Gossypol Promotes Bone Formation in Ovariectomy-Induced Osteoporosis through Regulating Cell Apoptosis

Osteoporosis is among the most common forms of age-related diseases, especially for females, which has been a grave public health problem. Drug therapies have shown promising outcomes to promote bone formation and bone density. This study identified a novel potential drug, gossypol, for the treatment of osteoporosis. Treatments of ovariectomy-induced osteoporosis mice with gossypol significantly increased serum osteocalcin and osteoprotegerin (OPG) levels; meanwhile they decreased serum RANKL levels. Microcomputed tomography (microCT) analysis showed that treatment of gossypol improved bone density and strength and decreased bone postyield displacement for both medullar and cortical bones. In vitro experiments also showed that gossypol increased cell viability in a time- and dose-dependent manner. Furthermore, incubation of the osteoblast MC3T3-E1 cells with gossypol inhibited cell apoptosis through intrinsic apoptotic pathway as evidenced by the Annexin V/PI assay, TUNEL assay, biochemical analysis, and western blot assays. Moreover, the classical Wnt/β-catenin signaling pathway was found to be regulated by gossypol treatments. Inhibition of Wnt/β-catenin signaling reversed the prevention effects of gossypol in osteoporosis. Our findings provided novel clues for the treatment of osteoporosis in clinic.