Anti-biofilm and bactericidal effects of magnolia bark-derived magnolol and honokiol on Streptococcus mutans

作者：Sakaue Yuuki; Domon Hisanori; Oda Masataka; Takenaka Shoji; Kubo Miwa; Fukuyama Yoshiyasu; Okiji Takashi; Terao Yutaka^*

来源：Microbiology and Immunology, 2016, 60(1): 10-16.

DOI：10.1111/1348-0421.12343

• honokiol
• magnolia bark
• magnolol
• Streptococcus mutans

Dental caries affects people of all ages and is a worldwide health concern. Streptococcus mutans is a major cariogenic bacterium because of its ability to form biofilm and induce an acidic environment. In this study, the antibacterial activities of magnolol and honokiol, the main constituents of the bark of magnolia plants, toward planktonic cell and biofilm of S. mutans were examined and compared with those of chlorhexidine. The minimal inhibitory concentrations of magnolol, honokiol and chlorhexidine for S. mutans were 10, 10 and 0.25 mu g/mL, respectively. In addition, each agent showed bactericidal activity against S. mutans planktonic cells and inhibited biofilmformationin a dose-andtime-dependent manner. Magnolol (50 mu g/mL) had greater bactericidal activity against S. mutans biofilm than honokiol (50 mu g/mL) and chlorhexidine (500 mu g/mL) at 5min after exposure, while all showed scant activity against biofilm at 30 s. Furthermore; chlorhexidine (0.5-500 mu g/mL) exhibited high cellular toxicity for the gingival epithelial cell lineCa9-22 at 1 hr, whereas magnolol (50 mu g/mL) and honokiol (50 mu g/mL) did not. Thus; it was found that magnolol has antimicrobial activities against planktonic and biofilm cells of S. mutans. Magnolol may be a candidate for prevention and management of dental caries.

• 出版日期2016-1