BACKGROUND:Currently, there are few researches on the effect of punicalagin on the formation and differentiation of osteoclasts, and fewer researches on the mechanism of bone resorption diseases induced by wear particles. OBJECTIVE: To establish a model of titanium particles induced mouse monocyte/macrophage cel line (RAW264.7) differentiating into osteoclasts and to observe the effect of different concentrations of punicalagins on osteoclast proliferation and differentiation. METHODS: Mouse monocyte/macrophage cel lines (RAW264.7) were divided into five groups, cultured in the culture medium of common (blank group), 0.1 g/L titanium particle suspension, 0.1 g/L titanium particle suspension with 25 μmol/L punicalagins, 0.1 g/L titanium particle suspension with 50 μmol/L punicalagins, 0.1 g/L titanium particle suspension with 100 μmol/L punicalagins, respectively. The cel proliferative activity was detected by cel counting kit-8 assay at 1, 3 and 5 days. At 5 days after culture, number of osteoclasts was measured by tartrate-resistant acid phosphatase staining, the phosphorylation of IκBα and NF-κB p65 was detected by western blot assay, the mRNA expressions of nuclear factor of activated Tc1, tartrate-resistant acid phosphatase and matrix metaloproteinase-9 were measured by reverse transcription-PCR. RESULTS AND CONCLUSION:Compared with control group, titanium particles and different concentrations of punicalagin had no effect on the proliferation of RAW264.7 cels (P > 0.05). The number of tartrate-resistant acid phosphatase staining -positive cels, the phosphorylation of IκBα and NF-κB p65 as wel as the mRNA expressions of nuclear factor of activated Tc1, tartrate-resistant acid phosphatase and matrix metaloproteinase-9 were significantly increased compared with those of control group (P < 0.05,P < 0.01). And punicalagins in a concentration-dependent manner decreased the expression of the above indicators. These results indicate that punicalagin can inhibit osteoclast formation and differentiation.