Estrogen deprivation in postmenopausal women causes disruption of bone homeostasis, resulting in bone loss and osteoporosis. Conventional therapies can exert adverse effects. The sclerotum of Poria cocos has been used in traditional medicine and as a nutritional supplement and to treat various diseases. However, the effects of P. cocos on the bone remain largely undetermined. In this study, we examined the effects of P. cocos hydroethanolic extract (PC) on osteoclast differentiation and estrogen-deprivation-induced bone loss in an ovariectomized mouse model of postmenopausal osteoporosis. PC-mediated inhibition of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation and resorption activity suppressed RANKL-induced expression of nuclear factor of activated T cells cytoplasmic 1 (NFATc1), which is a crucial transcription factor for osteoclast differentiation. In ovariectomized mice, PC markedly alleviated trabecular bone loss and reduced the accumulation of lipid droplets in the bone marrow. We additionally identified ten triterpenoid constituents of PC using UPLC-MS/MS analysis. Our results indicate that PC negatively regulated osteoclast differentiation and function, and can potentially be used to manage postmenopausal osteoporosis.
Keywords: Poria cocos; menopause; osteoclast; osteoporosis; ovariectomy.