Anticariogenic activity of licorice and glycyrrhizine I: Inhibition of in vitro plaque formation by Streptococcus mutans.

The effect of licorice and its active sweet component glycyrrhizin was tested on the growth and adherence to glass of the cariogenic Streptococcus mutans. Neither licorice nor glycyrrhizin promoted growth or induced plaque formation. In the presence of sucrose, glycyrrhizin did not affect bacterial growth, but the adherence (plaque formation) was markedly inhibited. At 0.5-1% glycyrrhizin, inhibition was almost complete. These results support our previous suggestions that glycyrrhizin might serve as an efficient vehicle for topical oral medications.