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Previous issue date: 2011-03-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The species of the genus Marsdenia, Apocynaceae, are widely used in folk
medicine of several countries. In Brazil is found several species belonging to this
genus. The in vitro antioxidant, anticoagulant and antiproliferative activities were
evaluated to aqueous extracts of stalk, leaf and root of Marsdenia megalantha. In
the total antioxidant capacity assay (expressed as ascorbic acid equivalents) the
stalk extract showed 76.0 mg/g, while leaf and root extracts 141.3 mg/g and 57.0
mg/g, respectively. The stalk and leaf extracts showed chelating activity around 40%
at 1.5 mg/mL, while root extract, at the same concentration showed, 17%. Only the
leaf extract showed a significant ability in superoxide scavenging (80% at 0.8
mg/mL). Any extract was able in scavenge hydroxyl, as well anticoagulant activity.
The antiproliferative activity of the extracts was evaluated against HeLa tumor cell
line. The extracts inhibited in a dose-dependent manner the cell growth. However,
the leaf extract showed 80% of inhibition at 1.0 mg/mL, while stalk and root extracts
inhibited 63% and 30%, respectively. To assess the mechanism of cell death caused
by the leaf extract in HeLa, was performed flow cytometry and western blot. The
results show that leaf extract induces cell death by apoptosis through an activation
caspase-independent pathway. These data indicate that stalk and leaf extracts
obtained have potential to be used as antioxidants and anticancer drugs / As esp?cies do g?nero Marsdenia, Apocynaceae, s?o bastante utilizadas na
medicina popular de v?rios pa?ses. No Brasil s?o encontradas v?rias esp?cies
pertencentes a esse g?nero. As atividades antioxidante, anticoagulante e
antiproliferativa foram avaliadas para os extratos de caule, folha e raiz de Marsdenia
megalantha. Na capacidade antioxidante total (expressa como equivalente de ?cido
asc?rbico), o extrato do caule apresentou 76,0 mg/g, enquanto os extratos da folha e
raiz apresentaram, respectivamente, 14,3 mg/g e 57,0 mg/g. Os extratos do caule e
da folha mostraram habilidade quelante em torno de 40% na concentra??o de 1,5
mg/mL, enquanto o extrato da raiz, na mesma concentra??o, apresentou 17%.
Apenas o extrato da folha apresentou uma capacidade significante em sequestrar
radicais super?xidos (80% em 0,8 mg/mL). Nenhum extrato mostrou capacidade em
seq?estrar radicais hidroxila, bem como atividade anticoagulante. A atividade
antiproliferativa dos extratos foi avaliada contra a linhagem tumoral HeLa. Os
extratos inibiram, de forma dose-dependente, o crescimento celular. Entretanto, o
extrato da folha foi capaz de inibir em 80% a prolifera??o celular na concentra??o de
1,0 mg/mL, enquanto os extratos de caule e raiz inibiram 63% e 30%,
respectivamente. Para avaliar o mecanismo de morte celular causada pelo extrato
da folha nas c?lulas HeLa, foi realizada citometria de fluxo e western blot. Os
resultados mostraram que o extrato da folha induz morte celular por apoptose
atrav?s de uma via de ativa??o independente de caspase. Estes resultados indicam
que os extratos de caule e folha obtidos t?m potencial para serem futuramente
utilizados como f?rmacos antioxidantes e antic?ncer
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/12576 |
| Date | 21 March 2011 |
| Creators | Oliveira, Ruth Medeiros de |
| Contributors | CPF:76111830449, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4799567J8&dataRevisao=null, Trindade, Edvaldo da Silva, CPF:10746082835, http://lattes.cnpq.br/7677279818472797, Scortecci, K?tia Castanho, CPF:13451112825, http://lattes.cnpq.br/4808910380593455, Rocha, Hugo Alexandre de Oliveira |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Bioqu?mica, UFRN, BR, Bioqu?mica; Biologia Molecular |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/embargoedAccess |
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