In Brief:
Oleanolic acid exerts an osteoprotective effect in OVX-induced osteoporotic rats via increasing osteoblast number, elevating osteocalcin and runt-related protein 2 protein levels in vivo, facilitating the osteoblastic differentiation of bMSCs in vitro. The Notch-related genes Numb/Numbl, Jag1, Aph1a, and Lfng might be involved in the osteogenetic effect of oleanolic acid.