Rg1’s Effect upon Oxidative Stress and Anti-Oxidant Activity of BMSCs in Aged Rats. The BMSCs were collected on day 5 of passage 3. (A) Reactive oxygen species (ROS) levels, (B) superoxide dismutase (SOD) activity, and (C) malondialdehyde (MDA) content. a: comparison with the control group (p < 0.05); b: comparison with the D-gal-administration group (p < 0.05). Each error bar represents the standard deviation (SD).