Effect of seaweed extracts on Streptococcus sobrinus adsorption to saliva-coated hydroxyapatite.

The inhibitory effect of the extracts of seaweeds on the adsorption of Streptococcus sobrinus B13 to the tooth surface was investigated in vitro. Using saliva-coated hydroxyapatite beads (S-HA) as experimental salivary pellicle, extracts from Gloiopeltis furcata and Gigartina teedii (Rhodopheceae) strongly inhibited the adsorption of S. sobrinus B13 to S-HA. The G. furcata extract, which strongly inhibited the adsorption of S. sobrinus B13 to S-HA, was a high molecular weight sulfated polysaccharide. The result of I.R. analysis indicated that the active component in this extract of G. furcata was funoran.