Inhibition of Streptococcus mutans biofilm accumulation and development of dental caries in vivo by 7-epiclusianone and fluoride.

7-Epiclusianone (7-epi), a novel naturally occurring compound isolated from Rheedia brasiliensis, effectively inhibits the synthesis of exopolymers and biofilm formation by Streptococcus mutans. In the present study, the ability of 7-epi, alone or in combination with fluoride (F), to disrupt biofilm development and pathogenicity of S. mutans in vivo was examined using a rodent model of dental caries. Treatment (twice-daily, 60s exposure) with 7-epi, alone or in combination with 125 ppm F, resulted in biofilms with less biomass and fewer insoluble glucans than did those treated with vehicle-control, and they also displayed significant cariostatic effects in vivo (p < 0.05). The combination 7-epi + 125 ppm F was as effective as 250 ppm F (positive-control) in reducing the development of both smooth- and sulcal-caries. No histopathological alterations were observed in the animals after the experimental period. The data show that 7-epiclusianone is a novel and effective antibiofilm/anticaries agent, which may enhance the cariostatic properties of fluoride.

In vitro and in vivo effects of isolated fractions of Brazilian propolis on caries development.

Recently, two chemically different types of Brazilian propolis (type-3 and -12) were shown to have cariostatic properties. This study aimed to evaluate the influence of their isolated fractions on mutans streptococci viability, glucosyltransferases (GTFs) activity and caries development in rats. The ethanolic extracts of propolis (EEPs) were serially fractionated into hexane (H-fr), chloroform, ethyl acetate, and ethanol. The ability of the four fractions and EEP to inhibit Streptococcus mutans and Streptococcus sobrinus growth and adherence to a glass surface was examined. The effect on GTFs B and C activity was also determined. For the caries study, 60 Wistar rats infected with Streptococcus sobrinus were treated topically twice daily as follows: (1) EEP type-3, (2) H-fr type-3, (3) EEP type-12, (4) H-fr type-12, and (5) control. In general, the H-fr from both types of propolis showed the highest antibacterial activity and GTFs inhibition. Furthermore, the EEP and H-fr type-3 and -12 were equally effective in reducing dental caries in rats. The data suggest that the putative cariostatic compounds of propolis type-3 and -12 are mostly non-polar; and H-fr should be the fraction of choice for identifying further potentially novel anti-caries agents.