OBJECTIVE: To investigate the effect of icariin on proliferation of bone marrow mesenchymal stem cells(BMSCs) in Sprague-Dawley(SD) rats.METHODS: BMSCs were obtained from SD rat bone marrow with differential time adherent method. Its characteristic was identified through differentiation cell surface antigens and the multi-lineage(osteo/adipo/chondo) differentiation potential. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) method and 5-Bromo-2-Deoxyuridine(Brd U) incorporation were applied to detect the effect of icariin on BMSCs proliferation.Flow cytometry was used to detect proliferation in-dex of BMSCs. The m RNA level and the distribution of β-catenin were evaluated by Real-time Polymerase Chain Reaction(PCR) and Immunofluorescent staining respectively. Western blot was used to detect protein expression levels of β-catenin, glycogen synthase kinase-3 beta(GSK-3β), phospho-glycogen synthase kinase-3 beta(p GSK-3β)and cyclin D1.RESULTS: Icariin promoted BMSCs proliferation at the concentration of 0.05-2.0 mg/L. The percentage of Brd U positive cells of BMSCs was increased from40.98% to 70.42%, and the proliferation index value was increased from 8.9% to 17.5% with the treatment of 0.05 mg/L icariin, which significance values were both less than 0.05. Compared with the control group, total and nuclear β-catenin proteins, as well as β-catenin m RNA expression, were all increased with icariin treatment. Meanwhile, the phosphorylation level of GSK-3β and cyclin D1 protein expressions were also increased in BMSCs with icariin treatment.CONCLUSION: The findings of the present study demonstrated that low dosage of icariin could promote BMSCs proliferation. The activation of Wnt/β-catenin pathways was involved in this process.