Abstract

The use of natural products as an alternative for treatment and prevention of diseases has been increasing daily. Lippia alba is a shrub widely distributed throughout Brazil and its aqueous extracts, as infusion and decoction made from its leaves, are currently being used in popular medicine. Thus, the objective of the study was to do a phytochemical screening of these solutions as well as evaluate in vitro antimicrobial activity of these solutions in the reduction of: Streptococcus mutans (ATCC 25175), Streptococcus mitis (ATCC 49456), Staphylococcus aureus (ATCC 12600) and Lactobacillus casei (ATCC 27216). The negative and positive controls were respectively, BHI and Chlorhexidine. Statistical analysis was performed using the Mann-Whitney and Kruskal-Wallis test with Bonferroni's penalization, showing significant difference between the products tested (p<0.001). We found some phenolic compounds in the solutions. In all the microorganisms, the decoction and the infusion were more effective as compared to other products, having significant difference (p< 0.05). Therefore, the aqueous extracts of L. alba as well as being natural and easy to handle, were more effective against oral bacterias than chlorhexidine, which is considered a gold standard bactericidal agent.

Key words: Phytotherapy, dentistry, antimicrobial activity.