Detection of anti-caries substances in oolong tea extract

研究了乌龙茶提取物(OTE)在体外对变形链球菌致龋性的抑制作用。在抑制变形链球菌生长的同时，GTE降低了变形链球菌的产酸率，而层析分离的乌龙茶多酚(OTF6)的作用较弱。另一方面，这两种乌龙茶产品都降低了几乎所有被检测的口腔链球菌的细胞表面疏水性，并诱导变形链球菌、口腔葡萄球菌、血链球菌和戈登葡萄球菌的细胞聚集。在这些反应中，OTF6表现出比OTE更明显的活性结果表明，乌龙茶多酚可能通过降低变形链球菌的疏水性而抑制细菌在牙面的定植，而OTE则可能通过降低产酸率来抑制致龋性。

The inhibitory effects of oolong tea extract (0TE) on the caries-inducing properties of mutans streptococci were examined in vitro.GTE reduced the rate of acid production by mutans streptococci accompanied with the retardation of growth rate of mutans streptococci, while the action by chromatographically isolated oolong tea polyphenol (OTF6) was weak.On the other hand, both oolong tea products decreased cell surface hydrophobicity of almost all the oral streptococci examined in the present study, and also induced cellular aggregation of S.mutans, S.oralis, S.sanguis or S.gordonii.In these reactions, OTF6 showed a more pronounced activity than OTE.Furthermore, the oolong tea products inhibited the adherence of mutans streptococci to saliva-coated hydroxyapatite.These results indicate that oolong tea polyphenols may inhibit bacterial colonization on tooth surfaces by reducing the hydrophobicity of mutans streptococci, and OTE may inhibit caries-inducing activity by reducing the rate of acid production.