RAW cells were treated with indicated concentration of DA in the presence of 10 ng/mL RANKL for 4 days. (A) TRAP staining and quantification of OC. TRAP positive, multinucleated OC in red were counted. n=4. Scale bar is 200μm. (B) Relative expression of osteoclastic genes (c-Fos, Nfatc1, Trap, Ctsk) on day 4 after DA+RANKL treatment were determined by RT-qPCR; normalized to B2m. n=3. *P < 0.05, **P < 0.01, ***P < 0.001 vs. Ctrl group. Data shown as mean ± SEM.