In vitro antimicrobial activities of bakuchiol against oral microorganisms

Bakuchiol was isolated from the seeds of Psoralea corylifolia, a tree nativ e to China with various uses in traditional medicine, followed by extractio n with ether and column chromatography combined with silica gel and octylde cyl silane. In this study, the antimicrobial activities of bakuchiol agains t some oral microorganisms were evaluated in vitro. The cell growth of Stre ptococcus mutans was inhibited in a bakuchiol concentration-dependent manne r, and growth of S. mutans was completely prevented by 20 mug of bakuchiol per mi. The bactericidal effect of bakuchiol on S. mutans was dependent on temperature and stable under the following conditions: sucrose, 0 to 10% (w t/vol); pH, 3.0 to 7.0; organic acids (3% [wt/vol] citric and malic acids). Bakuchiol showed bactericidal effects against all bacteria tested, includi ng S. mutans, Streptococcus sanguis, Streptococcus salivarius, Streptococcu s sobrinus, Enterococcus faecalis, Enterococcus faecium, Lactobacillus acid ophilus, Lactobacillus casei, Lactobacillus plantarum, Actinomyces viscosus , and Porphyromonas gingivalis, with MICs ranging from I to 4 mug/ml and th e sterilizing concentration for 15 min ranging from 5 to 20 mug/ml. Further more, bakuchiol was also effective against adherent cells of S. mutans in w ater-insoluble glucan in the presence of sucrose and inhibited the reductio n of pH in the broth. Thus, bakuchiol would be a useful compound for develo pment of antibacterial agents against oral pathogens and has great potentia l for use in food additives and mouthwash for preventing and treating denta l caries.