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Pisula, Nikki Leigh. "Does evolutionary exposure mediate allelopathic effects? /". View online, 2010. http://repository.eiu.edu/theses/docs/32211131524889.pdf.
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Hudson, Christine Cecilia. "Isolation of signal transduction inhibitors by bioassay-directed fractionation of plant extracts". Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/30636.
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Castillo-Ruiz, Priscila. "Plant activation of different chemicals by tobacco and brassica cell cultures, using the plant cellmicrobe coincubation assay". Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39239.
Testo completoAbstract (sommario):
In this study, the ability of various chemicals to be biotransformed into mutagens by plant cells was investigated. Two thiocarbamate herbicides, diallate and triallate, the sulfonylurea herbicide chlorsulfuron, and the aniline derivative m-phenylenediamine were tested for their ability to revert Salmonella typhimurium (strains TA100 and TA98) in the presence and absence of Nicotiana tabacum (TX1) cell cultures in liquid suspension. Chlorsulfuron and m-phenylenediamine were also tested in the presence and absence of Brassica napus cv. 'Topas' cells. Diallate was found to be activated by TX1 cells into a mutagen that induces base-pair substitution mutations. In the presence of the TX1 plant cell line, chlorsulfuron significantly increased the number of mutations on the strain TA98 of Salmonella. Tobacco TX1 cells did not activate triallate into a mutagen. m-Phenylenediamine was activated into a mutagen by TX1 and Brassica cells as detected by Salmonella TA98. This aniline derivative, in the absence of plant cells and at concentrations higher than 20 $ mu$ Moles/plate, was also able to significantly increase the number of TA98 revertants as compared to the control plants. Finally, Brassica napus cells activated chlorsulfuron into a mutagen that induces frameshift mutations.
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Adewusi, Emmanuel Adekanmi. "Evaluation of the effect of Pelargonium reniforme Curtis extract on alcohol induced liver damage in Nkonkobe Municipality Eastern Cape Province South Africa". Thesis, University of Fort Hare, 2009. http://hdl.handle.net/10353/263.
Testo completoAbstract (sommario):
Alcohol abuse is a very common practice (just like in many other parts of the world) in Nkonkobe Municipality, Eastern Cape Province, South Africa. This is associated with liver disease. An ethnobotanical survey of plants used for the treatment of alcohol-induced liver damage in Nkonkobe Municipality was conducted. During the survey and also from information gathered in the literature, Pelargonium reniforme Curtis, was prominently mentioned, among other plants, as the species used generally for the treatment of alcohol-induced liver damage. This project was designed to evaluate the effects of the plant on alcohol-induced liver damage, including its antioxidant and antimicrobial properties. It also involves safety evaluation studies to determine if the plant is safe for consumption. Studies using rats of the Wistar strain were carried out to determine the protective and curative effects of P. reniforme on alcohol-induced liver damage. Results obtained showed that the plant extract can protect the liver cells as well as enhance recovery from tissue damage. The plant also showed good antimicrobial and antioxidant activity and this further validates its use in the treatment of liver diseases. Safety evaluation studies of the extract were carried out by investigating the effects of the oral administration on some haematological and biochemical parameters in male Wistar rats. The results obtained from the study suggest that the plant extract is not toxic at the doses used and is therefore safe for medicinal uses. The results of the various bioassays carried out in this project have justified the traditional uses of P. reniforme for the treatment of alcohol-induced liver damage.
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Voigt, Astrid. "Bioavailability of trace metals to plants". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19561.
Testo completoAbstract (sommario):
Soil quality guidelines are currently based on total trace metal loads. There is a need to define indices of bioavailability to allow reasonable predictions for plant metal uptake and toxicity in soils. Trace metal toxicities to plants often correlate best with free metal ion activities. The first objective was to develop a plant bioassay that is sensitive to trace metals at concentrations realistic for soils. The root elongation of lettuce Lactuca sativa 'Buttercrunch' was used as toxicological endpoint. This endpoint was sensitive and reproducible to environmentally relevant concentrations of Cd, Cu, Ni, Pb and Zn. The second objective was to test whether free metal ion activities are constant predictors of metal toxicities in synthetic solutions and in soil extracts that differ in their concentrations of cations and ligands. The root elongation assay was used to test this hypothesis. In synthetic solutions, the rhizotoxicity of Cd, Cu, Ni, Pb and Zn decreased with increasing Ca and H concentrations. This could not be explained with the effect of higher cationic concentrations on root growth or on solution speciation. It was concluded that Ca and H inhibited the rhizotoxicity of all metals tested. The rhizotoxicity of Cu and Cd was further examined in soil extracts. Both metals became less rhizotoxic at higher H and dissolved organic matter concentrations. The rhizotoxicity endpoints from the experiments in synthetic solution were used to develop parameters for a Biotic Ligand Model (BLM) for Cd, Cu, Ni, Pb and Zn. The BLM accounts for solution speciation and interprets cationic inhibition of rhizotoxicity as competition of metals with Ca and H for potential sites of rhizotoxicity. The BLM predicted metal rhizotoxicity better than the free metal ion activity in synthetic solutions and in soil extracts. Different models were tested against literature rhizotoxicity data for metals at different Ca and H concentrations. Predictions for metal rhizotoxicity given by BLM, Gouy-Chapman-Stern model and Freundlich equation model were compared with predictions based on free metal ion activities in solution. The BLM predicted rhizotoxicity most accurately. The BLM seems promising for predictions of metal toxicity and metal bioavailability in soils to support site-specific environmental risk assessments.
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Kotze, Danelle. "Production and pharmacological analysis of microcultures of Pelargonium sidoides DC and Pelargonium reniforme Curtis". Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/18115.
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Naman, Charles Benjamin. "Phytochemical Investigation of the Medicinal Plant Taxodium distichum and Library Screening of Thalictrum Alkaloids for New Antileishmanial Drug Leads". The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429283826.
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Reed, Donna K. "Impact zone delineation for biological assessment of power plant effluent effects on snail populations in the Clinch River". Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/38639.
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Blanco, Carcache Peter Josephin. "Chemical Characterization and Biological Evaluation of Secondary Metabolites Isolated from Glycosmis ovoidea". The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1580383951030389.
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Conan, Cécile. "Metabolomics investigations of seaweed extracts used as plant growth biostimulants and transcriptomic studies of their physiological effects on A. thaliana". Electronic Thesis or Diss., Paris 6, 2016. http://www.theses.fr/2016PA066760.
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Développer une agriculture durable et respectueuse de l’environnement, implique l’utilisation de biostimulants tels que les extraits de macro-algues marines dans le but d’améliorer la croissance des plantes ainsi que leur tolérance aux stress biotiques et abiotiques. Ces extraits commerciaux d’algues sont utilisés en agriculture afin de favoriser la nutrition des plantes, d’améliorer leur qualité nutritionnelle et d’accroitre leur rendement. Dans ce domaine quelques modes d’action ont été élucidés par le centre R&D des Laboratoires Goëmar-Arysta. Cependant, jusqu’à présent, les matières actives n’ont pas été identifiées via une approche classique de fractionnement bio-guidé. De ce fait, leurs mécanismes d’action restent non élucidés. L’objectif premier de ce projet de thèse était d’identifier ces molécules biostimulantes via une approche de fractionnement assistée par la métabolomique, réalisée sur des extraits d’algues commerciaux. Les analyses RMN et LC-MS réalisées sur ces extraits se sont révélées infructueuses dans l’identification de molécules candidates. Ainsi, un classique fractionnement bio-guidé a conduit à la purification d’une fraction favorisant la croissance des plantes. Les analyses U-HPLC-HR-MS réalisées sur cette fraction et ses sous-fractions ont permis d’identifier deux molécules candidates. Un procédé de fractionnement utilisé au cours de ce travail fait l’objet d’une procédure de dépôt de brevet, afin d’apporter une valeur ajoutée à ces extraits biostimulants et de valoriser de nouveaux produits. Le deuxième objectif de ce projet, était d’étudier les réponses physiologiques de la plante modèle Arabidopsis thaliana à l’aide d’analyse transcriptomique. Ceci afin d’élucider les voies métaboliques régulées suite à l’application d’un extrait d’algue produit par Goëmar et d’une fraction stimulante de croissance purifiée au cours de ce projet. L’analyse du transcriptome d’Arabidopsis thaliana révèle la régulation de voies métaboliques complétement différentes par l’extrait d’algues en comparaison de celles régulées par sa fraction purifiée. De plus, les gènes dérégulés par la fraction purifiée constituent des biomarqueurs potentiels de croissance chez les plantes qui pourront être utilisés pour assister l’isolement bio-guidé de molécules candidates. Finalement, ces deux approches combinant fractionnement bio-guidé et analyses métabolomiques sur l’extrait d’Ascophyllum nodosum ainsi que les analyses transcriptomiques réalisées apportent de nouvelles connaissances sur les structures et les modes d’action de molécules candidatesTo further develop a sustainable agriculture, new bio-solutions include the use of biostimulants such as seaweed aqueous extracts to improve plant growth or/and alleviate the effect of biotic and abiotic stress. These commercial products aim to improve plant nutrition, in order to impact yield and quality parameters. In this domain, some modes of action have been proposed by the Goëmar-Arysta R&D center. However, the bioactive ingredients have not been identified so far, using classical methods of bioassay-guided fractionation. Therefore, their mechanisms of action remain also elusive. The aim of this thesis project was first to identify, using a strategy of metabolomic profiling of seaweed extracts, the bioactive compounds responsible for plant growth stimulation. The 1H-NMR-based profiling and LC-MS metabolomic analyses of commercial seaweed extracts were not suitable to identify candidate molecules that promote plant growth. A classical bioassay-guided fractionation achieved on a Goëmar extract provided a growth promoting purified fraction and further bioactive sub-fractions. The U-HPLC-HR-MS analyses of these sub-fractions highlighted two candidate molecules. A fractionation process used in this work should be patented in order to improve added-value of growth-promoting filtrate and valorize new by-products. In parallel, the physiological effects of these seaweed extracts were studied in the model plant Arabidopsis thaliana through transcriptomic approaches in order to decipher patterns of gene regulation in response to a crude commercial extract and its purified fraction. The transcriptome in response to the application of seaweed extract was completely different of those obtained using its purified fraction. Genes dysregulated by this purified fraction provided potential biomarkers of plant growth that could be used. to assist the bioactive molecule isolation. Finally these two approaches combining, metabolomics-guided and bioassay-guided fractionation of extracts from the brown seaweed Ascophyllum nodosum, and global transcriptomics in Arabidopsis provided several new insights into the nature and structure of different molecules that trigger different physiological responses in plants
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Gutu, Ketema Tolossa. "Bioassay-guided phytochemical study of indigenous medicinal plants of Ethiopia". Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/28964.
Testo completoAbstract (sommario):
In many developing countries, farmers and pastoralists still rely on their indigenous knowledge, practices and locally available plants to control nematode parasitic infections, both in livestock and humans. The overall aim of my thesis was to undertake bioassay-guided phyto-chemical study of extracts and their constituents from Ethiopian anti-parasitic plants used by healers to control gastrointestinal nematode parasites in livestock to validate their ethno-medicinal use and to characterise and identify their active ingredients. As a first experiment (Chapter Three), four types of crude extracts (water, 70% methyl-alcohol, absolute methanol and acetone) of four indigenous Ethiopian medicinal plants (Adenia species, Cissus ruspolii, Ipomoea eriocarpa and Euphorbia thymifolia) were screened against Teladorsagia circumcincta egg hatching in vitro, not only as a first step to validate the traditional healers claim but also to choose the most promising plant extract(s) for further phyto-chemical studies. The egg hatching inhibition (EHI) test results revealed that the anti-parasitic properties of these plants depended on plant species, dose, and solvent polarity. The water extracts of both C. ruspolii and Adenia sp. exhibited largest, up to 100% EHI but also larval migration inhibition activities, and were selected for further studies. The second experiment (Chapter Four) assessed the nature of active constituents in these extracts by physico-chemical methods. It was observed that the major constituents of both plant extracts responsible for the EHI activities are likely highly polar, water-soluble, small and moderately heat-labile molecules. The third and fourth experiments (Chapters Five and Six) consisted of separating Cissus ruspolii and Adenia sp. water extracts into discrete fractions by gel-permeation chromatography, EHI tests of Bio-Gel P-2 fractions followed by thin layer chromatography (TLC) profiling of these fractions to detect separated spots (in day light, under UV-light or after staining with various staining reagents) and also to see how elution patterns of separated spots affected by column parameters. The EHI tests on the fractions obtained revealed that the active constituents of C. ruspolii and Adenia sp. water crude extracts were eluted into few fractions based on their molecular sizes. The TLC profilings of these fractions identified spot patterns of active and inactive fractions, which allowed pooling of active constituents based on their EHI and TLC profiling into three pools for each plant. The fifth experiment (Chapter Seven) was to isolate and purify compounds from these pools using various preparative planar and column chromatographic methods. Sequential applications of column chromatography followed by preparative thin layer chromatography isolated and purified five active compounds from C. ruspolii and two active compounds from Adenia sp. The sixth experiment (Chapter Eight) was to characterize and propose/elucidate structures of compounds from the active fractions using chromatographic, analytical and spectroscopic methods. In this regard, the structures of two oleanane type triterpenoid saponins isolated from one of active fractions of Adenia sp. were proposed based on their mass spectrometry (MS) and nuclear magnetic resonance (NMR) data with support of compounds property, TLC and literature. Similar outcomes for C. ruspolii were not achieved due to lack of sufficient sample to run 13C-nuclear magnetic resonance spectroscopy and distortionless enhancement by polarization transfer (DEPT), contamination of some purified compounds with ill-characterised substance from the preparative TLC matrix and in some cases mass spectrometry (MS) and nuclear magnetic resonance (NMR) data did not support each other. The last experiment (Chapter Nine) was to assess anthelmintic efficacy and safety of C. ruspolii and Adenia sp. crude water extracts in Heligmosomoides bakeri infected mice. This in vivo test revealed that both plant extracts exhibited significant reduction in worm burdens and worm egg excretion, with moderate effects on haematology and organ weights at tolerated dosages. In conclusion, both in vitro and in vivo data revealed that Adenia sp. and C. ruspolii have anthelmintic properties, thus validating traditional healer claims and supporting ethno-medicinal use. The bioassay-guided phytochemical study resulted in the isolation of a number of active compounds from these plants, for some of which a structure has been proposed.
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Furbacher, Todd Raymond. "Bioassay-guided isolation of potential antineoplastic natural products from Southwestern plants". Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/279927.
Testo completoAbstract (sommario):
This dissertation details the investigation of numerous plants for potential antineoplastic compounds. 144 plants (391 extracts) were prescreened with an assortment of assays. The pre-screens included an Agrobacterium tumefaciens/potato disk gall tumor inhibition assay, a Saccharomyces cerevisiae mutant topoisomerase assay, and an Escherichia coli plasmid scission assay. Bioassay-guided fractionation was conducted on three plants, Phoradendron juniperinum, Psorothamnus thompsoniae , and Acourtia thurberi, using a different assay for each. Phoradendron juniperinum (Viscaceae) was screened with a plasmid scission assay and the novel compound, 5-caffeoyl-epi-quinic acid (I) was isolated, the first chlorogenic acid to be reported for the genus. Chemical structure was established using NMR and MS data and published structural information. The EC₅₀ for 5-caffeoyl- epi-quinic acid-mediated plasmid DNA cleavage was 76 μM. Fractionation of Psorothamnus thompsoniae (Fabaceae) was directed using the potato disk assay. The active component was dalrubone (II). P. emoryi was fractionated to obtain dalrubone and to search for related compounds. 5-Methoxydalrubone (III) was isolated and tested with dalrubone in cell line assays. 5-Methoxydalrubone was active against MCF-7 (IC₅₀ = 28.2 μM), while dalrubone (IC₅₀ = 1.3 mM) was not. Neither compound significantly inhibited the growth of NCI-H460 or SF-268. Acourtia thurberi (Asteraceae) was active in the yeast mutant assay. Fractionation yielded the sesquiterpene, 14,15-diacetoxy-,8-hydroxy-,3-(3-methylbutanoyl)-14, 15-epoxy-isocedrene (IV). This compound was weakly active against the topoisomerase II sensitive yeast strain, RS321N, with an IC12 of 342 μg/mL. The isocedrene was active in the yeast assay but inactive against human topoisomerase IIalpha. Ten celastroloids (unsaturated, oxygenated D:A-friedo-nor-oleanane triterpenoids from Sri Lankan Celastraceae) and their derivatives, some of which were also weakly active against RS321N, were tested for activity against human topoisomerase IIalpha. Demethylzeylasterone (ex. Kokoona zeylanica) strongly inhibited topo IIalpha with an IC50 of 17.6 μM. All others, including the structurally similar zeylasterone, possessed no activity at 100 μM. Demethylzeylasterone was determined to be a "catalytic inhibitor," preventing DNA from binding to the enzyme while not interacting with the DNA itself. Demethylzeylasterone selectively inhibits the MCF-7 breast cancer cell line with an IC50 of 12.5 μM.
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Silva, Ana Rita Rego Gouveia. "Toxicity and bioremediation evaluation of TBT: bioassays with plants". Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/5657.
Testo completoAbstract (sommario):
Mestrado em Biologia Aplicada - Toxicologia e EcotoxicologiaA poluição ambiental é um problema que afecta todo o ecossistema. Os compostos orgânicos de estanho, e em particular o tributilestanho (TBT), estão amplamente dispersos, por terem uma variedade de aplicações, sendo utilizados como estabilizadores de cloreto de polivinila (PVC), em canalizações de água, como catalisadores, conservantes da madeira e em vários productos de consumo doméstico, como líquidos de limpeza, esponjas e papel. Devido à acção biocida do TBT, este composto era principalmente utilizado em tintas antivegetativas. A sua crescente libertação para o ambiente contribui para a sua presença em quase todos os compartimentos, desde água, sedimentos, solos e até organismos. O coeficiente de partição octanol/água atinge um valor de 3.85, e por isso, o TBT tende a acumular-se na matéria orgânica e nos organismos. Devido à sua persistência e potencial de bioacumulação os compostos orgânicos de estanho tri-substituidos, como o TBT, são considerados extremamente tóxicos para organismos não-alvo, causando disrupção endócrina, incluindo impossexo em fêmeas de gastrópodes. O tempo de meia-vida do TBT nos sedimentos chega a atingir vários anos. Sendo o compartimento sedimentar um reservatório destes compostos. Actividades como a dragagem de sedimentos contaminados com TBT e posterior deposição nos solos, juntamente com a deposição atmosférica e pulverização directa de pesticidas, constituem fontes de contaminação destes compostos no solo. Além disso, a propagação de esgotos contaminados e águas de irrigação contaminadas podem levar a uma contaminação dos solos e das águas subterrâneas. A biorremediação pode acelerar a biodegradação natural dos contaminantes, sendo importante na remoção do TBT. A bactéria Aeromonas molluscorum Av27 tem a capacidade de degradar o TBT nos seus produtos de degradação, dibutilestanho e monobutilestanho, em meio de cultura, Marine Broth. Sendo, deste modo, uma potencial ferramenta para diminuir a contaminação do TBT no ambiente. Este estudo tem como objectivo investigar o efeito de um solo contaminado com tributilestanho em duas espécies de plantas, o nabo Brassica rapa e o trigo comum Triticum aestivum. Foram realizados bioensaios com plantas, onde se avaliou a emergência das sementes e parâmetros de crescimento (comprimento da parte aérea da planta e produção de biomassa). Na segunda parte do estudo, a bactéria Aeromonas molluscorum Av 27 foi adicionada ao solo previamente contaminado para avaliar a sua capacidade para biorremediar TBT. Esta avalição foi realizada com o mesmo bioensaio usando uma espécie teste de ciclo rápido, Brassica rapa. As plantas, quando expostas ao TBT, mostraram um atraso e diminuição na germinação das sementes juntamente com uma dimuição nos parâmetros de crescimento, apresentando um comprimento menor, bem como uma produção de biomassa baixa quando comparadas com as réplicas do controlo (sem TBT). No teste com a bactéria A. molluscorum Av27 e no teste com meio de cultura, no final do ensaio, observou-se um menor número total das plantas germinadas quando comparadas com o teste controlo, no entanto, as plantas eram maiores e consequente possuiam uma maior produção de biomassa (peso fresco). Em conclusão, são necessários mais estudos para avaliar a capacidade da Aeromonas molluscorum Av27 remediar solos contaminados com TBT, uma vez que a toxicidade do TBT no solo não diminuiu num dos parâmetros avaliados (germinação das sementes).
Environmental pollution is a real problem that affects the entire ecosystem. Organotin compounds, particularly tributyltin (TBT), are widespread contaminants that are applied as polyvinyl chloride (PVC) stabilizers, water pipes, catalysts, wood preservatives and in several consumer products such as washing liquids, sponges and paper. TBT was mainly used in antifouling paints, because of its biocide action. Its increasing discharge into the environment leads to its inclusion in almost all compartments, such as water, sediments, soils and organisms. The octanol/water partition coefficient of TBT reaches 3.85, thus it tends to accumulate in organic matter or organisms. Due to is persistence and bioaccumulation potential trisubstituted organotins, like TBT, are considered to be extremely toxic, even to non-target species, causing endocrine disruption, including imposex in female gastropods. TBT half-life in sediments is estimated to reach several years. The sedimentary compartment acts as a sink for these compounds. Some activities where dredging of sediments contaminated with TBT will follow a disposal in soil, jointly with atmospheric deposition and direct pulverization of pesticide products are sources of tributyltin contamination in soils. Moreover, spreading of contaminated sewage sludge and irrigation with contaminated water may lead to soils and groundwater contamination. Bioremediation processes can accelerate the natural biodegradation of contaminants, playing an important role in TBT removal. Aeromonas molluscorum Av27 has the ability to degrade TBT in its less toxic byproducts, dibutyltin and monobutyltin, in the liquid culture medium, Marine Broth. Therefore it can be used as a powerful tool to diminish contamination of TBT in the environment. The present study aims to investigate the effect of tributyltin contaminated soil in two plants species, Brassica rapa and Triticum aestivum. Plant bioassays were carried out by measuring seed germination and growth parameters (shoot length and biomass production). In the second part of the study, Aeromonas molluscorum Av 27 was added to the previously contaminated soil to evaluate its capability to bioremediate TBT. This evaluation was carried out with the same plant bioassays using as test-species the rapid cycle turnip Brassica rapa. When exposed to tributyltin, plant species showed a delay and diminish in seed germination and a decrease on growth parameters, with smaller plants and lower biomass production when compared to the control replicates. In the Av27 test and test with culture medium a lower value of total number of germinated seeds at the end of the assay was observed when compared to the replicates of the control test, but plants were bigger and consequently had a higher biomass production (fresh weight). In conclusion, further studies are needed to clearly evaluate the ability to remediate TBT in soils by Aeromonas molluscorum Av27 because the toxicity of TBT in soil did not decrease in one of the parameters measured (seed germination).
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Hayd, Ramão Luciano Nogueira. "Níveis de clorofórmio na água potável distribuída pela estação da tratamento de Boa Vista, Roraima e relação com insuficiência renal". Universidade Federal de Roraima, 2011. http://www.bdtd.ufrr.br/tde_busca/arquivo.php?codArquivo=105.
Testo completoAbstract (sommario):
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorO abastecimento público de água em termos de qualidade e quantidade é uma preocupação crescente da humanidade, em função da escassez de recurso hídrico e da deterioração da qualidade dos mananciais. A desinfecção é o objetivo principal e mais comum da cloração, porem aparecem os subprodutos como os THMs (trihalometanos), como produtos resultantes da reação entre substâncias químicas que se utilizam no tratamento oxidativo e matérias orgânicas naturalmente presentes na água. A doença renal crônica constitui, atualmente, importante problema de saúde pública. No Brasil, a prevalência de pacientes mantidos em programas ssistenciais destinados ao controle e tratamento de Insuficiência Renal Crônica (IRC) dobrou nos últimos anos. Em Boa Vista, Roraima não foi realizado nenhum estudo com relação a níveis de THM na água potável distribuída pela Estação de Tratamento. Portanto, houve necessidade de identificar os níveis de clorofórmio na água potável distribuída e verificar possível relação com incidência de insuficiência renal crônica na população atendida pela Estação de Tratamento de Água (ETA). Utilizamos amostras de água da ETA de Boa Vista, Roraima, e estas foram analisadas através da Extração em Fase Sólida (SPE) e posteriormente pela espectrofotometria. Nossas amostras foram coletadas nos meses de janeiro a julho de 2011 na saída da Estação de Tratamento de Água de Boa. Também verificamos a incidência de Insuficiência Renal Crônica em Boa Vista, RR nos anos de 2008 e 2009 no serviço de faturamento do Hospital Geral de Roraima. Realizamos um bioensaio com Ratos Wistar Rattus norvegicusm, fornecido pelo Biotério da Universidade Federal de Mato Grosso do Sul. Os ratos ao término de 80 dias foram sacrificados, retirados os rins e enviados ao Laboratório Central de Roraima para confecção das lâminas histológicas e análise da lesão renal. Obtivemos concentrações de clorofórmio em todos os meses analisados. Durante o bioensaio recriamos as condições onde os ratos ingeriram dosagens diferentes de clorofórmio na água potável (100 e 300 mg/kg). Em nosso estudo elaboramos um método novo para confecção da curva analítica de calibração para o clorofórmio, sendo este um método de baixo custo de mercado e de fácil aplicação. O método proposto apresentou boa precisão e linearidade atendendo o interesse aos limites máximos estabelecidos pela Portaria 518/2004 do Ministério da Saúde, garantindo a aplicabilidade do mesmo para a análise simultânea de clorofórmio em água destinada ao consumo humano.
The public water supply in terms of quality and quantity is a growing concern of mankind, because of water scarcity and deteriorating quality of water sources. Disinfection is the primary purpose of chlorination and more common, but it appears as the by-products like THMs products of the reaction between chemicals that are used to treat oxidative and organic materials naturally present in water. Chronic kidney disease is currently an important public health problem. In Brazil, the prevalence of patients maintained on welfare programs for the control and treatment of chronic renal failure (CRF) has doubled in recent years. In Boa Vista, Roraima was not carried out any studies regarding THM levels in drinking water by sewage treatment plant. Therefore, it was necessary to identify the levels of chloroform in drinking water and check the possible relation with the incidence of chronic renal failure in the population served by ETA. We use water from the water treatment station in Boa Vista, Roraima, and these were analyzed by Solid Phase Extraction (SPE) and subsequently by spectrophotometry. Our samples were collected in January, February, March, April, May and June 2011 off the Water Treatment Plant for Good. We found the incidence of chronic renal failure in Boa Vista, in the years 2007 to 2009 in billing service General Hospital of Roraima. For the bioassay used adult females, with approximately five weeks, Wistar rats Rattus lineage norvegicusm provided by the vivarium of the Federal University of Mato Grosso do Sul mice at the end of 80 days were sacrificed, kidneys removed and sent to Central Laboratory Roraima to make the slides and histological analysis of renal injury. Obtained concentrations of chloroform in all months analyzed. During the bioassay re-create the conditions where rats ingested different doses of chloroform in drinking water (100 and 300 mg / kg). In our study we developed a new method to construct the analytical calibration curve for chloroform, which is a low-cost market and easy to apply. The proposed method showed good precision and linearity having the interest to the ceilings established by Decree 518/2004 of the Ministry of Health, ensuring the applicability thereof to the simultaneous analysis of chloroform in water intended for human consumption.
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Huang, Wuyang, e 黃午陽. "Traditional Chinese medicinal plants and their endophytic fungi: isolation, identification, and bioassay". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40987899.
Testo completo
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Huang, Wuyang. "Traditional Chinese medicinal plants and their endophytic fungi isolation, identification, and bioassay /". Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40987899.
Testo completo
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Brady, Chad R. "Pest management for SCN bioassays and creation of new RNAI constructs for nematode suppression". Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/16787.
Testo completoAbstract (sommario):
Master of ScienceDepartment of Plant Pathology
Harold Trick
The object of this study was to find a target sequence for the known Heterodera glycines Y25 sequence that contained no homology to any known Glycine max genes so homologous endogenous soybean gene expression will not be effected. In addition, in attempt to improve the accuracy of SCN bioassays performed in greenhouse settings, applications of a variety of insecticides with differing modes of action were applied to screen for any detectable effects on the SCN populations. The full-length sequence of the Y25 gene was blasted against the G. max genome using the National Center for Biotechnology Information blast database and a portion of the gene was found to contained no homology to the G. max genome. A rapid hairy root assay was used to screen for resistance to H. glycines. The sequence was transformed into Agrobacterium rhizogenes using a modified heat shock method. The transformed A. rhizogenes were used to inoculate soybean seedlings. The inoculated seedlings developed hairy roots expressing the target sequence. Upon finishing the hairy root assay it was discovered that there were no detectable differences across any of the treatments or the controls. It was neither proved nor disproved that the new target sequence containing no homology to the G. max genome was as effective as the original target. Further investigation will need to be conducted to show the level of control for the new target sequence.
18
Ichoku, Emmanuel. "Isolation and Bioassay evaluation of Angiotensin Converting Enzyme inhibitory compounds of Centella asiatica". University of the Western Cape, 2019. http://hdl.handle.net/11394/7322.
Testo completoAbstract (sommario):
Magister Pharmaceuticae - MPharmHypertension is by far the most common risk factor for cardiovascular disease (CVD), which has been identified as the leading cause of death worldwide and a major economic burden in developing countries. Over the years, there has been an increased interest in isolating and identifying bioactive compounds from medicinal plant, with the aim of finding alternative sources of therapy to some of the problematic synthetic drugs and to validate the therapeutic use of some traditional plants. The renin angiotensin aldosterone system is a key regulator of blood pressure, on which ACE (Angiotensin Converting Enzyme) inhibitors act and have been at the forefront of therapeutic strategy for treatment and management of hypertension and CVD. But despite the success of ACEI’s, their long term use has been associated with side- effects coupled with its contraindication in pregnancy. The plant of interest, Centella asiatica is a widely known medicinal plant, used in treatment of a variety of conditions including hypertension. There is currently no scientific evidence validating its claimed use in hypertension. This study therefore, investigated the ACE inhibitory effects of Centella asiatica. Crude methanol, ethanol and aqueous extracts of Centella asiatica were assayed for ACE inhibition activity. Methanol and ethanol crude extract(s) was subjected to a bioassay guided fractionation process to isolate and identify the active compounds. A fluorescence based ACE assay was utilized at various stages of the process including HPLC purification stage to screen the fractions and compounds for ACE inhibition activity.
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Ringbom, Therese. "Bioassay Development for Identification of Cyclooxygenase-2 Inhibitors of Natural Origin". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2002. http://publications.uu.se/theses/91-554-5276-0/.
Testo completo
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Majewsky, Vera [Verfasser]. "Basic Research in Homeopathy – Development of Plant Bioassays to Investigate Effects of Potentised Preparations / Vera Majewsky". Berlin : Freie Universität Berlin, 2018. http://d-nb.info/1176705547/34.
Testo completo
21
Lynde, Stuart R. "Techniques for Evaluating Power Plant Discharges Using In-Situ Breakdown and Flow Though Laboratory Sediment Bioassays". Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/36646.
Testo completoAbstract (sommario):
This research is divided into two main parts. Chapters 1 and 2 address the effect of thermal addition on the breakdown of Boxelder leaves (Acer negundo) in insitu and artificial stream studies. In both studies the rates for the decline in penetrance values decreased significantly in the thermally influenced treatments. Reduction in mass-loss rate coefficients was significant in the in-situ study, but not in the artificial streams. This result was due to differences in flow and macroinvertebrate colonization.
Chapters 3 and 4 address the development of a methodology for testing 24-48 hr old juvenile Asiatic clams (Corbicula fluminea) to sediments in 10-day bioassays. These organisms had acceptable survivorship in the controls (>70%), excellent recovery of all exposed organisms (97.5%) and were sensitive to copper-spiked sediments. Comparitive sensitivity of this age class demonstrated them to be equally or more sensitive than other commonly used sediment test organisms including Chironomus tentans, Daphnia magna and Hyalella azteca for survival and growth endpoints in 10-day exposures. Survival and growth effects for Corbicula juveniles were seen at 25 ppb copper in the sediment.Master of Science
22
Lynde, Stuart R. "Techniques for evaluating power plant discharges using in-situ leaf breakdown and flow-through laboratory sediment bioassays /". This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06102009-063152/.
Testo completo
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Zorloni, Alberto. "Evaluation of plants used for the control of animal ectoparasitoses in Southern Ethiopia (Oromiya and Somali regions)". Diss., University of Pretoria, 2008. http://hdl.handle.net/2263/26482.
Testo completoAbstract (sommario):
The burden of ticks in semi-arid lands of Ethiopia is not as pronounced as in some more humid areas of the continent. Nevertheless, the increasing recourse to chemicals smuggled by illegal traders has led to serious problems, including poisoning of humans and animals, discontinuous and irrational treatment regimens, tick-resistance to acaricidal products, loss of traditional knowledge and weakening of social structures. In order to encourage a resumption of the long-established ethnoveterinary practices, a survey on plants locally used in tick control was undertaken, and plant species used in other parts of the continent for the same purpose were considered. On these bases, 28 plant species or varieties were collected in the study area: Acacia seyal var. seyal, Adenium somalense, Aloe calidophila, Aloe parvidens, Azadirachta indica, Boscia angustifolia, Calotropis procera, Calpurnia aurea, Cissus quadrangularis, Commiphora erythraea, Cordia africana, Croton macrostachys, Croton megalocarpus, Datura stramonium, Euphorbia candelabrum, Euphorbia tirucalli, Ficus sycomorus, Ficus thonningii, Lantana camara, Maerua triphylla, Ocimum suave, two varieties of Ricinus communis (one with green fruits and another with red ones), Solanum incanum, Solanum somalense, Sterculia rhynchocarpa, Tagetes minuta and Vernonia amygdalina. In general, leaves were collected and used. However, due to the scarcity of foliar material, the whole plant of T. minuta and O. suave, the whole stem of A. somalense and C. quadrangularis, the branches of E. candelabrum and E. tirucalli, the bark in the case of A. seyal, C. erythraea and S. rhynchocarpa, were examined. After drying and grinding, the plant material was extracted with hexane and acetone, and made up to different concentrations to test the relevant repellent and toxic properties on adult Rhipicephalus pulchellus unfed ticks. For every bioassay, four replications, each using ten ticks, were performed. For the repellency bioassays, ticks were placed on a rectangular polystyrene platform stuck in a plastic basin and surrounded by water, in order to prevent them from moving away. Two glass rods, each provided with filter paper at the top and at the base, were inserted at opposite edges of the platform. The two filter papers of one rod were impregnated with the testing solution (i.e. solvent plus extract) at different concentrations while those of the other rod were treated with the pertinent extractant (hexane or acetone). Because of their inherent tendency to climb, most of the ticks settled onto the rods (mainly at the top), and their distribution was different depending on the repellency capacity of the extracts. The relevant data were then converted into repellency indexes using the formula [(Nc - Nt)/(Nc + Nt)] x 100, where Nc refers to the number of ticks on the control rod and Nt to the number of ticks on the test rod (Lwande et al., 1999; Pascual-Villalobos and Robledo, 1998). For the toxicity bioassays, 1 ìl of the extract at different concentrations was placed onto each tick and the mortality or weakening ratio was recorded after 24 hours. Because of the intrinsic toxicity of hexane, only acetone extracts were used for these assays. Due to the efficacy in extracting volatile compounds, hexane extracts had, for 24 plant species, better repellent properties than acetone extracts. Moreover, at a concentration of 10%, four species had negative repellency indexes with hexane extracts and five with acetone ones. At such concentration, these extracts therefore seemed to attract the ticks rather than repel them. At a concentration of 10%, thirteen hexane and five acetone extracts had repellency indexes > 50. At a concentration of 5%, only five hexane extracts and no acetone ones exceeded this value. Finally, only one species had a repellency index > 50 with the hexane extract at a 1% concentration. The plants showing good repellency indexes with at least one of the two solvents were A. calidophila, C. quadrangularis, C. erythraea, C. macrostachys, C. megalocarpus, D. stramonium, L. camara, M. triphylla, O. suave, the two varieties of R. communis and T. minuta. Amomg them, from a practical point of view, it is suitable to concentrate on O. suave, T. minuta and, to a certain extent, A. calidophila. In fact, C. quadrangularis, C. erythraea, C. macrostachys, D. stramonium, M. triphylla and the two varieties of R. communis had good repellent properties using hexane extracts at 10%, but not at 5%. Because trees like C. erythraea, C. macrostachys, C. megalocarpus and M. triphylla are highly valuable in a very dry environment, an excessive exploitation can put them in danger. Since D. stramonium, L. camara and R. communis are toxic plants, their extracts can be a serious threat for both humans and animals. Furthermore, L. camara is one of the worst weeds in the world, making it very inappropriate for lands already subject to the problem of bush encroachment. For all these reasons, T. minuta and O. suave appear to be the most promising plants; moreover, they are very well known in Southern Ethiopia and occur widely all over the area. On the contrary, A. calidophila is limited to just some places and the cultivation of Aloe species needs special attention, so it is not very suitable for people with a nomadic lifestyle. Concerning the toxicity bioassays, C. aurea extracts yielded by far the best results. In fact, all the ticks used had severe movement impairment when put in contact with acetone extracts at the concentrations of 20% and 10%. At a 5% concentration, 85% of the ticks had the same symptoms. In a separate test, a 10% water extract had a similar effect on 30 ticks out of 40, demonstrating the ease of extraction and application of the active compounds. The plant is well known, mainly by the Borana pastoralists, and is resistant to drought. It is also well able to grow in overgrazed areas, and its cultivation does not require special skills. Some of the extracts of other species gave good or fair results in the toxicity bioassays but, apart from S. incanum, only at a very high concentration (20%). Further studies may include isolation and characterization of the active compounds from the best species, setting up of a suitable plan for livestock treatment, and organization of a production and distribution cycle of appropriate phytomedicines in the pertinent pastoral area.Dissertation (MSc (Veterinary Science))--University of Pretoria, 2007.
Paraclinical Sciences
unrestricted
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Ta, Chieu Anh Kim. "Bacterial Biofilm Inhibition and Antifungal Activity of Neotropical Plants". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32419.
Testo completoAbstract (sommario):
This thesis examined the antimicrobial activity of select neotropical plants from Costa Rica and traditional Q’eqchi Maya medicines from Belize. In particular the potential for interference with bacterial quorum sensing (QS) and biofilm formation as well as fungal growth were assessed. Of one hundred and twenty six extracts collected from Costa Rica, one third showed significant QS inhibition while 13 species displayed more biofilm inhibitory activities than the positive control allicin. The active species belonged to the Lepidobotryaceae, Melastomataceae, Meliaceae, Sapindaceae, and Simaroubaceae. Twelve Marcgraviaceae species were tested for the same biological activities; of these, three showed similar QS inhibition to that of the positive control Delisea pulchra (Greville) Montagne and five with at least 30% biofilm inhibition. Only one species inhibited fungal growth – Marcgravia nervosa Triana & Planch. Bioassay-guided isolation of this plant resulted in the identification of the active principle as a naphthoquinone, with a minimum inhibitory concentration (MIC) ranging from 85 to 100 μM against Saccharomyces cerevisiae. Similarly, sixty one Q’eqchi’ Maya medicinal plant species were evaluated for their antimicrobial activities. Of these, four species showed more QS inhibition than D. pulchra, seven with comparable biofilm inhibitory activities that of allicin, and two with similarly antifungal activity to berberine. Two spirostanol saponins were isolated from Cestrum schlechtendahlii G.Don, an active antifungal plant. The major saponin showed growth inhibition against Saccharomyces cerevisiae and Fusarium graminearum, with MICs of 16.5 μM and 132 μM, respectively. Further analyses of this compound using chemical genomics suggested that its antifungal mechanism of action is pleiotropic, affecting multiple targets. Taken together, these findings showed that neotropical plants and traditional Q’eqchi’ Maya medicines contain phytochemicals that interfere with bacterial biofilm formation and quorum sensing as well as fungal growth.
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Wang, Ruxi [Verfasser], e Andreas [Akademischer Betreuer] Hensel. "Bioassays guided in vitro investigations on skin active plants from traditional Chinese medicine / Ruxi Wang. Betreuer: Andreas Hensel". Münster : Universitäts- und Landesbibliothek der Westfälischen Wilhelms-Universität, 2012. http://d-nb.info/1027021069/34.
Testo completo
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CASTRO, FLAVIA J. de. "Avaliação ecotoxicológica dos percolados das colunas de cinza de carvão e de solos com cinza de carvão utilizando Lactuca sativa e Daphnia similis como organismos teste". reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10517.
Testo completoAbstract (sommario):
Made available in DSpace on 2014-10-09T12:41:24Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:03:39Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Urminská, Barbora. "Posouzení účinnosti čištění odpadních vod pomocí testů ekotoxicity". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2015. http://www.nusl.cz/ntk/nusl-217119.
Testo completoAbstract (sommario):
The possibilities of environmental pollution control are increasing and more advanced wastewater treatment methods are being emphasized, as well as more specific control of contaminants presence in treated waters. That is why it becomes relevant to perform not only chemical analysis but also ecotoxicological bioassays as the means of evaluation of biological effects caused by wastewater discharges to ecosystems. No wastewater treatment plant is able to treat the water perfectly – it can only decrease the pollution level to an acceptable value. Therefore it is important to find out if the treatment process is sufficient to provide a satisfactory decrease of ecotoxicity and also what effects to the organisms in recipient will be caused by wastewater discharges. The thesis is focused on the evaluation of wastewater ecotoxicity. In the experimental part of the thesis, wastewater samples were collected at four wastewater treatment plants in the Czech Republic. At one of them also the sludge samples were taken. The aim was to evaluate the efficiency of wastewater treatment by selected ecotoxicological bioassays. The results have shown that the efficiency of wastewater treatment plants with secondary treatment is sufficient to reduce acute toxic effects to the minimum. Average toxicity removal was over 80 % at three of four evaluated wastewater treatment plants. At the fourth WWTP it was 41 %, however, at this WWTP high efficiency of treatment is not necessary.
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Balbinotte, Juliana. "Desenvolvimento de sistemas de aquisição de Bacillus thuringiensis por Diaphorina citri Kuwayama (Hemiptera:Psyllidae) para estudos de patogenicidade". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-22032012-111908/.
Testo completoAbstract (sommario):
Bacillus thuringiensis (Bt) é uma bactéria entomopatogênica utilizada como biopesticida contra insetos, principalmente Lepidoptera, Coleoptera e Diptera, e na produção de organismos geneticamente modificados. Com a descoberta da capacidade de Bt se movimentar sistemicamente em plantas, potencialmente atingindo insetos sugadores, surge uma nova possibilidade para o controle de Diaphorina citri Kuwayama, que transmite bactérias associadas ao Huanglongbing, uma séria doença da citricultura. O objetivo do trabalho foi desenvolver sistemas de aquisição de Bt por D. citri, in vitro e in planta, para estudos de patogenicidade. Uma estirpe de Bt transformada com o gene green fluorescent protein (Btk-gfp), cultivada em meio NYSM, foi usada como marcador de aquisição pelo inseto e movimentação nas plantas. Para o sistema de aquisição in vitro, selecionaram-se dietas com base na sobrevivência e atividade alimentar de D. citri. Btk-gfp foi adicionada à dieta selecionada, composta por uma solução de sacarose a 30% em água mineral com corantes alimentícios (verde 0,1% e amarelo 0,4%). A dieta foi acondicionada em um sachê formado por duas membranas de Parafilm®, sobre a parte inferior de uma placa de Petri de 40 mm de diâmetro (gaiola de alimentação). Dez insetos foram confinados em cada gaiola para períodos de acesso à aquisição (PAA) de até 48 h, estabelecendo-se 10 gaiolas por tratamento; como controle, utilizou-se a dieta sem Btk-gfp. Para testes de aquisição in planta, suspensões de Btk-gfp foram inoculadas em ramos novos cortados e no solo, próximo à haste de seedlings de laranja doce [Citrus sinensis (L.) Osbeck] e de murta [Murraya paniculata (L.) Jack], e em diferentes concentrações, avaliando-se a movimentação da bactéria após um período de 48 h. Posteriormente, adultos e ninfas de D. citri foram confinados nestas plantas para avaliar a aquisição de Btk-gfp, usando-se plantas inoculadas apenas com água como controle. Para os bioensaios de patogenicidade a D. citri, 21 estirpes de Bt foram testadas no sistema de aquisição em ramos cortados de murta e 5 estirpes em ramos cortados de laranja para ninfas de 3º. ínstar. In vitro, testaram-se 3 estirpes contra ninfas de 3º. ínstar e 9 contra adultos. Btgfp foi absorvido pelas raízes e ramos novos cortados de seedlings de laranja doce e de murta, e translocado até as folhas, mostrando movimentação sistêmica. Esta estirpe foi adquirida por adultos e ninfas de D. citri que se alimentaram nos ramos novos cortados, mantidos em suspensão bacteriana. O sistema de alimentação in vitro permitiu a aquisição de Bt-gfp (pellet ressuspendido na dieta de sacarose com corantes) por adultos de D. citri com apenas 12 h de PAA, mas 30 h é um período ótimo para exposição do inseto ao sistema. Nenhuma das nove estirpes testadas no sistema in vitro foi patogênica aos adultos de D. citri. Das 21 estirpes testadas contra ninfas de 3º. ínstar em ramos novos de murta, cinco causaram mortalidade de 24 a 45%, em 5 dias. Essas cinco estirpes também foram testadas contra ninfas dem ramos de citros cortados, causando mortalidade de 35 a 75% em 48 h.Bacillus thuringiensis (Bt) is an entomopathogenic bacterium widely used as a biopesticide against insect pests, mainly Coleoptera, Lepidoptera and Diptera, or for engineering genetically-modified plants. The recent finding that Bt is able to move systemically within plants, potentially targeting piercing-sucking insects, suggests that the bacterium may be effective for microbial control of Diaphorina citri Kuwayama, the vector of Huanglongbing-associated bacteria, a serious citrus disease. The goal of this research was to develop in vitro and in planta acquisition systems of Bt by D. citri for pathogenicity assays. A transformed Bt strain with the green fluorescent protein gene (Btk-gfp), grown in NYSM medium, was used as a marker to demonstrate bacterial acquisition by the insect and movement within the plants. Artificial diets were selected for the in vitro acquisition system based on insect survival and feeding activity. Btk-gfp was added to the selected diet, a 30% sucrose solution in mineral water with green (0.1%) and yellow (0.4%) food coloring. The diet was placed inside a Parafilm® membrane sachet, covering the opening of the lower half of a 40-mm diameter culture plate, and forming the feeding cage. Ten D. citri adults or nymphs were introduced in each cage and allowed acquisition access periods (AAP) of up to 48 h on the diet; as a control, a diet without Btk-gfp was used. For testing the in planta acquisition system, Btk-gfp suspensions were inoculated in young stem cuttings or in the soil, near the stem of Citrus sinensis (L.) Osbeck and Murraya paniculata (L.) Jack seedlings, as well as in different concentrations, and bacterial movement was assessed after 48 h; plants inoculated with water were used as controls. D. citri adults and nymphs were confined on inoculated plants to verify Btk-gfp acquisition. In pathogenicity assays, 21 Bt strains were tested against 3rd instars of D. citri using the acquisition system with stem cuttings of M. paniculata and 5 strains were tested using citrus stem cuttings. The in vitro acquisition system was used to test pathogenicity of 3 and 9 Bt strains against 3rd-instar nymphs and adults, respectively. Bt-gfp absorbed by roots or young stem cuttings of inoculated C. sinensis and M. paniculata was detected in the leaves, showing systemic movement. Bt-gfp was isolated from groups of nymphs and adults that were fed on inoculated stem cuttings or on artificial diets with bacterial suspension, showing that both in planta and in vitro acquisition take place. D. citri adults can acquire Bt-gfp within 12 h of AAP to the artificial diet with bacterium inoculum, but 30 h is the optimum AAP. None of the nine Bt strains assayed in vitro were pathogenic to D. citri adults. Of 21 strains tested for pathogenicity against nymphs using inoculated stem cuttings of M. paniculata, five caused mortality rates varying from 24 to 45% mortality within 5 days. These five Bt strains were also tested against D. citri nymphs using young stem cuttings of C. sinensis, causing mortality rates of 35 to 75% within 48 h.
29
Iovine, Priscila. "Usando biomonitoramento para avaliar o impacto da poluição atmosférica no entorno de indústrias". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-28022013-131953/.
Testo completoAbstract (sommario):
Fontes de poluição atmosférica têm aumentado em países em desenvolvimento, tornando extremamente difícil o acesso aos efeitos da poluição atmosférica na saúde pública. Bioensaios com plantas têm sido extensivamente utilizados para monitorar a poluição atmosférica em áreas desprovidas de sistemas de monitoramento da qualidade do ar convencionais pela sua simplicidade, baixo custo e alta sensibilidade. O presente estudo visa caracterizar a distribuição espacial da concentração de poluentes no entorno de indústrias através de evidências de toxicidade celular e acúmulo foliar utilizando planta local (Catharanthus roseus (L.) G. Don). O abortamento polínico foi quantificado em microscópio óptico (400x). O acúmulo de elementos traços foi avaliado em EDXRF (Energy Dispersive X-Ray Fluorescence). Os resultados obtidos para a área de estudo 1 mostram que a taxa de abortamento polínico é maior quanto mais próximo da indústria (p=0,047). Para o acúmulo foliar, foram encontrados os elementos S, Fe e Na que se relacionam com produtos de combustão; processo industrial; e aerossol marinho. Para a área de estudo 2, a taxa de abortamento polínico aumenta com a proximidade da área de alto tráfego veicular assim como a concentração dos elementos Al, Cu, S e Zn nas folhas pela Análise de Regressão Linear. Este estudo mostra que as áreas no entorno de fontes emissoras de poluição têm alta concentração de elementos - traço e dano celular o que indica riscos à saúde da população local. Nossos resultados reforçam que o uso de metodologias alternativas e simples como testes de abortamento polínico e bioacumulação em folhas são apropriados para caracterizar gradientes de concentração em áreas desprovidas de sistema de monitoramento da qualidade do ar, em escalas maiores do que as já estudadas. A combinação de técnicas de biomonitoramento e geoprocessamento pode ser utilizada para monitoramento ambiental em áreas com tecnologia limitadaDeveloping countries are experiencing increases in air pollution sources, making assessment of air pollution impact on human health extremely difficult. Plant bioassays have been widely employed to monitor air pollution in areas devoid of conventional air pollution monitoring systems because of their simplicity, low cost and high sensitivity. The aim of this study was to determine the area of influence of industries using local flora (Catharanthus roseus (L.) G. Don). Abortive pollen tests and the accumulation of toxic elements in leaves were used to detect possible risks to health of the local population. Abortive grains were evaluated through the use of a microscope under 400-fold magnification. The trace elements accumulation was evaluated by using EDXRF (Energy Dispersive X-Ray Fluorescence). Results for study site 1 shown that the closer the distance from the industry, the higher the pollen abortion rate (p=0,047). For bioaccumulation test, S, Fe and Na were associated to combustion of fossil fuels, industrial process and marine aerosol. For study site 2, the closer the distance from the major source of traffic, the higher the pollen abortion rate. The same behavior was observed for Al, Cu, S and Zn concentrations in Linear Regression Analyses. The distribution of element concentrations was elaborated in maps with the obtained results. This work showed that the areas surrounding the emission sources had a higher concentration of toxic elements, leading to greater biological damage, which indicates health risks to the local population. Our results reinforce that the use of alternative and simple methods such as pollen abortion rates and bioaccumulation in leaves are appropriate for characterizing air quality gradients in areas devoid of conventional air pollution monitoring systems, even at greater scales than have been tested before. The association of this technique and geographic information system can be used for environmental screening in areas with limited technology
30
MORENO, CAROLINA dos S. "Avaliação dos efeitos da radiação ionizante e do Resveratrol na cultura de células tumorais de pulmão". reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26829.
Testo completoAbstract (sommario):
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O carcinoma mucoepidermóide de pulmão, um tipo histológico que deriva das glândulas mucosas traqueobrônquicas, manifesta-se com sintomas obstrutivos e tende a comprometer a traqueia. Com finalidade curativa ou paliativa da doença, atualmente há uma forte tendência na oncologia em desenvolver estratégias terapêuticas que visam à administração de compostos com elevado potencial de otimizar o efeito do tratamento com a radiação ionizante, de modo a aumentar a morte de células tumorais e preservar íntegras as células dos tecidos sadios adjacentes. A intensa busca por tais estratégias evidenciou resultados promissores apresentados pelo composto denominado Resveratrol (3,4,5-trihidroxiestilbeno), tornando-o amplamente divulgado e alvo de intensas pesquisas. O principal objetivo do presente estudo foi determinar o efeito do resveratrol em cultura celular de carcinoma mucoepidermóide de pulmão exposta a diferentes doses de radiação ionizante. Para tal, os estudos de citotoxicidade utilizando o método de incorporação do vermelho neutro, e da determinação da dose letal 50 % (DL50) da radiação ionizante, foram realizados em cultura de células da linhagem NCI-H292 [H292] (ATCC® CRL-1848TM), CCIAL069. Com base nos resultados do IC50% (401,5 μM) e da DL50 (693 Gy) foram realizados o teste in vitro do micronúcleo e os ensaios para avaliar o efeito do resveratrol no ciclo celular, reparo da lesão no DNA e processo de lesão radioinduzida, necrose e apoptose celular. Os resultados evidenciaram que o resveratrol na concentração de 30 μM apresenta uma importante capacidade em promover danos às células NCI-H292 após 24 h da irradiação.
Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
31
Nate, Zondi. "Green synthesis of copper and silver nanoparticles and their antimicrobial activity". Thesis, Vaal University of Technology, 2018. http://hdl.handle.net/10352/424.
Testo completoAbstract (sommario):
M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of TechnologyThe present study includes the use of a green synthetic method to prepare copper and silver nanoparticles using chitosan, aqueous extracts of Camellia sinensis, Combretum molle and Melia azedarach linn leaves. This study aims to investigate the influence of capping and precursor concentration on the properties of silver nanoparticles with emphasis on the medicinal plants chosen. The effect of capping agent on the properties of copper nanoparticles is also investigated. The phytochemical properties of plant extracts and the antimicrobial activity of the synthesized particles were also studied; this was achieved by using microdilution bioassay. Decoction method was used to extract secondary metabolites from plant leaves. Preliminary phytochemical screening carried out on the aqueous extracts of the plant leaves showed the presence of tannins, proteins, flavonoids, phenols, and carbohydrates. The total phenolic and flavonoids content of the aqueous extract was determined using spectroscopic methods. The highest phenolic content was found in the aqueous extract of Combretum molle (135 mg/g), and the highest flavonoid content was found in the aqueous extract of Camellia sinensis (0.4 mg/g). Characterization was done by a combination of spectroscopic, microscopy and XRD techniques. Both the size and shape of the synthesized silver nanoparticles were dependent on the identity of the capping molecule, precursor and capping agent concentration as depicted from their TEM and XRD results. Silver nanoparticles were found to be predominantly spherical. The capping agent concentration was also found to influence the degree of agglomeration, with an increase in capping agent concentration giving lesser agglomeration. FTIR spectral analysis showed that silver nanoparticles interact with bioactive compounds found in the plants through the hydroxyl functional group. Other shapes including diamond were observed for the effect of precursor concentration. The XRD micrographs revealed a face-centered cubic geometry and the phase remained the same with an increase in precursor concentration. The synthesized silver nanoparticles were all blue shifted compared to the bulk material. The TEM results revealed that copper nanoparticles with different sizes and shapes were successfully synthesized. All the prepared copper and silver nanoparticles showed satisfactory antifungal and antibacterial activity against Candida albicans, Cryptococcus neoformans, Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumonia and Pseudomonas aeruginosa. The capping molecules used in this study also showed some antibacterial and antifungal activity against the selected strains. However nanoparticles performed better than these capping molecules. Both silver and copper nanoparticles were found to be more active against gram-negative bacteria compared to gram-positive bacteria. Amongst all the prepared silver nanoparticles Combretum molle capped nanoparticles were found to be the most active nanoparticles. Also with copper nanoparticles, it was found that Combretum molle capped nanoparticles were the most active nanoparticles. Between the two metal nanoparticles, silver nanoparticles showed high antibacterial and antifungal activity compared to copper nanoparticles. The antioxidant activity of silver nanoparticles was assessed using 2.2-diphenyl-1-picrylhydrazyl. Silver nanoparticles were found to have some antioxidant activity. However, the capping molecules were found to be more active than the synthesized nanoparticles. This observation is attributed to the presence of some bioactive compounds in the plant extracts.
32
Techer, Sophie. "Criblage d’activités biologiques de plantes endémiques ou indigènes de La Réunion - Recherche de molécules antivirales ciblant le virus du chikungunya". Thesis, La Réunion, 2013. http://www.theses.fr/2013LARE0014/document.
Testo completoAbstract (sommario):
Ce travail de thèse s'attache à identifier des plantes et/ou molécules à activités cytotoxique, antioxydante, anti-inflammatoire et antivirale ciblant le virus du chikungunya (CHIKV) dans le but de trouver des alternatives thérapeutiques vis-à-vis du stress oxydatif et de l'inflammation, mécanismes impliqués dans les maladies chroniques non transmissibles (diabète, obésité…), et de la maladie du chikungunya, maladie vectorielle réémergente. La première partie de ces travaux présente les résultats obtenus lors d'un criblage d'activités biologiques réalisé sur une sélection de dix-huit plantes endémiques et indigènes de La Réunion. Les activités ciblées ont été les activités cytotoxiques sur une lignée cellulaire humaine (cellules THP-1), les activités antioxydantes évaluées par un test in cellulo d'hémolyse et par quatre tests chimiques (TEAC/DPPH/FRAP/ORAC) ainsi qu'une évaluation de la teneur en composés phénoliques (test FOLIN) et les activités anti-inflammatoires testées sur des macrophages murins (cellules RAW-BlueTM). Les résultats obtenus ont permis de mettre, plus particulièrement, en évidence les activités de différents extraits : cytotoxique pour Carissa spinarum, antioxydantes pour Agarista buxifolia et Dryopteris wallichiana et anti-inflammatoire pour Stillingia lineata et Indigofera ammoxylum. La deuxième partie du travail est consacrée à l'étude phytochimique d'une espèce indigène de La Réunion, Stillingia lineata, choisie en raison des résultats obtenus lors de ce criblage biologique préliminaire et de ceux du programme Phytochik. Un fractionnement bioguidé par un test antiviral, réalisé sur des cellules Vero (cellules rénales de singe vert Cercopithecus aethiops) contaminées par le CHIKV, a conduit à l'isolement de trois macrocycles diterpéniques rares de type tonantzitlolone dont l'un présente une structure non caractérisée jusque-là, et d'un pimarane de structure nouvelle. La 4'-acétoxytonantzitlolone a été identifiée comme molécule candidate contre le CHIKV (CE50 = 7 μM). Des relations structure-activité ont pu être définies ; la présence d'un groupement oxygéné sur la chaîne latérale des tonantzitlolones semble jouer un rôle important sur la réponse antivirale de ces squelettes diterpéniquesThe aims of this PhD work were to identify plants and/or molecules with cytotoxic, antioxidant, anti-inflammatory or antiviral (chikungunya virus , CHIKV) activities in order to find therapeutic alternatives towards oxidative stress and inflammation, mechanisms involved in chronic noncommunicable diseases (diabetes, obesity ...), and chikungunya disease, reemerging vector-borne disease. The first part of this work presents the results obtained from a biological screening carried out on a selection of eighteen endemic and indigenous plants of La Réunion. The targeted activities were cytotoxicity on a human cell line (THP-1), antioxidant activities evaluated using an in cellulo hemolysis assay and four chemical tests (TEAC / DPPH / FRAP / ORAC) together with an evaluation of the content of phenolic compounds (FOLIN test) and anti-inflammatory activity tested in murine macrophages (RAW cells-BlueTM). The results allowed to highlight activities of different extracts in particular : cytotoxic for Carissa spinarum, antioxidant for Dryopteris wallichiana and Agarista buxifolia and anti-inflammatory for Stillingia lineata and Indigofera ammoxylum.The second part of this work is devoted to the phytochemical study of Stillingia lineata, an indigenous species of La Réunion chosen because of the results obtained in this preliminary biological screening and those carried out in Phytochik programme. Bioassay-guided fractionation performed on Vero cells (green monkey kidney cells Cercopithecus aethiops) infected with CHIKV led to the isolation of three rare macrocycle-type diterpenes called tonantzitlolone and a new pimarane. The 4'-acetoxytonantzitlolone was identified as a candidate molecule against CHIKV (EC50 = 7 μM). Structure-activity relationships have been defined, the presence of an oxygenated group on the side chain of tonantzitlolones seems to play an important role in the antiviral response of the diterpene skeleton
33
AHMAD, NURIE AHMAD. "Contribution a l'etude de la croissance et de la toxinogenese du genre fusarium (link) sur mais apres recolte". Nantes, 1986. http://www.theses.fr/1986NANT2036.
Testo completoAbstract (sommario):
La premiere partie des travaux a porte sur la mise au point des methodes permettant le dosage de cinq toxines du groupe des trichothecenes. Les methodes mises au point concernent les toxines responsables de contaminations naturelles; t2-toxine, ht2-toxine, t2-tetraol, diacetoxyscirpenol, deoxynivalenol. L'etude de modalites des biosyntheses de ces toxines a ete precedee de differents essais preliminaires: une trentaine de souches, appartenant a une dizaine d'especes fusariennes frequentes sur mais en france, ont ete examinees pour leur aptitude a la synthese des trichothecenes. Deux especes caracteristiques (f. Lateritium et f. Sporotrichioides) ont ete retenues et etudiees en detail
34
Chuang, Po-chih, e 莊博智. "Investigation of the acute toxicity of wastewater from treatment plants using bioassay". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/74246015050005777926.
Testo completoAbstract (sommario):
碩士嘉南藥理科技大學
環境工程與科學系碩士班
94
The objectives of this study were intended to investigate the acute toxicity of different treatment plants, including a wetland treatment system, a sewage treatment plant and a school sewage treatment plant by the Microtox® tests. Moreover, analysis of the primary source of acute toxicity was determined by means of linear regression for several parameters of water quality and toxicity unit (TU) of Microtox® tests. Results indicated that the acute toxicity of three different treatment plant effluent were zero, the reduction of acute toxicity were 100％. For the acute toxicity of influent from the wetland treatment system, we found that the maximum of acute toxicity in TU50,5min is 3.23, and the TU50,15min is 41.66 in the December first sampling. The acute toxicity of influent from the sewage treatment plant, the maximum of acute toxicity in TU50,5min is 33.3 in the September first sampling, and the maximum of acute toxicity in TU50,15min is 100 in the June first sampling. We need to qualitative analysis in order to decide the primary source of acute toxicity in the distinctive sampling. The acute toxicity of influent from the school sewage treatment plant, we assay that have the acute toxicity in the canal of UV disinfection even than the acute toxicity of influent, maybe produce from residue O3. The maximum of acute toxicity in TU50,5min is 25.12 in the canal of UV disinfection. The highest acute toxicity of influent in the three treatment plant is sewage treatment plant, the high toxicity is 50％；the higher acute toxicity of influent is school sewage treatment plant, the high toxicity is 23％；the last is wetland treatment system, the high toxicity is 0％. Results indicated the correlation in several parameters of water quality and toxicity unit (TU) of Microtox® tests are bad, due to the sources of compose are not one single matter, so we need to co-operate different analysis to determine the sampling toxicity. So, using chemical assay harmony with biomonitoring test could evaluate the effluent of water tocicity in organism.
35
Cid, Eva Berenice Rivera Del, e 蕾薇拉. "Ecotoxicity Assessment of Municipal Solid Waste Incineration (MSWI) Bottom-Ash Wastewater Using Plant Bioassays". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/40631036027158619072.
Testo completoAbstract (sommario):
博士國立屏東科技大學
熱帶農業暨國際合作系所
99
Municipal solid waste incineration (MSWI) is one of the most widely accepted technologies for waste disposal. However, in spite of its advantages, this process generates many kind of ash wastes, which if managed improperly can increase environmental pollution. Through the years it has become generally accepted that, chemical data alone do not allow evaluation of toxic effects. Reason for which, plant bioassays are gaining more importance, since they are inexpensive and in many cases more sensitive than other available systems. Two concentrations (50 and 100%) of MSWI bottom-ash wastewater (treated and untreated) were used for germination and root elongation tests of Ipomoea aquatica (water spinach) and two Oriza sativa (rice) varieties, Variety 9 and Variety 139. In addition, water spinach was hydroponically grown in order to asses the MSWI bottom-ash wastewater. Results for hydroponically grown water spinach show that 50% of untreated wastewater resulted in acute toxicity (plants died within less than 24 hours). Uses of lower doses (3 and 6%) of both types of wastewater presented no significant difference when compared to the control. Seed germination inhibition ranged from 21 to 30% in water spinach and from 7 to 35% in rice. Root length in water spinach and in rice Variety 139 was only inhibited by the use of 100% untreated wastewater, the rest of the treatments promoted root length. Root length in rice Variety 9 was inhibited by both treated and untreated wastewater (16% reduction). Overall, for seed germination and root elongation tests the use of 100% treated and untreated wastewater (trt100 and unt100) were the most toxic for both species. Results from both bioassays sustain that; biological assays can be effectively used to complement physical and chemical analysis in order to asses wastewater effluent toxicity. Further treat the wastewater by physical (filtration) or chemical means in order to reduce not only the dissolve solute content but also to lower the pH and the salt content of the wastewater. Special attention must be place to the accumulation of heavy metals (e.g., Sr, Cu, Sn) in living organism that grow near MSWI facilities or plants that are irrigated with MSWI wastewater effluents.
36
Howell, Janet Sue. "Evaluation of three in vitro bioassays for measuring the anthelmintic activity of plant extracts containing condensed tannins". 2009. http://purl.galileo.usg.edu/uga%5Fetd/howell%5Fjanet%5Fs%5F200905%5Fms.
Testo completo
37
Wangchuk, Phurpa. "Phytochemical analysis, bioassays and the identification of drug lead compounds from seven Bhutanese medicinal plants". Thesis, 2014. http://ro.uow.edu.au/theses/4076/.
Testo completoAbstract (sommario):
The Bhutanese traditional medicine (BTM) has been integrated with biomedicine since 1967 and serves as one of the important health care delivery systems in Bhutan. Therefore, the need to improve its quality through scientific studies have become paramount. In our efforts to address this important issue, we authenticated the botanical names of low altitude medicinal plants, determined the major classes of phytochemicals of 25 selected species, evaluated the bioactivities of the crude extracts of seven of them, and finally isolated the phytochemicals from six of these plants. We have established the antimalarial, anti-inflammatory, antimicrobial, and cytotoxicity activities of these phytochemicals and also identified five novel drug lead compounds.
In our ethnobotanical study; we resolved the traditional and taxonomical discrepancies for Bhutanese medicinal plants, assessed the current BTM formulations, and carried out the field survey for the low altitude medicinal plants (LAMP), which is described in Chapter 2. Out of 113 LAMP, 92 species are used in the current multiingredient formulations produced by Manjong Sorig Pharmaceuticals (MSP) and 28 of them are currently imported from India. Out of these 28 species, 16 of them are found growing abundantly in Bhutan and most of them have not been studied for their phytochemicals and pharmacological properties. In this study, we have selected 25 of these plants and assessed them for their major classes of phytochemicals which we have described in Chapter 3. Of these, the crude extracts of seven selected plants (Corydalis crispa, C. dubia, Ajania nubegina, Meconopsis simplicifolia, Pleurospermum amabile, Aconitum laciniatum and Codonopsis bhutanica) were investigated for their biological activities and we found that five of them possessed significant antiplasmodial activities, one species showed moderate cytotoxicity, two species exhibited moderate anti-Trypanosoma brucei rhodesiense activity, six species exhibited significant to mild TNF-α inhibitory activities, and all seven plants exhibited mild antimicrobial activity. The highest antiplasmodial activity was exhibited by the chloroform extract of M. simplicifolia with an IC₅₀ value of 0.40 μg/mL against the TM4/8.2 strain without cytotoxicity. The chloroform extract of C. crispa showed moderate cytotoxicity with an IC₅₀ value of 12.5 μg/mL and the highest antiinflammatory activities. The chloroform extracts of P. amabile and also C. crispa exhibited moderate anti-Trypanosoma brucei rhodesiense activity with IC₅₀ values of 16.1 and 4.6 μg/mL, respectively. The dichloromethane extract of P. amabile showed the highest antibacterial activity with a MIC value of 312 μg/mL or a MIZ value of 14 mm against B. subtilis. Guided by these preliminary bioactivity results, we have carried out the isolation of the phytochemicals from six of the seven aforementioned plants.
A total of 43 compounds were isolated from these plants. Of these, 25 were alkaloids, nine were terpenoids, six were furanocoumarins, two were flavones and one was a glycosylated flavone. From C. crispa (described in Chapter 4), nine isoquinoline alkaloids 1-9 were isolated and protopine (1) was identified as the major alkaloid component. The characterization of compounds 2 and 3 with complete NMR data analysis was achieved by us for the first time. Similarly, from C. dubia (described in Chapter 5), another group of isoquinoline alkaloids 10-15 were isolated along with the alkaloids 1 and 9. Alkaloid 15 was isolated as a new natural product which we named as dubiamine after the plant’s name (C. dubia) and its structure was confirmed from its single crystal X-ray structural analysis. From A. nubigena (Chapter 6), nine compounds, 19-26 belonging to terpenoids, flavonoids and glycosylated flavones were isolated from the essential oil and crude methanol extract. While luteolin (25) was the major constituent of the MeOH extract, (3R,6R)-linalool oxide acetate (19) was the major constituent (75.8 %) of the essential oil. Out of 53 constituent peaks detected by GC/GC-MS, 45 of them were identified with chamazulene (20) as a new subchemotype of the genus Ajania. From the MeOH extract of M. simplicifolia, one new protoberberine alkaloid (27), with protopine (1) as the major alkaloid, and four benzophenanthridine type alkaloids (29-32) were isolated. The new alkaloid was named as simplicifolianine after its plant species, M. simplicifolia. The GC/GC-MS identified 37 constituents from its essential oil with 14 of them (38% of total oil) being fatty acid esters and dimethyl 1,4-benzenedicarboxylate (29.2%) as the major constituent. From P. amabile, 10 known compounds were isolated for the first time. Its essential oil yielded terpenoids (37-40) with (E)-isomyristicin (37) as the major constituent, and the crude MeOH extract yielded furanocoumarins (41-46) with bergapten as the major one. Through GC/GC-MS analysis, we have also identified 52 compounds from the essential oil component of this plant. From A. laciniatum, five known lycoctonine-type C19- diterpenoid alkaloids (54-58), with pseudaconitine (54) as the major compound, were isolated.
Following the same bioassay methods conducted for the crude extracts of the selected seven plants, we tested 32 of the total of 43 compounds isolated from the six plants investigated. Of these, 18 compounds showed interesting biological activities. Among these 18 active compounds, protopine (1), cheilanthifoline (11), scoulerine (14), luteolin-7-O-β-D-glucopyranoside (26) and simplicifolianine (27) exhibited highly significant antiplasmodial activities against chloroquine sensitive and multidrug resistant strains of P. falciparum and were identified as antimalarial drug lead compounds. Scoulerine (14) significantly inhibited acetylcholinesterase with a minimum inhibitory requirement of 0.0015 nmol which is almost twofold better than that of galanthamine (0.003 nmol), the currently used standard drug to treat Alzheimer disease. Only protopine showed anti-inflammatory activity against TNF-α with a statistically significant p-value of p<0.05. Apart from compounds 25 and 26, which exhibited mild cytotoxicity, the other compounds were not cytotoxic.
In general, the biological activities of the crude extracts of the seven selected medicinal plants and the 18 pure compounds that we have studied were in alignment with their ethnopharmacological uses. Thus, our studies have validated the use of these plants in BTM either individually or in combination with other medicinal ingredients to treat diseases (especially malaria) as described in the pharmacopoeia and the formulary compendium of BTM.
38
Lai, Wan-Chun, e 賴宛君. "I.Estrogenic/antiestrogenic Bioassay Using Transgenic Plants, pER8:GUS and pER8:GFPII.Studies on the Chemical Constituents and Bioactivities of Caesalpinia sappan L". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/36493483430705198027.
Testo completoAbstract (sommario):
碩士高雄醫學大學
天然藥物研究所
96
In recent years, phytoestrogens have substituted synthetic estrogens, as the supplement source of estrogen, used to modify symptoms of postmenopausal women. Most of Phytoestrogens belong to isoflavonoids widely existent in our daily diet. The bioactivity of phytoestrogen is lower than estrogen around 1/102 ~ 1/105. According to some researches, phytoestrogens induced cell proliferation of hormone-dependent carcinoma. In the other articles, phytoestrogens also showed antiestrogenic activity. Therefore, investigations on the physiological functions of phytoestrogens still have no identical conclusion about the advantage and harm. For the reason, the research of phytoestrogens is imperative and very important. In this study, we applied pER8:GFP, a transgenic plant as a tool of estrogenic activity assay model to screen anti-estrogenic activity combined with the clinical drug Tamoxifen. Further, we used the other transgenic plant pER8:GUS as a detector for estrogenic activity. The new estrogenic assay model showed higher sensitivity and needed shorter time to culture. In addition, we determined twenty Chinese traditional herbs according to traditional Chinese medical theory by pER8:GUS estrogenic activity assay. Then, we got an active extract from Su Mu, Caesalpinia sappan. Su Mu is a natural, sweet and salty traditional Chinese medicine, which can invigorate circulation, break up blood stasis condition, and promote menstruation including injuries from impact, swollen boils, irregular menses, and pain from blood stasis after birth. It is an important Chinese medicine in gynecology. Bioactivity-guided fractionation of the active extract of Su Mu led to the isolation of eleven compounds including ten known compounds and one new compound. Ten known compounds are as follows: brazilein (1)、brazilin (2)、protosappain A (3)、3,7-dihydroxy-4H-chromen-4-one (4)、3’-deoxyepisappanol (6)、3’-deoxysappanol (7)、3-deoxysappanone B (8)、4-(7-hydroxy-2,2-dimethyl-9bH-1,3,5-trioxa-cyclopenta[a]naphthalene- 3a-ylmethyl-)-benzene-1,2-diol (9)、3-deoxysappanchalcone (10)、3’-deoxysappanone B (11). Moreover, (S)-2,3-dihydro-3,7-dihydroxychromen-4-one (5) is a new compound. Most pure compounds belong to homoisoflavonoids. Compounds 3、4、8、10 and 11 showed estrogenic activity. Among those five compounds , compounds 3、8 and 11 also proposed antiestrogenic activity. Compounds 1、2、5 and 10 exhibited cytotoxicity to different cancer cell. Furthermore, compounds 1、3、4、7 and 10 inhibited platelet aggregation.
39
Yi-PoYeh e 葉奕伯. "Analysis of endocrine disrupting chemicals and their derivatives in wastewater treatment plants using bioassays and liquid chromatography tandem mass spectrometry". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/09033299969399051031.
Testo completoAbstract (sommario):
碩士國立成功大學
環境工程學系
102
There are various kinds of endocrine disrupting chemicals (EDCs) in effluents from wastewater treatment plants (WWTPs), including compounds showing estrogen receptor (ER) disrupting activities, androgen receptor (AR) disrupting activities, and thyroid hormonal receptor (TR) disrupting activities, etc. In this study, wastewater samples were collected and analyzed using bioassays and liquid chromatography tandem mass spectrometry to know occurrence of EDCs in WWTPs. Derivatives of EDCs generated in WWTPs were also investigated. The results showed that estrogenic, anti-estrogenic, androgenic, anti-androgenic and thyroid hormone disrupting activities were detected in water samples from WWTPs. Anti-estrogenic, anti-androgenic and thyroid hormone disrupting activities were also detected in suspended solids from WWTPs. Natural estrogens (estrone, estradiol, estriol), progesterone, testosterone, bisphenol A, nonylphenol, triclosan and triclocarban were detected in samples from WWTPs at low ng/L to μg/L levels. Chlorinated bisphenol A that showed stronger estrogenic, anti-androgenic, and thyroid hormone disruptong activities than bisphenol A were also detected in WWTP effluents. More attention should be paid to the formation of EDC derivatives in WWTPs.
40
Wei-PoLin e 林緯博. "Comprehensive assessment of endocrine disrupting chemicals and their chlorinated derivatives in wastewater treatment plants using bioassays and LC-MS/MS". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8jkwrt.
Testo completoAbstract (sommario):
碩士國立成功大學
環境工程學系
105
There are various kinds of endocrine disrupting chemicals (EDCs) present in the effluent of wastewater treatment plants (WWTPs), such as chemicals showing disrupting activities for aryl hydrocarbon receptor (AhR), androgen receptor (AR), or mineralocorticoid receptor (MR). These EDCs may further react with chlorine to form chlorinated derivatives in disinfection process of WWTPs. In this study, samples from different treatment stages of WWTPs were collected and analyzed by recombinant yeast bioassays and LC-MS/MS to investigate the endocrine disrupting activities and concentrations of target EDCs and their chlorinated derivatives. Our results showed that AhR agonist activities, anti-androgenic activities, and anti-mineralocorticoid activities were detected frequently in the dissolved phase of WWTP influents and effluents. The chlorinated derivatives of selected EDCs still showed AhR agonist activities, AR antagonist activities, and MR antagonist activities in the bioassays, which were even stronger than their parent compounds. LC-MS/MS results showed that some EDCs, such as methylparaben, nonylphenol, and triclosan were often detected at ng/L to μg/L levels. In addition, chlorinated derivatives of methylparaben and bisphenol A were also often detected in WWTP samples. More attention should be paid to the formation of chlorinated EDCs and their potential risk to aquatic organisms.
41
Gutierrez, Irene Bermudez. "Ecotoxicological and biochemical impacts of S-metolachlor and terbuthylazine on Scrobicularia plana". Master's thesis, 2018. http://hdl.handle.net/10316/86232.
Testo completoAbstract (sommario):
Dissertação de Mestrado em Biologia apresentada à Faculdade de Ciências e TecnologiaA sobre-exploração agrícola na região do Mediterrâneo tem contribuído para o uso excessivo de herbicidas, poluindo as áreas circundantes, como acontece no estuário do Mondego, localizado perto da cidade da Figueira da Foz (Portugal). Primextra® Gold TZ é o herbicida mais utilizado nos campos agrícolas que rodeiam o estuário do Mondego e é constituído por dois princípios ativos, S-metolacloro (SMOC) e terbutilazina (TBA), que têm exibido toxicidade em espécies aquáticas em estudos prévios. A espécie estudo deste trabalho é o bivalve Scrobicularia plana, a qual apresenta elevada capacidade de filtrar poluentes e uma importante posição na estrutura e no funcionamento das comunidades estuarinas. Organismos de duas classes de tamanho (grandes e pequenos) foram expostos individualmente a uma gama de concentrações de cada princípio ativo para avaliar as suas respostas e tolerâncias a ambos os compostos. S. plana mostrou uma sensibilidade claramente maior a SMOC (tamanho grande LC50 = 40,702 mg/L; tamanho pequeno LC50 = 41,517 mg/L) do que a TBA (tamanho grande LC50 = 118,590 mg/L; tamanho pequeno LC50 = 108,418 mg/L), e os organismos da classe de tamanho maior foram ligeiramente mais sensíveis a SMOC do que a classe pequena de organismos, mostrando uma tendência oposta quando expostos a TBA. A fim de avaliar áreas contaminadas e as suas potenciais consequências para a saúde humana e para o sistema aquático, é necessário desenvolver estratégias laboratoriais alternativas para estimar os potenciais impactos de poluentes de maneira rápida, simples e eficiente. Assim, selecionou-se um conjunto de biomarcadores que inclui as enzimas antioxidantes Glutationa S-transferase (GST), glutationa peroxidase total (tGPx) e glutationa redutase (GRed), e a atividade de peroxidação lipídica calculada pela quantificação das substâncias reativas do ácido tiobarbitúrico (TBARs). O presente trabalho revela que a enzima GRed e a enzima GST mostraram correlações positivas entre as atividades das enzimas e a toxicidade dos produtos químicos. Além disso, GRed mostra especificidade para detetar impactos de TBA, enquanto GST mostrou ser mais precisa para detetar a contaminação por SMOC. Por outro lado, os contaminantes orgânicos podem afetar os perfis de ácidos gordos de espécies aquáticas não-alvo, como por exemplo S. plana, além de que o valor nutricional de espécies edíveis pode ficar comprometido. Para compreender os efeitos bioquímicos destes compostos na espécie e classes de tamanhos estudadas, compararam-se os perfis de ácidos gordos e o teor de glicose total dos indivíduos expostos aos herbicidas em condições de laboratório e em indivíduos procedentes do campo. As análises bioquímicas foram realizadas em dois tecidos distintos: no músculo (ou pé) e na massa visceral restante, a fim de perceber se se complementam entre si ou se é possível identificar o tecido que poderá ser usado como indicador da presença dos tóxicos e ser usado em futuros trabalhos como endpoint em ecotoxicologia. Os resultados mostraram que o músculo é o tecido mais representativo de todo o organismo em termos de variações das quantidades de ácidos gordos e, portanto, o melhor tecido para determinar potenciais alterações bioquímicas. Os organismos de tamanho pequeno foram mais sensíveis a nível molecular do que os indivíduos maiores, coincidindo a sua sensibilidade em termos de variações no perfil de ácidos gordos e conteúdo total de glicose com a sua sensibilidade em termos de efeitos letais.
The overexploitation of the farmlands in the Mediterranean region contributes to an overuse of herbicides and, thus, the pollution of the surrounding aquatic systems, like the Mondego estuary, located near the city of Figueira da Foz (Portugal). Primextra® Gold TZ is the most-used herbicide at agriculture fields that surround the Mondego estuary and it is constituted by two active ingredients (a.i.), S-metolachlor (SMOC) and terbuthylazine (TBA), that have exhibited toxicity to aquatic species in previous studies. The benthic bivalve species Scrobicularia plana was selected to carry out bioassays because of its capacity to filter pollutants and its important position in the structure and functioning of estuarine communities. Organisms of two size classes (big and small) were exposed individually to a range of concentrations of each a.i. to assess their responses and tolerance to both compounds. S. plana showed a clear higher sensitivity to SMOC (big size LC50 = 40.702 mg/L; small size LC50 = 41.517 mg/L) than to TBA (big size LC50 = 118.590 mg/L; small size LC50 = 108.418 mg/L), and big size class organisms were slightly more sensitive to SMOC than the small size class of organisms, showing an opposite trend when exposed to TBA. In order to evaluate contaminated areas and the potential adverse impacts on human health and the environment, it is necessary to develop alternative strategies to rapidly assess the potential impacts of pollutants, therefore, it is necessary to develop alternative laboratorial strategies to assess their potential impacts. Thus, a battery of biomarkers was selected that includes the antioxidant enzymes Glutathione S-transferase (GST), total glutathione peroxidase (tGPx) and glutathione reductase (GRed), and the activity of lipid peroxidation by quantification of the reactive substances of the thiobarbituric acid (TBARs). The present work reports that GRed and GST showed positive correlations between enzymes’ activities and chemicals’ toxicity. Moreover, GRed shows specificity to detect TBA impacts, whereas GST seems to be more accurate to detect SMOC contamination. Furthermore, organic contaminants may affect the fatty acid (FA) profiles of non-target aquatic species like S. plana, besides its nutritional value may be also compromised. To understand the biochemical effects of these chemicals at the studied species and size classes, it was compared the FA profiles and the total glucose content of the individuals exposed to the a.i. under laboratory conditions and at the field. Biochemical measurements were conducted at distinct tissues - the muscle (foot) and the remaining visceral mass, in order to compare if they complement each other or if is possible to identify the most appropriate and thus the best indicator tissue to be used as endpoint in ecotoxicology studies. The results showed that the muscle is the tissue most representative of the whole organism in terms of variations of FA content and thus the best tissue to determine potential biochemical changes. Besides, small size class is more sensitive at molecular level than big size class, coinciding its sensitiveness in terms of variations on FA profile and total glucose content with its sensitiveness in terms of lethal effects.
FCT
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Po-YuChen e 陳柏佑. "Detecting the variations of (anti-)estrogenic, (anti-)androgenic, and (anti-)mineralocorticoid activities in Taiwanese wastewater treatment plants using bioassays and LC-MS/MS". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/99942170710568299001.
Testo completoAbstract (sommario):
碩士國立成功大學
環境工程學系
104
SUMMARY Endocrine disrupting chemicals (EDCs) are synthetic or naturally chemicals which can effect endocrine system of organisms. Different kinds of EDCs would show various kinds of activities, such as estrogen receptor (ER) disrupting activities, androgen receptor (AR) disrupting activities, or mineralocorticoid receptor (MR) disrupting activities, etc. In this work, recombinant yeast bioassays were used to identify ER, AR, and MR disrupting activities in samples collected from wastewater treatment plants (WWTPs) in Taiwan. Also, chemical analysis was carried out using LC-MS/MS to analyze the concentrations of target EDCs. results showed that endocrine disrupting activities could be found in different treatment processes of WWTPs. Estrogenic, anti-androgenic and anti-mineralocorticoid activities were detected frequently in WWTP influent and effluent. LC-MS/MS results revealed that some EDCs, such as bisphenol A, nonylphenol, and triclosan were often detected in samples from WWTPs. More attention should be paid to the potential risk to aquatic organisms and further expansion of other bioassays for endocrine disrupting activity detection is recommended. Key words: Endocrine disrupting chemicals, Yeast-based reporter gene assays, Liquid chromatography tandem mass spectrometry INTRODUCTION Endocrine disrupting chemicals (EDCs) are synthetic or natural chemicals which can affect the endocrine system of organisms, including the disruption of hormone synthesis, secretion, transport, binding, or action in the body. Different EDCs may show various kinds of endocrine disrupting activities, such as estrogen receptor (ER), androgen receptor (AR) or mineralocorticoid receptor (MR) disrupting activities. To detect EDCs in the environment, liquid chromatography tandem mass spectrometry (LC-MS/MS) are often used to quantify target compounds, and yeast bioassays are also reliable tools for assessing potential endocrine disrupting activities in environmental samples. In this work, recombinant yeast bioassays were used to identify ER, AR, and MR disrupting activities in samples collected from wastewater treatment plants (WWTPs) in Taiwan. Also, chemical analysis was carried out using LC-MS/MS to analyze the concentrations of target EDCs. MATERIALS AND METHODS Wastewater samples were collected from four municipal WWTPs and one hospital WWTP in Taiwan. Samples were separated into particulate phase (SS) and water phase (W) by filtration. Water samples were extracted by solid phase extraction (SPE) with Oasis HLB Plus cartridges. SS samples were extracted by Soxhlet extraction using hexane:acetone (1:1, v:v) for 24 hrs. Yeast-based reporter gene assays were used to detect ER, AR and MR disrupting activities in these samples. The yeast cells which contained estrogen response element/androgen response element/mineralocorticoid response element and reporter gene Lac-Z would produce β-galactosidase to react with o-nitrophenyl-β-galactoside and chlorophenol red-β-D-galactopyranoside if being coincubated with ER, AR, or MR disruptors. LC-MS/MS was selected to determine target EDCs in WWTP samples. The liquid chromatography system was Agilient 1260 Infinity (Agilent, USA) and the MS/MS system was Thermo TSQ Quantum Ultra (Thermo, USA). RESULTS AND DISCUSSION Bioassay results showed that endocrine disrupting activities could be found in different treatment processes of WWTPs. Estrogenic, anti-androgenic and anti-mineralocorticoid activities were detected frequently in WWTP influent and effluent. Higher estrogenic activities were found in water phase samples than particulate phase samples. The highest estrogenic activities were detected in the water phase samples of primary sedimentation tank effluent of HW (Dec 2015) WWTP (132.5 E2-EQ ng/L) and influent of H (Oct 2015) WWTP (119.6 E2-EQ ng/L). The highest anti-androgenic activity was found in the particulate phase sample of H (Oct 2015) influent (3299.6 FLU-EQ μg/L), and effluent of aeration basin (2411.8 FLU-EQ μg/L) was also very high. The results showed a little difference with estrogenic activities, which were seldom detected in particulate phase samples. The results indicated that anti-androgenic compounds might be more likely to exist in particulate phase. Influent of NZ (Mar 2016) showed the highest anti-mineralocorticoid activity (26390.0 SPL-EQ ng/L), and most of the WWTP influent samples also exhibited higher anti-mineralocorticoid activities than other process units. LC-MS/MS results revealed that some EDCs, such as bisphenol A (8.7~5187.8 ng/L), nonylphenol (ND~122.3 ng/L), and triclosan (ND~1438.6) were often detected in samples from WWTPs. Endocrine disrupting activities of chemicals determined by LC-MS/MS were also converted to equivalent factor (EQLC-MS/MS) by using bioassay to determine their endocrine disrupting activities relative to standards and were compared to the endocrine disrupting activities obtained by bioassay analysis (EQbioassay).There is no significant correlation between EQBioassay and EQLC-MS/MS. CONCLUSION Our results indicated that WWTPs in Taiwan may need further improvement to remove these harmful compounds, and more attention should be paid to the potential risk to aquatic organisms. Influent of WWTPs showed higher endocrine disrupting activities in most samples. Lower endocrine disrupting activities were detected in particulate phase samples except for anti-androgenic activities. Bioassay and instrumental analyses showed that WWTPs in Taiwan failed to completely remove EDCs in wastewater samples, and these EDCs may adversely impact the environment. Further expansion of other bioassays for endocrine disrupting activity detection is recommended.
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"In vitro and in vivo mechanistic studies of the wound-healing effects of Astragali Radix and phytochemical analysis of its active fractions/components isolated using bioassay-guided fractionation". 2013. http://library.cuhk.edu.hk/record=b5884429.
Testo completoAbstract (sommario):
Lai, Kwok Kin.Thesis (Ph.D.)--Chinese University of Hong Kong, 2013.
Includes bibliographical references (leaves 229-251).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.
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Shang, Nan. "Bioassay-guided fractionation of Larix laricina du Roi, and antidiabetic potentials of ethanol and hot water extracts of seventeen medicinal plants from the traditional pharmacopeia of the James Bay Cree". Thèse, 2013. http://hdl.handle.net/1866/12626.
Testo completoAbstract (sommario):
Nous avons utilisé une approche ethnobotanique pour identifier des espèces de plantes utilisées par les Cris afin de traiter les symptômes du diabète de type 2. Larix laricina du Roi (L. laricina) a récemment été identifiée comme une des meilleures plantes qui a stimulé le transport de glucose dans les cellules C2C12 et fortement potentialisé la différenciation des 3T3-L1 en indiquant une sensibilité potentiellement accrue à l’insuline. Ensuite, ces études de criblage ont été effectuées sur des extraits éthanolique (EE) en utilisant une série de bioessais in vitro. Cependant, les préparations traditionnelles des plantes sont souvent faites avec l’eau chaude. Le but de cette thèse de doctorat était d’isoler les principes actifs de L. laricina par un fractionnement guidé par l’adipogenèse; d’évaluer et de comparer l’activité et les mécanismes antidiabétiques des EE et des extraits aqueux (HWE) de ces 17 plantes.
Pour le fractionnement de L. laricina, on a isolé plusieurs composés connus et identifié un nouveau composé actif cycloartane triterpene, qui a amélioré fortement l’adipogenèse et a été responsable en partie de l’activité adipogénique (potentiellement similaire à l’effet sensibilisateur à l’insuline des glitazone) de l’extrait éthanolique issu de l’écorce de L. laricina.
Pour le métabolisme lipidique, nos résultats ont confirmé que 10 parmi les 17 EE ont augmenté la différenciation des adipocytes alors que 2 extraits seulement l’ont inhibée. Les HWE ont montré une faible activité adipogénique ou antiadipogénique. Les EE de R. groenlandicum et K. angustifolia ont le PPAR γ (peroxisome proliferator-activated receptor γ), le SREBP-1 (sterol regulatory element binding protein-1) et le C/EBP (CCAAT-enhancer binding proteins) α, alors que ceux de P. balsamifera et A. incana les ont inhibés. L’effet inhibiteur de P. balsamifera a également été prouvé d’avoir impliqué l’activation de la protéine kinase activée par l’AMP (AMPK). Les EE et HWE de R. groenlandicum ont stimulé les mêmes facteurs de transcription alors que les extraits aqueux d’autres plantes sélectionnées ont perdu ces effets en comparaison avec leurs extraits éthanoliques respectifs. L’analyse phytochimique a également identifié le groupe des espèces actives et inactives, notamment lorsque les espèces ont été séparées par famille de plante.
Finalement concernant l’homéostasie de glucose, nos résultats ont confirmé que plusieurs EE ont stimulé le transport de glucose musculaire et inhibé l’activité de la glucose-6-phosphatase (G6Pase) hépatique. Certains des HWE ont partiellement ou complètement perdu ces activités antidiabétiques par rapport aux EE, tandis qu’une seule plante (R.groenlandicum) a juste conservé un potentiel similaire entre les EE et HWE dans les deux essais. Dans les cellules musculaires, les EE de R.groenlandicum, A. incana et S. purpurea ont stimulé le transport de glucose en activant la voie de signalisation de l’AMPK et en augmentant le niveau d’expression des GLUT4. En comparaison avec les EE, les HWE de R.groenlandicum ont montré des activités similaires; les HWE de A. incana ont complètement perdu leur effet sur tous les paramètres étudiés; les HWE de S. purpurea ont activé la voie de l’insuline au lieu de celle de l’AMPK pour augmenter le transport de glucose. Dans les cellules H4IIE, les EE et HWE des 5 plantes ont activé la voie de l’AMPK, et en plus les EE et HWE de 2 plantes ont activé la voie de l’insuline. La quercétine-3-O-galactoside et la quercétine 3-O-α-L-arabinopyranoside ont été identifiées comme des composés ayant un fort potentiel antidiabétique et donc responsables de l'activité biologique des plantes HWE actifs avec le transport du glucose.
En conclusion, on a isolé plusieurs composés connus et identifié un nouveau triterpène actif à partir du fractionnement de L. laricina. Nous avons fourni également une preuve directe pour l'évaluation et la comparaison d'une action analogue à l'insuline ou insulino-sensibilisateur des EE et HWE de plantes médicinales Cris au niveau de muscle, de foie et de tissus adipeux. Une partie de leur action peut être liée à la stimulation des voies de signalisation intracellulaire insulino-dépendante et non-insulino-dépendante, ainsi que l’activation de PPARγ. Nos résultats indiquent que les espèces de plantes, les tissus ou les cellules cibles, ainsi que les méthodes d'extraction sont tous des déterminants significatifs de l'activité biologique de plantes médicinales Cris sur le métabolisme glucidique et lipidique.We have used a collaborative ethnobotanical approach to identify plant species used by the Cree of Eeyou Istchee (CEI) to treat symptoms of type 2 diabetes. Several screening studies were performed on 17 species identified in a survey of the Cree Nation. Firstly, Larix laricina du Roi (L. laricina) was recently identified as one of the top plants, which stimulated glucose uptake in C2C12 muscle cells and strongly potentiated the differentiation of 3T3-L1 pre-adipocytes suggesting enhanced insulin sensitivity. Secondly, these screening studies were performed on ethanol extracts (EE) using an in vitro bioassay platform, however, traditional preparations are often based on hot water. So the purpose of this PhD thesis was to isolate the active principles from L. laricina through adipogenesis-guided fractionation, and to evaluate and compare the antidiabetic activity and mechanisms of EE and hot water extracts (HWE) of these 17 Cree plants. For the fractionation of L. laricina, we isolated several known compounds and identified a new active cycloartane triterpene, which strongly enhanced adipogenesis in 3T3-L1 cells and was responsible partly for the adipogenic (potentially glitazone-like insulin sensitizing) activity of the ethanol extract of the bark of L. laricina. In the adipocyte lipid metabolism course, the results confirmed that 10 of the 17 EE stimulated adipocyte differentiation and adipogenesis, whereas 2 had inhibitory effects. Corresponding HWE exhibited partial or complete loss of such adipogenic or anti-adipogenic activity. R. groenlandicum and K. angustifolia EEs activated Peroxisome proliferator-activated receptor γ (PPAR γ), sterol regulatory element binding protein-1 (SREBP-1) and CCAAT-enhancer binding protein (C/EBP) α, whereas P. balsamifera and A. incana decreased these transcription factors. P. balsamifera’s inhibitory effect was also found to involve AMP-activated protein kinase (AMPK) activation. R. groenlandicum HWE and EE stimulated similar transcription factors, but HWE of other selected plants lost such effects compared to their respective EE. Phytochemical analysis also uncovered clustering of active versus inactive species, notably when species were segregated by plant family. The results showed that several EE stimulated muscle glucose uptake and inhibited hepatic glucose-6-phosphatase (G6Pase) activity. Some of the HWE partially or completely lost these antidiabetic activities in comparison to EE; while one plant (R.groenlandicum) retained similar potential between EE and HWE in both assays. In C2C12 muscle cells, EE of R.groenlandicum, A. incana and S. purpurea stimulated glucose uptake by activating AMPK pathway and increasing GLUT4 expression level. In comparison to EE, HWE of R.groenlandicum exhibited similar activities; HWE of A. incana completely lost its effect on all parameters; interestingly, HWE of S. purpurea activated insulin pathway instead of AMPK pathway to increase glucose uptake. In the H4IIE cells, all selected 5 plants HWE and EE activated AMPK pathway, and in addition, 2 plants EE and HWE also activated insulin pathways. Quercetin-3-O-galactoside and quercetin 3-O-α-L-arabinopyranoside were identified as potential candidates to be responsible for the biological activity of the active HWE plants in the glucose transport assay. In conclusion, we isolated several known compounds and identified a new active triterpene from fractionation of L. laricina. We also provide direct evidence evaluating and comparing of an insulin-like or insulin-sensitizing action of EE and HWE of Cree medicinal plants at the level of muscle, liver and adipose tissue. Part of their actions may be related to stimulation of insulin-dependent and insulin-independent intracellular signaling pathways, as well as to PPARγ activation. The results indicate that plant species, target tissues or cells, as well as extraction methods, are all significant determinants of the biological activity of Cree medicinal plants on glucose and lipid metabolism.
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"Hormetic dietary phytochemicals from Western Canadian plants: Identification, characterization and mechanistic insights". Thesis, 2013. http://hdl.handle.net/10388/ETD-2013-06-1066.
Testo completoAbstract (sommario):
Activation of mammalian stress responsive pathways by plant secondary metabolites may contribute to the protection against certain chronic diseases afforded by fruit and vegetable consumption. This work focuses on the identification of plant compounds that activate the stress-responsive enzyme quinone reductase (QR) by stabilizing the transcription factor NF-E2 related factor-2 (Nrf2). Screening methanolic extracts of plants from Western Canada for QR induction in a mouse hepatoma cell line (Hepa-1c1c7) led to the identification of twenty-one extracts capable of doubling the activity of QR. Bioassay-guided fractionation of six extracts led to the identification of novel classes of compounds with QR-inducing activity including fatty-acid derived polyacetylenes, phthalides, and cannabinoids. Studies using low molecular weight thiols and the recombinantly expressed protein Keap1, the principal negative regulator of Nrf2, supported a mechanism of QR activation involving covalent modification of Keap1 cysteines for the polyacetylenes and phthalides. Analysis of transcriptional changes in response to treatment with a panel of QR-inducing compounds provided strong support for Nrf2 activation by the polyacetylene (3S,8S)-falcarindiol and the isothiocyanate (R)-sulforaphane and weaker support for the compounds (3R,8S)-falcarindiol, 6-isovaleryl-umbelliferone (6-IVU) and (Z)-ligustilide. Additionally, transcript level analyses supported a role for the aryl-hydrocarbon receptor in QR-activation by (3R,8S)-falcarindiol, (Z)-ligustilide, (R)-sulforaphane, 6-IVU and cannabidiol and suggested that treatment with polyacetylenes with a (3R)-configuration, (Z)-ligustilide and 6-IVU causes substantial changes in the expression of genes associated with lipid homeostasis and energy metabolism. As a whole, this work provides evidence that compounds that activate QR (and Nrf2) are widely distributed in the Canadian flora. However, of these QR activators, few are active at concentrations that are expected to be achieved through dietary consumption. Nevertheless, the most exceptional compounds isolated in this work, the compounds (3S,8S)-falcarindiol and epoxyfalcarindiol are highly potent and appear to be or are expected to be specific for activating Nrf2 and thus warrant attention with respect to dietary implications and as drug candidate leads.
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Ndou, Zwivhuya Leonard. "Effectiveness of indigenous tree species (Spirostachys africana) extracts against Sitophilus Zeamais (Mostschulsky)". Diss., 2016. http://hdl.handle.net/11602/392.
Testo completo