Antibacterial effect of resveratrol extract compared to chlorhexidine mouthwash against primary cariogenic pathogen, Streptococcus mutans.

Background: Modern dental caries prevention methods have focused on using herbal products that ideally inhibit the critical cariogenic bacteria (Streptococcus mutans). The present study compared antibacterial efficacy of the resveratrol herbal extract and 0.12% chlorhexidine (CHX) against Streptococcus mutans (S. mutans).

Material and methods: In this in vitro study the pure powder of resveratrol (Bulksupplement) was dissolved in dimethyl sulfoxide as its solvent to produce a 1000-µg/mL concentration of resveratrol solution, which was later used at different dilutions. The antibacterial effects of resveratrol solution and 0.12% CHX mouthrinse on the standard strain of S. mutans were determined using a minimum inhibitory concentration (MIC) test in a tube, minimum bactericidal concentration (MBC) test in a solid medium, and a well diffusion test to measure the zone of inhibition. The data were analyzed using Kruskal-Wallis, Bonferroni, and Man-Whitney tests (α=0.05).

Results: The MIC and MBC of resveratrol was 250 µg/mL. In addition, this extract exhibited a diameter of 6.67 mm for the inhibition zone at only the 1000-µg/mL concentration. The MIC of CHX was 15.6 µg/mL, and its MBC was 31.25 µg/mL. The highest growth inhibition zone of CHX was 16.67 mm.

Conclusions: Resveratrol extract exhibited a dose-dependent antibacterial (bacteriostatic and bactericidal) activity against S. mutans. Although it was not as effective as CHX, it might be a suitable alternative to prevent dental caries. Key words:Antibacterial agents, Chlorhexidine digluconate, mouthwashe, resveratrol, streptococcus mutans.