RESUMO
OBJECTIVES: The present study aimed to assess the antibacterial activity against bacteria with cariogenic relevance, toxic and genotoxic potential of the plants Anacardium occidentale L. and Anadenanthera macrocarpa (Benth.) Bernam. DESIGN: Using a microdilution technique, the extracts were submitted to minimum inhibitory concentration (MIC) testing against Streptococcus mitis (ATCC 903), Streptococcus mutans (ATCC 25175), Streptococcus oralis (ATCC 10557), Streptococcus salivarius (ATCC 7073), Streptococcus sanguinis (ATCC 15300) and Streptococcus sobrinus (ATCC 27609). The toxicity of the extracts was then verified against eukaryotic cells. Additionally, a micronucleus assay was performed to investigate the potential mutagenic effects of the extracts on rat erythrocytes. The Student's t-test, Bonferroni test, and one-way ANOVA followed by Tukey's tests were used for statistical analysis, at a significance level of 5%. RESULTS: While the A. occidentale extract was able to inhibit all of the tested strains, with S. mutans and S. mitis being the most susceptible to that extractÌs action, the A. macrocarpa did not show antimicrobial activity. Interestingly, the hemolytic, oxidant and antioxidant activities were slightly observed for either extract, even at high concentrations (1000mg/mL). The micronucleus assay showed no significant changes in the cells exposed to the extracts. CONCLUSION: The A. occidentale extract has potential as an antimicrobial agent with low eukaryotic cell toxicity or mutagenic activity. The A. macrocarpa extract, although absent of antibacterial activity might as well be a safe and effective phytotherapeutic alternative.