Effects of dioscin on the expression levels of ER- α and ER-β proteins in MC3T3- E1 cells and MG- 63 cells. MC3T3-E1 cells and MG-63 cells were treated with vehicle, different concentrations of dioscin (0.25 μg/ml, 0.5 μg/ml and 1.0 μg/ml) or lovastatin (0.04 μM) for 72 h. Then the expression levels of ER-α (A, C) and ER-β (A, D) proteins in MC3T3-E1 cells and the proteins expression levels of ER-α (G, H) and ER-β (G, I) in MG-63 cells were examined by Western blot. Pretreatment of MC3T3-E1 cells with ICI 182, 780 (100 nM) for 1 h, cells were treated with dioscin (1.0 μg/ml) for 72 h, and then the expression levels of ER-α (B, E) and ER-β (B, F) proteins were examined by Western blot. Results were obtained from three independent experiments and expressed as mean ± SD. *P < 0.05; **P < 0.01 vs Control.