Icariin suppresses bone resorption activity of rabbit osteoclasts in vitro

The effect of icariin on the bone resorption activity of rabbit osteoclasts is assessed in vitro. Osteoclasts were isolated from Japanese white rabbits and cultured on plates with a sterilized bone slice in each well. After treatment with icariin at various concentrations, the bone resorption activity of osteoclasts was evaluated by examining pit areas, superoxide anion (·O2-) generation, size and number of actin rings and intracellular calcium concentration [Ca2+]i. As revealed by these data, icariin elicited continuous decline of [Ca2+]i, making actin ring constricted and ·O2- generation decreased. These events resulted in smaller and fewer pits which indicate suppressed bone resorption activity of rabbit osteoclasts by icariin.