Therapy for nifedipine-induced gingival overgrowth by saireito in rats

OBJECTIVE A calcium antagonist, nifedipine, causes gingival overgrowth as a side effect. It has been confirmed that the Japanese traditional medicine, Saireito, inhibits the nifedipine-induced proliferation of gingival fibroblasts in vitro. We performed an in vivo experiment to determine whether Saireito has a therapeutic use in the treatment of nifedipine-induced gingival overgrowth. METHODS The rats had significant gingival overgrowth induced by the administration of nifedipine. The space between the submandibular incisors and the width of buccal gingiva of maxillary left first molar were macroscopically measured. The buccal gingiva was microscopically examined. RESULTS Eight weeks after Saireito was administrated together with nifedipine, Saireito decreased both the incisor space and the gingiva width which had been enlarged by nifedipine and furthermore, the area of connective tissue of nifedipine + Saireito group was significantly smaller than that of nifedipine alone. CONCLUSION In conclusion, Saireito may be clinically effective in therapy for calcium antagonist-induced gingival overgrowth.