The study of curcumin modulates nuclear factor-kappa B signaling pathway to inhibit wear particle inducted osteolysis in vitro

Objective To investigate the effect of curcumin on osteolysis through regulating nuclear factor-kappa B (NF-κB) signal pathway, by establishing the model of wear particle induced osteolysis in vitro. Methods Wear particles induced cellular model of osteolysis was build by co-culturing ultra high molecular weight polyethylene (UHMWPE) with mouse monocytes/macrophages RAW264.7 cells, intervented by adding curcumin. Four groups were involved: A: blank group; B: polyethylene particle induced group; C: polyethylene particle induced + low concentration of curcumin treatment group; D: poly-ethylene particle induced + high concentration of curcumin. Proteins were extracted from each group to detect the expression of the key protein inhibitor of NF-κB (IκB)and phosphorylated IκB (p-IκB) in the NF-κB pathway by using Western blotting. The same grouping method was used to detect the expression of transcription factor c-Fos and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) by using real time polymerase chain reaction (Realtime-PCR). Results (1) Western blotting results: in group B, the grave value ratio of IκBα and β-actin (IκBα/β-actin) was 0.029±0.004, which was lower than the other three groups (P=0.001) (group A: 0.321±0.014, group C: 0.352±0.019, group D: 0.554±0.009). Comparing group C with group D, the P value was 0.001; Group B’s p-IκBα/β-actin was 1.450±0.081, which was higher than other three groups (P=0.001) (group A: 0.593±0.041, group C: 0.480±0.023, group D: 0.511±0.024). The comparison between group C and group D had no statistical significance (P=0.163). (2) Real-time PCR results: expression of c-Fos (1.243±0.040) and NFATc1 (1.255±0.009) was the highest. Group C’s c-Fos expression (0.868±0.032) was higher than group D’s (0.814±0.009) (P=0.015). Group C’s NFATc1 expression (0.956±0.016) was higher than group D’s (0.624±0.009) (P=0.001). Conclusion Curcumin can inhibit the occurrence of periprosthetic osteolysis by inhibiting the activation of NF-κB signal pathway in vitro. Key words: Curcumin; Wear particles; Aseptic loosening; Osteolysis