IPRIFLAVONE DIRECTLY INHIBITS OSTEOCLASTIC ACTIVITY

Ipriflavone, an isoflavone derivative, is a new drug used in an attemp t to decrease bone loss in osteoporosis. Experimental studies have sho wn that this compound acts by inhibiting osteoclastic bone resorption both in vivo and in vitro, but the mechanism of its inhibitory action on resorbing cells remains unclear. Using bone resorption assays, vide o image analysis together with measurements of intracellular free calc ium in isolated osteoclasts, we show here that IP directly inhibits os teoclastic activity by the modulation of intracellular free calcium. ( C) 1994 Academic Press, Inc.