Potent anticariogenic activity of Aceriphyllum rossii and its components, aceriphyllic acid A and 3-oxoolean-12-en-27-oic acid.

Aceriphyllum rossii Engler (Saxifragaceae) have been used as a nutritious food in Korea. We found that the methanol extract of A. rossii root and its components, aceriphyllic acid A and 3-oxoolean-12-en-27-oic acid, potently inhibited the growth of the key cariogenic bacteria, Streptococcus mutans, with MIC of 2 to 4 microg/mL. They also showed antibacterial activity against other cariogenic bacteria such as S. oralis, S. sobrinus, and S. salivarius with the similar potency. In the time-kill study, aceriphyllic acid A reduced the viable counts of S. mutans by 90% in 1 min at 8 microg/mL, indicating that aceriphyllic acid A had the fast bacteriostatic activity. Severe damages of the cell surface of S. mutans by aceriphyllic acid A were observed by transmission electron microscopy, suggesting with its fast antibacterial activity that its mechanism of action might be membrane disruption. These results suggest that the methanol extract of A. rossii root and its components, aceriphyllic acid A and 3-oxoolean-12-en-27-oic acid, could have the great potential as natural agents for preventing dental caries.