is one such important candidate. It is a underutilized grain that grows widely in Australia. A wide range of PPs, including phenolic acids and flavonoids are present in sorghum grain. However, no study has investigated its neuroprotective activities to date.
Aim: The overall objective of the current study was the in vitro investigation of the neuroprotective effect of PP-rich extracts from six different sorghum varieties (Shawaya short black-1 (Black), IS1311C(Brown), QL33/QL36(Red), B923296(Red), QL12(White) and QL33(Red) on AD hallmarks.
Method and results: The PPs were extracted from sorghum and the polyphenolic content has been assessed. The sorghum Shawaya short black-1 and IS1311C showed the highest level of phenolic and flavonoid content compared to the other varieties. Nine different PPs have been identified through the HPLC-DAD assay. Then, we continued the experiments at the cellular level. First, the extracts were tested on human BE (2)-M17 neuroblastoma cells to determine the highest concentration which is non-toxic. The protective effects of these non-toxic doses of the extracts were then investigated for their ability to preserve cell viability in an Aβ42-induced cell model of AD. All six extracts (dissolved in DMSO) increased cell viability, but QL33(2000 μg/ml) was the most potent extract, increasing viability by 28%. To further evaluate whether there is a synergistic effect, these extracts were tested as paired combinations. However, no synergistic effect was noted. In addition, the extracts had significant anti-Aβ aggregation effects as assessed by the thioflavin T assay (Th-T). Shawaya short black-1 and B923296 demonstrated the highest and lowest inhibition effects, respectively. The extracts also affected Aβ42-induced reactive oxygen species (ROS), tau proteins and mitochondrial dysfunction. Except for B923296, the other five sorghum extracts showed a significant reduction of ROS and mitochondrial superoxide. Sorghum extracts also decreased the Aβ-induced total tau, tau phosphorylated at threonine- 231 (pT231) and Serine-199(pS199) (except for B923296). Furthermore, most of the sorghum extracts restored the mitochondrial membrane potential (Δψm) and adenosine triphosphate (ATP).
Conclusion: Overall, the sorghum extracts attenuated Aβ42-induced toxicity through multiple mechanisms. These extracts possess compounds that have the potential therapeutic value for AD. However, further studies using other in vitro and in vivo models of AD are required to validate these findings.
7
Tran, Dong tien. "Conception et synthèse de sondes moléculaires pour l'étude d'interactions polyphénol-protéine." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0443/document.
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Les polyphénols sont des métabolites secondaires d’origine végétale. Ces substances naturelles connues pour leurs pouvoirs antioxydants et anti-radicalaires, contribuent à la protection de la santé humaine notamment contre les maladies cardiovasculaires et neurodégénératives, mais également contre certains cancers et diabètes. Dans certains cas, ces effets biologiques bénéfiques pour la santé pourraient également être liés à une interaction spécifique polyphénol-protéine peu étudiée à ce jour par manque d’outils moléculaires adaptés. Les travaux effectués au cours de cette thèse ont consisté à concevoir, à synthétiser et à évaluer des sondes moléculaires polyvalentes porteuses de polyphénols comme substrats d’affinité pour l’analyse des interactions polyphénol-protéine. Dans ce contexte, de nombreuses sondes arborant différents types de polyphénols ont été synthétisées. Ces différentes sondes pourront être utilisées en protéomique chimique du type "Affinity-Based Protein Profiling" (ABPP) pour identifier au sein d’un mélange complexe de protéines, une protéine ayant une affinité spécifique pour un polyphénol donné. Ces mêmes sondes permettront également d’étudier de manière qualitative les interactions d’un polyphénol avec une protéine donnée en temps réel par la technique de résonance plasmonique de surface (SPR)Polyphenols are plant secondary metabolites. These natural substances, known for their antioxidant and anti-free radical properties, generally contribute to the protection of human health not only against cardiovascular and neurodegenerative diseases, but also against certain cancers and diabetes. In some cases, these beneficial biological effects could also be related to specific polyphenol-protein interactions. However, studying this type of interactions has suffered from the lack of adequate molecular tools. The work carried out during this thesis has included designing, synthesizing and evaluating modulable polyfunctional molecular probes carrying polyphenols as affinity substrates to analyze polyphenol-protein interactions. In this context, various probes harboring different kinds of polyphenols were synthesized. These probes could be used in chemical proteomics following an “Affinity-Based Protein Profiling” approach (ABPP) to identify a protein within complex protein mixtures, which has a specific affinity with a given polyphenol. These probes will also allow studying the interactions of a polyphenol with a given protein in real time in a qualitative way by surface plasmon resonance (SPR)
8
Ghnimi, Wafa. "Étude phytochimique des extraits de deux Euphorbiaceae : Ricinus communis et Jatropha curcas. Évaluation de leur propriété anti-oxydante et de leur action inhibitrice sur l’activité de l'acétylcholinestérase." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0006/document.
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Ce travail de recherche est centré sur la valorisation de deux Euphorbiacées : Ricinus communis et Jatropha curcas. La première est une espèce autochtone connue comme plante dont l’huile des graines est utilisée pour ses vertus cosmétiques quant à la deuxième, c’est une espèce allochtone récemment introduite à titre expérimental en Tunisie et connue comme plante bioénergetique. Pour le ricin huit populations Tunisiennes ont été étudiées: Riadh Andalous, Nefza, Béja, Nabeul, Hammamet, Bouficha, Khanguet Hajej et Aouled Amer. Quant au jatropha, le matériel végétal est récolté dans la station expérimentale de Nabeul (Tunisie). Il s’agit de huit populations qui proviennent d’Arusha en Tanzanie, de Mozambique, de Suriname et de Brésil à partir de cinq provenances à savoir : Paranà, Norte de Minas, Mato Grosso, Regiao sudeste et Vale do Jequitinhonha. Le travail comprend une première partie consacrée à une étude bibliographique. Une deuxième partie est consacrée aux matériels et méthodes utilisés et une dernière partie qui montre l’ensemble des résultats obtenues. Ainsi, les résultats montrent que les extraits des feuilles des populations des deux espèces étudiées sont plus riches en composés phénoliques que les extraits des racines. L’étude phytochimique a montré que le ricin contient surtout de l’acide gentisique. Quant au jatropha, il contient surtout de l’épicatechine et de la naringine. L’étude chimique des huiles fixes des deux espèces montrent que l’huile de ricin renferme essentiellement d’acide ricinoléique. Quant à l’huile de jatropha, elle contient deux acides gras en proportions majeures qui sont l’acide oléique et l’acide linoléique. L’évaluation des activités anti-oxydantes des extraits des deux espèces indique une corrélation positive entre ces activités et les teneurs en composés phénoliques. Par ailleurs, l’étude de l’activité anti-acétylcholinestérase des extraits testés montrent que ces extraits sont des inhibiteurs de l’AChE plus puissants que la galanthamine utilisée comme contrôle positif. Notre étude a confirmé que les différents extraits de ricin et de jatropha, autres que les huiles fixes, peuvent donc être exploités pour d’autres activités biologiques, parmi les quelles l’action inhibitrice de l’AChE une des principales cibles des traitements contre la maladie l’Alzheimer et le piégeage des radicaux libres, en raison de leur richesse en composés phénoliquesThe aim of this study is to promote two Euphorbiaceae plants the Ricinus communis and the Jatropha curcas, the first one is known for its oil used in the cosmetic products, whereas the second one is known especially for its seeds used in the production of biodiesel. For the castor plant, eight Tunisian populations are studied: Riadh Andalous, Nefza, Beja, Nabeul, Hammamet, Bouficha, Khanguet Hajej and Aouled Amer. For the jatropha, recently introduced in Tunisia, the plant material is collected from the Nabeul station (Tunisia). Eight populations coming from Arusha in Tanzania, Mozambique, Suriname and Brazil from regions of Paraná, Minas Norte, Mato Grosso, Regiao sudeste and Vale do Jequitinhonha are studied. In first, a bibliographic study is made. In second, the used materials and methods are cited. Fanilly, all the results are mentioned. The study shows that the phenolic compounds are higher in the leaves extracts than in the roots extracts for both species. The phytochemical study shows that the gentisic acid is the major phenolic compound identified in the castor plant extracts. In contrast, the epicatechin and the naringin are the most important phenolic compounds identified in the jatropha extracts. The GC-MS analysis reveals that the castor oil contains mainly the ricinoleic acid. For the jatropha oil, two major fatty acids are identified: the oleic and the linoleic acids. Results of the antioxidant properties of leaves and roots of both species indicate a positive correlation between the leaves and the roots activities and their contents of phenolic compounds. Furthermore, the anti-acetylcholinesterase activity of the tested extracts shows for the first time that some tested extracts are more active than the galantamine used as a positive control. Our study confirmed that, in addition to their oils, different extracts of the castor plant and the jatropha can be used for biological activities such as the scavenging free radicals and the inhibitory action of AChE enzyme, which is a major target for treatments against the Alzheimer's disease due to their high levels of phenolic compounds. Owing to the activities of the leaves and the roots extracts confirmed by this study, the agricultural exploitation of the castor plant and the jatropha can be economically more profitable
9
Teutschbein, Liana Morais Vianna. "Atividade cicatrizante de três espécies adaptadas ao cerrado brasileiro em modelo experimental de úlceras dérmicas em coelhos com análise imunohistológica e morfológica." Universidade Federal de Juiz de Fora (UFJF), 2011. https://repositorio.ufjf.br/jspui/handle/ufjf/2468.
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O cerrado brasileiro é um dos maiores biomas de diversidade biológica do planeta, abrigando uma ampla variedade de espécies medicinais utilizadas como parte da tradição e costume das comunidades locais. Os objetivos deste estudo foram determinar os teores de polifenóis e flavonóides; avaliar a atividade antioxidante; correlacionar os teores de polifenóis e flavonóides entre si e com a atividade antioxidante e avaliar a atividade cicatrizantes de três espécies deste bioma: Lippia sidoides; Synadenium grantii e Stachytarpheta gesnerioides. Através dos extratos etanólicos (EE), obtidos das folhas, foram quantificados espectrofotometricamente os teores de polifenóis e de flavonóides e, ainda, avaliada a atividade antioxidante (DPPH) e as correlações. Os EE foram incorporados ao creme base (10% de L. sidoides; 10% de Synadenium grantii e 10% de Stachytarpheta gesnerioides) e avaliados quanto à atividade cicatrizante, empregando o modelo de indução de úlceras dérmicas em coelhos albinos da Nova Zelândia (machos 1.5-2.0 kg; n=6). As úlceras foram analisadas macroscopicamente quanto ao aspecto da lesão e a contração de sua área durante 10 dias. Após este período, foi feito estudo histológico em lâminas coradas com hematoxilina-eosina para comparação do número de células inflamatórias; fibroblastos; vasos sanguíneos; área de colágeno e área de matriz extracelular entre os grupos e imunoistoquímica com a contagem dos miofibroblastos. Foram realizadas análises estatísticas descritivas para avaliar a significância das diferenças entre as médias dos resultados dos grupos, foi aplicada a análise de variância (ANOVA) e teste post hoc de Tukey, utilizando o SPSS versão 14.0 e p < 0,05. Foi avaliada a correlação de Pearson entre os teores de polifenóis e flavonóides e entre esses teores e a atividade antioxidante. Todos os EE das espécies utilizadas apresentaram presença de polifenóis, flavonóides e atividade antioxidante. Foi demonstrada uma correlação positiva entre os teores de polifenóis e flavonóides e atividade antioxidante. Não foi observada diferença na contração da lesão quando comparados os grupos controle e tratados e em relação ao número de miofibroblastos os grupos testados foram estatisticamente similares ao controle positivo. O tratamento com L. sidoides apresentou número de vasos sanguíneos, área de colágeno e área de matriz extracelular similar ao controle positivo; o número de fibroblastos e células inflamatórias foi 24% (p=0,002) e 54% (p < 0,001) menor, respectivamente, em relação ao controle positivo. O tratamento com Synadenium grantii apresentou número de fibroblastos, área de colágeno e área de matriz extracelular semelhante ao controle positivo e reduziu o número de células inflamatórias (61%) e vasos sanguíneos (54%) (p < 0,001 para ambos), em relação ao controle positivo. O tratamento com Stachytarpheta gesnerioides apresentou número de fibroblastos; área de colágeno e área de matriz extracelular semelhante ao controle positivo e reduziu o número de células inflamatórias (65%, p < 0,001) e vasos sanguíneos (42%, p=0,005) em relação ao controle positivo. Em relação ao número de miofibroblastos, todos os tratamentos foram estatisticamente similares ao controle positivo. A análise conjunta dos resultados inéditos sugere a realização de novos estudos científicos relacionados à atividade cicatrizante de L. sidoides.
The Brazilian cerrado is one of the planet’s major biological diversity biomes, hosting a wide variety of medicinal plants used as part of the tradition and customs of local communities. The objectives of this study were to determine the levels of polyphenols and flavonoids; evaluate the antioxidant activity; correlate the levels of polyphenols and flavonoids among themselves and with the antioxidant activity and to evaluate the healing activity of the ethanol extracts (EE) of three species of the cerrado: Lippia sidoides, Synadenium grantii and Stachytarpheta gesnerioides. With the ethanol extracts (EE), obtained from leaves, it were spectrophotometrically quantified the concentrations of polyphenols and flavonoids, and it was also evaluated the antioxidant activity (DPPH) and their correlations. The EE obtained from the leaves were incorporated into the cream base (10% of L. sidoides, 10% of Synadenium grantii and 10% of Stachytarpheta gesnerioides) and their healing activity was evalluated. It was used as experimental model the induction of dermal ulcers in New Zealand albino rabbits (males 1.5-2.0 kg; n = 6). The ulcers were analyzed for the appearance of the lesion and the contraction of the wound area during 10 days. After this period, the histology was conducted using histological sections stained with hematoxylin-eosin to compare the number of inflammatory cells, fibroblasts and blood vessels and immunohistochemistry to compare the number of myofibroblasts among the experimental groups. Descriptive statistics analysis were conducted and, to assess the significance of differences between the mean results of groups, It was also applied the analysis of variance (ANOVA) and Tukey's post hoc test, using SPSS version 14.0 and p <0.05. It was evaluated the Pearson correlation between the levels of polyphenols and flavonoids and between these levels and the antioxidant activity. All the EE of the used species showed the presence of polyphenols, flavonoids and antioxidant activity. It was demonstrated a positive correlation among these constituents and antioxidant activity. No difference was observed in the contraction of the lesion when compared to the control and treated groups. At microscopic analysis, treatment with L. sidoides showed the number of blood vessels, collagen area and area of extracellular matrix similar to the positive control; the number of fibroblasts and inflammatory cells was 24% (p = 0.002) and 54% (p <0.001) lower, respectively, compared to positive control. Treatment with Synadenium grantii presented number of fibroblasts, collagen area and area of extracellular matrix similar to the positive control and reduced the number of inflammatory cells (61%) and blood vessels (54%) (p <0.001 for both) compared the positive control. Treatment with Stachytarpheta gesnerioides presented number of fibroblasts, collagen area and area of extracellular matrix similar to the positive control and reduced the number of inflammatory cells (65%, p <0.001) and blood vessels (42%, p = 0.005) compared the positive control. In relation to the myofibroblasts, all treatments presented number of myofibroblasts similar to the positive control A combined analysis of these results suggest to perform further scientific studies related to healing activity of L. sidoides.
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Achaintre, David. "Développement d’une nouvelle méthode analytique pour le dosage des polyphénols dans les fluides biologiques et application à l’épidémiologie du cancer dans la cohorte EPIC." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1239/document.
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Les polyphénols sont un groupe de métabolites secondaires communément trouvés dans l’alimentation et plus de 500 composés différents sont retrouvés dans plus de 450 denrées alimentaires. Au cours des 30 dernières années, de nombreuses études in vitro et chez l’animal ont suggéré un rôle bénéfique des polyphénols dans des maladies chroniques comme le cancer 1-3. Les études épidémiologiques basées majoritairement sur des questionnaires alimentaires sont cependant plus contradictoires 4-6. De nouvelles méthodes sont requises pour quantifier un plus grand nombre de composés dans une même série afin de réaliser des études épidémiologiques à grande échelle. Le but de cette thèse est de développer des méthodes de quantification d’une large gamme de polyphénols représentatifs des principales classes et sous-classes de polyphénols dans le sang et urine, d’évaluer les excrétions urinaires de polyphénols et leurs associations avec la consommation d’aliments source dans une population Européenne, d’évaluer les concentrations dans le sang dans une étude cas-témoin sur cancer colorectal dans l’étude prospective européenne sur le cancer et la nutrition (EPIC). Après une brève présentation des polyphénols et du cancer colorectal dans le chapitre II, une méthode originale basée sur la dilution isotopique différentielle et l’analyse en spectrométrie de masse est développée pour quantifier 38 polyphénols dans l’urine et présentée dans le chapitre III. Cette méthode est basée sur un marquage différentiel en 12C et 13C des polyphénols grâce à une dérivatisation par les isotopes du chlorure de dansyl. Différentes conditions pour l’hydrolyse des polyphénols conjugués, l’extraction et la dérivatisation des aglycones ont été évaluées et la méthode a été validée pour la mesure de 37 polyphénols. Les niveaux d’excrétion urinaire de ces 37 polyphénols mesurés chez 475 individus de la cohorte EPIC issues de quatre pays européens sont présentés dans le chapitre IV. Une grande variabilité d’excrétion urinaire dans les quatre pays Européens a pu être montrée et des corrélations significatives avec la consommation de certains aliments source de ces composés ont été observées suggérant l’utilisation possible de plusieurs de ces polyphénols en tant que biomarqueurs de l’alimentation. Une méthode d’analyse pour les mêmes 37 polyphénols également basée sur la dilution isotopique différentielle est développée, validée et appliquée à 1618 échantillons dans la cohorte EPIC (chapitre V). Les changements majeurs en comparaison de la méthode sur la matrice urinaire sont essentiellement les difficultés d’hydrolyse des polyphénols conjugués et des effets de matrice importants mais réduits par la méthode de dilution isotopique. Enfin l’étude des associations entre l’exposition aux polyphénols mesurée à l’aide des marqueurs plasmatique avec le risque de cancer colorectal a été conduite dans une étude cas-témoin nichée dans la cohorte EPIC et est présentée dans le chapitre VI. Une association inverse entre les concentrations plasmatiques d’equol, et une association positive entre l’acide homovanillique et le risque de cancer du côlon ont été trouvées. Les résultats obtenus constituent une nouvelle base pour des applications futures dans le domaine de l’épidémiologie des polyphénolsPolyphenols are secondary plant metabolites found in diet and more than 500 different compounds are found in more than 450 foods. Along the last 30 years, many in vitro and animals studies have suggested a beneficial role of polyphenols in chronic diseases such as cancer. However, epidemiological studies based mainly on dietary questionnaires are inconsistent. New methodologies with broader polyphenol coverage are required to quantify a large diversity of compounds within large scale epidemiological studies.The goal of this thesis is to develop methods to quantify a large number of polyphenols representative of the main classes and sub-classes in blood and urine, evaluate urinary excretions of polyphenols and their association with food consumption in an European population, evaluate concentrations in blood in a nested case-control study on colorectal cancer within the European prospective investigation study on cancer and nutrition (EPIC).After a short presentation of polyphenols and colorectal cancer in chapter II, an original method based on differential isotopic dilution and analyse by tandem mass spectrometry is developed to quantify 38 polyphenols in urine and presented in chapter III. This method is based on differential 12C-/13C- isotope labelling of polyphenols through derivatisation with isotopic dansyl chloride reagents. Different conditions for enzymatic hydrolysis of conjugated polyphenols, extraction and dansylation of unconjugated aglycones have been tested, optimized and validated for the measure of 37 polyphenols.Urinary excretion levels of these 37 polyphenols in 475 subjects within EPIC cohort from 4 European countries are presented in chapter IV. Large urinary excretion variability in the 4 European countries has been shown and significant correlations with the consumption of specific food containing polyphenols have been observed suggesting the possible used of some polyphenols as biomarker for food consumption.A similar method on plasma for the 37 polyphenols, based on differential isotopic dilution, is developed, validated and applied to 1618 samples within the EPIC cohort (Chapter V). Main changes compared to the method developed on urine are essentially difficulties to hydrolyse conjugated polyphenols and huge matrix effects but reduced by the isotopic dilution method.Finally, the study on the association between polyphenols exposure measured owing to plasmatic marker with colorectal cancer risk has been driven in a nested case-control study within the EPIC cohort and is presented in chapter VI. An inverse association between plasmatic concentrations of equol, and a positive association between homovanillic acid and colon cancer risk have been found.Results obtained constitute a new approach for future applications in large scale epidemiology study on polyphenols
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Major, Hedda. "Untersuchungen zur Wirkungsweise von Birkenblättern (Betulae folium) und phenolischer Verbindungen." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2002. http://dx.doi.org/10.18452/14727.
Abstract:
Die Anwendung von Birkenblättern (Betulae folium) erfolgt zur Durchspülung der Harnwege. In der vorliegenden Arbeit wurde die Wirkungsweise der Birkenblätter auf verschiedenen Ebenen der Phytopharmakaforschung untersucht. Zunächst wurde in-vitro die Beeinflussung der Metallopeptidasen Neutrale Endopeptidase (NEP, EC 3.4.24.11), Angiotensin-Converting-Enzym (ACE, EC 3.4.15.1) und Leucin-Aminopeptidase (LAP, EC 3.4.11.2) durch Birkenblätterextrakte, -fraktionen und reine Naturstoffe untersucht. Die Auftrennung eines Methanol- und eines Ethylacetatextraktes führte nicht zur Gewinnung einzelner, für die Gesamtwirkungen der Extrakte verantwortlicher Fraktionen bzw. Komponenten. Die Eigenschaft der Flavonoide als wirksamkeitsmitbestimmende Inhaltsstoffe konnte jedoch bestätigt werden. Ein systematisches Screening von Flavonoiden ergab u.a., dass das Ausmaß der Enzymhemmung von der Anzahl der freien phenolischen OH-Funktionen bestimmt wurde und dass Flavonoidaglyka stärker die Enzyme hemmten, als die im Pflanzenmaterial vorliegenden Glykoside (IC50 NEP: Myricetin 42 Mikromol/L, Quercetin 192 Mikromol/L). Die in der Birkenrinde vorkommenden Triterpene Betulinsäure und Betulinol wurden als starke Inhibitoren der LAP erkannt (IC50 LAP: 7,3 +/- 1,4 bzw. 8,8 +/- 1,78 Mikromol/L). In einem nächsten Abschnitt der Arbeit wurden die Absorptionseigenschaften von Hyperosid und Rutin mit einem In-vitro-Perfusionsmodell am isolierten Rattendünndarm untersucht. Sowohl Rutin als auch Hyperosid traten unverändert als Glykoside durch den Darm in das Akzeptorkompartiment über. Auch in Form eines Birkenblätterextraktes wurde Hyperosid am Rattendünndarm absorbiert, der Extrakt veränderte jedoch nicht die Absorptionsrate. Als Mechanismus wurde der passive Transport durch die Poren der Tight junctions der Dünndarmzellen angenommen. Abschließend wurde eine Pilotstudie (n=14) durchgeführt, in der das ausgeschiedene Harnvolumen nach einmaliger Einnahme eines Birkenblättertees im Vergleich zu einer entsprechenden Menge Leitungswasser bestimmt wurde. Bei 50 % der Probanden wurde innerhalb der vierstündigen Testphase eine Zunahme der Harnproduktion beobachtet, bei den anderen 50 % stellte sich eine gegensätzliche Reaktion auf Tee und Placebo ein. Eine signifikante Erhöhung der Harnproduktion konnte somit, unter dem angegebenen Studiendesign, nicht nachgewiesen werden.Irrigation of the urinary tract is the therapeutic indication for Birch leaf (Betulae folium). In the present thesis, effects and efficacy of Birch leaves were investigated in various fields of medicinal plant research. The effects of Birch leaf extracts, their fractions, and pure natural compounds on the metallopeptidases - Neutral Endopeptidase (NEP, EC 3.4.24.11), Angiotensin Converting Enzyme (ACE, EC 3.4.15.1), and Leucine Aminopeptidase (LAP, EC 3.4.11.2) - were investigated in vitro. Phytochemical separation of extracts obtained by methanol and ethyl acetate did not result in more active fractions compared to those of the whole extracts. The ability of flavonoids to contribute to the efficacy reached by Birch leaf extracts, could be confirmed. A systematic screening could show that the inhibitory potency of flavonoids is dependent on the number of phenolic hydroxyl functions in their chemical structure. Aglycones of flavonoids were more active than their corresponding glycosides occurring in the plant material (IC50 NEP: myricetin 42 mikromol/L, quercetin 192 mikromol/L). Betulinic acid and betulinol, triterpenes of the bark of Betula, inhibited LAP strongly by reaching an IC50 of 7,3 +/- 1,4 mikromol/L and 8,8 +/- 1,78 mikromol/L, respectively. Furthermore, this thesis showed the absorption profiles of hyperoside and rutin in an isolated small intestine model of the rat. Both glycosides were detected in the acceptor compartment without being metabolised. Administration of hyperoside by a Birch leaf extract did not influence the absorption rate. A passive transport through the pores of the tight junctions, localized between the intestinal cells, was considered to be the mechanism of absorption of the flavonol glycosides. Finally, a human pilot study (n=14) was carried out. The excreted urinary volume was determined after a single intake of a Birch leaf infusion or tap water. An increased urine output after 4 hours of the test period was found in 50% of the volunteers. In the contrary, an opposite effect was determined in 50% of the volunteers after administration of the herbal infusion and of a placebo solution. Thus, no significant increase of urine volume could be observed under these test conditions.
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OLIVEIRA, Fausto Vaz de. "Aplicação da espectroscopia fotoacústica na identificação de biomoléculas funcionais do grupo dos polifenóis em frutas e vegetais." Universidade Federal de Campina Grande, 2014. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1980.
Abstract:
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CNPq
Neste trabalho usamos a técnica de Espectroscopia Fotoacústica na identificação de Biomoléculas Funcionais, presentes em várias frutas e vegetais. Essas biomoléculas, em geral compostos polifenólicos, formam grupos de substâncias amplamente distribuídos em plantas, frutas e legumes, componentes comuns da alimentação humana, especialmente flavonóides e taninos que possuem diversas propriedades terapêuticas e farmacológicas. Dentre as espécies de frutas e cereais investigadas, cientificamente estabelecidas como depositárias de moléculas bioativas, algumas se destacam por suas excelentes propriedades funcionais, tendo, por este motivo, recebido o nome pomposo de “superfrutas”. São elas caracterizadas por apresentarem altas concentrações de polifenóis tais como as antocianinas, os flavonóis (quercetinas, kaempferol, catequinas, resveratrol e taninos), os ácidos fenólicos como o gálico, o ascórbico, o elágico, o clorogênico, o benzóico, o felúrico, etc e os carotenóides, onde se destacam o β–caroteno, licopeno, violaxantina, zeaxantina, luteína, neoaxantina, dentre outras. As superfrutas são assim classificadas por exibirem extraordinário valor funcional. Os resultados experimentais obtidos por espectroscopia fotoacústica para os comprimentos de onda λmax que representa os picos de absorção em cada amostra de frutas e vegetais investigados evidenciam a existência de Biomoléculas Funcionais, que fazem bem a saúde humana. Nossos resultados, obtidos pela técnica de Espectroscopia Fotoacústica, confirmam esta como uma ferramenta experimental de grande potencial e eficiência na identificação de biomoléculas em sistemas biológicos “in natura”, sem necessidade de utilização de processos exaustivos de extração molecular.
In this work we have used the technique of Photoacoustic Spectroscopy to identify Functional Biomolecules, present in various fruits and vegetables. These polyphenolic compounds constitute groups of substances widely distributed in plants, fruits and vegetables, common components of the human diet, especially anthocyanins, flavonols, tannins and carotenoids that have been found to exhibit several therapeutic and pharmacological properties. Among the fruits and vegetables species investigated and scientifically established as host for bioactive or functional biomolecules, some of them are detached by their excellent functional properties, then, have been nominates as “superfruits”. They are characterized by exhibit high concentrations of polyphenols compounds such as anthocyanins, flavonols (quercitins, kaempferol, catechins, tannins), the phenolic acids such as the gallic, ascorbic, ellagic, chlorogenic, benzoic, ferulic, etc, and the carotenoids β–carotene, lycopene, violaxanthin, zeaxanthin, lutein, neoaxanthin among others. The “superfruits” are classified in this way for exhibit functional extraordinary value. The experimental results obtained by photoacoustic spectroscopy λmax for the wave lengths representing the absorption peaks of each sample of fruits and vegetables investigated showed the existence of Functional Biomolecules, which are human health as well. Our results obtained by the technique Photoacoustic Spectroscopy confirm this as an experimental tool with great potential and efficiency in the detection of biomolecules in biological systems “in nature”, without the need of using exhaustive molecular extraction processes.
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Vejrostová, Petra. "Studium směsných přírodních antimikrobiálních preparátů a možnosti jejich stabilizace." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240734.
Abstract:
Present diploma thesis is focused on natural antimicrobial substances. The aim of the experimental part of thesis was testing of antimicrobial activity of selected natural substances in free and encapsulated forms, preparation of particles and monitoring of their long-term stability. Various teas extracts (aqueous, ethanoic and DMSO) and aqueous herbs extracts were used as plant antimicrobial substances. Liposomes and chitosan particles with encapsulated aqueous teas extracts were prepared by ultrasonication. Encapsulation efficiency, size, stability and antioxidant activity for all particles were specified. Consequently, within a two months period, long-term stability for these particles was monitored. Spectrophotometric method for determining total polyphenols was used for evaluating encapsulation efficiency as well as for monitoring of long-term stability. The DLS method was used for determination of size and stability of particles. Antioxidation activity was monitored by using spectrophotometric method using ABTS. For testing antimicrobial activity of various types of teas, herbs extracts and their mixtures and combianitons with lysozyme and antibiotics, broth dilution methods were used while using both Gram positive and Gram negative bacterial test strains. Antimicrobial activity of prepared particles was also monitored, the antimicrobial activity was especially significant with the chitosan particles. Suitable combinations of natural substances whatever with antimicrobial or antioxidation effect either in free or encapsulated form could be used for applications for example in cosmetics industry, food processing or in medicine.
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Vacková, Hana. "Studium biologických účinků technického konopí a jeho frakcí." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316189.
Abstract:
Cannabis is the only plant which contains cannabinoids and thanks to these compounds it has enormous potential. This thesis deals with the analysis of technical hemp. Effects of cannabinoids and methods used for cannabis analysis are discussed in the theoretical part. The experimental part includes spectrophotometric characterization of cannabis, it´s antimicrobial effects and thin layer chromatography analysis. Three sorts of Cannabis sativa L. were analyzed, namely Finola, Fedora and Kompolti. Firstly, the content of polyphenols, flavonoids and antioxidant activity in prepared tinctures were determined. Moreover, antimicrobial test were performed using disk test and turbidity determination. Gram-positive and Gram-negative bacteria and yeast organism were tested. It was found that cannabis tinctures possess good antimicrobial effects. Some of them are comparable with synthetic antibiotics. Finally, thin layer chromatography enabled visualization of cannabinoids in prepared tinctures.
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Štindlová, Jitka. "Možnosti enkapsulace přírodních antioxidantů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-216837.
Abstract:
In theoretical part of this diploma thesis the basic properties of antioxidants, especially anthocyanins and phenolic compounds are described, as well as the basic features and principles of free radicals formation. The theoretical part also describes some possible ways of encapsulation of antioxidants into polysaccharide and lipid particles. In the experimental part basic characteristics of extracts from selected lyophilized fruits and vegetables (carrots, apples and mixed berries) are described. As group parameters of plant extracts the total antioxidant activity, content of flavonoids and phenolics, carotenoids, anthocyanins and ascorbic acid were determined. In experimental part also various encapsulation techniques were tested, encapsulation effectiveness of each technique was evaluated and the stability and size of the created particles were determined. As the best encapsulation method in terms of encapsulation efficiency in most of samples/parameters ethanol injection was found. On the other hand the particles prepared by ethanol injection are relatively unstable in terms of zeta potential, which is followed by their tendency to aggregate. As the most stable particles prepared by thin layer evaporation (TLE) and reverse phase thin layer evaporation (RP-TLE) were evaluated. Particles prepared by TLE, RP-TLE and chitosan-alginate particles exhibited a negative charge, while particles prepared by ethanol injection stayed uncharged and chitosan particles have a positive charge.
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Cruz, Ritiel Corrêa da. "COMPOSTOS FENÓLICOS E ATIVIDADE ANTIMICOBACTERIANA DAS FOLHAS DE Ficus benjamina L. e Ficus luschnathiana (MIQ.) MIQ." Universidade Federal de Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/5924.
Abstract:
The following work presents an evaluation of the antimycobacterial activity
(against Mycobacterium smegmatis) of the extracts, fractions and some phenolic
compounds present in the leaves of Ficus benjamina L. and Ficus luschnathiana
(Miq.) Miq., along with an estimation of the total phenolic content and the
quantification of some of these compounds by High Performance Liquid
Chromatography (HPLC). The phenolic estimation (Folin-Ciocalteu method) revealed
that the crude extracts and the high polarity fractions from these extracts (ethyl
acetate and n-butanol) are rich in polyphenols, although, its amount are not directly
related to the antimycobacterial activity. The evaluation of this biological activity was
performed by broth microdilution method, furnishing the minimum inhibitory
concentration (MIC) of the extracts, fractions and tested compounds. The better
biological activity was verified with butanolic fraction from F. luschnathiana (MIC =
156,25 μg/mL) and ethyl acetate fraction from F. benjamina (MIC = 312,50 μg/mL).
However, the correlation of these good results with specific compounds was not
possible, since technical difficulties prevented the isolation of substances from these
fractions; and concerning the screened polyphenols only quercetin was encountered
in butanolic fraction. In addition, quercetin exerted weak antimycobacterial activity
against M. smegmatis (MIC = 625,00 μg/mL), much weaker than that observed for
the fraction. The other investigated standards that were encountered in the extracts
and fractions (caffeic and chlorogenic acids, rutin and kaempferol), also exhibited
weak inhibitory effect. Thus, the good antimycobacterial activity observed for the
fractions above mentioned are probably not related to these phenolics, still it may be
related to compounds of the same nature. Many polyphenols, such as flavonoids,
have been reported as mycobacterial growth inhibitors, thus it is also possible to
conclude that the structural characteristics of quercetin, rutin and kaempferol do not
support the biological activity studied.A seguinte dissertação apresenta uma avaliação da atividade antimicobacteriana (frente à Mycobacterium smegmatis) de extratos, frações e substâncias fenólicas presentes nas folhas de Ficus benjamina L. e Ficus luschnathiana (Miq.) Miq., juntamente com uma estimativa do teor de polifenóis totais e a quantificação de alguns destes compostos por Cromatografia Líquida de Alta Eficiência (CLAE). O doseamento de polifenóis (método de Folin-Ciocalteu) revelou que os extratos brutos e as frações mais polares destes extratos (acetato de etila e n-butanol) são bastante providos de substâncias fenólicas, ainda que este teor não esteja diretamente relacionado à atividade antimicobacteriana. A avaliação desta atividade biológica foi realizada por método de microdiluição em caldo, que fornece a concentração inibitória mínima (CIM) dos extratos, frações e substâncias testadas. Uma boa atividade inibitória foi constatada para a fração butanólica de F. luschnathiana (MIC = 156,25 μg/mL) e para a fração acetato de etila de F. benjamina (MIC = 312,50 μg/mL). Entretanto, não foi possível correlacionar estes bons resultados a compostos em específico, visto que por dificuldades técnicas não foi realizado o isolamento de substâncias destas frações; e dos polifenóis pesquisados, somente a quercetina foi encontrada na fração butanólica. Esta por sua vez apresentou fraca atividade inibitória sobre M. smegmatis (MIC = 625,00 μg/mL), inferior a própria fração. Outros padrões investigados e que foram encontrados nos extratos e frações (ácidos cafeico e clorogênico, rutina e canferol), também apresentaram fraca atividade antimicobacteriana. Desta forma, a boa atividade inibitória das frações citadas acima possivelmente não se deve a estes polifenóis, ainda que possa estar relacionada a substâncias de natureza semelhante. Diversos polifenóis, como os flavonóides, têm sido reportados como inibidores do crescimento de micobactérias, de forma que também se pode concluir que as características estruturais da quercetina, rutina e canferol não favoreçam esta atividade biológica aqui apresentada.
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Plášková, Anna. "Stanovení autenticity potravin rostlinného původu pomocí molekulárních metod." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433058.
Abstract:
The aim of presented diploma thesis was to determination of authenticity of fruit baby foods for early infant feeding using molecular methods. In the experimental part, isolation kit was used for isolation of plant DNA from fruits (strawberry, apricot, raspberry, apple) and from six commercial fruit products for children. Isolated DNA was characterized and verified using PCR methods with primers specific for plant rDNA (ITS2). Specific primer pairs were designed to amplify DNA for the detection of one fruit species. Primer specificity was assessed with four fruit species. A mixture of fruit puree from the two fruits was used to determine the sensitivity of the multiplex PCR assay. Six commercial fruit products were evaluated to verify the applicability of the multiplex PCR assay. The methodology of molecular detection of fruit DNA by qPCR and multiplex qPCR (duplex) includes approaches, which enable to detect two fruits (strawberry-raspberry, apricot-apple) in one reaction and thus reduces time and money requirements.
18
Ben, Nasr Rania. "Investigation phytochimique, évaluation des activités larvicide et anti-acétylcholinestérase de différents extraits de Mercurialis annua L." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0155.
Abstract:
Ce travail rapporte le lien entre l'activité larvicide et la composition chimique des différents extraits des pieds mâles et femelles de Mercurialis annua L. une Euphorbiaceae souvent utilisées dans la médecine traditionnelle. Le matériel végétal exploité dans notre étude est ramassé dans quatre régions de la Tunisie situées dans des étages bioclimatiques différents : Bizerte, Jandouba, Nabeul et Beja. Cette étude comprend une première partie consacrée à une synthèse bibliographique. La deuxième partie est consacrée aux expérimentations et résultats. En effet, nous avons évalué l’activité antioxydante des différents extraits à l'aide d'essais DPPH. Les composés phénoliques ont été identifiés et quantifiés par chromatographie liquide couplée à un détecteur UV et à la spectrométrie de masse (LC-UV-ESI / MS). Nos résultats ont montré que les extraits méthanoliques des plantes mâles ont une activité antioxydante (AOA) plus élevé que celle détectée dans les extraits des plantes femelles. D’autre part, les extraits de plantes mâles et femelles de Bizerte ont affiché le taux d'AOA le plus élevé. Pour les deux sexes, les extraits de plantes de Beja ont la plus faible AOA. Certains composés phénoliques tels que : la narcissine, la gallocatéchine, la rutine, l'épigallocatéchine et l'épicatéchine ont été identifiés et quantifiés par LC-MS. D’autre part, l'activité larvicide des différents extraits aqueux de Mercurialis annua L. contre les larves de Tribolium confusum (Du Val) ont montré que la mortalité pouvait atteindre 100% après 48 heures d'exposition pour certains extraits, ceci est confirmé par leur faible LC50. Par ailleurs, l’étude de l’activité anti-acétylcholinestérase des extraits testés montrent que ces derniers sont des inhibiteurs de l’AChE plus puissants que la galantamine utilisée comme contrôle positif. Notre étude a confirmé que des extraits des feuilles et des graines des deux sexes de Mercurialis annua L., provenant des différentes régions de la Tunisie, peuvent donc être exploités pour d’autres activités biologiques, parmi lesquelles l’action inhibitrice de l’AChE En effet ces extraits sont riches en composés phénoliques, ce qui leur confère cette propriété thérapeutique contre la maladie d'Alzheimer et le piégeage les radicaux libresThis work reports the link between the larvicidal activity and the chemical composition of the different extracts of the male and female feet of Mercurialis annua L. a Euphorbiaceae often used in traditional medicine. The plant material used in our study is collected in four regions of Tunisia located in different bioclimatic stages: Bizerte, Jandouba, Nabeul and Beja. This study includes a first part devoted to a bibliographic synthesis. The second part is devoted to experiments and results. Indeed, we evaluated the antioxidant activity of the different extracts using DPPH tests. The phenolic compounds were identified and quantified by liquid chromatography coupled with a UV detector and mass spectrometry (LC-UV-ESI / MS). Our results showed that methanolic extracts from male plants have higher antioxidant activity (AOA) than that detected in extracts from female plants. On the other hand, male and female plant extracts from Bizerte showed the highest AOA level. For both sexes, Beja plant extracts have the lowest AOA. Certain phenolic compounds such as: narcissin, gallocatechin, rutin, epigallocatechin and epicatechin have been identified and quantified by LC-MS. On the other hand, the larvicidal activity of the various aqueous extracts of Mercurialis annua L. against the larvae of Tribolium confusum (Du Val) showed that the mortality could reach 100% after 48 hours of exposure for certain extracts, this is confirmed. by their low LC50. Furthermore, the study of the anti-acetylcholinesterase activity of the extracts tested shows that they are more potent AChE inhibitors than galantamine used as a positive control.Our study confirmed that extracts of the leaves and seeds of both sexes of Mercurialis annua L., coming from different regions of Tunisia, can therefore be exploited for other biological activities, among which the inhibitory action of AChE. Indeed, these extracts are rich in phenolic compounds, which gives them this therapeutic property against Alzheimer's disease and scavenging free radicals
19
Cotten, Bradley Matthew. "Structural Modification of the Flavanone Naringenin – Potential Impacts in Dietary Polyphenol Research." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1525275809703267.
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Jungbluth, Gerd. "Wechselwirkungen von Polyphenolen mit Cu2+, Fe3+ und Al3+ Analyse der Reaktionsprodukte mittels HPLC /." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=96064296X.
21
Abi, Aad Elizabeth. "Impact de la Détente Instantanée Contrôlée (DIC) sur l’extraction des molécules bioactives de rhizomes de Rheum ribes L." Electronic Thesis or Diss., La Rochelle, 2023. http://www.theses.fr/2023LAROS008.
Abstract:
Rheum ribes L. (la rhubarbe) est l'une des plantes médicinales méditerranéennes les plus importantes. La préparation des décoctions aqueuses des rhizomes de cette plante est devenue une pratique courante chez les patients souffrant de diverses maladies. La Détente Instantanée Contrôlée (DIC) est un traitement à haute température et à courte durée (HTST high-temperature/short-time) suivi d'une chute brutale de pression vers le vide (Pression absolue de 5 kPa environ). Le traitement DIC induit l’expansion et réduit la tortuosité de la matrice traitée, et assure ainsi une meilleure diffusivité des solvants d’extraction et par la suite une plus grande disponibilité des molécules actives. D’une part, nos travaux de recherche ont visé l’identification de l’impact du traitement par DIC des rhizomes d’une espèce libanaise de R. ribes L. Les évaluations ont été basées sur les teneurs en polyphénols totaux (TPC) et en flavonoïdes (TFC) ainsi que sur les pouvoirs antioxydants des extraits aqueux de rhizomes traités. Les résultats ont montré qu’une corrélation négative existe entre la pression de vapeur saturée appliquée et les valeurs de TPC, TFC et les activités antioxydantes des échantillons traités. Cependant, il n'y avait pas d'influence significative du temps de traitement par DIC sur les variables réponses. A ces deux facteurs opératoires de la DIC, pression et temps de traitement, s’ajoute la teneur en eau (W) des rhizomes. Les résultats ont montré qu’une augmentation ne provoque pas des meilleurs rendements en composés phénoliques. D’autre part, ce travail inclut également l’étude de l’impact du traitement par DIC sur les activités biologiques (effets antibactériens et antiprolifératifs) des extraits de rhizomes. Les résultats ont mis en évidence que les extraits aqueux de rhizomes traités par DIC présentent, aux concentrations testées, de très faibles pouvoirs antibactériens sur E. coli et S. aureus, avec des résultats légèrement supérieurs au niveau de l’inhibition de la croissance de S. aureus. En ce qui concerne le test de viabilité des cellules cancéreuses du mélanome, les résultats ont montré que le traitement par DIC a un impact positif sur le pouvoir antiprolifératif des échantillons traités en comparaison avec une matrice non-traitée par DIC et extraite par voie aqueuse. En particulier, deux échantillons parmi ceux testés, ont enregistré un pouvoir antiprolifératif de 60%. Les dosages par HPLC et UHPLC ont révélé la présence de trois anthraquinones (l’émodine, le chrysophanol et le physcion) dans les extraits de rhizomes ainsi qu’une vingtaine de composés de la famille des flavonoïdes. Cependant, les quantités d’anthraquinones détectés ne sont pas significativement plus élevées dans les extraits traités par DIC que dans ceux non-traités. Finalement, il a été constaté que la teneur phénolique totale d'un échantillon aqueux traité avec les paramètres optimaux de la DIC est égale à celle d'un point hydroalcoolique non traité. Des expérimentations supplémentaires seront nécessaires pour la validation de ce résultatRheum ribes L. (rhubarb) is one of the most important Mediterranean medicinal plants. Preparing its rhizomes’ aqueous decoctions has become common among patients suffering from various diseases. Instant Controlled Pressure Drop (DIC) is a High-Temperature Short-Time treatment (HTST) followed by an abrupt pressure drop towards the vacuum (approximately 5 kPa). This technology increases the expansion and reduces the tortuosity of the treated matrix to ensure better diffusivity of the extraction solvents and greater availability of the active molecules. On the one hand, our research aimed at the impact of DIC treatment on the rhizomes of a Lebanese species of R. ribes L. The evaluations were based on the contents of total phenolics (TPC) and flavonoids (TFC) as well as the antioxidant capacities of aqueous extracts of the treated rhizomes. The results showed a negative correlation between the saturated steam pressure applied and the values of TPC, TFC, and the antioxidant activities of the samples. However, DIC treatment time had no significant influence on the response variables. In addition to these two DIC operating factors (pressure and treatment time), the effect of the rhizomes water content (W) was also studied. The results showed that the increase of “W” does not lead to better yields of phenolic compounds. On the other hand, this study presents the impact of DIC treatment on the biological activities (antibacterial and antiproliferative effects) of rhizome extracts. The results revealed that the aqueous extracts of DIC-treated rhizomes show weak antibacterial powers on E. coli and S. aureus, with slightly superior results in inhibiting the growth of S. aureus. Regarding the viability test of melanoma cancer cells, the results showed that the DIC treatment positively impacts the antiproliferative power of the treated samples compared with the untreated point (aqueous MP). In particular, two samples among those tested recorded an antiproliferative power of 60%. The HPLC and UHPLC assays revealed the presence of three anthraquinones (emodin, chrysophanol, and physcion) in the rhizome extracts and about twenty compounds from the flavonoid family. However, the amounts of anthraquinones detected are not significantly higher in the extracts treated with DIC than in the untreated ones. Finally, it was found that the total phenolic content of an aqueous sample treated with the optimal DIC parameters is equal to that of an untreated hydroalcoholic sample. Further experiments will be necessary to validate this result
22
Connell, Mary J. "Determination of the Total Dietary Polyphenol Load of a Population of Healthy Adults in Appalachia, Ohio." Ohio University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1618492915308894.
23
Hümmer, Wolfgang. "Analyse potentiell chemopräventiv wirksamer Inhaltsstoffe von Apfelsaft." kostenfrei, 2009. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2009/3709/.
24
Roy, Sutapa. "POLYPHENOL CONTENT AND DIFFERENTIAL EXPRESSION OF FLAVONOID BIOSYNTHETIC PATHWAY GENES OF FRAGARIA SPP. WITH WHITE FRUIT." UKnowledge, 2016. http://uknowledge.uky.edu/pss_etds/72.
Abstract:
Strawberries are a rich source of polyphenols which contribute to berry color and plant disease resistance, and have been shown to lower the risk of many chronic when consumed. While a considerable body of work exists on the polyphenolic composition of commercial strawberry (Fragaria x ananassa Duch.), less information is available concerning polyphenols in Fragaria vesca, or Alpine strawberry, considered a model system for the Rosaceae family of crop species. The study of natural and genetically-engineered F. vesca mutants with white fruit can provide unique insight into regulation of metabolic flux through the complex branched phenylpropanoid/flavonoid biosynthetic pathway. Thus, the identity and quantity of major phenolic-derived anthocyanins, flavonols, flavan-3-ols, hydroxycinnamic acids, and ellagic acid (EA)-derived compounds, of red-fruited versus white-fruited genotypes of F. vesca and F. x ananassa were compared by high performance liquid chromatography-mass spectrometry. Due to the unknown origin of all but one white-fruited mutant of F. vesca, it was assumed that each resulted from independent mutation events and would exhibit different flavonoid profiles. A total of 27 phenolic-derived compounds were identified. The white genotypes of both species had very low anthocyanin levels. Total content of free EA and its conjugated forms were generally higher in white than in red F. vesca, but were the opposite in F. x ananassa, more in red than in white berries. Differences in content of individual flavonoids and in group totals among the white F. vesca genotypes suggested that they may represent different mutations affecting flavonoid production. Polyphenol profiles of a red and a white cultivar of F. vesca during four fruit developmental stages were determined along with transcriptional analyses of key structural and regulatory genes of the phenylpropanoid/ flavonoid biosynthesis. The final concentration of polyphenolic groups in red versus white F. vesca was due to the differential expression patterns of key pathway genes, especially dihydroflavonol-4-reductase, anthocyanidin synthase, and UDP-glucose-flavonoid-3-O-glucosyltransferase. The efficacy of phenolic compounds were evaluated in an in vitro study for inhibiting growth of Colletotrichum spp. associated with anthracnose fruit rot of strawberry. Only trans-cinnamic, p-coumaric, and ferulic acid inhibited isolates of the pathogen.
25
Meng, Linghua. "Caractérisation et extraction par techniques séparatives membranaires de polyphenols actifs et fonctionnels de Perilla frutescens." Aix-Marseille 3, 2007. http://www.theses.fr/2007AIX30045.
Abstract:
L’extraction des polyphénols de Perilla frutescens est optimisée à l’échelle du laboratoire pour obtenir un extrait rouge riche en antioxydants. Les composés phénoliques sont identifiés par RMN ou CL-SM, dont l’acide coutarique, la lutéoline-7-O-glucuronide et la vicénine-2 sont pour la première fois identifiés chez Perilla. L’extraction, la purification et la concentration de l’extrait de Perilla en grande quantité sont réalisées à l’échelle pilote par des procédés membranaires : microfiltration tangentielle, couplée avec l’osmose inverse (OI), équipées de membranes de type industriel. Les extraits microfiltrés sont concentrés par OI et/ou évaporation, jusqu’à un facteur de réduction volumique de 117. La stabilisation des extraits anthocyaniques est réalisée par atomisation, et l’activité antioxydante (AAO) est analysée par méthode DPPH. On a comparé l’AAO et la composition en polyphénols de 10 chémovars de Perilla. La malonylshisonine et l’acide rosmarinique sont les plus actifs en AAOThe extraction of polyphenols of Perilla frutescens is optimized at the laboratory scale to obtain a red extract, rich in antioxidant. The extracted polyphenolics are identified by NMR and LC-MS. Coutaric acid, luteolin O-glucuronide and vicenin-2 are for the first time identified in Perilla. The extraction, the purification and the concentration of Perilla extracts in large quantity are carried out at the pilot plant scale using coupled-membrane process: cross-flow microfiltration (CFM) and reverse osmosis (RO) equipped with industrial-type membranes. The microfiltrated extracts were concentrated by RO and/or by evaporation, up to a volume reduction factor of 117. Stabilization of anthocyanin extracts was carried out by spray-drying pilot unit to preserve their antioxidant activity (AOA), determined using DPPH method. AOA and polyphenol composition of 10 Perilla chemovars were compared. Malonylshisonin and rosmarinic acid are the most active compounds amongst all phenolics extracted from Perilla samples
26
Nay, Bastien. "Intérêts, statégies et approches expérimentales en synthèse chimique totale de flavanoi͏̈des et tanins condensés." Bordeaux 2, 1998. http://www.theses.fr/1998BOR2P100.
27
Herzog, Angelika. "Wirkung zweier Flavonoide - Flavon und Quercetin - auf das Proteom humaner transformierter und nicht transformierter Kolonozyten." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971006512.
28
WANG, GAI. "Effect of Frozen Storage on Antioxidant Capacity, Polyphenol Oxidase Activity, and Phenolic and Flavonoid Content and Color of Pawpaw Pulp." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1373373703.
29
Perromat, Guillaume. "Etude des composés phénoliques des feuilles de noisetier, Corylus avellana L : isolement et structure par RMN." Bordeaux 2, 1991. http://www.theses.fr/1991BOR2P069.
30
Pinto, Joana Mona e. "Avaliação de parâmetros imunológicos inatos e morfologia intestinal de trutas arco-íris (Oncorhynchus mykiss, Walbaum, 1792), alimentadas com ácido ascórbico e flavonoides após aplicação de glicocorticoide exógeno." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/42/42134/tde-12032015-165629/.
Abstract:
Os teleósteos submetidos a estresse ocorre aumento dos níveis de glicocorticoides, desencadeando uma reorganização metabólica, que resulta na imunossupressão dos animais, deixando-os mais suscetível a potenciais patógenos. Os antibióticos são comumente utilizados no controle das enfermidades bacterianas, porém, o uso indiscriminado pode provocar a seleção de cepas resistentes. Uma alternativa é a prevenção, através do uso de aditivos dietários imunoestimulantes. Os flavonoides e o ácido ascórbico (AA) são conhecidos por suas atividades anti-inflamatória, antioxidante e antiestresse. Assim, o estudo em questão visou avaliar a sua influência no desempenho; no intestino e nos parâmetros de imunidade inata de trutas arco-íris, em condições ideais e após aplicação de glicocorticoide exógeno (dexametasona). Foram realizados dois experimentos: 1 - grupos controle (GC) e o aditivo (GA), tratados por noventa dias; 2 - grupos controle (GC), aditivo (GA), dexametasona (GD) e aditivo + dexametasona (GAD), por trinta dias. No primeiro experimento o aditivo proporcionou o aumento da altura do epitélio no início do intestino, além da diminuição da densidade de células de muco nos cecos pilóricos, e o aumento no início do intestino. No segundo experimento, o aditivo causou a diminuição da altura do epitélio nos cecos pilóricos e início do intestino. O glicocorticoide exógeno causou perda de peso dos animais e a diminuição da altura do epitélio em todas as porções intestinais. Ainda, resultados positivos foram vistos em relação ao numero de leucócitos, do GAD, assim o aditivo foi diferencial e pareceu compensar as ações do glicocorticoide. Os resultados indicam que o uso de ácido ascórbico e flavonoides apresenta vantagens em situações de estresse.Teleosts subjected to stress show increase in glucocorticoids levels, this triggers a metabolic reorganization, resulting in the animal immunosuppression, this let animals susceptible to potential pathogens. The antibiotics are commonly used to control bacterial diseases, but their indiscriminate use can lead to selection of resistant pathogenic strains. A viable alternative is to work on prevention, through the use of immunostimulant dietary additives. Flavonoids and ascorbic acid (AA) are known for their anti-inflammatory, antioxidant and anti-stress activity. For this reason, the present study aimed to evaluate their influence in the growth performance; the gut; the innate immunity parameters of rainbow trouts in ideal conditions and after an exogenous glucocorticoid application (dexamethasone). For this, two experiments were performed: 1- groups control (GC) and the additive (GA) for ninety days. 2 - with four groups control (GC), additive (GA), dexamethasone (GD) and additive + dexamethasone (GAD) lasting thirty ninety days. In the first experiment, the additive increased epithelial height at the initial intestine, in addition to decreased mucus cell density of the pyloric caeca, and the increase in the initial intestine. In the second experiment, the additive decreased epithelial height in pyloric caeca and initial intestine. The exogenous glucocorticoid caused animal weight loss, and epithelial height decrease in all intestinal portions. Positive results was observed on GAD leukocytes number, so the additive was differential and seemed to compensate the glucocorticoids actions. The results indicate that the use of ascorbic acid and flavonoids has advantages in stress situations.
31
Seguin, Catherine. "Arbutus Unedo L. Et autres éricacées médicinales." Bordeaux 2, 1997. http://www.theses.fr/1997BOR2P049.
32
Matito, Sánchez Cecilia. "Polyphenolic fractions from wine by-products as potential antitumoral and/or protective agents against UV damage." Doctoral thesis, Universitat de Barcelona, 2006. http://hdl.handle.net/10803/989.
Abstract:
Cancer is one of the leading causes of death in countries throughout the world. Increase in the production of Reactive Oxygen Species (ROS) has been implicated in many human disease processes, including aging and carcinogenesis. Detoxification of ROS in the cell is provided by both enzymatic and non-enzymatic systems, which constitute the antioxidant defence systems and is crucial to the survival of organisms. The cancer inhibitory propierties of antioxidant compounds such as polyphenols have been well established in experimental and epidemiological studies, showing the intake of these antioxidants within our diet can carry out an effective protective action toward the oxidative stress created in the body by imbalance between ROS and its endogenous defence mechanism. However, the molecular mechanisms responsibles for these effects are not so well known and more studies are needed to provide clear evidence of their protective effects.The aim of this study is to determine and compare the posible antitumoral properties of several polyphenolic fractions, obtained from the extraction and fractionation of wine by-products consisting of grape skins, seeds and stems. These polyphenolic fractions have high antiradical potential and are mainly composed by flavanol monomers with or without gallate groups, glycosylated flavonols and mostly procyanidin oligomers. The effect of these fractions is analysed on cancer cells at cellular and metabolic levels. Moreover, as solar radiation in the UV range is the major source of adverse reactions in the skin and is one of the most efficient environmental carcinogen known, the possible capacity of these fractions to protect against cellular damage induced by ultraviolet radiation is evaluated and compared.
The results obtained in this study let us to confirm the polyphenolic fractions studied are very specific antiproliferative agents with very low cytotoxicity to non-proliferative normal cells, such as peripherial blood lymphocites (PBLs). Moreover, treatment with these fractions results in intracellular metabolic changes, restricting the ability of tumoral cells to proliferate and inhibiting glycolysis, being higher for the fraction rich in ECG containing oligomeric flavanols.
Like for the study of antitumoral effect at cellular and metabolic levels, the results obtained in the analysis of the protective capacity of these polyphenolic fractions against UV-induced damage, confirm them as potential natural chemopreventive agents.
Briefly, the results obtained in this study let us to conclude the polyphenolic fractions rich in procyanidin oligomers and gallate esters are the most efficient as antitumoral agents, active at both cellular and metabolic levels with low cytotoxicity. Additionally, polymerization and percentge of galloylation are also important in the efficacy of the polyphenolic fractions as protectors against damage induced by ultraviolet radiation, suggesting they may be useful for the prevention and treatment of a variety of solar UV light-induced human skin disorders.
33
Gonzalez, Rojas Alvaro. "Effect of plant growth regulator applications on phenolic quality of red grape berry skin and wine Vitis vinifera L., cvs Cabernet Sauvignon and Carmenère." Thesis, Bordeaux 2, 2012. http://www.theses.fr/2012BOR21920/document.
Abstract:
La composition phénolique du vin rouge détermine fortement sa qualité: couleur, goût, texture et la plupart des bienfaits pour la santé. Les conditions ambiantes de la vigne modulent l'équilibre hormonal endogène et l'expression de gènes qui contrôlent la voie de synthèse des composés flavonoïdes, en déterminant la composition phénolique finale du raisin. Même s'ils ont été étudiés, les effets des applications des régulateurs de croissance végétale sur l'équilibre hormonal endogène et la qualité du raisin, les effets de ces substances sur la composition et la qualité du vin sont pauvrement documentés. Le traitement des raisins destinés à la vinification avec des régulateurs de croissance végétale est un outil potentiel pour modifier la qualité des raisins et du vin rouge. Ce projet de thèse a pour objectif d’étudier l’impact d'applications de régulateur de croissance végétale sur la composition phénolique des raisins de Vitis vinifera L. cépages Cabernet Sauvignon et Carménère. L’acide abscissique, l’acide indole-3-acétique et l'acide 2-chloroethilphosphonique ont été appliqués à divers stades phénologiques du raisin, doses et conditions environnementales: Les essais ont été menés à Maipo et Cachapoal au Chili et à Bordeaux en France, dans des vignobles commerciaux et expérimentaux ainsi que sur des plantes cultivées en pots. Il a été examiné l'effet de ces traitements sur le contenu interne d'hormones, sur l'expression de gènes structuraux et régulateurs de la synthèse de composés flavonoides et sur la qualité des raisins, en particulier la composition phénolique de sa pellicule. De plus, des vinifications ont été réalisées à partir de raisins traités pour déterminer l'effet des traitements sur la composition chimique et phénolique du vin, ainsi que sur des attributs qualitatifs tels que les arômes et la texture des vins, jugés par un panel d'évaluation sensoriellePhenolic composition strongly determines red wine quality: color, taste, texture and most health benefits. Vineyard environmental conditions modulate endogenous hormonal balance and gene expression which control the flavonoid biosynthetic pathway leading to final grape phenolic composition. Even when the effects of plant growth regulator applications on grape endogenous hormonal balance and quality have been studied, the effect of these substances on wine composition and quality is poorly documented. The treatment of wine grapes with plant growth regulators is a potential tool in order to modify red wine phenolic composition and quality. This thesis project describes six experiments on plant growth regulator applications on developing grapes of Vitis vinifera L., cvs Cabernet Sauvignon and Carménère. Abscisic acid, Indole-3-acetic acid and 2-chloroethylphosphonic acid were applied in different phenological stages, doses and environmental conditions: Maipo and Cachapoal regions in Chile and Bordeaux region in France, commercial and experimental vineyards and plants in containers. The effect on changes in the internal hormonal content, expression of flavonoid biosynthetic and regulatory genes and grape quality, in particular grape skin phenolic composition were examined. In addition, winemaking was performed in order to assess the effect of treatments on wine chemical and phenolic composition and on wine aroma and texture attributes judged by a sensory panel
34
Almeida, Priscila Aparecida de. "Taxifolina: quantificação do flavonoide no extrato seco da casca de Pinus pinaster e avaliação da liberação in vitro e permeação vaginal ex vivo." Universidade Federal de Juiz de Fora (UFJF), 2015. https://repositorio.ufjf.br/jspui/handle/ufjf/4955.
Abstract:
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CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico
FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais
O extrato seco obtido da casca de Pinus pinaster, popularmente conhecido como Pinho Marítimo Francês, possui elevada concentração de polifenóis, representados por procianidinas, taxifolina, ácidos fenólicos e cinâmicos e as formas glicosiladas dessas moléculas. É obtido por extração aquosa da casca do pinheiro, seguido por eliminação da água. O seu controle de qualidade é especificado na United States Pharmacopeia, sendo o teste de doseamento realizado mediante a determinação do conteúdo total de procianidinas, a classe de polifenóis majoritária (entre 65 e 75 %). Porém, a determinação do conteúdo de polifenóis individuais pode representar um parâmetro de qualidade adicional para o extrato. Nesse sentido, a taxifolina (flavonoide conhecido como dihidroquercetina) aparece como um possível marcador químico para doseamento, uma vez que é encontrada no gênero Pinus, de forma geral, e por representar o polifenol monomérico presente em maior concentração no extrato. Essa molécula possui propriedades antioxidante e anti-inflamatória, podendo ser empregada no tratamento de patologias que possuam o estresse oxidativo e a inflamação envolvidos na patogênese. A endometriose é o foco principal deste estudo, cujo tratamento farmacológico, realizado com anticoncepcionais principalmente, apresenta uma série de inconvenientes, como o grau elevado de efeitos adversos; a recorrência dos sintomas poucos meses após a interrupção do tratamento, na maioria dos casos; e a contracepção, impedindo que a paciente possa engravidar, o que incentiva a busca por novos fármacos para o tratamento dessa patologia. Contudo, apesar da potencialidade farmacológica da taxifolina, esta apresenta baixa biodisponibilidade por via oral, devido à baixa solubilidade em água, o que limita a sua aplicação terapêutica e estimula a busca por rotas alternativas de administração para esse flavonoide. Partindo desses pressupostos, os seguintes objetivos são propostos: (i) desenvolver e validar métodos analíticos empregando cromatografia líquida de alta eficiência para a quantificação da taxifolina no extrato e em creme vaginal e (ii) avaliar a liberação in vitro dessa substância a partir do creme e sua permeação ex vivo, empregando o modelo de mucosa vaginal suína. Os métodos analíticos desenvolvidos e otimizados para a quantificação da taxifolina no extrato e no creme vaginal empregaram cromatografia em fase reversa com fase estacionária octadecilsilano e fase móvel constituída por água, acetonitrila e ácido fórmico, em diferentes proporções para os métodos. Foi empregada eluição por gradiente de fase móvel e de fluxo no método do extrato e eluição isocrática no método do creme. A detecção foi realizada em 288 nm em detector de arranjo de fotodiodos. Os perfis cromatográficos obtidos apresentaram linhas de base regulares, adequada resolução da taxifolina e boa simetria do pico. Todos os parâmetros de validação analítica encontraram-se dentro das especificações. O valor de fluxo obtido para a taxifolina a partir do creme no estudo de liberação in vitro (74,89 µg cm−2 h−1) indica que este é um possível veículo para a administração vaginal desse flavonoide. Adicionalmente, a porcentagem de permeação obtida para a taxifolina por dose (89,22 %) sugere um potencial desta para exercer suas ações a nível sistêmico in vivo, quando administrada via mucosa vaginal, podendo ser uma alternativa para o tratamento da endometriose, destacando-se que ela não possui efeito contraceptivo.
The dry extract obtained from the bark of the Pinus pinaster, popularly known as French Maritime Pine, has a high concentration of polyphenols represented by procyanidins, taxifolin, phenolic and cinnamic acids and glycosylated forms of these molecules. It is obtained by aqueous extraction of the pine bark, followed by water removal. Its quality control is specified in the United States Pharmacopeia, and the assay test is performed by determining of the total procyanidins content (between 65 and 75 %). However, determining of the individual polyphenol content may represent an additional quality parameter for this extract. In this sense, the taxifolin (flavonoid known as dihydroquercetin) appears as a possible chemical marker for assay, since it is found in the genus Pinus, in general, and because it represents the monomeric polyphenol in the highest concentration. This molecule possesses antioxidant and anti-inflammatory properties and may be used in the treatment of diseases which have oxidative stress and inflammation involved in the pathogenesis. Endometriosis is the main focus of this current study, whose pharmacological treatment is performed with contraceptives mainly, and presents a widely range of disadvantages, such as the high degree of adverse effects; recurrence of symptoms a few months after discontinuation of treatment, in most cases; and contraception, which prevents that the patient to become pregnant. These factors encourage the search for new drugs to treat endometriosis. However, despite of the pharmacological potential of taxifolin, it shows low oral bioavailability due to poor water solubility, which limits its therapeutic application and encourages the search for alternative routes of administration for this flavonoid. Within this context, the present study has like aims: (i) to develop and validate analytical methods by high performance liquid chromatography for quantification of taxifolin in the extract and vaginal cream and (ii) to evaluate the in vitro release profile of taxifolin from the cream and its ex vivo permeation across porcine vaginal mucosa. The analytical methods developed and optimized for the quantification of taxifolin in the extract and vaginal cream employed reversed phase chromatography with octadecylsilane stationary phase and mobile phase composed by water, acetonitrile and formic acid in different proportions to the methods. It was used gradient elution (mobile phase composition and flow rate) in the extract method, and isocratic elution in the cream method. The detection was performed at 288 nm in photodiode array detector. The chromatographic profiles showed regular baselines, appropriate resolution of taxifolin, and good symmetry of the peak. All analytical validation parameters were within specifications. The in vitro drug release study showed that the cream is a possible vehicle for vaginal administration of taxifolin due to high release rate (74.89 µg cm−2 h−1). Additionally, the permeated percentage of taxifolin by dose (89.22 %) suggests a potential of this flavonoid to exercise its systemic effects in vivo when administered via vaginal route, and may be an alternative for the treatment of endometriosis, emphasizing that it has no contraceptive effect.
35
Serem, June Cheptoo. "An exploratory investigation into the physicochemical, antioxidant and cellular effects of a selection of honey samples from the Southern African region." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/24881.
Abstract:
The unique floral biodiversity of Southern Africa would be reflected in the phenolic acid and flavonoid composition as well as the antioxidant activity of honeys from this region. In this exploratory investigation the total polyphenolic (TPC) and flavonoid (TFC) content, antioxidant activity as well as the cellular protective effects of a selection of honeys collected in this region was evaluated. Thirteen honey samples representative of the Western Cape (WCa, WCb and WCc), Eastern Cape (ECa, ECb and ECc), South East Mozambique (SEMa, SEMb and SEMc) and Agricultural: A-E (Eucalyptus) (A-E1 and A-E2), A-L (Litchi) and A-O (Orange) were collected. These samples were subjected to physicochemical analysis, the antioxidant content (TPC and TFC) and both enzymatic (catalase activity) and non-enzymatic activity, using the 2,2-diphenyl-2-picrylhydrazyl (DPPH), trolox equivalent antioxidant capacity (TEAC) and oxygen radical antioxidant capacity (ORAC) assays was determined. From the DPPH, TEAC and ORAC data the Relative Antioxidant Capacity Index (RACI) was calculated. To determine whether high antioxidant activity translates into significant cellular protection, biological and cellular assays were undertaken. Using the pBR322 plasmid assay and the erythrocyte haemolysis assay the ability of honeys to protect against 2,2’-Azobis(2-amidinopropane) dihydrochloride (AAPH) oxidative damage was evaluated. Further evaluation was undertaken in the SC-1 fibroblast cell line and the physiologically more relevant Caco-2 cell line. Toxicity and antioxidant effects were evaluated in the SC-1 cell line while antioxidant effects were only evaluated in the Caco-2 cell line. The long-term mitogenic and toxic effects were determined in the SC-1 cell line using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Neutral Red (NR) and Crystal Violet (CV) assays. Short term, total- and intracellular antioxidant effects were determined in both cell lines using the dichlorofluorescein diacetate assay (DCFH-DA) assay. For all cellular experiments honey at concentrations of 0.01% and 1% were used. The physiochemical properties of the honeys evaluated fulfilled the regulatory standards compiled in the Codex Alimentarius (CODEX STAN12-1981 revision 2001). The results were as follows: SEMb had the highest TPC (167.96 mg GAE/100g) and TFC (51.60 mg CE/100g) while A-E2 had the highest catalase (38.48 µmol H2O2/g) activity. RACI revealed that WCb had the highest antioxidant activity.SEMc showed the highest protection of plasmid DNA against oxidative-induced strand breaks while SEMa showed the highest protection of erythrocytes against AAPH-induced haemolysis. Although correlations were found between antioxidant content and antioxidant activity assays, no correlation was found these parameters and the biological assays. For the long-term cytotoxicity assay, AAPH showed significant cytoxicity at 0.78mM, 1.56mM and 0.28mM when measured using the MTT, NR and CV assays, respectively. Some honeys 4/13 and 3/13 showed a mitogenic effect at a concentration of 0.01% and 1% respectively. Toxic effects, were observed for 1/13 and 8/13 at 0.01% and 1% honey respectively. Toxicity after 72 h exposure varied from 10-30% (CV assay). The same concetrations of honey was used to determine the short-term, 2h, antioxidant effects in both the SC-1 and Caco-2 cell lines. No oxidative effect was found for all honeys at these concentrations. For the DCFH-DA assay using the SC-1 cell line at 1%, 12/13 and 7/13 honeys showed total and intracellular protection respectively. The highest extracellular protection was for SEMa (% Protection (%P) = 95) and SEMb (%P = 93). Intracellular protection was the highest for SEMc (%P = 21) and A-L (%P = 20). At 0.01%, 7/13 and 8/13 honeys exhibited total and intracellular protection, respectively. For both the highest protection was found for SEMc (%P = 43, total and %P = 30, intracellular). For the Caco-2 cell line at 1%, 11/13 and 4/13 showed total and intracellular protection, respectively. Of these the highest extracellular protection was for SEMb (% Protection (%P) = 90). Intracellular protection was the highest for ECa (%P = 28) and WCc (%P = 26). At 0.01%, 4/13 and 8/13 honeys showed total and intracellular protection respectively. The highest extracellular protection was found for SEMc (%P = 62) and intracellular protection was ECc (%P = 28). The SC-1 cell line was found to be the most sensitive to the antioxidant effects of honey compared to the Caco-2 cell line. The honeys SEMa, SEMb and SEMc showed protection against oxidative damage in both cell lines. In conclusion, the antioxidant activity of honeys from Southern Africa is of a high quality. The WC, SEM and EC honeys showed the highest antioxidant effects and could provide health benefits against diseases associated with oxidative stress as indicated by these results. CopyrightDissertation (MSc)--University of Pretoria, 2011.
Anatomy
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36
Chepkwony, Sarah Cherono. "Étude de la variabilité et modification chimique du Mesquitol, extractible polyphénolique de Prosopis juliflora : application à la préservation du bois." Electronic Thesis or Diss., Université de Lorraine, 2019. http://docnum.univ-lorraine.fr/ulprive/DDOC_T_2019_0258_CHEPKWONY.pdf.
Abstract:
Prosopis juliflora a été classé parmi les pires espèces envahissantes au monde et par conséquent, cette espèce se répand rapidement dans des zones destinées à l'agriculture ou le pâturage. Cette étude visait donc à trouver des solutions face cette menace à travers la valorisation du composé le plus abondant de P. juliflora : le mesquitol. En effet, des travaux antérieurs effectués au laboratoire (LERMaB, France) ont permis de mettre en évidence que le bois de Prosopis juliflora contient des quantités importantes de mesquitol (2-(3,4-dihydroxyphenyl)chromane-3,7,8-triol), un flavonoïde relativement rare présentant des propriétés antioxydantes. En l'absence de données précises sur les proportions de mesquitol dans P. juliflora ou sur la variabilité en fonction de l'emplacement géographique de l'arbre ou l'âge de l'arbre, la première partie de l'étude a été consacrée à l’établissement de ces données. Pour cela des échantillons de P. juliflora de trois différentes régions géographiques du Kenya (Baringo, Garissa et Turkana) ont été collectés. Les extraits ont été caractérisés par GC-MS et la LC-ESI-MS/MS. La quantification de certains des composés identifiés a été effectuée en mode d'ionisation négative en LC-ESI-MS/MS. L’étude des spectres de masse a permis de mettre en lumière la richesse de P. juliflora en composés phénoliques. Parmi ces composés, un dimère de mesquitol a été identifié pour la première fois. Les résultats ont également montré que le mesquitol est bien le composé le plus abondant dans P. juliflora avec des quantités élevées de 11 % dans le bois de cœur des grands arbres de Baringo. La seconde partie de l’étude porte sur l'utilisation du mesquitol comme matière première pour la synthèse, par modifications chimiques, de différents dérivés dans le but d’améliorer la lipophilie de ce composé, ce qui pourrait contribuer à réduire sa lixiviabilité. Les réactions du mesquitol avec divers acides carboxyliques ont permis d’obtenir des dérivés greffés avec des chaînes grasses en position aliphatique. Les propriétés antifongiques de certains de ces dérivés ont été testées pour évaluer leur potentiel pour des applications dans la protection du bois. D’après les résultats de cette étude, il est évident que les dérivés du mesquitol obtenus par réaction avec des acides carboxyliques peuvent être utilisés comme agents de préservation du bois lorsqu’ils sont utilisés avec de faibles quantités de tébuconazoleEarlier work from the laboratory (LERMaB, France) helped to highlight that the heartwood of Prosopis juliflora contains significant amounts of mesquitol, a relatively rare flavonoid with antioxidant properties, otherwise identified as 2-(3,4-dihydroxyphenyl)chromane-3,7,8-triol. P. juliflora has been rated among the worst world invasive species and therefore this study aimed at finding solutions to this menace that is fast spreading into areas that are otherwise intended for useful purposes like farming or grazing. With no data existing on the exact amounts of mesquitol present in P. juliflora or its variability depending on the geographic location of the tree or the tree’s age, the study commenced by first availing this data. This was done by a substantive study on P. juliflora stem samples that had been collected from three different geographic regions in Kenya (Baringo County, Garissa County and Turkana County). Compounds identification and quantification were done one using the GC-MS and the LC-ESI-MS/MS. A systematic study on the mass spectra and the observed fragmentations illustrated a rich array of phenolic compounds present in P. juliflora. Among these compounds is a mesquitol dimer, which has been identified for the very first time here. The results also showed that mesquitol compound is the most abundant compound in P. juliflora with high amounts of 11 % being found in the heartwood of the big trees from Baringo County. The second part of the study focused on the chemical modification of mesquitol targeting specific derivatives which could enhance the lipophilicity of mesquitol hence help in decreasing leachability. Various reactions of mesquitol with various carboxylic acids were performed allowing grafting of long fatty chains (lipophilic part) onto mesquitol through the aliphatic 3-OH position. Some of these derivatives were used to evaluate their ability to protect wood against fungal attack from both a white-rot and a brown-rot fungus. From the results of this study, it is evident that mesquitol derivatives obtained from reaction with carboxylic acids can be used as wood preservatives when used together with low amounts of tebuconazole
37
Chanet, Audrey. "Impact des flavanones des agrumes sur la prévention de l'athérosclérose et mécanismes d'action mis en jeu." Thesis, Clermont-Ferrand 1, 2011. http://www.theses.fr/2011CLF1MM02.
Abstract:
Les maladies cardiovasculaires représentent l’une des principales causes de mortalitédans le monde et leur prévention constitue un enjeu majeur de santé publique. Les études épidémiologiques montrent que la consommation de fruits et légumes est associée à un moindre risque cardiovasculaire. Ces effets pourraient être expliqués par leur richesse en micronutriments et plus particulièrement en polyphénols. La consommation de flavanones, une classe de polyphénols présente spécifiquement et en grandes quantités dans les agrumes, a été inversement associée au risque d’accidents coronaires et d’accidents vasculaires cérébraux. Des données expérimentales obtenues in vivo et in vitro suggèrent que les flavanones (hespéridine ou naringine) possèdent des propriétés hypolipémiantes, hypotensives et anti-inflammatoires. Ces effets pourraient notamment être médiés par une modulation de l’expression de gènes par les flavanones. Cependant jusqu’à présent, l’action anti-athérogène des flavanones in vivo n’a été explorée qu’à des doses supra-nutritionnelles et les mécanismes responsables de ces effets sont encore largement méconnus. Par ailleurs, les données mécanistiques in vitro sont peu informatives, car obtenues avec des formes de flavanones non présentes dans l’organisme. Les objectifs de cette thèse ont donc été : (1) d’évaluer l’impact d’une consommation de flavanones (naringine et hespéridine) à dose nutritionnelle sur le développement de la lésion athéromateuse chez différents modèles murins d’hypercholestérolémie et d’appréhender les mécanismes moléculaires mis en jeu par une approche transcriptomique ; (2) de déterminer l’impact des métabolites circulants sur la fonction des cellules endothéliales et d’identifier les mécanismes moléculaires sous-jacents. In vivo, nous avons montré que seule la supplémentation en naringine (0,02%), la flavanone majoritaire du pamplemousse, réduisait la progression des lésions athéromateuses dans un modèle murin d’athérosclérose induite par l’alimentation (souris C57Bl/6J sous régime riche en graisse et en cholestérol). Cet effet était associé à une réduction des concentrations plasmatiques de non HDL-Chol et de biomarqueurs de la dysfonctionendothéliale, mais semblait indépendant d’une modulation du statut anti-oxydant. Une analyse transcriptomique pangénomique de l’aorte de ces animaux, a montré, que la supplémentation en naringine induisait une variation de l’expression de gènes impliqués dans des processus, tels que l’adhésion cellulaire ou l’organisation du cytosquelette, qui sont impliqués dans la migration trans-endothéliale des leucocytes. Ces résultats mettent en évidence de nouvelles cibles moléculaires d’action des flavanones qui ont été plus largement abordées in vitro. Les données obtenues in vitro montrent que l’exposition de cellules endothéliales(HUVEC) à des concentrations physiologiques de métabolites circulants de la naringénine(dérivés glucuronidés) ou de l’hespérétine (dérivés glucuronidés et sulfatés) diminue l’adhésion des monocytes (U937) aux cellules endothéliales, une étape clé de la migrationtrans-endothéliale. En accord avec ces résultats, une analyse TaqMan Low Density Array a montré que l’exposition des cellules endothéliales aux métabolites circulants de flavanones affectait l’expression de gènes impliqués dans l’inflammation, le chimiotactisme, l’adhésion ou encore la migration trans-endothéliale des leucocytes. Pris dans leur ensemble, les résultats de ce travail de thèse montrent que les effets antiathérogènesdes flavanones ne découlent pas exclusivement d’un effet hypolipémiant, mais aussi d’une action directe sur des étapes clés du développement de l’athérosclérose au niveau de l’endothélium, en particulier les processus d’adhésion et migration trans-endothélialeCardiovascular disease is a major cause of mortality worldwide and its prevention is a major public health issue. Epidemiological studies have shown that fruit and vegetables consumption is associated with a lower cardiovascular risk. These effects could be explainedby their richness in micronutrients, especially polyphenols. Consumption of flavanones, a class of polyphenols present specifically and in large amounts in citrus fruits, was inversely associated with risk of coronary events and stroke. Experimental data obtained in vivo and invitro suggest that the flavanones (hesperidin or naringin) have lipid-lowering, hypotensive and anti-inflammatory properties. These effects could be mediated via modulation of gene expression by these bioactives. However, the anti-atherogenic effect of flavanones in vivo has been only explored at supra-nutritional doses and the mechanisms responsible for these effects are largely unknown. Furthermore, in vitro mechanistic data are questionable as they have been obtained using native forms of flavanones which are not present in the body.The objectives of this thesis were: (1) to assess the impact of consumption of flavanones (naringin and hesperidin) at nutritional doses on the development of atherosclerotic lesions indifferent mouse models of hypercholesterolemia and decipher molecular mechanisms brought into play, using a transcriptomic approach, (2) to determine the impact of physiological concentrations of plasma flavanone metabolites on endothelial cell function and theunderlying molecular mechanisms. In vivo, we showed that only naringin supplementation (0.02%), the major flavanonein grapefruit, reduced the progression of atherosclerotic lesions in a mouse model of dietinduced atherosclerosis (C57BL/6J mice fed an enriched diet in fat and cholesterol). Thiseffect was associated with a reduction in plasma non-HDL-Chol and biomarkers ofendothelial dysfunction, but appeared independent of a modulation of antioxidant status. Agenome-wide transcriptome analysis of the aorta of these animals showed that naringin supplementation modulated expression of genes involved in processes such as cell adhesion and cytoskeleton organization; these latter being involved in leukocytes trans-endothelialmigration. These results reveal new molecular targets of action of flavanones that have beenfurther studied in vitro.The in vitro data showed that exposure of endothelial cells (HUVEC) to physiological concentrations of circulating metabolites of naringenin (glucuronides) or hesperetin(glucuronides and sulfate) decreased the adhesion of monocytes (U937) to endothelial cells, a key step in the trans-endothelial migration. Consistent with these results, a TaqMan Low Density Array analysis showed that exposure of endothelial cells to these flavanone metabolites affected the expression of genes involved in inflammation, chemotaxis, adhesionas well as leukocytes trans-endothelial migration. Overall, the results of this work show that the anti-atherogenic effect of flavanones is not exclusively derived from lipid-lowering effect, but also due to a direct action on the endothelium by modulating key processes of atherosclerosis development, particularly adhesion and trans-endothelial migration
38
Way, Tzong-Der. "Chemoprevention against breast cancer by flavonoids and tea polyphenols." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-0807200416072900.
39
Way, Tzong-Der, and 魏宗德. "Chemoprevention against breast cancer by flavonoids and tea polyphenols." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/09469640876182180859.
Abstract:
博士國立臺灣大學
生物化學暨分子生物學研究所
92
Part I: Flavonoids are a diverse group of phytochemicals that are produced by various plants. Among the flavonoids, apigenin (4'',5,7-trihydroxyflavone) is one of the most effective in inducing cell growth inhibition and is relatively nontoxic and nonmutagenic. Here we examined several human breast cancer cell lines having different levels of HER2/neu expression, and found that apigenin exhibited potent growth-inhibitory activity in HER2/neu-overexpressing breast cancer cells, but was much less effective for those cells expressing basal levels of HER2/neu. Induction of apoptosis was also observed in HER2/neu-overexpressing breast cancer cells in a dose- and time-dependent manner. However, the molecular mechanism(s) of apigenin-induced apoptosis in HER2/neu-overexpressing breast cancer cells remained to be elucidated. A cell survival pathway involving phosphatidylinositol-3�S-kinase (PI3K) and Akt is known to play an important role in inhibiting apoptosis in response to HER2/neu-overexpressing breast cancer cells, which prompted us to investigate whether this pathway plays a role in apigenin-induced apoptosis in HER2/neu-overexpressing breast cancer cells. Our results showed that apigenin inhibits Akt function in tumor cells in a complex manner. First, apigenin directly inhibited the PI3K activity while indirectly inhibited the Akt kinase activity. Second, inhibition of HER2/neu autophosphorylation and transphosphorylation resulting from depleting HER2/neu protein in vivo was also observed. In addition, apigenin inhibited Akt kinase activity by preventing the docking of PI3K to HER2/HER3 heterodimers. Therefore, we proposed that apigenin-induced cellular effects result from loss of HER2/neu and HER3 expression with subsequent inactivation of PI3K and AKT in cells that are dependent on this pathway for cell proliferation and inhibition of apoptosis. This implies that the inhibition of the HER2/HER3 heterodimer function provided an especially effective strategy for blocking the HER2/neu-mediated transformation of breast cancer cells. Our results also demonstrated that apigenin dissociated the complex of HER2/neu and GRP94 that preceded the depletion of HER2/neu. Apigenin-induced degradation of mature HER2/neu involves polyubiquitination of HER2/neu and subsequent hydrolysis by the proteasome. These findings suggest that apigenin may be an effective chemotherapeutic and preventive agent against HER2/neu-overexpressing breast cancer cells. Next, to examine whether inhibition of this pathway play a role in the antitumor effect, we demonstrated that treatment with apigenin induced apoptosis through cytochrome c release and caused a rapid induction of caspase-3 activity and stimulated proteolytic cleavage of DFF-45. Furthermore, apigenin down-regulated cyclin D1 and cyclin D3, and increased p27 protein levels. Colony formation in the soft agar assay, a hallmark of the transformation phenotype, was preferentially suppressed in HER2/neu-overexpressing breast cancer cells by apigenin. A structure-activity study indicated that (1) the position of B ring; and (2) the existence of the 3'', 4''-hydroxyl group on the 2-phenyl group are important factors affecting flavonoids depleted HER2/neu protein. This provides new information on the structure-activity relationship of flavonoids. Part II: The aromatase enzyme, which converts androstenedione to estrone, regulates the availability of estrogen to support the growth of hormone-dependent breast tumors. In this study, we investigated the inhibitory effects on aromatase activities by the black tea polyphenols. We found that black tea polyphenols, TF1, TF2 and TF3 significantly inhibited rat ovarian and human placental aromatase activities. In addition, using an in vivo model, these black tea polyphenols also inhibited the proliferation induced by 100 nM DHEA in MCF-7 cells. Transfection of HER2/neu in MCF-7 breast cancer cells appeared to be associated with an increased resistance of the cells to hormonal therapy. Interestingly, unlike the selective estrogen receptor modulator (SERM) tamoxifen, black tea polyphenols expressed antiproliferation effects in breast cancer cells with hormonal resistance. The inhibitory effect of black tea polyphenols on hormone-resistant breast cancer cells suppressed the basal receptor tyrosine phosphorylation in HER2/neu-overexpressing MCF-7 cells. These findings suggest the use of black tea polyphenols may be beneficial in chemoprevention of hormone-dependent breast tumors and represent a possible remedy to overcome hormonal resistance of hormone-independent breast tumors.
40
"Characterization of flavonoid antioxidants in Vigna sinensis seeds." 2003. http://library.cuhk.edu.hk/record=b5896112.
Abstract:
Chiang Yee-Ting.Thesis submitted in: December 2002.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2003.
Includes bibliographical references (leaves 116-130).
Abstracts in English and Chinese.
Acknowledgements --- p.i
Abstract --- p.ii
List of Abbreviations --- p.iv
List of Tables --- p.v
List of Figures --- p.vi
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- "Free radical, oxidative stress and antioxidants" --- p.2
Chapter 1.1.1 --- Free radicals and reactive oxygen species (ROS) --- p.2
Chapter 1.1.2 --- Oxidative stress and human diseases --- p.3
Chapter 1.1.3 --- Dietary antioxidants --- p.5
Chapter 1.1.4 --- Synthetic antioxidants --- p.5
Chapter 1.2 --- Flavonoids ´ؤ polyphenolic compounds in plants --- p.8
Chapter 1.2.1 --- Sources and biosynthesis of flavonoids --- p.8
Chapter 1.2.2 --- Classification and dietary occurrence of flavonoids --- p.11
Chapter 1.2.3 --- Functions of flavonoids in plants --- p.15
Chapter 1.2.4 --- Effects of flavonoids in mammals --- p.16
Chapter 1.2.5 --- Therapeutic application of flavonoids --- p.17
Chapter 1.2.6 --- Absorption and metabolism of flavonoids --- p.26
Chapter 1.3 --- Plant of interest --- p.28
Chapter 1.4 --- Method used to characterize flaovnoid antioxidants in Vigna sinensis seeds --- p.30
Chapter 1.5 --- Method used to evaluate the antioxidant activity --- p.31
Chapter 1.5.1 --- p-carotene bleaching method --- p.31
Chapter 1.5.2 --- "a,a-diphenyl- --- p.32
Chapter 1.5.3 --- Single cell gel electrophoresis assay (Comet assay) --- p.32
Chapter 1.6 --- Research objectives --- p.34
Chapter 2 --- Materials and Methods --- p.35
Chapter 2.1 --- Plant materials and chemicals --- p.35
Chapter 2.2 --- Sample preparation --- p.36
Chapter 2.2.1 --- Methanolic extraction method --- p.36
Chapter 2.2.2 --- Acidic methanolic extraction method --- p.36
Chapter 2.2.3 --- Optimization of extraction time --- p.37
Chapter 2.3 --- Standards preparation --- p.37
Chapter 2.4 --- Characterization of flavonoid antioxidants in V. sinensis seed extracts --- p.38
Chapter 2.5 --- Evaluation of antioxidant activity --- p.39
Chapter 2.6 --- Determination of free radical scavenging ability --- p.41
Chapter 2.7 --- Evaluation of the protective effects on DNA damage --- p.42
Chapter 2.7.1 --- Preparation of reagents --- p.42
Chapter 2.7.2 --- Blood sample --- p.43
Chapter 2.7.3 --- Hydrogen peroxide treatment --- p.43
Chapter 2.7.3.1 --- Co-incubation system --- p.43
Chapter 2.7.3.2 --- Pre-incubation system --- p.43
Chapter 2.7.4 --- Establishment of optimal assay conditions --- p.44
Chapter 2.7.4.1 --- Hydrogen peroxide concentration --- p.44
Chapter 2.7.4.2 --- Sample volume --- p.44
Chapter 2.7.4.3 --- Incubation time --- p.44
Chapter 2.7.4.4 --- Hydrogen peroxide treatment time --- p.44
Chapter 2.7.5 --- Ethidium bromide-acridine orange cell viability determination --- p.45
Chapter 2.7.6 --- Slide preparation --- p.45
Chapter 2.7.7 --- Comet assay --- p.45
Chapter 2.7.8 --- Quantification of DNA damage --- p.47
Chapter 2.7.9 --- Statistical analysis --- p.47
Chapter 3 --- Results
Chapter 3.1 --- Comparison on the free radical scavenging abilities on two different V. sinensis seed extracts --- p.48
Chapter 3.1.1 --- Optimal extraction time of methanolic extraction method --- p.48
Chapter 3.1.2 --- Optimal extraction time of acidic methanolic extraction method --- p.48
Chapter 3.1.3 --- pH values of two different V. sinensis seed extracts --- p.49
Chapter 3.1.4 --- Free radical scavenging abilities of the two different V. sinensis seed extracts --- p.49
Chapter 3.2 --- Determination of the stability of the V. sinensis seed extracts --- p.50
Chapter 3.2.1 --- Effects of storage on the free radical scavenging ability of methanolic V. sinensis seed extract --- p.50
Chapter 3.2.2 --- Effects of storage on the free radical scavenging ability of acidic V. sinensis seed extract --- p.50
Chapter 3.2.3 --- Effect of storage on the antioxidant activity of methanolic V.sinensis seed extract --- p.51
Chapter 3.2.4 --- Effect of storage on the antioxidant activity of acidic V. sinensis seed extract --- p.52
Chapter 3.3 --- Identification of the flavonoid antioxidants in the acidic V. sinensis seed extract --- p.53
Chapter 3.4 --- Evaluation of free radical scavenging abilitiesof identified flavonoids using the DPPH radical scavenging method --- p.54
Chapter 3.5 --- Evaluation of antioxidant activities of the identified flavonoids using the β-carotene bleaching assay --- p.56
Chapter 3.6 --- Evaluation of protective effects on DNA damage using the Comet assay --- p.57
Chapter 3.6.1 --- Optimal comet assay conditions --- p.57
Chapter 3.6.1.1 --- Hydrogen peroxide concentration --- p.57
Chapter 3.6.1.2 --- Sample volume --- p.58
Chapter 3.6.1.3 --- Incubation time with the seed extract in the co-incubation system --- p.58
Chapter 3.6.1.4 --- Hydrogen peroxide treatment time --- p.58
Chapter 3.6.1.5 --- Incubation time with the seed extract in the pre-incubation system --- p.59
Chapter 3.6.2 --- Protective effects of the V. sinensis seed extracts and phenolic compounds --- p.59
Chapter 3.6.2.1 --- Protective effects in pre-incubation system --- p.59
Chapter 3.6.2.2 --- Protective effects in co-incubation system --- p.60
Chapter 3.6.3 --- Protective effects of the identified flavonoids in acidic V.sinensis seed extracts and phenolic compounds --- p.60
Chapter 3.6.3.1 --- Protective effects in pre-incubation system --- p.60
Chapter 3.6.3.1.1 --- At 0.5 mM concentration --- p.60
Chapter 3.6.3.1.2 --- At 1 mM concentration --- p.61
Chapter 3.6.3.2 --- Protective effects in co-incubation system --- p.62
Chapter 3.6.3.2.1 --- At 0.5 mM concentration --- p.62
Chapter 3.6.3.2.2 --- At 1 mM concentration --- p.62
Chapter 4 --- Discussion --- p.100
Chapter 4.1 --- Comparison on the two different extraction methods --- p.100
Chapter 4.1.1 --- Methanolic extraction and acidic methanolic extraction --- p.100
Chapter 4.1.2 --- Free radical scavenging abilities on the two different V sinensis seed extracts --- p.100
Chapter 4.2 --- Stabilities of two different V. sinensis seed extracts --- p.101
Chapter 4.2.1 --- Change in antioxidant activity during storage --- p.101
Chapter 4.2.2 --- Comparison on the stabilities of the extracts assayed under different conditions --- p.102
Chapter 4.3 --- Identification of flavonoid antioxidants in the acidic methanolic V sinensis seed extract --- p.103
Chapter 4.4 --- Antioxidant activities of the individual identified flavonoid antioxidants --- p.104
Chapter 4.4.1 --- Antioxidant activities of the identified flavonoid antioxidants and the selected phenolic compounds in hydrophilic assay system --- p.106
Chapter 4.4.2 --- Antioxidant activities of the identified flavonoid antioxidants and the selected phenolic compounds in lipophilic assay system --- p.107
Chapter 4.5 --- Evaluation of protective effects on DNA damage using Comet assay --- p.109
Chapter 4.5.1 --- Optimal conditions in Comet assay --- p.109
Chapter 4.5.1.1 --- Effect of hydrogen peroxide concentration --- p.109
Chapter 4.5.1.2 --- Effect of sample volume --- p.109
Chapter 4.5.1.3 --- Effect of hydrogen treatment time --- p.110
Chapter 4.5.1.4 --- Pre-incubation and co-incubation systems --- p.110
Chapter 4.5.2 --- Protective effects of two different V. sinensis seed extracts and six phenolic compounds --- p.111
Chapter 4.5.3 --- Protective effects of the identified flavonoids and the phenolic compounds --- p.112
Chapter 4.6 --- Health beneficial properties of V. sinensis seeds --- p.113
Chapter 5 --- Conclusion --- p.114
References --- p.116
41
Malone, Sara Rae. "The bioavailability of 90MX cranberry powder and quercetin when administered to horses." 2008. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.17519.
42
Liang, Yu-Chih, and 梁有志. "Studies on the molecular mechanisms of anti-carcinogenesis and anti-inflammation by tea polyphenols and flavonoids." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/68206297502770769706.
Abstract:
博士國立臺灣大學
生化學研究所
87
Part I. We have isolated the tea catechins from green tea water extracts by liquid chromatography with Sephadex LH-20 and C18 column. An isocratic HPLC procedure was developed for simultaneous determination of six catechins, gallic acid and three methylxanthines in tea water extract. A base-line separation was achieved on a Cosmosil C18-MS packed column with a solvent mixture of methanol/doubly-distilled water/formic acid (19.5/80.2/0.3, v/v/v) as mobile phase. A gradient HPLC procedure was also provided for the separation of these tea components. The contents of catechins, gallic acid and methylxanthines have been measured in infusions of various tea samples. The young leaves (apical bud and the two youngest leaves) were found to be richer (1.9-fold) in polyphenols than old leaves (from the tenth leaf to the fifth leaf). Also, the tea polyphenols were found to be higher (1.4-fold) in summer than in spring. Ten different types of commercial tea (manufactured tea), including unfermented, semifermented and fermented tea, were analyzed for their polyphenol compounds, and it was found that both yields of solids in tea water extracts (TWEs), and the amount of EGCG in these products, varied with different tea leaves and processing methods. Longjing tea (unfermented green tea) contained the highest concentration of EGCG and polyphenols, whereas Assam black tea (most fermented) contained the least. Part II. Tea polyphenols are known to inhibit a wide variety of enzyme activities that are associated with cell proliferation and tumor progression. But, its molecular mechanisms of antiproliferation are remained to be elucidated. In this study, we investigated the effects of the major tea polyphenol (-)-epigallocatechin gallate (EGCG) on the proliferation of human epidermoid carcinoma cell line, A431. Using a [3H]-thymidine incorporation assay, EGCG could significantly inhibit the DNA synthesis of A431 cells. In vitro assay, EGCG strongly inhibited the protein tyrosine kinase (PTKs) activities of EGF-R, PDGF-R and FGF-R, and exhibited an IC50 value of 0.5 ~ 1 mg/ml. But EGCG scarcely inhibited the protein kinase activities of pp60v-src, PKC and PKA ( IC50 > 10 mg/ml ). In vivo assay, EGCG could reduce the autophosphorylation level of EGF-R by EGF. Phosphoamino acid analysis of the EGF-R revealed that EGCG inhibited the EGF-stimulated increase in phosphotyrosine level in A431 cells. In addition, we showed that EGCG blocked EGF binding to its receptor. The results of further studies suggested that the inhibition of proliferation and suppression of the EGF signaling by EGCG might mainly mediate dose-dependent blocking of ligand-binding to its receptor, and subsequently through inhibition of EGF-R kinase activity. Previous studies have shown that the major green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG) suppressed autophosphorylation of EGF receptor induced by EGF in human A431 epidermoid carcinoma cells. In this study, we examined the inhibitory effects of black tea polyphenols, including theaflavin (TF-1), the mixture (TF-2) of theaflavin-3-gallate (TF-2a) and theaflavin-3￠-gallate (TF-2b), theaflavin-3, 3￠-digallate (TF-3) and thearubigin fraction on the autophosphorylation of EGF receptor and PDGF receptor in A431 cells and mouse NIH3T3 fibroblast cells respectively. First, we examined the effects of these polyphenols on the proliferation of A431 and NIH3T3 cells. Both of EGCG and TF-3 strongly inhibited the proliferation of A431 and NIH3T3 cells than the other theaflavins. In cultured cells, TF-3 was stronger than EGCG on the reduction of EGF receptor and PDGF receptor autophosphorylation induced by EGF and PDGF respectively. Other theaflavins slightly reduced the autophosphorylation of EGF receptor and PDGF receptor. TF-3 could reduce the autophosphorylation of EGF receptor (or PDGF receptor) even cotreatment with EGF (or PDGF). In addition, TF-3 was stronger than EGCG in blocking of EGF binding to its receptor. These results suggest that not only green tea polyphenol (EGCG) but also black tea polyphenol (TF-3) has antiproliferative activity on tumor cells, and the molecular mechanisms of antiproliferation may mediate blocking of growth factor binding to its receptor and then suppress mitogenic signal transduction. Part III. (-)-Epigallocatechin-3-gallate (EGCG) potently inhibits cell proliferation and suppresses tumor growth in vitro and vivo, but little is known regarding the cell cycle regulatory proteins mediating these effects. This study investigated the effects of EGCG and other catechins on the cell cycle progression. DNA flow cytometric analysis indicated that 30mM of EGCG blocked cell cycle progression at G1 phase in asynchronous MCF-7 cells. In addition, cells exposed to 30mM of EGCG remained in the G1 phase after release from aphidicolin block. Over a 24h exposure to EGCG, the Rb protein changed from hyper- to hypophosphorylated form and G1 arrest developed. The protein expression of cyclin D1, and E reduced slightly under the same conditions. Immunocomplex kinase experiments showed that EGCG inhibited the activities of cyclin-dependent kinase 2 (Cdk 2) and 4 (Cdk4) in a dose-dependent manner in the cell-free system. As the cells were exposed to EGCG (30 mM) over 24h a gradual loss of both Cdk2 & 4 kinase activities occurred. EGCG also induced the expression of the Cdk inhibitor p21 protein and this effect correlated with the increase in p53 levels. The level of p21 mRNA also increased under the same conditions. In addition, EGCG also increased the expression of the Cdk inhibitor p27 protein within 6h after EGCG treatment. These results suggest that EGCG either exerts its growth-inhibitory effects through modulation of the activities of several key G1 regulatory proteins such as Cdk2 and Cdk4 or mediates the induction of Cdk inhibitor p21 and p27. Part IV. The inhibition of various tea catechins on the cell migration and invasion were evaluated using a clongenic growth assay in soft agar and Transwell with or without Matrigel-coated membrane. (-)-Epigallocatechin-3-gallate (EGCG) was the most effective inhibitor for anti-invasion in in vitro assay. Moreover, EGCG showed a significant dose-dependent suppression of cell spreading on various extracellular matrix (ECM) components such as Matrigel, fibronectin (FN), laminin (LN), and type IV collagen, and inhibited spontaneous aggregation, while the EGCG treatment slightly inhibited attachment of the cells to these substrates. Further analysis, EGCG showed potent inhibition of serum-induced tyrosine phosphorylation of focal adhesion kinase (FAK) and matrix metalloproteinase-9 (MMP-9) secretion, both were associated with capacity of tumor invasion. Following the i.p. administration of EGCG (2 mg/0.1 ml) to mouse the concentrations of free-form EGCG in the blood was lower than 10 mM and the lung metastasis of B16-F3m melanoma cells was inhibited. The combination of EGCG and dacarbazine was more effective than either single agent in reducing the number of pulmonary metastases of mice-bearing melanoma and in increasing survival rate. These results demonstrated that combination treatment of EGCG and dacarbazine has a high potential for antimetastasis, and the mechanisms of the antimetastatic effect of EGCG was associated to its inhibition of cell spreading, cell-ECM and cell-cell interaction, MMP-9 secretion, and FAK activity. Part V. Prostaglandins biosynthesis and nitric oxide production have been implicated in the process of inflammation and carcinogenesis. In this study, we investigated that various flavonoids and EGCG on the activities of inducible cyclooxygenase (COX-2) and iNOS in LPS-activated RAW 264.7 macrophages. Apigenin, genistein and kaempferol were markedly active inhibitors of COX-2, with IC50 < 15 mM. On the other hand, apigenin and kaempferol were also markedly active inhibitor of iNOS, with IC50 < 15 mM. Of those compounds tested, apigenin was the most potent COX-2 and iNOS inhibitors. Western blot and Northern blot analyses demonstrated that apigenin significantly blocked the protein and mRNA expression of COX-2 and iNOS in LPS-activated macrophages. Transient transfection experiments showed that LPS caused about a 4-fold increase in both COX-2 and iNOS promoter activities, these increments were suppressed by apigenin. Moreover, electrophoretic mobility shift assay indicated that apigenin blocked the LPS-induced activation of nuclear factor-kB (NF-kB). The inhibition of NF-kB activation occurs through the prevention of IkB degradation. Transient transfection experiment also showed that apigenin inhibited NF-kB-dependent transcriptional activity. This study suggests that the modulation of COX-2 and iNOS by apigenin and related flavonoids may be important in the prevention of carcinogenesis and inflammation.
43
"Effects of octadecaenoic acids and apple polyphenols on blood cholesterol." 2007. http://library.cuhk.edu.hk/record=b5893326.
Abstract:
Lam, Cheuk Kai.Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (leaves 148-173).
Abstracts in English and Chinese.
ACKNOWLEDGEMENTS --- p.i
ABSTRACT --- p.ii
LIST OF ABBREVIATIONS --- p.vi
TABLE OF CONTENTS --- p.x
Chapter CHAPTER 1 --- GENERAL INTRODUCTION
Chapter 1.1 --- Introduction to Cholesterol and Its Related Diseases --- p.1
Chapter 1.1.1 --- Chemistry of cholesterol --- p.1
Chapter 1.1.2 --- Physiological importance of cholesterol --- p.1
Chapter 1.1.3 --- Pathological effects of cholesterol --- p.3
Chapter 1.1.3.1 --- Mechanism of atherosclerosis --- p.3
Chapter 1.2 --- Cholesterol Homeostasis --- p.6
Chapter 1.2.1 --- Liver as the main organ for cholesterol metabolism --- p.6
Chapter 1.2.2 --- Regulatory sites of cholesterol metabolism --- p.6
Chapter 1.2.2.1 --- Regulation of cholesterol absorption by acyl coenzyme A: cholesterol acyltransferase (ACAT) --- p.6
Chapter 1.2.2.2 --- Sterol regulatory element-binding protein 2 (SREBP-2) as a transcription factor for 3 -hydroxy-3 -methylglutaryl coenzyme A reductase (HMGR) and low-density lipoprotein receptor (LDLR) --- p.10
Chapter 1.2.2.3 --- Roles ofLDLR --- p.11
Chapter 1.2.2.4 --- Rate limiting role of HMGR in cholesterol de novo synthesis --- p.14
Chapter 1.2.2.5 --- Roles of liver-X-receptor-a (LXR-a) in cholesterol catabolism --- p.16
Chapter 1.2.2.6 --- Roles of CYP7A1 in catabolism of cholesterol into bile acids --- p.19
Chapter 1.2.2.7 --- Roles of cholesterol ester transfer protein (CETP) in maintaining cholesterol distribution in blood --- p.22
Chapter CHAPTER 2 --- EFFECT OF OCTADECAENOIC ACIDS ON BLOOD CHOLESTEROL IN HAMSTERS
Chapter 2.1 --- Introduction --- p.25
Chapter 2.1.1 --- Effects of polyunsaturated fatty acids (PUFAs) on blood cholesterol --- p.25
Chapter 2.1.2 --- Differential effects of 18-C PUFAs on lowering blood cholesterol in vivo --- p.25
Chapter 2.1.3 --- "Structures, metabolism and conjugation of octadecaenoic acids (ODA)" --- p.26
Chapter 2.1.4 --- Objectives --- p.26
Chapter 2.2 --- Experiment 1 --- p.28
Chapter 2.2.1 --- Materials and methods --- p.28
Chapter 2.2.1.1 --- Experimental fatty acids --- p.28
Chapter 2.2.1.1.1 --- Isolation of LN from flaxseed --- p.28
Chapter 2.2.1.1.2 --- Isolation of CLN from tung seed --- p.28
Chapter 2.2.1.2 --- Animals --- p.29
Chapter 2.2.1.3 --- Diets --- p.30
Chapter 2.2.1.4 --- Plasma lipid measurements --- p.30
Chapter 2.2.1.5 --- Plasma CETP activity measurement --- p.30
Chapter 2.2.1.6 --- "Measurement of liver SREBP-2, LDLR, HMGR and CYP7A1 protein abundance by Western blotting" --- p.34
Chapter 2.2.1.7 --- "Measurement of hepatic SREBP-2, LDLR, HMGR, LXR, CYP7A1, CETP, SR-B1 and LCAT mRNA by real time PCR" --- p.35
Chapter 2.2.1.7.1 --- Extraction of mRNA --- p.35
Chapter 2.2.1.1.2 --- Complementary DNA synthesis --- p.36
Chapter 2.2.1.7.3 --- Real-time polymerase chain reaction (PCR) anaylsis --- p.36
Chapter 2.2.1.8 --- Determination of cholesterol in liver --- p.37
Chapter 2.2.1.9 --- Determination of fecal neutral and acidic sterols --- p.38
Chapter 2.2.1.9.1 --- Determination of fecal neutral sterols --- p.39
Chapter 2.2.1.9.2 --- Determination of fecal acidic sterols --- p.41
Chapter 2.2.1.10 --- Statistics --- p.43
Chapter 2.2.2 --- Results --- p.44
Chapter 2.2.2.1 --- Growth and food intake --- p.44
Chapter 2.2.2.2 --- Organ weights --- p.44
Chapter 2.2.2.3 --- "Effects of ODA on serum TC, TG and HDL-C" --- p.44
Chapter 2.2.2.4 --- Effect of ODA on liver cholesterol --- p.48
Chapter 2.2.2.5 --- Effect of ODA on fecal neutral sterol output --- p.48
Chapter 2.2.2.6 --- Effect of ODA on fecal acidic sterol output --- p.48
Chapter 2.2.2.7 --- Effect of ODA on cholesterol balance in hamsters --- p.52
Chapter 2.2.2.8 --- Effect of ODA on plasma CETP activity --- p.52
Chapter 2.2.2.9 --- Correlation between blood TC and liver cholesterol --- p.52
Chapter 2.2.2.10 --- Correlation between blood HDL-C and liver cholesterol --- p.52
Chapter 2.2.2.11 --- Correlation between blood nHDL/HDL ratio and liver cholesterol --- p.52
Chapter 2.2.2.12 --- Effect ofODA on liver SREBP-2 immunoreactive mass --- p.58
Chapter 2.2.2.13 --- Effect of ODA on liver LDLR immunoreactive mass --- p.58
Chapter 2.2.2.14 --- Effect of ODA on liver HMGR immunoreactive mass --- p.58
Chapter 2.2.2.15 --- Effect of ODA on liver LXR immunoreactive mass --- p.58
Chapter 2.2.2.16 --- Effect of ODA on liver CYP7A1 immunoreactive mass --- p.63
Chapter 2.2.2.17 --- Effects ofODA on hepatic CETP mRNA --- p.65
Chapter 2.2.2.18 --- Effects of ODA on hepatic LDLR mRNA --- p.65
Chapter 2.2.2.19 --- Effects of ODA on hepatic LXR mRNA --- p.65
Chapter 2.2.2.20 --- Effects of ODA on hepatic CYP7A1 mRNA --- p.65
Chapter 2.3 --- Experiment 2 --- p.70
Chapter 2.3.1 --- Materials and Methods --- p.70
Chapter 2.3.1.1 --- Experimental diets --- p.70
Chapter 2.3.1.2 --- Animals --- p.70
Chapter 2.3.1.3 --- Intestinal acyl coenzyme A: cholesterol acyltransferase (ACAT) activity measurement --- p.70
Chapter 2.3.1.3.1 --- Preparation of intestinal microsome --- p.71
Chapter 2.3.1.3.2 --- ACAT activity assay --- p.71
Chapter 2.3.2 --- Results --- p.73
Chapter 2.3.2.1 --- Growth and food intake --- p.73
Chapter 2.3.2.2 --- Organ weights --- p.73
Chapter 2.3.2.3 --- "Effect of ODA on serum TC, TG and HDL-C" --- p.73
Chapter 2.3.2.4 --- Effect of ODA feeding on fecal neutral sterol content --- p.77
Chapter 2.3.2.5 --- Effect of ODA feeding on fecal acidic sterol content --- p.77
Chapter 2.3.2.6 --- Effect of ODA feeding on intestinal acyl coenzyme A: acyl cholesterol transferase (ACAT) activity --- p.77
Chapter 2.4 --- Discussion --- p.81
Chapter CHAPTER 3 --- EFFECT OF OCTADECAENOIC ACIDS ON CHOLESTEROL-REGULATING GENES IN HepG2
Chapter 3.1 --- Introduction --- p.86
Chapter 3.1.1 --- HepG2 as a model of cholesterol regulation --- p.86
Chapter 3.1.2 --- Effect of polyunsaturated fatty acids (PUFAs) on cholesterol regulating genes in cultured cells --- p.87
Chapter 3.1.3 --- Objectives --- p.89
Chapter 3.2 --- Materials and Methods --- p.90
Chapter 3.2.1 --- Cell culture --- p.90
Chapter 3.2.2 --- "Measurement of SREBP-2, LDLR, HMGR and CYP7A1 protein abundance by Western blotting" --- p.92
Chapter 3.2.3 --- "Measurement of cellular SREBP-2, LDLR, HMGR, LXR, CYP7A1 and CETP mRNA by real time PCR" --- p.93
Chapter 3.2.4 --- Statistics --- p.93
Chapter 3.3 --- Results --- p.95
Chapter 3.3.1 --- Effect of ODA on HepG2 SREBP-2 immunoreactive mass --- p.95
Chapter 3.3.2 --- Effect of ODA on HepG2 HMGR immunoreactive mass --- p.95
Chapter 3.3.3 --- Effect of ODA on HepG2 LDLR immunoreactive mass --- p.95
Chapter 3.3.4 --- Effect of ODA on HepG2 LXR immunoreactive mass --- p.95
Chapter 3.3.5 --- Effect of ODA on HepG2 CYP7A1 immunoreactive mass --- p.96
Chapter 3.3.6 --- Effect of ODA supplementation on HepG2 SREBP-2 mRNA expression --- p.102
Chapter 3.3.7 --- Effect of ODA supplementation on HepG2 SREBP-2 mRNA expression --- p.102
Chapter 3.3.8 --- Effect of ODA supplementation on HepG2 LDLR mRNA expression --- p.102
Chapter 3.3.9 --- Effect of ODA supplementation on HepG2 LXR mRNA expression --- p.106
Chapter 3.3.10 --- Effect of ODA supplementation on HepG2 CYP7A1 mRNA expression --- p.106
Chapter 3.3.11 --- Effect of ODA supplementation on HepG2 CETP mRNA expression --- p.106
Chapter 3.4 --- Discussion --- p.110
Chapter CHAPTER 4 --- EFFECT OF APPLE POLYPHENOLS ON BLOOD CHOLESTEROL IN HAMSTERS
Chapter 4.1 --- Introduction --- p.114
Chapter 4.1.1 --- Apple is a commonly consumed fruit worldwide --- p.114
Chapter 4.1.2 --- Potential health effects of apples --- p.114
Chapter 4.1.3 --- Abundance of polyphenols in apple --- p.115
Chapter 4.1.4 --- Fuji variety of apple --- p.116
Chapter 4.1.5 --- Objectives --- p.116
Chapter 4.2 --- Materials and Methods --- p.118
Chapter 4.2.1 --- Isolation of AP --- p.118
Chapter 4.2.2 --- Characterization of AP extract --- p.118
Chapter 4.2.3 --- Effect of AP on CETP activity in vitro --- p.118
Chapter 4.2.4 --- Effect of AP on blood cholesterol in hamsters --- p.119
Chapter 4.2.4.1 --- Animals --- p.119
Chapter 4.2.4.2 --- Diets --- p.120
Chapter 4.2.4.3 --- Plasma lipids measurement --- p.121
Chapter 4.2.4.4 --- Plasma CETP activity measurement and immunoreactive mass by Western blotting --- p.123
Chapter 4.2.4.5 --- "Measurement of liver SREBP-2, LDL-R, HMG-R and CYP7A1 protein abundance by Western blotting" --- p.124
Chapter 4.2.4.6 --- Statistics --- p.124
Chapter 4.3 --- Results --- p.125
Chapter 4.3.1 --- Polyphenol content in AP --- p.125
Chapter 4.3.2 --- Effect of AP on CETP activity in vitro --- p.125
Chapter 4.3.3 --- Growth and food intake --- p.128
Chapter 4.3.4 --- Organ weights --- p.128
Chapter 4.3.5 --- Effect of AP supplementation on the plasma lipid profile of hamsters --- p.131
Chapter 4.3.6 --- Effect of AP feeding on plasma CETP activity of the hamsters --- p.131
Chapter 4.3.7 --- Effect of AP on plasma CETP immunoreactive mass --- p.134
Chapter 4.3.8 --- Effect of AP on liver SREBP-2 immunoreactive mass --- p.134
Chapter 4.3.9 --- Effect of AP on liver LDLR immunoreactive mass --- p.134
Chapter 4.3.10 --- Effect of AP on liver HMGR immunoreactive mass --- p.134
Chapter 4.3.11 --- Effect of AP on liver CYP7A1 immunoreactive mass --- p.134
Chapter 4.3.12 --- Effect of AP on liver cholesterol level --- p.140
Chapter 4.4 --- Discussion --- p.142
Chapter CHAPTER 5 --- CONCLUSION --- p.145
REFERENCES --- p.148
44
(6406343), Maria Maiz Rodriguez. "A blueberry-enriched diet may aid in the amelioration of bone loss in the ovariectomized rat model." Thesis, 2019.
Abstract:
Osteoporosis is the most common bone disease in older adults and is characterized by low bone mass and increased fragility. Women are at a higher risk for osteoporosis because of the rapid loss of bone during menopause. The decline of estrogen is accompanied by an increased bone resorption and a decreased bone formation which results in negative bone balance. Due to adverse effects on the uterus, breast and cardiovascular system, hormone replacement therapy has been discouraged. Nutritional strategies for osteoporosis prevention are being sought. It has been suggested that (poly)phenol-rich fruits may have bone protective effects. Blueberries are one of the richest sources of (poly)phenols, thus the aim of this dissertation was to determine whether a blueberry-enriched diet could aid in bone loss prevention in the ovariectomized rat model.
There are hundreds of blueberry varieties which differ in (poly)phenol profiles and content. Five blueberry varieties (Ira, Montgomery, SHF2B1-21:3, Onslow and Wild Blueberry) were chosen to assess the bioavailability of its individual (poly)phenols. Bioavailability of individual phenolic metabolites was determined through a pharmacokinetic study in ovariectomized rats. The results showed that Montgomery blueberry had significantly higher bioavailability of malvidin, cyanidin and myricetin metabolites, while Ira had significantly higher bioavailability of quercetin metabolites, thus suggesting that the absorption of blueberry polyphenols and their potential to reach target tissues differed between blueberry varieties.
It is important to assess what is the most appropriate dose of blueberry necessary to exert beneficial effects on bone. To determine the most adequate dose of wild blueberry to prevent bone loss in ovariectomized rats, a randomized crossover study was carried out to assess the effects of four different blueberry doses on net bone calcium retention over a 10-day treatment period. The results showed that the only dose to significantly increase net bone calcium retention by 25.6% (p = 0.0426) was the 5% blueberry diet (% w/w), while the higher doses of 10% and 15% had no effect on net bone calcium retention. This informed the last study where Montgomery blueberry and wild blueberry at a 5% dose (% w/w) were chosen to investigate the effects of an 8-week chronic feeding study on calcium metabolism, kinetics, bone microarchitecture and strength and polyphenol metabolism and distribution. A chronic consumption of the wild blueberry resulted in a trend towards minimal trabecular bone loss protection in comparison to the control diet (p=0.08). Kinetic modeling of calcium showed that the Montgomery blueberry had anabolic effects on bone through significantly increasing calcium absorption and bone deposition. The phenolic metabolism differed among blueberry varieties due to each berry’s polyphenol content and profiles and a chronic consumption of blueberry resulted in significant changes in absorption and metabolism of polyphenols. The bone marrow was investigated to determine whether there was any accumulation of phenolic acids in the tissue. Hippuric acid accumulation was significantly higher with the Montgomery blueberry treatments in comparison to control diet. Interestingly, hippuric acid content in the bone marrow was significantly and positively correlated with bone deposition calculated from kinetic modeling. Although no differences were observed on bone mineral density, strength, and microarchitecture, previous studies with a duration of 12-14 weeks have shown significant protection of a blueberry-enriched diet on bone mineral density. Because our study showed a trend for increased trabecular bone (p = 0.08) with the blueberry treatments, we conclude that an 8-week treatment was insufficient time to detect significant differences between the control and blueberry treatments. Since previous researchers before us have reported significant attenuation to bone loss immediately after OVX, it is possible that blueberry that in our study, blueberry was unable to rescue bone once lost after ovariectomy.
A blueberry-enriched diet resulted in a minimal protection to bone after stabilized to OVX, but showed significant increases in calcium absorption and bone turnover in ovariectomized rats. Colonic metabolite profiles from the chronic consumption of blueberry significantly changed over time, thus providing an insight into the effects of blueberry consumption on polyphenol metabolism.
45
Ngiewih, Yufanyi [Verfasser]. "Effect of selected flavonoids and polyphenols on key elements involved in the regulation of the glucose-glycogen homeostasis and the Wnt signalling pathway / vorgelegt von Yufanyi Ngiewih." 2008. http://d-nb.info/99169726X/34.
46
Karnpanit, Weeraya. "Effect of cultivar and processing on anti-nutritional factors and bioaccessibility of minerals of Australian sweet lupin (Lupinus angustifolius L.)." Thesis, 2016. http://hdl.handle.net/1959.7/uws:38285.
Abstract:
Australian sweet lupin (ASL) (Lupinus angustifolius L.) is an underutilised grain legume with a unique chemical composition. It contains high protein and dietary fibre and is a good source of vitamins, minerals and bioactive compounds. Due to various health benefits, there is an increasing interest in developing lupin incorporated functional foods. However, the presence of anti-nutritional factors is one of the reasons that limit commercial production of lupin based foods. Major anti-nutritional factors in lupin include raffinose family oligosaccharides (RFOs), phytate and polyphenols. Phytate and polyphenols have negative effects on the minerals bioavailability. RFOs also cause flatulence and abdominal discomfort.
Published information on the anti-nutritional factors and mineral bioavailability of ASL is limited. The present study aimed at investigating the effect of cultivar, cultivation year and dehulling on mineral (calcium, iron, magnesium, potassium and zinc), anti-nutritional factors (RFOs, phytate, total phenolics, total flavonoids and condensed tannins) and mineral bioaccessibility (calcium, iron and zinc) of ASL. The relationships between minerals or anti-nutritional factors, and mineral bioaccessibility were also determined.
Ten cultivars of ASL (Belara, Corumup, Gungurru, Jenabillup, Mandelup, PBA Barlock, PBA Gunyidi, Quilinock, Tanjil, and Walan 2385) cultivated at Wongan Hills Research Station in 2011, 2012 and 2013 were obtained from the Department of Agriculture and Food, Western Australia. Lupin samples were analysed for RFOs, phytate, total phenolics, total flavonoids, condensed tannins, calcium, iron, magnesium, potassium and zinc contents. Bioaccessibility of calcium, iron and zinc in heat treated lupin samples were determined using a dialysability method.
The results showed that most of ASL cultivars are good sources of RFOs. Average total RFOs content in ASL (dehulled seeds) was 10.5 g/100 g DM which is higher than most of the other pulses such as black gram and mung bean. Phytate content in lupin is similar to some other pulses such as chickpea and mung bean but lower than kidney bean and soybean. ASL cultivars had low levels of total phenolics (< 100 mg GAE/100 g DM), total flavonoids (< 20 mg CE/100 g DM) and condensed tannins (< 80 mg CE/100 g DM). Dehulled seed of ASL contained relatively high amount of calcium (95 mg/100 g DM) and potassium (1120 mg/100 g DM). Iron (3 mg/100 g DM) and zinc (4 mg/100 g DM) contents in ASL (dehulled seed) were similar to some other grain legumes such as soybean and lentil.
The results showed that cultivar has a significant influence on RFOs, phytate, total phenolics, total flavonoids, condensed tannins, calcium, iron, magnesium, potassium and zinc contents in lupin. Belara and Mandelup contain high levels of total RFOs and recommended for prebiotic rich functional food product development. Gungurru and PBA Barlock had low RFOs and suitable for lupin-enriched foods with low flatulence effect. PBA Barlock contained higher level of polyphenols and flavonoids than most of the other lupin cultivars. Walan 2385 has the highest condensed tannin content and high in flavonoids contents. The highest iron (3.2 mg/100 g DM) and zinc (3.8 mg/100 g DM) contents were found in Belara and Quilinock, respectively. Belara and Quilinock also contain high calcium contents. These findings on the effect of cultivar on anti-nutritional factors and minerals are helpful in selecting suitable cultivars for particular food applications.
Lupin flour for food applications is commercially produced by the dry dehulling technique. Lupin flour can be incorporated into various foods. The effect of dry dehulling on iron, magnesium, zinc, RFOs, phytate, total phenolic and total flavonoid contents depends on the lupin cultivar. Dehulling increases condensed tannin and potassium contents in most lupin cultivars. Calcium contents in all lupin cultivars were reduced as a result of dehulling.
Average calcium, iron and zinc bioaccessibility values of ASL (dehulled seeds) were 11, 21 and 12%. Calcium and zinc bioaccessibility values of lupin were poor and lower than some other grain legumes such as cowpea and mung bean. The low calcium and zinc bioaccessibility values indicate that these minerals may form large complexes which are difficult to be digested by the human digestive system. In contrast, iron bioaccessibility of ASL is higher than values reported for other pulses including red grams and black grams. Cultivar had a significant effect on calcium and iron bioaccessibility of lupin but had no effect on zinc bioaccessibility. PBA Gunyidi had higher calcium bioaccessibility than some of the other cultivars. High iron bioaccessibility values were found in Gungurru and Mandelup.
Calcium bioaccessibility of most of the lupin cultivars were increased after dehulling.
Phytate to calcium molar ratios of dehulled lupin samples present poor calcium bioavailability. All tested lupin cultivars had high phytate to iron molar ratios indicating poor iron bioavailability. High phytate to zinc molar ratios were recorded in almost all of the lupin samples implying poor zinc bioavailability. Although the phytate to mineral molar ratios are widely used as predictors of mineral bioavailability, the result of the study shows that the phytate to mineral molar ratio is not correlated to the mineral bioaccessibility of lupin. Therefore, the phytate to mineral molar ratio may be not a suitable predictor of the mineral bioaccessibility of lupin.
Bioaccessibility was not directly related to calcium, iron or zinc contents of lupin which shows that high mineral content is not always related to high mineral bioaccessibility. Calcium content was negatively correlated to bioaccessibility of calcium of lupin. Results also showed negative trend between iron content and iron bioaccessibility as well as zinc content and zinc bioaccessibility. Poor correlations between minerals (calcium, iron and zinc) bioaccessibility values and anti-nutritional factors (RFOs, phytate, total phenolics, total flavonoids and condensed tannins) were found. This finding indicates that the anti-nutritional factors studied are not likely to significantly affect the minerals bioaccessibility of lupin.
A stepwise multiple regressions were performed to develop predictive equations to predict mineral bioaccessibility using the minerals and anti-nutritional factors contents. A predictive equation using calcium, phytate and RFOs contents can predict 69% of the calcium bioaccessibility of lupin. Iron, calcium, RFOs and polyphenols contents can be used to predict 70% of the iron bioaccessibility of lupin. A regression equation using zinc, calcium and condensed tannin contents can estimate 59% of zinc bioaccessibility of lupin. These predictive equations indicate that there are other factors affecting the minerals bioaccessibility of lupin in addition to the factors studied.
47
Fernandez, Amanda. "In vivo evaluation of "Meriva" curcumin, and apigenin as anti-inflammatory drugs in a mouse model of chronic neuroinflammation." Thesis, 2018. http://hdl.handle.net/1959.7/uws:51756.
Abstract:
Purpose: The current project was divided into two separate, but related studies: the curcumin project and the apigenin project. In these projects, we aimed to assess the potential of two polyphenolic compounds in treating neuroinflammation and neurodegenerative disease: curcumin and apigenin. Curcumin project purpose (pilot study): To develop a valid UPLC-MS/MS method to quantify the plasma concentration of a phosphatidylcholine curcumin formulation (Meriva® curcumin), administered orally (via chow) to GFAP-IL6 mice for 30 days. We also endeavoured to determine if this formulation is able to increase bioavailability of Meriva® curcumin, in comparison to unformulated curcumin (naïve curcumin). We also aimed to confirm, using spectrophotometry, the curcumin concentration within the chow, in order to validate our experiment. Apigenin project purpose: To assess the viability of apigenin in rescuing motor, learning and memory deficits in a GFAP-IL6 mouse model of chronic neuroinflammation.
48
Rodríguez, Gerardo. "Flavonoids and related polyphenolic compounds in forage legumes." 1999. http://catalog.hathitrust.org/api/volumes/oclc/45262156.html.
49
Galati, Giuseppe. "Dietary flavonoid/polyphenolic reactive metabolites and their biological properties." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=80354&T=F.
50
Ferreira, Patrícia da Silva. "Preparation of new bioactive flavonoid derivatives." Master's thesis, 2017. http://hdl.handle.net/10316/83642.
Abstract:
Dissertação de Mestrado em Química Farmacêutica Industrial apresentada à Faculdade de FarmáciaOs polifénois são compostos naturais de grande interesse. Estes estão presentes em diversos produtos do nosso quotidiano. Estes compostos são muito importantes devido às diversas atividades biológicas comprovadas, nomeadamente atividade antioxidante, atividade anti-inflamatória e atividade anticancerígena. No entanto, a sua aplicabilidade na indústria farmacêutica está condicionada pela baixa estabilidade e solubilidade em meio lipofílico.Uma das estratégias eficazes utilizadas para melhorar as propriedades destes compostos é através da modificação da sua estrutura, nomeadamente as reações de acilação.Neste trabalho de investigação realizou-se a semi - síntese de novos derivados bioativos através de reações de acilação regiosseletivas através da combinação de métodos enzimáticos, tendo-se usado as lípases como biocatalisadores e químicos tendo-se usado o anidrido acético e o cloreto de benzoílo como grupos acilantes. Assim, o objetivo desta dissertação foi o de sintetizar, isolar e caracterizar derivados acilados através de substratos polihidroxilados nomeadamente a molécula resveratrol e a molécula naringenina, com atividade biológica reconhecida. A caracterização destes compostos foi feita recorrendo a três tipos de ressonância: RMN 1H, RMN 13C e DEPT 135.Através destes estudos, foi possível observar a regiosseletividade das reações enzimáticas e das reações químicas perante substratos com diferentes grupos hidroxilo. Isto levou à obtenção de um conjunto de novos compostos ésteres com elevada regiosselectividade e bons rendimentos.
Polyphenols are a class of natural compounds with great interest. They are present in several products of our daily lives, due to the diverse biological demonstrated activities, specifically the antioxidant activity, the anti - inflammatory activity and the anti - carcinogenic activity. However, its applicability in the pharmaceutical industry is conditioned because of their low stability and low solubility in lipophilic environments . One of the effective strategies used to improve the properties of these compounds is the modification of their structure through acylation reactions.In this research, the semi - synthesis of new bioactive derivatives was performed through regiosselective acylation reactions by combination of enzymatic, using lipases as biocatalysts and chemical methods, using acetic anhydride and benzoyl chloride asdonors of the acyl group.Therefore, the objective of this dissertation was to synthesize, isolate and characterize acylated derivatives through polyhydroxylated substrates, namely resveratrol compound and naringenin compound, with recognizable biological activity. The characterization was performed by three types of nuclear magnetic resonance: 1 H - NMR, 13 C - NMR e DEPT 135.Through these studies, it was possible to observe the regioselectivity of the enzymatic reactions and the chemical reactions towards to substrates with different hydroxyl groups. This leaded to the production of a new series of esters with high regionselectivity and good yields.