Backhousia citriodora (lemon myrtle) extract has been found to inhibit glucansucrase activity, which plays an important role in biofilm formation by Streptococcus mutans. In addition to glucansucrase, various virulence factors in S. mutans are involved in the initiation of caries. Lactate produced by S. mutans demineralizes the tooth enamel. This study investigated whether lemon myrtle extract can inhibit S. mutans lactate production. Lemon myrtle extract reduced the glycolytic pH drop in S. mutans culture and inhibited lactate production by at least 46%. Ellagic acid, quercetin, hesperetin, and myricetin, major polyphenols in lemon myrtle, reduced the glycolytic pH drop and lactate production, but not lactate dehydrogenase activity. Furthermore, these polyphenols reduced the viable S. mutans cell count. Thus, lemon myrtle extracts may inhibit S. mutans-mediated acidification of the oral cavity, thereby preventing dental caries and tooth decay.

中文翻译：

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柠檬香桃木提取物抑制变形链球菌产生乳酸。


Backhousia citriodora（柠檬桃金娘）提取物被发现可以抑制葡聚糖蔗糖酶活性，而葡聚糖蔗糖酶在变形链球菌生物膜形成中发挥着重要作用。除了葡聚糖蔗糖酶之外，变形链球菌中的多种毒力因子也参与龋齿的引发。变形链球菌产生的乳酸使牙釉质脱矿质。本研究调查了柠檬香桃木提取物是否可以抑制变形链球菌乳酸的产生。柠檬香桃木提取物降低了变形链球菌培养物中糖酵解 pH 值的下降，并抑制乳酸产生至少 46%。柠檬香桃木中的主要多酚鞣花酸、槲皮素、橙皮素和杨梅素可降低糖酵解 pH 值下降和乳酸生成，但不会降低乳酸脱氢酶活性。此外，这些多酚还减少了变形链球菌的活细胞数量。因此，柠檬香桃木提取物可以抑制变形链球菌介导的口腔酸化，从而预防龋齿和蛀牙。