Anti-cariogenic Effect of Compound Isolated from Aralia continentalis

Objective: Dental caries is the most common chronic disease in the dental field. Because of increasing sugar consumption and extension of average human life, this disease is widely found all over the world as the most typical cause for a person to lose a tooth. Therefore, the development of more effective, substantial and safe preventive agents against dental caries is strongly required. Streptococcus mutans (S. mutans), known as the causative bacteria plays the most decisive role in forming plaque and it has been noticed as major causative bacteria of dental caries. In the present study, we investigated the antibacterial activity of Aralia continentalis (A. continentalis) and the antibacterial component, continentalic acid from A. continentalis has been isolated and identified by MS, ¹ H-NMR, and , ¹³ C-NMR. Method: Methanol extract showed concentration-dependent inhibitory activity against the growth and acid production of S. mutans. The MeOH extract was suspended in H₂O and sequentially partitioned with n-hexane, CHCl₃, EtOAc, and n-BuOH. The CHCl₃ fraction showed remarkable antibacterial activity against S. mutans. The antibacterial activity compound against S. mutans by MIC was isolated successively through the screening system and various chromatography methods. Results: From this active chloroform subfraction, isolation and identification finally gave (-)-pimara-8(14),15-diene-19-oic acid (continentalic acid) {1,[a]D ²⁵ : -120.1 ^o (c 0.8, CHCl₃)} by spectroscopic methods (MS, ¹H-NMR and , ¹³C-NMR) as an active principle. The compound, continentalic acid, showed significant growth, acid production, adhesion and water-insoluble glucan synthesis inhibitory effect against S. mutans. Conclusion: These results indicate that the continentalic acid from A. continentalis could be useful for controlling dental caries. Funding: This paper was supported by a grant No. R08-2004-000-10287-0 from Korean Science and Engineering Foundation.