ABSTRACT
OBJECTIVES: The present study aimed at investigating the potential of using 18β-glycyrrhetinic acid against the cariogenic characteristics of Streptococcus mutans UA159. METHODS: The effects of 18β-glycyrrhetinic acid on biofilm formation and acid production were evaluated; the latter are indicators of cariogenicity of S. mutans. Biofilm architecture was also analyzed by scanning electron microscopy (SEM), and changes in gene expression related to biofilm formation were studied by quantitative RT-PCR. RESULTS: Treatment with 18β-glycyrrhetinic acid at a concentration of 20 µg/ml inhibited biofilm formation by 95% in the absence of sucrose and 60% in its presence, reduced acid production by 88.8%, and significantly suppressed the gene expression of comDE, gbpB, gtfC and vicR, which are thought to be involved in the virulence of S. mutans. CONCLUSIONS: These results suggest that 18β-glycyrrhetinic acid could be used as a complementary or alternative agent for preventing dental caries by interfering with the virulence properties of S. mutans without affecting the viability of the bacterial population.