Inhibition of Nifedipine-induced Proliferation of Cultured Human Gingival Fibroblasts by Saireito, a Chinese Herbal Medicine

We examined whether Saireito, a Chinese herbal medicine, inhibits nifedipine-induced gingival fibroblast proliferation. Nifedipine (10 μM) significantly enhanced proliferation from the ninth day of the culture period. When added together with nifedipine, Saireito dose (0.05–0.2%) -dependently inhibited nifedipine-induced proliferation. Saireito at the highest concentration (0.2%), inhibited normal proliferation on the ninth and fourteenth days. Sole application of nifedipine (10 μM) augmented bFGF release. Saireito concentration (0.05–0.2%) -dependently reduced the level of bFGF in the nifedipine-containing culture medium. In the case of Saireito at concentrations of 0.1% and above, there was a significant difference between the control (nifedipine alone) and test (nifedipine + Saireito) groups. Saireito had no effect on normal bFGF release. Nifedipine (10 μM) increased the production of collagen compared with that of the control (normal medium), and Saireito at 0.1% and above significantly reduced nifedipine-induced production of type I collagen. Saireito did not inhibit the normal production of type I collagen. Our findings indicate that Saireito indeed inhibits nifedipine-induced proliferation by depressing the release of bFGF, and reduces nifedipine-induced collagen synthesis in the gingival fibroblasts. Administration of Saireito may thus be clinically effective for the treatment of drug-induced gingival overgrowth.