Effect of EETC on DPB-induced osteoclastic bone resorption. a For osteoclast formation, mouse BMMs were treated with M-CSF and RANKL and were stained to detect expression of TRAP. Pit formation was also performed in M-CSF and RANKL on calcium phosphate apatite-coated plates, and light microscopy indicated resorptive pitting. To observe the stimulating effect of DPB-LPS on osteoclast formation and pit formation, both assays were performed at a low concentration of RANKL (10 ng/ml). The graph shows the total number of TRAP-positive multinucleated (≥3 nuclei) osteoclasts (MNC) per well. Data are expressed as mean ± SE of three independent experiments. *P < 0.01 vs. only 10 ng/ml RANKL condition, # P < 0.001 vs. DPB1#-LPS plus 10 ng/ml RANKL condition. b RANKL and OPG mRNA expression was analyzed in hFOB1.19 human osteoblastic cells. Eco-LPS (LPS from Escherichia coli) was the positive control. The data shown are representative of three independent experiments. c Effect of EETC on DPB#1-LPS-induced RANKL and OPG mRNA expression were analyzed by RT-PCR. The ratio of RANKL to OPG was determined after normalization to the intensity of GAPDH. The data shown are representative of three independent experiments. *P < 0.001 vs. control (Ctl), # P < 0.001 vs. DPB#1-LPS condition