Natural 2-phenyl chroman flavonoids against Streptococcus mutans: prospects of herbal remedies for dental caries

Dental caries is a multi-factorial oral infectious disease worldwide. Among the 600 different types of bacteria inhabiting the oral cavity, Streptococcus mutans is considered the most prolific colonizer contributing to dental caries. Although fluorides and broad-spectrum antimicrobials such as chlorhexidine remain the primary approaches for caries treatment, natural flavonoids can serve as helpful alternatives. Although flavonoids are effective against different biofilm-forming pathogens, in the present review, attempts have been made to emphasize the antibiofilm properties of only such flavonoids that are effective against S. mutans mediated biofilm formation, along with their possible mode of action and their future prospective as anticaries agent. Different flavonoids decrease bacterial virulence in the oral cavity by different mechanisms: decreasing biofilm adhesivity and formation, inhibiting sortase A (SrtA), inhibiting glucosyltransferase, etc. Fluorides and chlorohexidine, which show anticaries effects altogether by a different mechanism, can effectively combine with flavonoids in combating dental caries. Although most natural products are devoid of acute toxicity, the toxicity profile following brief exposure of topically applied flavonoids in the oral cavity must be assessed before clinical studies. Furthermore, innovative drug delivery systems could greatly enhance the applicability and utility of these flavonoids. This virulence-selective study will lay the foundation for preclinical and clinical studies to further investigate the potential of these flavonoids as possible anticariogenic drugs.