Abstract: The purpose of the present study was to investigate the estrogic effect of total flavonoids of Epimedii Folium (EF) on the osteogenesis of human bone marrow mesenchymal stem cells (hBMSCs).The first generation of hBMSCs were cultured,subcultured and purified,and the fourth generation of hBMSCs were used to detect the cell surface markers CD90 and CD45 by flow cytometry.In the drug experiment,The effect of different concentrations of EF on the proliferation of hBMSCs was detected with the method of CCK-8.Three groups were set:Blank,EF and EF+ICI182780.Alizarin red staining was used to observe the formation of calcium nodules and RT-PCR was used to detect the expression of OPN and ALP gene.The results indicated that the CD90 expression on the surface purified hBMSCs cells was positive while the CD45 expression was negative.Low concentration of EF (2.5 and  5 μg/mL) promoted the proliferation of hBMSCs,while high concentration of EF (10,20,40 μg/mL) inhibited the proliferation of hBMSCs.The cells cultured with EF present an osteoblastic appearance under the microscope.Alizarin red staining showed that EF could promote the formation of calcium nodules,while estrogen receptor (ER) inhibitor ICI182780 could antagonize this effect of EF.EF could up-regulate the expression of osteoblast-associated gene OPN,ALP (P<0.05) and ICI182780 could inhibit the effect of EF(P<0.05).In conclusion,EF can promote the osteogenic differentiation of hBMSC by activating ER.

Key words: total flavonoids of Epimedii Folium, hBMSCs, osteogenic differentiation, estrogen