木犀草素通过TLR/MyD88/NF-κB通路参与急性痛风性关节炎大鼠的抗炎作用

Anti-inflammatory effects of luteolin on acute gouty arthritis rats via TLR/MyD88/NF-κB pathway

目的:探讨木犀草素通过Toll样受体(Toll-like receptors,TLR)/髓样分化因子(myeloid differentiation factor 88,MyD88)/核因子κB(nuclear factor kappa-B,NF-κB)通路减轻急性痛风性关节大鼠炎症的作用及其机制。方法:将60只雄性Wistar大鼠随机分为5组:正常对照组、尿酸钠(monosodium urate,MSU)组、秋水仙碱组、木犀草素低剂量组(50 mg/kg)、木犀草素高剂量组(150 mg/kg)。于大鼠踝关节局部注射尿酸钠晶体混悬液制备急性痛风性关节炎模型,观察各组大鼠不同时间点的关节肿胀指数,并测定各组大鼠血清及滑膜中白细胞介素1β(interleukin-1β,IL-1β)、白细胞介素6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的水平,采用实时PCR检测滑膜组织中TLR2,TLR4,MyD88 mRNA水平,蛋白质印迹测定滑膜组织中TLR2,TLR4,MyD88,磷酸化核因子κBp65(phosphorylated-nuclear factorκB,p-NF-κB p65)蛋白表达,HE染色观察踝关节及其周围软组织炎症细胞情况,免疫组织化学法测定NF-κB表达。结果:与MSU组相比,木犀草素高、低剂量组及秋水仙碱组的关节肿胀指数均明显降低(P<0.05),IL-1β,IL-6,TNF-α的水平也显著降低(P<0.01),TLR2,TLR4,MyD88 mRNA和蛋白水平及NF-κB的蛋白水平均显著降低(P<0.01)。免疫组织化学结果显示:与正常对照组比较,木犀草素和秋水仙碱组大鼠踝关节的炎症细胞明显减少,滑膜增生减少,软骨表面光滑,无明显软骨和骨侵蚀。结论:木犀草素可通过下调TLR/MyD88/NF-κB通路减轻急性痛风性关节炎的炎症反应,有望成为治疗急性痛风性关节炎的有效药物。

Objective: To investigate the anti-inflammatory effect of luteolin on the acute gouty arthritis(AGA) rats and the underlying mechanisms.Method: A total of sixty rats were chosen and randomly divided into 5 groups: A control group, a monosodium urate(MSU) group, a colchicine group, 2 luteolin groups(50 mg/kg,150 mg/kg). The AGA model of rats was established by injecting monosodium urate(MSU) at the concentration of 25 mg/m L into the ankle joint cavity. Changes of joint swelling index at different time points and the levels of interleukin-1β(IL-1β), interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) in serum and synovial were measured. The m RNA expression of TLR2, TLR4, and My D88 in synovial tissue was detected by realtime PCR, and the protein expression of TLR2, TLR4, My D88, and NF-κB in synovial tissues was determined by Western blotting. The inflammatory cells of the ankle joint and its surrounding soft tissues were observed after HE staining, and the expression of NF-κB was determined by immunohistochemistry.Result: Compared with the MSU group, the joint swelling indexes of the luteolin group and the colchicine group were significantly decreased(P<0.05), and the levels of IL-1β, IL-6 and TNF-α were also significantly decreased(P<0.01). The m RNA levels of TLR2,TLR4, and My D88 and the protein levels of TLR2, TLR4, My D88, and NF-κB were significantly decreased(P<0.01).Conclusion: Luteolin can reduce the inflammatory response of acute gouty arthritis via down-regulating the TLR/My D88/NF-κB pathway, and it is expected to be an effective drug for the treatment of acute gouty arthritis.