Effect of Magnolia Officinalis Extract on Cariogenic Activity of Mutans Streptococci

Objective: To extract effective constituent from Magnolia officinalis Rehder et Wilson (Magnoliaceae) and elucidate its effect on cariogenic activity of mutans streptococci. Methods: The ethanol extract of Magnolia officinalis was partitioned between water and ether, and then applied to a silica gel column to afford a brown crystal (MO2). Susceptibilities of the oral pathogens to MO2 were analyzed by the micro-liquid dilution. The effects of MO2 on cell surface hydrophobicity and formation of water-insoluble glucan synthesis were assessed by incubating S. mutans MT703 or S. sobrinus B13 with two-fold serial dilution of MO2 in vitro. Results: The susceptibility testing showed that MO2 demonstrated significantly inhibitory effects on mutans streptococci. MO2 showed effectiveness in reducing both cell surface hydrophobicity and formation of water-insoluble glucan synthesis. The hydrophobicity sharply went down accompanied with the increasing concentration of MO2. At a concentration of 80 μg/ml, MO2 caused a 45.4% inhibition or 43.5% inhibition in glucan synthesis by S. mutans MT703 glucosyltransferase or S. sobrinus B13 glucosyltransferase respectively. Conclusion: These results suggested that MO2 possessed powerful anticariogenic potential against mutans streptococci.