The aqueous extracts of many of the 14 medicinal herbs demonstrated antimicrobial
activity against the five types of pathogenic oral bacteria. The extracts of Sappan Lignum,
Coptidis Rhizoma, and Psoraleae Semen effectively inhibited the growth of oral bacteria
and showed distinct bactericidal activity. The extracts of Notoginseng Radix, Perillae Herba,
and Psoraleae Semen decreased the synthesis of water-insoluble glucans by the S. mutans
enzyme glucosyltransferase (GTase). The present study is the first to confirm the antimicrobial
activity of the extract of Sappan Lignum against all five species of oral bacteria
strains