桔梗总皂苷对胶原性关节炎大鼠的抗炎作用及对TLR/MyD88/NF-κB通路的影响

Anti-inflammatory effect of Platycodon grandiflorum saponins on collagen-induced arthritis rats and its effect on TLR/MyD88/NF-κB

目的:探讨桔梗总皂苷对胶原性关节炎大鼠的抗炎作用及对Toll样受体4/髓样分子因子88/核因子-κB(TLR/MyD88/NF-κB)通路的影响,阐明桔梗总皂苷对类风湿性关节炎(RA)的治疗机制。方法:将70只大鼠根据随机数字法分为对照组、模型组、桔梗总皂苷(CKS)低剂量组、CKS高剂量组、雷公藤多苷组,每组14只。采用Ⅱ型胶原建立胶原性关节炎大鼠模型。CKS低剂量组和高剂量组大鼠分别给予CKS 100 mg/kg和200 mg/kg灌胃,雷公藤多苷组大鼠给予雷公藤多苷12 mg/kg灌胃作为阳性对照组。记录给药28 d后关节炎指数。HE染色观察踝关节滑膜组织病理学变化。ELISA法测定滑膜组织IL-1β、IL-6、肿瘤坏死因子-α(TNF-α)水平。Western blot测定滑膜组织TLR2、TLR4、MyD88、p-NF-κB p65蛋白水平。免疫组化法测定滑膜组织NF-κB蛋白表达。结果:与对照组比较,模型组大鼠踝关节滑膜组织中IL-1β、IL-6、TNF-α水平升高(P<0.05),滑膜组织TLR2、TLR4、MyD88、p-NF-κB p65蛋白水平升高(P<0.05),滑膜组织NF-κB蛋白IOD值升高(P<0.05);与模型组比较,CKS各剂量组大鼠关节炎指数降低(P<0.05),踝关节滑膜组织中IL-1β、IL-6、TNF-α水平降低(P<0.05),TLR2、TLR4、MyD88、p-NF-κB p65蛋白水平降低,NF-κB蛋白IOD值降低(P<0.05)。HE染色:对照组大鼠踝关节未见异常;模型组大鼠踝关节出现增生性滑膜炎表现,CKS各剂量组大鼠踝关节增生性滑膜炎表现明显减轻。CKS对各指标的影响呈剂量依赖性。结论:桔梗总皂苷可抑制胶原性关节炎滑膜组织炎症反应及TLR/MyD88/NF-κB信号通路,发挥对胶原性关节炎的防治作用。

Objective:To investigate the anti-inflammatory effect of Platycodon grandiflorum saponins on collagen-induced arthritis rats and the effect of Toll-like receptor 4/myeloid molecular factor 88/nuclear factor-κB(TLR/MyD88/NF-κB)pathway in order to clarify the treatment mechanism of platycodon grandiflorum saponins on rheumatoid arthritis(RA).Methods:Accorded to the random number method,70 rats were divided into control group,model group,platycodon grandiflorum(CKS)low dose group,CKS high dose group,tripterygium wilfordii polyglycoside group,14 rats in each group.The collagen-induced arthritis rat model was established using typeⅡcollagen.Rats in CKS low dose group and high dose group were given gavage of CKS 100 mg/kg and 200 mg/kg,respectively.Rats in tripterygium wilfordii polyglycoside group were given gavage of tripterygium wilfordii glycoside 12 mg/kg as a positive control group.The arthritis index was recorded at 28 days after administration.HE staining was used to observe the histopathological changes of ankle synovium.ELISA method was used to determine the levels of IL-1β,IL-6 and tumor necrosis factor-α(TNF-α)in synovial tissue.Western blot was used to determine the protein levels of TLR2,TLR4,MyD88 and p-NF-κB p65 in synovial tissue.The expression of NF-κB protein in synovial tissue was measured by immunohistochemistry.Results:Compared with the control group,the levels of IL-1β,IL-6 and TNF-αin the ankle synovial tissue of the model group were increased(P<0.05),the synovial tissue TLR2,TLR4,MyD88 and p-NF-κB p65 protein levels were increased(P<0.05),IOD value of synovial tissue NF-κB protein was increased(P<0.05);compared with the model group,the arthritis index of rats in each dose CKS groups was decreased(P<0.05),and the levels of IL-1β,IL-6 and TNF-αin ankle synovial tissue were decreased(P<0.05),TLR2,TLR4,MyD88 and p-NF-κB p65 protein levels were decreased,and NF-κB protein IOD value was decreased(P<0.05).HE staining:in the control group,the ankle joint was no abnormalities;in the model group,the ankle joint showed hyperplastic synovitis;in each dose CKS groups,the performance of proliferative synovitis of the ankle joint were significantly reduced.The impact of CKS on various indicators was dose-dependent.Conclusion:Platycodon grandiflorum saponins can inhibit collagen arthritis synovial tissue inflammation and TLR/MyD88/NF-κB signaling pathway,and play a role in preventing and treating collagen arthritis.