Qingluoyin granules protect against adjuvant-induced arthritis in rats via downregulating the CXCL12/CXCR4-NF-κB signalling pathway

Context Qingluoyin (QLY) is a traditional Chinese medicine (TCM) formula which has been used in treating human rheumatoid arthritis (RA) for years in China. Objective This study investigates the effect of QLY granules on adjuvant arthritis (AA) and the possible mechanism. Materials and methods Sprague-Dawley (SD) rats were injected with Complete Freund’s adjuvant (CFA) to induce the AA model. After the onset of arthritis, rats received intragastric administrations of the QLY granules (1.35, 2.70, and 5.40 g/kg) or Tripterygium glycosides (TG) tablets (positive drug, 10 mg/kg) for 14 d. After 28 d immunization, the symptoms, inflammatory parameters and molecular mechanisms were investigated. Results In the QLY granule (1.35, 2.70, and 5.40 g/kg) therapy groups, the arthritis index decreased to 6.30 ± 2.06, 5.80 ± 1.55, 5.30 ± 1.16 compared with the model (9.00 ± 3.01), paw swelling decreased to 1.56 ± 0.40, 1.28 ± 0.38, 1.12 ± 0.41 mL compared with the model (2.22 ± 0.73 mL). QLY granules (1.35, 2.70 and 5.40 g/kg) significantly reduced the thymus and the spleen indexes, inhibited the production of pro-inflammatory cytokines, and alleviated the pathological changes of joints compared with the model group. Furthermore, the treatment of QLY granules (2.70 and 5.40 g/kg) markedly inhibited CXCL12, CXCR4 (in spleen and synovium) and p-NF-κB p65 (in synovium) protein expression of AA rats. Conclusions QLY granules have obvious therapeutic effects on AA rats, which may be associated with downregulating the CXCL12/CXCR4-NF-κB signalling pathway. QLY granules can be used as a candidate for the treatment of RA, which deserves further study.