Avaliação do efeito vasorelaxante das folhas de Caryocar brasiliense camb. em aorta torácica de ratos

• Ano de defesa: 2012
• Autor(a) principal: Oliveira, Lais Moraes de
• Orientador(a): Ghedini, Paulo César
• Banca de defesa: Ghedini, Paulo César, Burger, Marilise Escobar, Lobato, Núbia de Souza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Biologia (ICB)
• Departamento: Instituto de Ciências Biológicas - ICB (RG)
• País: Brasil
• Palavras-chave em Português: Caryocar brasiliense Camb.; Aorta torácica; Vasorelaxante; Óxido nítrico; Dependente do endotélio
• Palavras-chave em Inglês: Thoracic aorta; Vasorelaxant; Nitric oxide; Endothelium-dependent
• Área do conhecimento CNPq: CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/3181

Caryocar brasiliense Camb. (“pequi”) is a native plant from the Cerrado region of Brazil that contains several bioactive components. Data from literature has demonstrated that dietary supplementation with pequi decreased the arterial pressure of volunteer athletes. In this work, we evaluated the vasorelaxant effect of the crude hydroalcoholic extract (CHE) of C. brasiliense leaves, and its organic fractions (hexane (HF), chloroform (CF), ethyl acetate (AEF), butanol (BF)), in the rat thoracic aorta. We found that CHE completely relaxed, in a concentration-dependent manner, rat aortic rings precontracted with phenylephrine, while butanolic fraction (BF) produced an effect similar to that of the CHE. Induced aortic relaxation BF by was abolished by endothelium removal, by incubation with the nitric oxide synthase inhibitor (L-NAME), and the soluble guanylate cyclase inhibitor (ODQ). However, incubation with either atropine (a muscarinic receptor antagonist) or pyrilamine (a histamine H1-receptor antagonist) had no effect on the BF-induced vasorelaxation. Moreover, this effect was not inhibited by indomethacin (a cyclooxygenase inhibitor) and tetraethylammonium (a non-selective K+ channel blocker). The vasorelaxation induced by BF in endothelium-intact aortic rings precontracted with KCl was reduced after incubation with L-NAME. Taken together, the results reveal that C. brasiliense possesses in vitro vasorelaxant effect in rat thoracic aorta and this effect involves stimulation of the nitric oxide/cyclic GMP pathway.