ABSTRACT
Objective To observe the effects of the drug pair of Rhizoma Polygoni Cuspidati ( Huzhang) and Ramulus Cinnamomi ( Guizhi) on the Toll-like receptor 4 mediated myeloid differentiation factor 88 ( TLRs/MyD88) signaling pathway of rats with acute gouty arthritis induced by monosodium sodium urate (MSU) , so as to explore its therapeutic mechanism. Methods Forty-eight male SD rats were divided into normal group, modele group, blank plasmid group, positive plasmid group, Huzhang- Guizhi herb-pair (7 g/kg) group, and Huzhang-Guizhi herb-pair ( 7 g/kg) siRNA group, 8 rats in each group. The normal group, plasmid groups and model group were given physiological saline, and the left groups were given the corresponding drug by intragastric administration for 10 continuous days ( once daily ) . On the seventh day of intragastric gavage, acute gouty arthritis were induced by injection of MSU into the rat ankle joint, and normal group was injected with the samevolume of normal saline. Positive plasmid group and Huzhang-Guizhi herb-pair siRNA group were injected with the constructed siRNA-TLR4 plasmid targeting TLR4 gene ( TLR4-siRNA) to inhibit the in-vivo TLR4 gene expression. Pathological changes of the synovial tissues were detected, the contents of peripheral blood tumor necrosis factor alpha ( TNF-α) and interleukin 1 beta ( IL-1β) were detected by double antibody sandwich method, and the mRNA and protein expression levels of TLR4, MyD88, TNF receptor-associated factor 6 ( TRAF-6) in peripheral blood mononuclear cells of rats were detected by real-time fluorescence quantitative polymerase chain reaction ( PCR) and Western blot methods. The nuclear factor kappa B ( NF-κB) p65 immunoactivity was assayed by immunohistochemistry. Results Compared with the normal group, the model group had obvious hyperplasia of synovial cells and the inflammatory cell infiltration ( dominated by lymphcytes and monocytes) , and had amount of cellulose adhesive on the synovial membrane surface. Compared to the model group, positive plasmid group, Huzhang- Guizhi herb-pair group and Huzhang-Guizhi herb-pair siRNA group could obviously relieve the inflammatory cell infiltration, and improve synovial cell proliferation reaction. Compared to the normal group, serum levels of TNF-α and IL-1β, and the expression levels of TLR4, MyD88, TRAF-6 mRNA and protein in the peripheral blood mononuclear cells as well as the synovial NF-κB p65 ex pression in the model group were significantly increased ( P<0.01). Compared to the model group, positive plasmid group, Huzhang-Guizhi herb-pair group and Huzhang- Guizhi herb-pair siRNA group showed significant decrease in the levels of TNF-α, IL-1β, TLR4 MyD88, TRAF-6 and NF-κB p65 ( P<0.05 or P<0.01) . Conclusion Huzhang-Guizhi herb-pair can regulate the cytokines of the synovial membrane tissue in acute gouty arthritis rats, which may be related with its effect on inhibiting abnormal activation of TLR4-MyD88-NF-κB pathway in synovial tissue.