In vitro Evaluation of Antimicrobial Activity of Brazilian Red Propolis Containing-dentifrice

Background: This study evaluated the antimicrobial activity of brazilian red propolis (BRP) dentifrice and compare in vitro. Materials and methods: Strains of S. mutans ATCC UA159 were used in the present study. This study compared the antibacterial effects of BRP extract, BRP containingdentifrice and one antimicrobial commercial dentifrice (Parodontax) against S. mutans. For the evaluation of the antimicrobial activity the microdilution method was used in culture broth. The strain was activated by incubation at 37°C overnight in Brain Heart Infusion (BHI) culture medium, in an anaerobic jar. To the wells of the microplates were added 100μL of BHI broth, 20μL of the substances tested (experimental groups), at concentrations ranging from 100 μL/mL to 0.0488 μL/mL, and 80 μL/mL of the standardized microbial suspension. The microplates were incubated for 24 hr in a bacteriological oven at 37°C. Visual inspection of the colour changes and reading in BioTek microplate reader at 570nm was performed to determine the Minimum Bactericidal Concentration (MBC). Mean values and standard deviations were calculated. ANOVA followed by Dunnett’s test was performed; p-value of less than 0.05 was considered significant. Results: BRP extract and BRP containing-dentifrice showed antimicrobial activity against S. mutans up to the concentration of 0.3906 μg/mL. The BRP extract and dentifrice showed bactericidal effect at a concentration of 1.5625, but was able to reduce microbial viability at a concentration of up to 0.3906. Parodontax dentifrice showed antimicrobial activity at all dilutions (p< 0.05), presenting a bactericidal effect in the same concentration of the extract (1.5625). It was concluded that all the groups observed had antimicrobial activity against S. mutans. There was no difference between the propolis extract and the common dentifrice. Conclusion: BRP in pure form and processed in a toothpaste shows some antimicrobial activity against S. mutans but less than a commercial toothpaste containing herbal extracts and sodium bicarbonate.