Avaliação de atividade antihepatotóxica de duas espécies vegetais popularmente conhecidas como "quina": Strychnos pseudoquina A. St. Hil. e Coutarea hexandra (Jacq.) K. Schum

• Ano de defesa: 2009
• Autor(a) principal: Carvalho, Izabela Maria Montezano de
• Orientador(a): Leite, João Paulo Viana
• Banca de defesa: Fontes, Elita Scio , Diaz, Marisa Alves Nogueira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Bioquímica Agrícola
• Departamento: Bioquímica e Biologia molecular de plantas; Bioquímica e Biologia molecular animal
• País: BR
• Palavras-chave em Português: Quina; Atividade antihepatotóxica
• Palavras-chave em Inglês: Quina; Antihepatotoxic activity
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA
• Link de acesso: http://locus.ufv.br/handle/123456789/2413

Brazil possesses the most abundant and diverse plant life in the world, home to nearly 22% of all higher plant species on the planet. Traditional knowledge of many of these Brazilian plants is associated to this genetic patrimony, especially the use of plants in popular medicine. Therefore, the proposal of the present work was to evaluate the antihepatotoxic potential of extracts obtained of bark and leafs from plant species popularly used for this purpose, Strychnos pseudoquina A. St.- Hil., family: Loganiaceae and Coutarea hexandra (Jacq.) K. Schum, family: Rubiaceae. A preliminary phytochemical analysis was separately performed on the ethanol extract of bark and leafs by thin film chromatography; as well as an in vitro evaluation of antioxidant potential. Subsequently, biological tests were conducted toinvestigate the capacity of the evaluated extracts to revert hepatic damage inducted by paracetamol in rats. In vivo antihepatotoxic tests were performed by employing three distinctive doses and thereafter, evaluating biochemical and histological parameters of the animals. From the preliminary phytochemical analysis, differences in the composition of evaluated secondary metabolitegroups were observed between the bark and leaf extracts for each of the studied species. In relation to antioxidant potential, in both species, the bark extracts showed better results compared with leafs. In the biological testof the species S. pseudoquina, the bark (100mg/kg) and leaf (200mg/kg) extracts presented possible beneficiary effects on the metabolism of the hepatobiliary system. On the other hand, results indicated the incapability of these extracts to revert the hepatocellular damages caused by the paracetamol. In the same test model conducted for C. hexandra, a weak antihepatotoxic effect was observed in toxicity induced by parecetamol from the bark extract (100mg/kg), while the leaf extract showed no activity. Histological observations confirmed the beneficiary effect of the bark extracts from both species against liver damage induced by paracetamol in rats. A possible acting mechanism may involve antioxidant activity of this extract, principally promoted by polyphenolic metabolites.