Effects of Magnolol and Honokiol on the activities of streptococcal glucosyltransferases both in solution and adsorbed on an experimental pellicle

AIMS: To investigate the inhibitory effects of Magnolol and Honokiol on the activity of streptococcal glucosyltransferases (Gtfs). METHODS AND RESULTS: The effect of Magnolol and Honokiol that inhibits the activities of streptococcal GtfB, GtfC, GtfD and GtfS was explored with standard assays. The results showed that both samples can efficiently inhibit the activity of all Gtfs in solution (66.4-96.3%) and adsorbed on the surface of saliva-coated hydroxyapatite (sHA) beads (65.5-92.7%) at concentrations between 1.25 and 5.0 mg ml(-1). Furthermore, Magnolol had a stronger inhibition of four kinds of Gtfs than Honokiol both in solution and adsorbed on the surface of sHA beads at concentrations between 0.04 and 0.63 mg ml(-1) (P < 0.05). CONCLUSIONS: Magnolol had significant effects on the activities of streptococcal Gtfs. SIGNIFICANCE AND IMPACT OF THE STUDY: Magnolol as a natural herb can be developed into a new oral hygiene product to prevent plaque formation.