Rg1’s Effect upon Cell Proliferation of BMSCs in Aged Rats. The BMSCs were collected on day 5 of passage 3. (A, B) There were no differences among the four groups at days one and two by analysis of variance (ANOVA). However, at days three, four, and five, there were significant differences between the four groups by ANOVA. 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).