Isolation of activity compounds against oral pathogens from

Objectives: To investigate the preventive agents for oral disease with natural product. Methods: Antibacterial active compound was successfully isolated from methanol extract of A. japonica by repeated column and prep-HPLC on the basis of bioassay guided fractionation and their structures were elucidated as inokosterone and hydroxyecdysone by 1D-NMR, 2D-NMR and ESI/LC/MS. We investigated the antibacterial activity against S. mutans, A. actinomycetemcomitans and P. gingivalis by MIC/MBC. Results: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in isolated compounds from natural products were 2.0-16.0 and 4-32 µg/mL respectively. Particularly, MIC/MBC of inokosterone against S. mutans causing dental caries was determined to be 2.0/4.0 µg/mL. The bactericidal test showed that inokosterone completely inactivated S. mutans at the concentration 8 µg/mL in 1 min. Anacardic acid also significantly inhibited the growth of other oral bacteria such as Streptococcus sobrinus, Streptococcus sanguis and Porpyromonas gingivalis causing periodontitis. Conclusion: The specific activity and fast-effectiveness of A. japonica against oral bacteria strongly suggests that it could be employed as a natural antibacterial agent in functional foods or oral care products.