Dextran glucosidase: a potential target of iminosugars in caries prevention.

It is well known that iminosugars are inhibitors of glycosyltransferases (GTFs) and glucosidases. Because of iminosugars' inhibitory effect on GTFs, scientists have made great effort to verify their roles in the prevention of caries. The inhibition of GTFs can reduce the synthesis of extracellular polysaccharides, especially the synthesis of water-insoluble α-1,3-linked glucan. Extracellular polysaccharides have a critical influence on the biofilm formation and virulence of the bacteria. However, another mechanism in which iminosugars can affect the biofilm is ignored. Extracellular polysaccharides are synthesized by bacteria via GTFs and modified by dextran glucosidase. Thus the authors propose that iminosugars be applied to caries prevention, which may involves in inhibiting the role of dextran glucosidase. The iminosugar can reduce glycosidases' hydrolysis of water-soluble α-1,6-linked glucan and raise the ration of α-1,6-linked glucan to α-1,3-linked glucan. As a result, it can change the components, structure and aqueous solubility of the biofilm extracellular polysaccharides, and finally reduce its cariogenicity. This will potentially decrease the incidence of dental caries, and improve the oral health.