Ensaios de atividade antimicrobiana in vitro e mutagênica in vivo com extrato de Vernonia polyanthes Less (Assa-peixe)

The effects of the hydroalcoholic extract from Vernonia polyanthes Less (Assa-peixe) were analyzed on the cellular growth and differentiation of the protozoan Herpertomonas samuelpessoai, the in vitro antimicrobial susceptibility, the LD50, and the in vivo mutagenicity (micronucleus test). The growth inhibition of H. samuelpessoai was found when it was exposed to increasing concentrations of the extract, but without the percentually relevant emergence of the opisthomastigote forms. The pattern-strains Bacillus cereus, Escherichia coli, Proteus mirabilis, Staphylococcus aureus, Streptococcus pyogenes and Salmonella Typhimurium showed inhibitory halo to V. polyanthes extract. However, the bacteriostatic effect was observed on Bacillus cereus (180.1 mg/mL), Escherichia coli (72.04 mg/mL) and Proteus mirabilis (144.08 mg/mL). The mutagenic evaluation of hydroalcoholic extract from V. polyantes revealed a lack or moderate clastogenic effects and/or aneugenic at the concentrations of 1000 and > 1500 mg/Kg, respectively, independently of the treatment time (24/48h) and the animal gender. These results were suggestive of an occurrence of systemic toxicity due to the increase of normochromatic erythrocytes in mice bone marrow, independently at the treatment time, extract dose and animal gender. However, absence of DL50 was observed in the all of tested concentrations (250-2000 mg/Kg).