The rBMSCs in the logarithmic growth phase were seeded in 12-well plates and cultured in the DMEM at 37°C with 5% CO2. The cells were allocated to the following groups: (a) blank group (rBMSCs cultured in DMEM without other treatment); (b) L-MOP group (rBMSCs treated with low concentration of MOP [10 μg/ml, HPLC >90%, wkq-08910, Weikeqi-biotech, Chengdu, Sichuan, China] for 48?h); (c) H-MOP group (rBMSCs treated with high concentration of MOP [50?μg/ml] for 48?h);