Effects of Hansu-Daebowon (HDW) on RANKL-induced Osteoclast Differentiation and Bone Loss in Mammal Model

Objective This study investigated the effects of Hansu-Daebowon (HDW) on bone resorption in vitro and bone loss in vivo. Methods Osteoclast differentiation was measured by counting TRAP (+) MNC formed from RAW 264.7 in the presence of RANKL. Bone pit formation was determined in an artificial bone slice loaded with RANKL-stimulated osteoclasts. To elucidate the mechanisms of the inhibitory effects of HDW on bone resorption and osteoclast differentiation, osteoclastogenic genes (i.e. TRAP, MMP-9, NFATc1, c-Fos, and Cathepsin K) were measured using real time PCR. Furthermore, bone loss was observed using micro-CT in an LPS-treated mammal model. Results HDW inhibited the bone pit formation in vitro and inhibited bone loss in vivo. Moreover, HDW decreased the number of TRAP (+) MNCs in the presence of RANKL, and HDW inhibited the expressions of cathepsin K, MMP-9, TRAP, NFATc1, and c-Fos in the osteoclasts. Conclusion HDW exerts inhibitory effects on bone loss and bone resorption resulting from the inhibitions of osteoclast differentiation and osteoclastogenic gene expression. Keywords: Hansu-Daebowon (HDW), osteoclast differentiation, TRAP, cathepsin K, NFATc1, bone loss, bone resorption