Zhuifeng Tougu capsules improve rheumatoid arthritis symptoms in rats by regulating the toll-like receptor 2/4-nuclear factor kappa-B signaling pathway.

ABSTRACT

OBJECTIVE: To investigate the efficacy of Zhuifeng tougu capsules (, ZFTG) in the treatment of rheumatoid arthritis (RA) in rats and study its mechanism, focusing on the toll-like receptor 2/4-nuclear factor kappa-B (TLR2/4-NF-κB) signaling pathway. METHODS: Type Ⅱ collagen and an artificial climate box were used to construct the rat model of collagen-induced arthritis with wind-cold-dampness arthralgia syndrome. The rats were divided randomly into a control group, wind-cold-dampness syndrome model group, and high-, medium-, and low-dose ZFTG groups. The methotrexate (MTX) control group was treated with the corresponding drug intervention for 28 d. The joint temperature, pain threshold, joint swelling degree, and arthritis index (AI) score were measured. The production of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factors (RFs) in the blood was detected by enzyme-linked immunosorbent assay. The protein expression of TLR2, TLR4, and NF-κB in synovial tissues was detected by Western blotting, and the mRNA expression of TLR2, TLR4, and NF-κB was detected by real-time polymerase chain reaction. RESULTS: Compared with the model group, the joint temperature in each treatment group, the MTX control group, and MTX group recovered, the degree of foot swelling, pain threshold, AI score decreased, serum CRP, ESR, RF level and the levels of TLR2, TLR4, and NF-κB in synovial tissue were decreased (P < 0.05). Among them, the curative effect in the medium-dose and MTX groups was more evident (P < 0.01). CONCLUSION: ZFTG has a significant effect on RA in rats, and its mechanism may involve regulating CRP levels, the ESR, and RFs via the TLR2/4-NF-κB signaling pathway.