OOLONG TEA POLYPHENOLS INHIBIT EXPERIMENTAL DENTAL-CARIES IN SPF RATSINFECTED WITH MUTANS STREPTOCOCCI

An extract of oolong tea (semifermented tea leaves of Camellia sinensi s) and its chromatographically isolated polyphenolic compound was exam ined for in vitro inhibitory effects on glucosyltransferases (GTases) of mutans streptococci and on caries development in Sprague-Dawley rat s infected with mutans streptococci. The samples showed no detectable effect on the growth of mutans streptococci. However, insoluble glucan synthesis from sucrose by the GTases of Streptococcus mutans MT8148R and Streptococcus sobrinus 6715 was markedly inhibited, as was sucrose -dependent cell adherence of these mutans streptococci. The administra tion of the oolong tea extract and the isolated polyphenol compound in to diet 2000 and drinking water resulted in significant reductions in caries development and plaque accumulation in the rats infected with m utans streptococci. The active components in the oolong tea extract we re presumptively identified as polymeric polyphenols which were specif ic for oolong tea leaves. These results indicate that the oolong tea p olyphenolic compounds could be useful for controlling dental caries.