| Objective To investigate the mechanism of GulaoYukang Pill in the treatment of rheumatoid arthritis by regulating Th17/Treg balance and inhibiting inflammatory factors. Methods CIA animal model was established. After successful evaluation, the rats were divided into 6 groups by random number table method: Normal control (NC) group, model control (model) group, low (0.27 g/kg), medium (0.54 g/kg), high (0.54 g/kg) dose groups and methotrexate group [(0.1 mg/(kg·w) ]with 10 ratsin each group were collected after continuous administration for 6 weeks. The pathological changes of ankle joint were observed by HE staining. The growth of osteoclasts was observed by TRAP staining. The expression of IL-17, TNF-α and IL-22 were detected by ELISA. The expressions of osteoclast differentiation-related proteins NFATcl, CTSK, MMP-9, CTR and transcriptional genes RORγt and Foxp3 proteins of Th17 and Treg cells were detected by Western blot. The number of Th17 and Treg cells was detected by flow cytometry. Results ① Compared with the NC group, there were a large number of inflammatory cells infiltrated in the synovial tissue of model group to form pannus. On the surface of cartilage, there was a large number of cell degeneration and necrosis, trabecular structure disorder, and the number of osteoclasts increased significantly. The expression of IL-17, TNF-α and IL-22 was increased (P<0.05); The expression levels of osteoclast differentiation related proteins NFATcl, CTSK, MMP-9 and CTR were increased (P<0.05); The expression of RORγt was increased (P<0.05), Foxp3 expression decreased (P<0.05); The number of Th17 increased, the number of Treg cells decreased, and the Th17/Treg ratio increased (P<0.05). ② Compared with model group, the degree of ankle joint lesions in GL, GM, GH and MTX groups decreased with the increase of dose, and the inflammatory cell infiltration in synovial tissue decreased. The degeneration and necrosis of cartilage surface cells decreased, the trabecular structure of bone was orderly, and the number of osteoclasts decreased with the increase of dosage. The expression of IL-17, TNF-α and IL-22 decreased (P<0.05); The expression levels of osteoclast differentiation related proteins NFATcl, CTSK, MMP-9 and CTR were decreased (P<0.05); The expression of RORγt decreased (P<0.05), the expression of Foxp3 was increased (P<0.05); The number of Th17 decreased, the number of Treg cells increased, and the Th17/Treg ratio decreased (P<0.05). Conclusion GulaoYukang Pill can inhibit the bone destruction of rheumatoid arthritis, and the mechanism may be related to the regulation of Th17/Treg balance to reduce the expression of inflammatory factors and reduce the level of osteoclast differentiation related proteins. |