Abstract
Icariin (ICA), isolated from Herba Epimedii, is a natural flavonoid glycoside that possesses antioxidant properties and inhibits osteoclastogenesis. However, the mechanism underlying osteoclastogenesis inhibition by ICA remains unclear. Here, we investigated the effects of ICA on receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced osteoclastogenesis in RAW264.7 cells. ICA inhibited the expression of osteoclastogenesis-related genes in RAW264.7 cells induced by RANKL. ICA could inhibit osteoclastogenesis without inhibiting the viability of RAW264.7 cells. In addition, ICA inhibited reactive oxygen species production in RANKL-induced RAW264.7 cells. ICA reduced the expression of nuclear factor in activated T cells, cytoplasmic 1, and tartrate-resistant acid phosphatase, which are osteoclast-related molecules. Moreover, ICA decreased the expression of nicotinamide adenine dinucleotide phosphate oxidase (NOX), specifically NOX1 and NOX4, in RANKL-induced RAW264.7 cells. Our findings suggest that ICA can be used as a potential therapeutic agent for osteolytic diseases such as osteoporosis.