Mutagenicity and antioxidant assessment of Stachitarpheta jamaicensis (L.) Vahl

Stachitarpheta jamaicensis (L.) Vahl. is a member of the Verbenaceae commonly used in Cuba, mainly as vermifugue and against diarrhoea. The mutagenic potential of a hydroalcohol extract of its aerial parts was assessed in vitro using the Salmonella/microsome assay and in vivo in the mouse bone marrow micronucleus test. No positive response was observed in a battery of four Salmonella typhimurium strains employed: TA 1535, TA 1537, TA 98 and TA 100, when exposed to concentrations up to 5 mg/plate, with and without mammalian metabolic activation. In the same way, no increase in the micronucleus frequency in mitotic erythropoietic tissue was observed when animals were administered the extract orally in doses of 500, 1000 and 2000 mg/kg. The extract inhibited lipid peroxidation in the rat liver microsomal fraction (IC(50) = 3.6 microg/mL) but it does not seem to be an effective.OH radical scavenger (IC(50) = 76.7 microg/mL). Noteworthy, it increased in a dose dependent way the level of revertant colonies in E. coli IC 203, a strain sensitive to oxidative mutagenesis, when assayed together with hydrogen peroxide and ferrous sulphate, which suggests a pro-oxidant action.