Inhibitory effects of β-caryophyllene on Streptococcus mutans biofilm

Objective: The biofilm of Streptococcus mutans is associated with induction of dental caries. Also, they produce glucan as an extracellular polysaccharide through glucosyltransferases and help the formation of cariogenic biofilm. beta-caryophyllene has been used for therapeutic agent in traditional medicine and has antimicrobial activity. The purpose of this study was to investigate the effect of beta-caryophyllene on S. mutans biofilm and the expression of biofilm-related factor. Design: The susceptibility assay of S. mutans for beta-caryophyllene was performed to investigate inhibitory concentration for S. mutans growth. To evaluated the effect of beta-caryophyllene on S. mutans biofilm, beta-caryophyllene was treated on S. mutans in the various concentrations before or after the biofilm formation. Live S. mutans in the biofilm was counted by inoculating on Mitis-salivarius agar plate, and S. mutans biofilm was analyzed by con focal laser scanning microscope after staining bacterial live/dead staining kit. Finally, the expression of glucosyltransferases of S. mutans was investigated by real-time RT-PCR after treating with beta-caryophyllene at the non killing concentration of S. mutans. Results: The growth of S. mutans was inhibited by beta-caryophyllene in above concentration of 0.078%, S. mutans biofilm was inhibited by beta-caryophyllene in above 0.32%. Also, 2.5% of beta-caryophyllene showed anti-biofilm activity for S. mutans biofilm. beta-caryophyllene reduced the expression of gtf genes at a non-killing concentration for S. mutans. On the basis on these results, beta-caryophyllene may have anti-biofilm activity and the inhibitory effect on biofilm related factor. Conclusions: beta-caryophyllene may inhibit cariogenic biofilm and may be a candidate agent for prevention of dental caries.