Cristiane F. da Silva*, Ania O. Pacheco, Rayane N. Alves, Josean F. Tavares, Marcelo S. da Silva and Julio C.E. Arranz Pages 556 - 562 ( 7 )
Background: Chagas disease is caused by the protozoan parasite Trypanosoma cruzi. This illness is found mainly in 21 Latin American countries and an estimated 8 million people are infected worldwide. The unsatisfactory chemotherapy provokes severe toxicity and resistant strains. Medicinal plants constitute a promising source of new drugs and remedies against all kinds of disorders, mainly infectious diseases arousing interest worldwide.
Objective: The aim of this study is the isolation, structural identification and evaluation of the trypanocidal activity of samples present in the Excoecaria lucida Sw. leaves.
Methods: Total extract (TE) of E. lucida Sw. leaves was obtained by ethanol extract therefore fractionated sequentially with hexane, ethyl acetate and n-butanol, to obtain three phases: Hex, EA and But, respectively. Ellagic acid (EL1) was purified from both EA and But phases, while EL2; a 1:1 stigmasterol-3-O-β-D-glucopyranoside plus sitosterol-3-O-β-D-glucopyranoside mixture was obtained from the Hex phase. Activity assays were performed using bloodstream and intracellular forms of T. cruzi and cytotoxicity assays using L929 fibroblasts.
Results: The EL1 and EL2 samples were more active against bloodstream trypomastigote forms with EC50 of 53.0±3.6 and 58.2±29.0 µg/mL, respectively; at 100 µg/mL. These samples also showed 70% of inhibition of L929 cells infection. Toxicity assays demonstrated that after 96 h of treatment only the fractions Hex and EA presented detectable cytotoxicity.
Conclusion: Ellagic acid, stigmasterol-3-O-β-D-glucopyranoside and sitosterol-3-O-β-Dglucopyranoside are reported for the first time in E. lucida Sw. leaves as well as their biological activity studies supporting further investigations for Chagas disease treatment.
Excoecaria lucida Sw., Chagas disease, Trypanosoma cruzi, in vitro studies, natural products, ellagic acid.
Laboratorio de Biologia Celular, Instituto Oswaldo Cruz, Fundacao Oswaldo Cruz, Rio de Janeiro, RJ, Pharmacy Department, Faculty of Natural and Exact Sciences, Universidad de Oriente, Santiago de Cuba, Laboratorio de Biologia Celular, Instituto Oswaldo Cruz, Fundacao Oswaldo Cruz, Rio de Janeiro, RJ, Programa de Pos-graduacao em Produtos Naturais e Sinteticos Bioativos, Universidade Federal de Paraiba, Joao Pessoa, Programa de Pos-graduacao em Produtos Naturais e Sinteticos Bioativos, Universidade Federal de Paraiba, Joao Pessoa, Pharmacy Department, Faculty of Natural and Exact Sciences, Universidad de Oriente, Santiago de Cuba