Abstract

The aqueous standard extract of Mangifera indica L stem bark (MSBE) is used as a food supplement in Cuba. In this study, the genotoxic effect of MSBE was measured using different variants of the in vitro Comet assay in human lymphocytes and rat hepatocytes incubated with MSBE at 37 degrees C for 1 hour. Lymphocytes were incubated with MSBE for the subcellular (at two different pH conditions) and the standard Comet assays, in presence of catalase or S-9 microsomal fraction. Hydrogen peroxide, benzo(a)pirene and UV radiation were used as positive controls. Results from standard and subcellular Comet assays clearly showed that MSBE (50 mu g/mL) induced primary DNA damage to lymphocytes. This genotoxic effect was slightly reduced when lymphocytes were incubated with MSBE plus catalase, which suggests that hydrogen peroxide is involved in this DNA injury. S-9 fraction also decreased MSBE-induced damage to DNA in human lymphocytes. Not genotoxic effect was observed when rat hepatocytes were exposed at MSBE, suggesting that the metabolic activity can be involved in the elimination of the DNA damage generated by the MSBE. In conclusion, MSBE causes primary DNA injury of human lymphocytes in vitro Comet assay, but not in rat hepatocytes in similar conditions.