Zhitong Jiangu decoction mitigates osteoarthritis in rabbits via regulation of NF-κB signaling pathway

Purpose: To investigate the effect of Zhitong Jiangu decoction (ZJD) on osteoarthritis rabbits, and the mechanism of action involved. Methods: Chondrocytes were obtained from the knees of osteoarthritic rabbits. These chondrocytes were randomly assigned to 7 groups: sham, 5, 10 and 20 % normal serum groups; 5 % ZJD, 10 % ZJD and 20 % ZJD groups. The gross and histopathological features of the rabbit cartilage were examined by microscopy. Each group was treated with a different concentration of rabbit normal serum or rabbit drug-containing serum. The protective effect of different concentrations of ZJD on the cells were determined. Cell proliferation and concentrations of IL-1 and MMP-3 were determined using cell counting kit (CCK) 8 and enzyme-linked immunosorbent assay (ELISA), respectively. The mRNA and protein expressions of inhibitor of nuclear factor-κB kinase α (IKK-α) and nuclear factor kappa B p65 (NF- κB p65) were determined by quantitative reverse transcription polymerase chain reaction (qRT- PCR) and immunoblotting, as appropriate. Results: Gross and histopathological examinations of rabbit cartilage showed that osteoarthritis was successfully established in rabbit knee joint. Cell proliferation significantly and time- and concentration-dependently increased in drug-containing serum groups, relative to sham and normal serum-containing groups. However, expressions of NF-κB p65, IL-1, MMP-3 and IKK-α were markedly and time- and concentration-dependently reduced in drug-containing serum groups, relative to sham and normal serum-containing groups (p < 0.05). Conclusion: These results indicate that ZJD mitigates osteoarthritis in rabbits via regulation of NF-κB signaling pathway. Thus, it can potentially be developed for the management of osteoarthritis.