Detection of anti-caries substances in oolong tea extract

本文研究了乌龙茶提取物（OTE）对变形链球菌致龋的抑制作用。GTE能降低变形链球菌的产酸速率，并使变形链球菌的生长速度减慢，而层析分离的乌龙茶多酚（OTF 6）的作用较弱。这两种乌龙茶产品降低了本研究中检测的几乎所有口腔链球菌的细胞表面疏水性，并且还诱导了变形链球菌、口腔链球菌、血链球菌或戈登链球菌的细胞聚集。在这些反应中，OTF 6的活性比OTE更强。此外，乌龙茶产品抑制变形链球菌在唾液包被的羟基磷灰石上的粘附。这些结果表明，乌龙茶茶多酚可能通过降低变形链球菌的疏水性来抑制细菌在牙齿表面的定植，OTE可通过降低产酸速率来抑制龋齿诱导活性。

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.