Effects of 7-epiclusianone on Streptococcus mutans and caries development in rats

The aim of this study was to evaluate the effects of 7-epiclusianone (7-epi) on specific virulence attributes of Streptococcus mutans in vitro and on development of dental caries in vivo. 7-Epi was obtained and purified from fruits of Rheedia brasiliensis. We investigated its influence on surface-adsorbed glucosyltransferase (Gtf) B activity, acid production, and viability of S. MUTANS in biofilms, as well as on caries development using a rodent model. 7-Epi (100 µg/mL) significantly reduced the activity of surface-adsorbed GtfB (up to 48.0 ± 1.8 of inhibition at 100 µg/mL) and glycolytic pH-drop by S. mutans in biofilms (125 and 250 µg/mL) (vs. vehicle control, p < 0.05). In contrast, the test compound did not significantly affect the bacterial viability when compared to vehicle control (15 % ethanol, p > 0.05). Wistar rats treated topically with 7-epi (twice daily, 60-s exposure) showed significantly smaller number of and less severe smooth- and sulcal-surface carious lesions (p < 0.05), without reducing the S. mutans viable population from the animals' dental biofilms. In conclusion, the natural compound 7-epiclusianone may be a potentially novel pharmacological agent to prevent and control dental caries disease.