Evaluation of cytoprotective effects of compounds isolated from Copaifera langsdorffii Desf. against induced cytotoxicity by exposure to methylmercury and lead.

Copaifera langsdorffii L. is one of the most known medicinal species in Brazil. Its leaves are rich in phenolic compounds with potential biological activities as an antioxidant and chelating agent. This paper reports the isolation of four compounds from the hydroalcoholic extract of the leaves of C. langsdorffii and the investigation of their possible cytoprotective effects against heavy metal poisoning. Quercitrin (1), afzelin (2), 3,5-di-O-(3-O-methyl galloyl) quinic acid (3) and 4,5-di-O-(3-O-methyl galloyl) quinic acid (4), were associated with toxic doses of methylmercury and lead and evaluated by Alamar blue cell viability assays in HepG2 and PC12. The compounds displayed significant cytoprotective effect for the HepG2 cell line against both metals. Compounds 1-4 did not protect PC12 cells against methylmercury induced-cytotoxicity, but at lower concentrations, they protected against lead induced-cytotoxicity. The evaluated compounds showed a promising cytoprotection effect against exposure to heavy metals and should be further investigated as protective agents.