PROTECTIVE EFFECT OF SIMULTANEOUS AND POST-TREATMENT WITH BACCHARIS DRACUNCULIFOLIA EXTRACT ON GENOTOXICITY OF METHYL METHANESUL

BM11

Munari, CC (1); Alves, JM (1); Bastos, JK (2); Tavares, DC (1)

(1) Universidade de Franca, Franca, São Paulo; (2) FCFRP – USP, Ribeirão Preto, São Paulo

Baccharis dracunculifolia D. C. (Asteraceae), a native plant from the Brazilian ‘cerrado’, is widely used in folk medicine as an anti-inflammatory agent and for the treatment of gastrointestinal diseases. B. dracunculifolia has been described as the most important plant source of propolis in southeastern Brazil, which is called green propolis due to its color. The aim of the present study was to evaluate the genotoxic and antigenotoxic effects of the ethyl acetate extract of B. dracunculifolia leaves (Bd-EAE) on Chinese hamster lung fibroblasts (V79 cells) by the comet assay. Methyl methanesulfonate (MMS; 200mM) was used as an inducer of DNA damage. For the evaluation of the genotoxicity, four different concentrations of EAE-Bd were used: 12.5; 25.0; 50.0 and 100.0 mg/mL The antigenotoxicity protocols used were before, simultaneously, and after the treatment with the mutagen. Cell viability was measured by the trypan blue dye-exclusion test, all measurements conduced with V79 indicated viability of >90% for all experimental groups. The results showed a significant increase in the frequencies of DNA damage at the cultures treated with 50.0 and 100.0 mg/mL of Bd-EAE. In relation antigenotoxicity, the lowest Bd-EAE concentration tested (12.5 µ/mL) showed protective activity in simultaneous and post-treatment when compare to MMS. The present results indicate that Bd-EAE has the characteristics of a so-called “Janus” compound, i.e., Bd-EAE is genotoxic at higher concentrations, whereas it displays a chemopreventive effect on MMS-induced genotoxicity at lower concentrations. The constituents of B. dracunculifolia responsible for its genotoxic and antigenotoxic effects are probably flavonoids and phenylpropanoids, since these compounds can act either as pro-oxidants or as free radical scavengers depending on their concentration.