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Kavuru, Padmini. "Crystal engineering of flavonoids". [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002463.
Pełny tekst źródłaOliveira, 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.
Pełny tekst źródłaBALASUBRAMANIAN, 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.
Pełny tekst źródłaKurzová, 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.
Pełny tekst źródłaCiburová, Alena. "Studium antimikrobiálních látek zázvoru". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401841.
Pełny tekst źródłaRezaee, 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.
Pełny tekst źródłaTran, Dong tien. "Conception et synthèse de sondes moléculaires pour l'étude d'interactions polyphénol-protéine". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0443/document.
Pełny tekst źródłaPolyphenols 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)
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.
Pełny tekst źródłaThe 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
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.
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.
Pełny tekst źródłaPolyphenols 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
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.
Pełny tekst źródłaIrrigation 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.
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.
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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.
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.
Pełny tekst źródłaVacková, 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.
Pełny tekst źródłaŠtindlová, Jitka. "Možnosti enkapsulace přírodních antioxidantů". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-216837.
Pełny tekst źródłaCruz, 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.
Pełny tekst źródłaA 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.
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.
Pełny tekst źródłaBen, 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.
Pełny tekst źródłaThis 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
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.
Pełny tekst źródłaJungbluth, 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.
Pełny tekst źródłaAbi, 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.
Pełny tekst źródłaRheum 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
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.
Pełny tekst źródłaHümmer, Wolfgang. "Analyse potentiell chemopräventiv wirksamer Inhaltsstoffe von Apfelsaft". kostenfrei, 2009. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2009/3709/.
Pełny tekst źródłaRoy, 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.
Pełny tekst źródłaMeng, 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.
Pełny tekst źródłaThe 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
Nay, Bastien. "Intérêts, statégies et approches expérimentales en synthèse chimique totale de flavanoi͏̈des et tanins condensés". Bordeaux 2, 1998. http://www.theses.fr/1998BOR2P100.
Pełny tekst źródłaHerzog, 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.
Pełny tekst źródłaWANG, 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.
Pełny tekst źródłaPerromat, 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.
Pełny tekst źródłaPinto, 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/.
Pełny tekst źródłaTeleosts 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.
Seguin, Catherine. "Arbutus Unedo L. Et autres éricacées médicinales". Bordeaux 2, 1997. http://www.theses.fr/1997BOR2P049.
Pełny tekst źródłaMatito, 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.
Pełny tekst źródłaThe 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.
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.
Pełny tekst źródłaPhenolic 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
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.
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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.
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.
Pełny tekst źródłaDissertation (MSc)--University of Pretoria, 2011.
Anatomy
unrestricted
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.
Pełny tekst źródłaEarlier 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
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.
Pełny tekst źródłaCardiovascular 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
Way, Tzong-Der. "Chemoprevention against breast cancer by flavonoids and tea polyphenols". 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-0807200416072900.
Pełny tekst źródłaWay, Tzong-Der, i 魏宗德. "Chemoprevention against breast cancer by flavonoids and tea polyphenols". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/09469640876182180859.
Pełny tekst źródła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.
"Characterization of flavonoid antioxidants in Vigna sinensis seeds". 2003. http://library.cuhk.edu.hk/record=b5896112.
Pełny tekst źródłaThesis 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
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.
Pełny tekst źródłaLiang, Yu-Chih, i 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.
Pełny tekst źródła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.
"Effects of octadecaenoic acids and apple polyphenols on blood cholesterol". 2007. http://library.cuhk.edu.hk/record=b5893326.
Pełny tekst źródłaThesis (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
(6406343), Maria Maiz Rodriguez. "A blueberry-enriched diet may aid in the amelioration of bone loss in the ovariectomized rat model". Thesis, 2019.
Znajdź pełny tekst źródłaNgiewih, 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.
Pełny tekst źródłaKarnpanit, 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.
Pełny tekst źródłaFernandez, 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.
Pełny tekst źródłaRodríguez, Gerardo. "Flavonoids and related polyphenolic compounds in forage legumes". 1999. http://catalog.hathitrust.org/api/volumes/oclc/45262156.html.
Pełny tekst źródłaGalati, Giuseppe. "Dietary flavonoid/polyphenolic reactive metabolites and their biological properties". 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=80354&T=F.
Pełny tekst źródłaFerreira, Patrícia da Silva. "Preparation of new bioactive flavonoid derivatives". Master's thesis, 2017. http://hdl.handle.net/10316/83642.
Pełny tekst źródłaOs 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.