The growth inhibition of Streptococcus mutans by 5'-nucleotidase inhibitors from Areca catechu L.

New 5'-nucleotidase inhibitors named NF-86I, NF-86II were recently isolated from the seeds of Areca catechu L. NF-86I and NF86II showed inhibitory effects on the growth of Streptococcus mutans MT8148(c) and Streptococcus mutans MT6715(g), respectively. In addition, these inhibitors could inhibit insoluble glucan formation from sucrose. NF-86I and NF-86II were found to be polyphenolic substances. Some polyphenols such as tannic acid bind non-specifically to proteins (tannic activity). The 5'-nucleotidase inhibitors that we isolated did not show any such activity. However, the growth inhibitory activity and the inhibitory effect on water-insoluble glucan production were equal to tannic acid. It is therefore considered that these inhibitors bind specifically to the bacterial cell surface. Our findings suggest that the 5'-nucleotidase inhibitors NF-86I and NF-86II may be useful anti-plaque preventing agents.