Extracts of Polygonum multiflorum Inhibit RANKL-mediated Osteoclast Differentiation

Osteoporosis is a disease caused by decreased bone density. The number of patients with osteoporosis is increasing, and the cost of medical treatment is rising because of the increase in fracture patients. Treatment of osteoporosis is important to prevention of bone loss. One treatment for osteoporosis is inhibition of osteoclast formation. Osteoclasts, which are multinucleated cells that absorb bone, are greatly increased and over-activated in bone disorders, including oste-oporosis and rheumatoid arthritis. In this study, we investigated whether extracts of P. multiflorum (PME) influence RANKL-induced osteoclast differentiation. The PME significantly inhibited RANKL-induced osteoclast differentiation by inhibiting transcriptional and translational expression of NFATc1, an essential element of RANKL-mediated osteoclast for-mation. Furthermore, it inhibited the mRNA expression of TRAP, DC-STAMP, and cathepsin K, which are all related to osteoclast differentiation and function. Thus, our results suggest that PME has the potential for use as a functional food and therapeutic substance for the treatment of osteoporosis.