• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 83
  • 41
  • 9
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 148
  • 66
  • 25
  • 23
  • 22
  • 20
  • 19
  • 19
  • 18
  • 18
  • 18
  • 16
  • 16
  • 15
  • 15
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Cancer du foie au Cambodge : état des lieux épidémiologiques, description des médecines traditionnelles utilisées et évaluation d'espèces médicinales sélectionnées / Liver cancer in Cambodia : epidemiological survey, description of traditional medicine used and biological evaluation of some medicinal plant species selected

Chassagne, François 17 October 2017 (has links)
Le cancer du foie est le 6ème cancer le plus fréquent et le 2ème plus meurtrier dans le monde. Au Cambodge, en raison du contexte historique et économique, les données précises concernant cette pathologie manquent. A l'aide d'outils épidémiologiques, nous avons décrit les caractéristiques de 553 patients atteints de cancer du foie à l'hôpital Calmette à Phnom Penh, et ainsi mis en évidence l'importance de l'infection par les virus des hépatites B et C chez les sujets étudiés. Puis, nous avons documenté les connaissances de 42 de ces patients vis-à-vis de leur maladie. Nous avons détaillé leurs itinéraires thérapeutiques, mis en évidences des pratiques à risques (forte utilisation d'injections thérapeutiques et de techniques de dermabrasion), et le recours fréquent à des médecines dites traditionnelles. Nous avons ensuite tenté de comprendre les stratégies de prise en charge des patients souffrant de maladies hépatiques par les médecins traditionnels, et mis en évidence la variété des remèdes utilisés et l'importance de la perception khmère des propriétés des plantes. Enfin, à l'aide d'un modèle in vitro de culture de cellules cancéreuses hépatiques couplé à des outils d'analyse métabolomique, nous avons évalué 10 espèces médicinales, sélectionnées sur des critères bibliographiques et de terrain, et tenté d'identifier les composés potentiellement responsables de l'activité antiproliférative observée. / Liver cancer is the 6th most common and 2nd most lethal cancer in the world. In Cambodia, due to the historical and economic context, there is a lack of accurate data on this pathology. Using epidemiological tools, we described the characteristics of 553 patients with liver cancer at the Calmette Hospital in Phnom Penh, and thus highlighted the importance of infection with hepatitis B and C viruses in the subjects studied. Then we documented the knowledge of 42 of these patients about their disease. We have detailed their therapeutic itineraries, highlighted risky practices (high use of therapeutic injections and dermabrasion techniques) and the use of traditional medicines. We then attempted to understand strategies for the management of patients with liver diseases by traditional healers, and highlighted the variety of remedies used and the importance of Khmer perception of plant properties. Finally, using an in vitro model of liver cancer cell culture coupled with metabolic analysis tools, we evaluated 10 medicinal species, selected on the basis of bibliographic and field criteria, and attempted to identify the compounds potentially responsible for the antiproliferative activity observed.
142

Atividade biológica de amidas e análogos de espécies de Piper e estudos biossintéticos / Biological activity of amides and analogs from Piper species and synthetic analogs

Joaquim Vogt Marques 18 March 2009 (has links)
Foram isoladas de Piper scutifolium e P. corcovadensis seis amidas, incluindo a piperovatina, piperlonguminina, isopiperlonguminina e corcovadina, duas inéditas (scutifoliamida A e scutifoliamida B), além de duas aristolactamas (piperolactama C e stigmalactama). A partir de P. tuberculatum foram isoladas as amidas piplartina e pelitorina e os ésteres (E)-3,4,5-trimetoxicinamato de etila (11) e 3,4,5- trimetoxidiidrocinamato de etila (12), esse último obtido pela primeira vez de origem natural. Em função da atividade biológica apresentada pelas amidas isoladas, foram sintetizadas 5-fenil-pentadienamidas e 3-cinamamidas com diferentes substituintes nos anéis aromáticos e na porção amídica. Os extratos, produtos naturais isolados e sintéticos foram submetidos a ensaios de atividade antifúngica frente Cladosporium cladosporioides e C. sphaerospermum, antimicrobiana frente à Candida albicans, C. krusei, C. parapsilosis e Cryptococcus neoformans, inibidora de acetilcolinesterase, carrapaticida frente à Boophilus microplus e citotóxica frente a linhagens tumorais humanas. Para a atividade antifúngica contra C. cladosporioides e C. sphaerospermum foi constatada maior atividade para as N-isobutil e N-pentilamidas sem substituintes no anel aromático. As N-isobutilamidas foram mais ativas como inibidores de acetilcolinesterase; contra B. microplus grande atividade foi apresentada por piperovatina, e os ensaios de citotoxicidade indicaram que o grupo 5,6-dihidropiridin- 2(1H)-ona é fundamental para a atividade. As plântulas de P. corcovadensis apresentaram em sua composição predominantemente piperovatina e assim foram utilizadas para estudos com incorporação de acetato de sódio-[1-14C] e L-fenilalanina - [U-14C] na mesma. As plântulas e calos obtidos para P. scutifolium não apresentaram produção significativa de metabólitos secundários. O estudo do metabolismo fenilpropanoídico de P. regnellii resultou no isolamento parcial da enzima responsável pela conversão de conocarpano em eupomatenóide-6. / Six amides were isolated from Piper scutifolium and P. corcovadensis including piperovatine, piperlonguminine, isopiperlonguminine and corcovadine, the new scutifoliamide A and scutifoliamide B and also two aristolactams (piperolactam C and stigmalactam). From P. tuberculatum the amides piplartine and pellitorine and two esters, ethyl (E)-3,4,5-trimethoxycinnamate (11) and ethyl 3,4,5- trimethoxydihydrocinnamate (12) were isolated, this last one obtained for the first time from natural sources. Due to the biological activity observed for the natural amides, 5- phenyl-pentadienamides and 3-cinnamamides having different substituents in the aromatic ring and amide moietis were synthesized. Extracts, isolated and synthetic compounds were assayed against Cladosporium cladosporioides, C. sphaerospermum, Candida albicans, C. krusei, C. parapsilosis and Cryptococcus neoformans, inhibitory of acetylcholinesterase, against the tick Boophilus microplus and citotoxic against human cell lines. A higher activity was observed against C. cladosporioides and C. sphaerospermum for N-isobutylamides and N-pentylamides having no substituents in the aromatic ring. N-isobutylamides were very active inhibitors of acetylcholinesterase; piperovatin was the most active against B. microplus and 5,6-dihydropyridin-2(1H)-one moiety was essential as the citotoxicity is concerned. Plantlets of P. corcovadensis contained piperovatine as major compound and thus were used as model for incorporation of sodium acetate-[1-14C] and L-phenylalanine-[U-14C]. The production of secondary metabolites in plantlets and callus of P. scutifolium was not significant. The studies of phenylpropanoid metabolism in P. regnellii was addressed to partial purification and characterization of the enzyme involved in the conversion of conocarpan to eupomatenoid-6.
143

Estudo químico monitorado pelas atividades larvicida antibacteriana e anti-inflamatória de duas espécies de bignoniaceae (Tabebuia elliptica (A. DC.) Sandwith e T. roseo-alba Ridl.) / Chemical study monitored by the antibacterial and anti-inflammatory larvicidal activities of two species of bignoniaceae (Tabebuia elliptica (A. DC.) Sandwith and T. roseo-alba Ridl.)

Ferreira Júnior, Jésu Costa 27 May 2015 (has links)
This work shows chemical study monitored by antinociceptive, anti-inflammatory, antimicrobial and larvicidal activities of two Bignoniaceae species [Tabebuia elliptica (A. DC.) Sandwith and T. roseo-alba Ridl.]. After drying at room temperature and grinding, the material from stem barks, stems and leaves of both species were extracted by maceration with methanol and/or acetone. After removal of the solvents under vacuum, crude extracts were suspended in methanol and water solution and successively extracted with hexane, chloroform and ethyl acetate. The fractions resulting from this procedure were evaluated in writhing model induced by acetic acid and exhibited a significant reduction of nociceptive response. Chemical studies of some fractions from these extracts of T. roseo-alba resulted in the isolation and identification by NMR technique of two neolignans [Icariside E4 and (7R, 8S) - dihydrodehydrodiconiferyl alcohol], a benzoic acid derivative (p-methoxibenzoic acid), a misture of two triterpenes (ursolic and oleanolic acids) and a phytosteroid (sitostenone); while from T. elliptica fractions resulted in the isolation of a chlorinated iridoid (rehmaglutin D), a phenylpropanoid (coumaric acid) and a phytosteroid (β-sitosterol). In pharmacological tests, Icariside E4 showed a peripheral antinociceptive effect, involving potassium channel ATP-K+ and coumaric acid significantly reduced levels of total leukocytes, neutrophils, as well as the percentage of ROS-producing cells in acute lung inflammation model induced by LPS showing an anti-inflammatory potential. Extracts from stems and leaves of both species showed antimicrobial activities against strains of S. aureus and E. faecalis and in the larvicidal assays, although the crude extracts of the barks, stems and leaves have exhibited low mortality at 250 ppm, hexane and chloroform fractions from barks and stems of T. roseo-alba and ethyl acetate from stems of T. elliptica, showed high mortality percentages. Substances, Icariside E4 and (7R, 8S) - dihydrodehydrodiconiferyl alcohol, are being described for the first time in the genus Tabebuia and the isolation of the chlorinated iridoid, Rehmaglutina D, in this work can aid in positioning the Tabebuia genus in the Bignoniaceae family. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho apresenta o estudo químico monitorado pelas atividades antinociceptiva, anti-inflamatória, antibacteriana e larvicida de duas espécies de Bignoniaceae [Tabebuia elliptica (A. DC.) Sandwith e T. roseo-alba Ridl.]. Após secagem a temperatura ambiente e trituração, materiais das cascas, caule e folhas de ambas as espécies foram extraídos através de maceração com metanol e/ou acetona. Após eliminação dos solventes a pressão reduzida, os extratos brutos foram suspensos em solução de metanol e água e extraídos sucessivamente com hexano, clorofórmio e acetato de etila. As frações resultantes deste procedimento foram avaliadas no modelo de contorção abdominal induzida pelo ácido acético e exibiram uma redução significativa da resposta nociceptiva. O estudo químico de algumas das frações de T. roseo-alba resultou no isolamento e identificação através da técnica de RMN de duas neolignanas [Icarisideo E4 e o (7R, 8S) - Álcool diidrodeidrodiconiferílico], um derivado do ácido benzoico (ácido p-metoxibenzoico), uma mistura de dois triterpenos (ácidos ursólico e oleanólico) e um fitoesteroide (sitostenona); enquanto que de frações de T. elliptica resultou no isolamento de um iridoide clorado (rehmaglutina D), um fenilpropanoide (ácido cumarico) e um fitoesteróide (β-sitosterol). Nos ensaios farmacológicos, Icarisideo E4 mostrou um efeito antinociceptivo periférico, com o envolvimento de canais de potássio ATP-K+ e o ácido cumárico reduziu significativamente os níveis de leucócitos totais, neutrófilos, bem como a porcentagem de células produtoras de ROS no modelo de inflamação pulmonar aguda induzida por LPS exibindo um potencial antiinflamatório. Extratos do caule e das folhas de ambas as espécies apresentaram potencial antibacteriano contra cepas de S. aureus e E. faecalis e nos ensaios larvicidas, embora os extratos brutos das cascas, caule e folhas tenham exibido baixos índices de mortalidade a 250 ppm, as frações em hexano e clorofórmio das cascas e do caule de T. roseo-alba e em acetato do caule de T. elliptica, apresentaram altos índices de mortalidade. As substâncias, Icarisideo E4 e (7R, 8S) - Álcool diidrodeidrodiconiferílico, estão sendo descritas pela primeira vez no gênero Tabebuia e o isolamento do iridoide clorado Rehmaglutina D neste trabalho poderá auxiliar no posicionamento do gênero Tabebuia dentro da família Bignoniaceae.
144

Chemical Characterization and Biological Evaluation of Secondary Metabolites Isolated from <i>Glycosmis ovoidea</i>

Blanco Carcache, Peter Josephin January 2020 (has links)
No description available.
145

Estudo fitoquímico e biológico do cambucá Plinia edulis (Vell.) Sobral - Myrtaceae / Phytochemical and Biological Studies of cambucá - Plinia edulis (Vell.) Sobral Myrtaceae

Ishikawa, Tati 10 November 2008 (has links)
Plinia edulis (Myrtaceae), espécie arbórea popularmente conhecida como cambucá, é nativa da Mata Atlântica brasileira. Apesar do emprego na medicina tradicional em diversas moléstias, incluindo distúrbios gástricos, não existem estudos relacionando as atividades biológicas e os constituintes químicos da espécie. Esta tese relata a avaliação da gastroproteção, da atividade antioxidante, da citotoxicidade e da mutagenicidade do extrato etanol/água de folhas de P. edulis e das frações. Com o objetivo de correlacionar os metabólitos secundários com a eficácia da droga vegetal na medicina tradicional, o extrato foi submetido à partição e posterior fracionamento cromatográfico. O extrato apresentou atividade gastroprotetora significativa em modelo de indução de úlceras por etanol acidificado em ratos em doses de 100, 200 e 400 mg/kg via oral, sendo mais ativo que o fármaco de referência lansoprazol. Entre as frações, a hexânica (100 mg/kg p.o.) foi a mais eficaz, mas apresentou menor atividade do que o extrato bruto. A gastroproteção do ácido ursólico também foi avaliada, mas embora outros triterpenos sejam conhecidos como gastroprotetores, o ácido ursólico (50 mg/kg p.o.) reduziu a área lesionada, mas não apresentou atividade significativa no modelo empregado. O extrato não evidenciou mutagenicidade na concentração de 20 mg/placa no Ensaio de Ames e apresentou atividade antioxidante pronunciada, com CE50 de 5,75 &#181;g/mL no ensaio com DPPH e valor de ORAC de 3.948 &#181;mol de Trolox/g de extrato. O extrato e as frações foram avaliados quanto à citotoxicidade em linhagens de células tumorais humanas de UACC62 (melanoma), MCF-7 (mama), NCI 460 (pulmão), OVCAR03 (ovário), PC-03 (próstata), HT-29 (cólon), 786-0 (rins), NCI-ADR (mama com fenótipo de resistência a múltiplos fármacos) e linhagem de células normais de ovário de hamster chinês (CHO) in vitro. O extrato e as frações apresentaram citotoxicidade seletiva dose-dependente em células cancerígenas e atividade proliferativa em células normais. A partir das frações de hexano e acetato de etila foram identificados &#946;-amirina, lupeol, &#946;-sitosterol, ácido oleanólico, ácido ursólico, ácido maslínico, ácido corosólico, galato de etila, ácido gálico, quercitrina, miricitrina e quercetina por meio de análises espectrométricas. Estes resultados dão suporte à utilização popular desta espécie e estão provavelmente associados à presença dos flavonóides e triterpenos identificados no extrato. / Plinia edulis (Myrtaceae), an arboreous species popularly known as cambucá, is native in Brazilian Atlantic Rain Forest. Despite its traditional uses in many diseases, which include gastric disorders, no reports are available on the relationship between the biological activities of its extract and its chemical constituents. This thesis reports the evaluations of the the aqueous ethanol extract of leaves of P. edulis and its fractions on gastroprotective effect, antioxidant capacity, cytotoxicity and mutagenicity of. In order to correlate the secondary metabolites and the efficacy of the crude drug in traditional medicine, the extract was submitted to solvent partition followed by chromatographic fractionation. The extract exhibited significant gastroprotective effect on HCl/ethanol-induced ulcers in rats at doses of 100, 200 and 400 mg/kg p.o., even more active than the reference drug lansoprazole. Among the fractions, the hexane fraction (100 mg/kg p.o.) was the most effective, but showed lower activity than the crude extract. In addition, the gastroprotective effect of ursolic acid was evaluated. Although others triterpenes are well known as gastroprotective agents, ursolic acid (50 mg/kg p.o.) reduced the lesion area, but did not show significant activity on this model. The extract did not show mutagenicity at the concentration of 20 mg/plate in the Ames test and exhibited high antioxidant activity, with EC50 of 5.75 &#181;g/mL on the DPPH assay and ORAC value of 3948 &#181;mol Trolox/g of extract. The extract and its fractions were evaluated for cytotoxic activity against human tumour cell lines as UACC62 (melanoma), MCF-7 (breast), NCI 460 (lung, non-small cells), OVCAR03 (ovarian), PC-03 (prostate), HT-29 (colon), 786-0 (renal), NCI-ADR (breast expressing phenotype multiple drugs resistance) and CHO (Chinese Hamster Ovary) normal cell line in vitro. The extract and its fractions showed selectively dose-dependent cytotoxicity against cancer cells and proliferative activity in normal cells. The hexane and ethyl acetate fractions yielded &#946;-amyrin, lupeol, &#946;-sitosterol, oleanolic acid, ursolic acid, maslinic acid, corosolic acid, ethyl gallate, gallic acid, quercitrin, myricitrin and quercetin, which were identified based on spectrometric analyses. These results provide scientific support to the traditional use of this species, which are probably associated with the flavonoids and triterpenoids identified in the extract.
146

Ethnobotanique de la Nation crie d'Eeyou Istchee et variation géographique des plantes médicinales antidiabétiques

Rapinski, Michel 12 1900 (has links)
Le diabète de type 2 affecte en moyenne 29% de la population adulte crie d’Eeyou Istchee (CEI). Afin d’identifier les plantes médicinales possédant un potentiel antidiabétique, des interviews ont été réalisés dans les communautés CEI de Wemindji et Oujé-Bougoumou. Utilisant une approche quantitative, les espèces mentionnées ont été classées et comparées à la pharmacopée des communautés avoisinantes. Seize et 25 plantes ont été mentionné à Wemindji et Oujé-Bougoumou, respectivement. Sept nouvelles espèces de plantes et une de champignon se sont ajoutées à la liste des espèces à potentiel antidiabétique, bien que la plupart de celles mentionnées pendant les interviews soit en communes à la pharmacopée CEI générale, démontrant ainsi leur importance culturelle. Des analyses phytochimiques sur deux de ces espèces, Rhododendron groenlandicum et Sarracenia purpurea, ont été réalisées à partir d’échantillons récoltés à différents endroits du territoire eeyouch. Bien qu’aucun patron n’ait été détecté dans la variation des composantes biologiquement actives chez S. purpurea, les composés phénoliques chez R. groenlandicum, particulièrement la (+)-catéchine, l’(-)-epicatéchine et la quercétine-3-galactoside, varient spatialement en fonction de paramètres d’insolation telles la radiation solaire ou la photopériode. Les échantillons de cette dernière espèce, testés in vitro dans le bioessai de l’adipogenèse des cellules adipocytes murines 3T3-L1, augmentent l’accumulation intracellulaire des triglycérides, leur conférant ainsi une activité diabétique semblable à la rosiglitazone. Cependant, cette activité était plus faible dans les échantillons à haute teneur en quercétine, cela pouvant ainsi avoir un impact sur la qualité d'un produit de santé naturel fabriqué à partir de cette espèce. / Type 2 diabetes has reached epidemic proportions among Canada’s aboriginal populations and affects on average 29% of adult Cree of Eeyou Istchee (CEI). In collaboration with the Cree Board of Health and Social Services of James Bay and the CIHR team in Traditional Antidiabetic Aboriginal Medicines, interviews were held in the CEI communities of Wemindji and Oujé-Bougoumou to identify potential antidiabetic plants. Using a quantitative approach, species mentioned were ranked and compared to the pharmacopoeia of other participating communities. Sixteen and 25 plants were mentioned in Wemindji and Oujé-Bougoumou respectively. Seven new plant and one fungal species were added to the list of potential antidiabetic species, although most of those mentioned were common to the general CEI pharmacopoeia, thus supporting the cultural importance that they hold. Phytochemical analyses of two of these species, Rhododendron groenlandicum and Sarracenia purpurea, were made from accessions harvested throughout Eeyou Istchee. While no pattern was detected in the variation of S. purpurea’s biologically active compounds, phenolic compounds from R. groenlandicum, specifically (+)-catchin, (-)-epicatechin and quercetin-3-galactoside, varied spatially as a function of insolation parameters such as solar radiation or photoperiod. Samples from the latter, tested in vitro in the 3T3-L1 murine adipocytes adipogenesis bioassay, increased the intracellular accumulation of triglycerides, thus conferring it a glitazone-like antidiabetic activity. This activity, however, was weaker in accessions with high quercetin content, which could have an impact on the quality of a natural health product made from this species.
147

Estudo fitoquímico e biológico do cambucá Plinia edulis (Vell.) Sobral - Myrtaceae / Phytochemical and Biological Studies of cambucá - Plinia edulis (Vell.) Sobral Myrtaceae

Tati Ishikawa 10 November 2008 (has links)
Plinia edulis (Myrtaceae), espécie arbórea popularmente conhecida como cambucá, é nativa da Mata Atlântica brasileira. Apesar do emprego na medicina tradicional em diversas moléstias, incluindo distúrbios gástricos, não existem estudos relacionando as atividades biológicas e os constituintes químicos da espécie. Esta tese relata a avaliação da gastroproteção, da atividade antioxidante, da citotoxicidade e da mutagenicidade do extrato etanol/água de folhas de P. edulis e das frações. Com o objetivo de correlacionar os metabólitos secundários com a eficácia da droga vegetal na medicina tradicional, o extrato foi submetido à partição e posterior fracionamento cromatográfico. O extrato apresentou atividade gastroprotetora significativa em modelo de indução de úlceras por etanol acidificado em ratos em doses de 100, 200 e 400 mg/kg via oral, sendo mais ativo que o fármaco de referência lansoprazol. Entre as frações, a hexânica (100 mg/kg p.o.) foi a mais eficaz, mas apresentou menor atividade do que o extrato bruto. A gastroproteção do ácido ursólico também foi avaliada, mas embora outros triterpenos sejam conhecidos como gastroprotetores, o ácido ursólico (50 mg/kg p.o.) reduziu a área lesionada, mas não apresentou atividade significativa no modelo empregado. O extrato não evidenciou mutagenicidade na concentração de 20 mg/placa no Ensaio de Ames e apresentou atividade antioxidante pronunciada, com CE50 de 5,75 &#181;g/mL no ensaio com DPPH e valor de ORAC de 3.948 &#181;mol de Trolox/g de extrato. O extrato e as frações foram avaliados quanto à citotoxicidade em linhagens de células tumorais humanas de UACC62 (melanoma), MCF-7 (mama), NCI 460 (pulmão), OVCAR03 (ovário), PC-03 (próstata), HT-29 (cólon), 786-0 (rins), NCI-ADR (mama com fenótipo de resistência a múltiplos fármacos) e linhagem de células normais de ovário de hamster chinês (CHO) in vitro. O extrato e as frações apresentaram citotoxicidade seletiva dose-dependente em células cancerígenas e atividade proliferativa em células normais. A partir das frações de hexano e acetato de etila foram identificados &#946;-amirina, lupeol, &#946;-sitosterol, ácido oleanólico, ácido ursólico, ácido maslínico, ácido corosólico, galato de etila, ácido gálico, quercitrina, miricitrina e quercetina por meio de análises espectrométricas. Estes resultados dão suporte à utilização popular desta espécie e estão provavelmente associados à presença dos flavonóides e triterpenos identificados no extrato. / Plinia edulis (Myrtaceae), an arboreous species popularly known as cambucá, is native in Brazilian Atlantic Rain Forest. Despite its traditional uses in many diseases, which include gastric disorders, no reports are available on the relationship between the biological activities of its extract and its chemical constituents. This thesis reports the evaluations of the the aqueous ethanol extract of leaves of P. edulis and its fractions on gastroprotective effect, antioxidant capacity, cytotoxicity and mutagenicity of. In order to correlate the secondary metabolites and the efficacy of the crude drug in traditional medicine, the extract was submitted to solvent partition followed by chromatographic fractionation. The extract exhibited significant gastroprotective effect on HCl/ethanol-induced ulcers in rats at doses of 100, 200 and 400 mg/kg p.o., even more active than the reference drug lansoprazole. Among the fractions, the hexane fraction (100 mg/kg p.o.) was the most effective, but showed lower activity than the crude extract. In addition, the gastroprotective effect of ursolic acid was evaluated. Although others triterpenes are well known as gastroprotective agents, ursolic acid (50 mg/kg p.o.) reduced the lesion area, but did not show significant activity on this model. The extract did not show mutagenicity at the concentration of 20 mg/plate in the Ames test and exhibited high antioxidant activity, with EC50 of 5.75 &#181;g/mL on the DPPH assay and ORAC value of 3948 &#181;mol Trolox/g of extract. The extract and its fractions were evaluated for cytotoxic activity against human tumour cell lines as UACC62 (melanoma), MCF-7 (breast), NCI 460 (lung, non-small cells), OVCAR03 (ovarian), PC-03 (prostate), HT-29 (colon), 786-0 (renal), NCI-ADR (breast expressing phenotype multiple drugs resistance) and CHO (Chinese Hamster Ovary) normal cell line in vitro. The extract and its fractions showed selectively dose-dependent cytotoxicity against cancer cells and proliferative activity in normal cells. The hexane and ethyl acetate fractions yielded &#946;-amyrin, lupeol, &#946;-sitosterol, oleanolic acid, ursolic acid, maslinic acid, corosolic acid, ethyl gallate, gallic acid, quercitrin, myricitrin and quercetin, which were identified based on spectrometric analyses. These results provide scientific support to the traditional use of this species, which are probably associated with the flavonoids and triterpenoids identified in the extract.
148

Ethnobotanique de la Nation crie d'Eeyou Istchee et variation géographique des plantes médicinales antidiabétiques

Rapinski, Michael 12 1900 (has links)
Le diabète de type 2 affecte en moyenne 29% de la population adulte crie d’Eeyou Istchee (CEI). Afin d’identifier les plantes médicinales possédant un potentiel antidiabétique, des interviews ont été réalisés dans les communautés CEI de Wemindji et Oujé-Bougoumou. Utilisant une approche quantitative, les espèces mentionnées ont été classées et comparées à la pharmacopée des communautés avoisinantes. Seize et 25 plantes ont été mentionné à Wemindji et Oujé-Bougoumou, respectivement. Sept nouvelles espèces de plantes et une de champignon se sont ajoutées à la liste des espèces à potentiel antidiabétique, bien que la plupart de celles mentionnées pendant les interviews soit en communes à la pharmacopée CEI générale, démontrant ainsi leur importance culturelle. Des analyses phytochimiques sur deux de ces espèces, Rhododendron groenlandicum et Sarracenia purpurea, ont été réalisées à partir d’échantillons récoltés à différents endroits du territoire eeyouch. Bien qu’aucun patron n’ait été détecté dans la variation des composantes biologiquement actives chez S. purpurea, les composés phénoliques chez R. groenlandicum, particulièrement la (+)-catéchine, l’(-)-epicatéchine et la quercétine-3-galactoside, varient spatialement en fonction de paramètres d’insolation telles la radiation solaire ou la photopériode. Les échantillons de cette dernière espèce, testés in vitro dans le bioessai de l’adipogenèse des cellules adipocytes murines 3T3-L1, augmentent l’accumulation intracellulaire des triglycérides, leur conférant ainsi une activité diabétique semblable à la rosiglitazone. Cependant, cette activité était plus faible dans les échantillons à haute teneur en quercétine, cela pouvant ainsi avoir un impact sur la qualité d'un produit de santé naturel fabriqué à partir de cette espèce. / Type 2 diabetes has reached epidemic proportions among Canada’s aboriginal populations and affects on average 29% of adult Cree of Eeyou Istchee (CEI). In collaboration with the Cree Board of Health and Social Services of James Bay and the CIHR team in Traditional Antidiabetic Aboriginal Medicines, interviews were held in the CEI communities of Wemindji and Oujé-Bougoumou to identify potential antidiabetic plants. Using a quantitative approach, species mentioned were ranked and compared to the pharmacopoeia of other participating communities. Sixteen and 25 plants were mentioned in Wemindji and Oujé-Bougoumou respectively. Seven new plant and one fungal species were added to the list of potential antidiabetic species, although most of those mentioned were common to the general CEI pharmacopoeia, thus supporting the cultural importance that they hold. Phytochemical analyses of two of these species, Rhododendron groenlandicum and Sarracenia purpurea, were made from accessions harvested throughout Eeyou Istchee. While no pattern was detected in the variation of S. purpurea’s biologically active compounds, phenolic compounds from R. groenlandicum, specifically (+)-catchin, (-)-epicatechin and quercetin-3-galactoside, varied spatially as a function of insolation parameters such as solar radiation or photoperiod. Samples from the latter, tested in vitro in the 3T3-L1 murine adipocytes adipogenesis bioassay, increased the intracellular accumulation of triglycerides, thus conferring it a glitazone-like antidiabetic activity. This activity, however, was weaker in accessions with high quercetin content, which could have an impact on the quality of a natural health product made from this species.

Page generated in 0.0462 seconds