Mutagenic and antimutagenic potential of the medicinal plants M. laevigata and C. xanthocarpa.

Aqueous extracts of medicinal plants (Mikania laevigata and Campomanesia xanthocarpa) were screened for the presence of mutagenic activity in the Salmonella/microsome assay. The extracts of Campomanesia xanthocarpa showed frameshift (TA97a strain) signs of mutagenic activity without exogenous metabolism (S9 fraction). The infusions of Mikania laevigata, negative for mutagenic activity, showed high percentages of inhibition of mutagenesis induced by mutagens 2AF (2-amino fluorene), in the presence of exogenous metabolism (S9 fraction), for frameshift (TA98) and base pair substitution (TA100) lesions. In addition, these inhibitions were observed against mutagen SAZ (sodium azide) in assays with the TA100 strain, without exogenous metabolism (S9 fraction). A synergistic effect was also observed in frameshift mutagenic events, with direct action in the presence of 4NQO (4-oxide-1-nitroquinoline) and a tendency to a low percentage of action enhancement, in the presence of the 2AF mutagen. The variable responses observed in the extract assays show the potentials for interaction of the different active principles in genetic material.