The inhibitory effect of plant extracts on the collagenolytic activity and cytotoxicity of human gingival fibroblasts by Porphyromonas gingivalis crude enzyme.

It is well known that plant extracts inhibit some enzymatic activities. The present study examined the inhibitory effects of natural plant extracts against the collagenolytic activity of Porphyromonas gingivalis. The enzyme was isolated from a culture supernatant of P. gingivalis 381. The aqueous and 50% ethanolic extracts of Ginkgo biloba, Mosla chinensis, Salvia officinalis, Cinnamomum cassia, and a catechin extract of Camellia sinensis exhibited strong inhibitory effects on collagenolytic activity. The activities of these plant extracts were higher than that of tetracycline-HCl. They also inhibited the cytotoxicity of P. gingivalis crude enzyme against human gingival fibroblasts. C. sinensis catechin was the most effective agent in neutralizing the cytotoxicity of P. gingivalis. The aqueous and 50% ethanolic extracts of C. cassia had relatively strong anti-cytotoxic activity. Although the other samples strongly inhibited the collagenolytic activity of P. gingivalis, they were not effectively anti-cytotoxic. The present findings suggest that C. sinensis and C. cassia extracts are effective in reducing the pathogenicity of periodontopathic bacteria.