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

• Autor(a) principal: Carvalho, Izabela Maria Montezano de
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2413
• topic: Quina; Atividade antihepatotóxica; Quina; Antihepatotoxic activity; CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA

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.