BA inhibition of differentiation, migration and bone resorption in osteoclasts, which was reversed by IL-1β treatment. BMMs were differentiated into osteoclasts via incubation with M-CSF and RANKL for 3 days, and the osteoclasts were incubated with BA in the absence or presence of IL-1β. (A) The cells were incubated with 10 μmol/L BA in the presence of IL-1β at the indicated concentrations for 2 days and subjected to TRAP staining. Scale bar, 200 μm. TRAP-positive MNCs were counted. (B) The cells were treated with 10 μmol/L BA for 2 days, and the amount of IL-1β in the culture media was determined by ELISA. (C) The cells were further incubated with 10 μmol/L BA in the absence or presence of IL-1β (20 ng/mL) for 15 h after gentle scratching and the cells migrating to the scratched area were counted. Scale bar, 200 μm. (D–F) The cells were cultured for 12 days on dentin discs (D) or 2 days (E and F) in the absence or presence of 10 μmol/L BA and IL-1β (20 ng/mL). The resorption pits were visualized by staining with hematoxylin (D). Cell lysates were subjected to immunoblotting analysis (E). The individual gene transcription was quantified by real-time PCR and presented as fold induction (F). Scale bar, 200 μm *P < 0.05, **P < 0.01 and ***P < 0.001 control vs. IL-1β in the absence and presence of BA (A), or between the indicated groups (A–D and E). ns, not significant.