Abstract: Objective To study the pharmacologic mechanism of Salvia miltiorrhiza Bunge(SMB) in the treatment of systemic scleroderma(SSc). Methods We used the cultured SSc skin fibroblasts as an experimental model and detected the effects of SMB both on the cell proliferation by MTT assay and on the collagen production in the culture medium by photometric determination.Results The results showed that the SMB water soluble extracts,such as SMB injection (10 mg/ml、7.5 mg/ml、 5 mg/ml、2.5 mg/ml) and its effective monomer Danshensu (60 μg/ml、45 μg/ml、30 μg/ml、15 μg/ml) and protocate chualdehyde (40μg/ml、 2 0μg/ml、 10μg/ml、 5μg/ml),as well as SMB total liposoluble extract (1mg/ml、0.5 mg/ml、0.25 mg/ml) and its effective monomer tanshinone A(4μg/ml、2 μg/ml),could not only significantly inhibit the proliferation of the cultured SSc skin fibroblasts,but also significantly reduce the soluble collagen production in the culture medium(P<0.05～0. 0 1).The inhibiting effect was increased along with the increasing the concentration of the drugs or the prolonging the time of action. The cell cycle determination by flow cytometer(FCM) analysis showed that the cell proportion in G0/G1 phases after treated by Danshensu and in G2+ M phases by protocate chualdehyde and tanshinone A increased significantly than the controls(P<0.01).Conclusion The above results demonstrated that SMB could significantly inhibit the proliferation and the collagen synthesis in cultured SSc skin fibroblasts and this maybe one of its pharmacologic mechanismin the treatment of SSc.

Key words: Scleroderma, systemic, Fibroblast, Salvia miltiorrhiza