金丝桃苷通过TLR4/NF-κB信号通路对动脉粥样硬化小鼠的干预作用

Intervention effect of hyperoside via TLR4/NF-κB signaling pathway on mice with atherosclerosis

目的探讨金丝桃苷通过Toll样受体4(TLR4)/核转录因子-κB(NF-κB)信号通路对动脉粥样硬化小鼠的干预作用。方法将50只雄性小鼠随机分为正常组、模型组、金丝桃苷低剂量组、金丝桃苷高剂量组、辛伐他汀组,各10只。除正常组小鼠外,其余各组建立动脉粥样硬化小鼠模型。建模完成后,分别给予金丝桃苷低剂量组、金丝桃苷高剂量组、辛伐他汀组小鼠灌胃30 mg/(kg•d)金丝桃苷、60 mg/(kg•d)金丝桃苷、辛伐他汀,给予正常组、模型组小鼠灌胃等量生理盐水,连续干预4周。采用HE染色观察各组小鼠主动脉组织病理学变化。除正常组外,检测其余小鼠斑块成分占比、斑块易损指数、斑块内新生血管密度。检测各组小鼠血清三酰甘油、总胆固醇、HDL-C、白细胞介素(IL)-6、肿瘤坏死因子α(TNF-α)、IL-8、谷胱甘肽过氧化物酶(GSH-Px)、活性氧簇、超氧化物歧化酶(SOD)、血管内皮生长因子(VEGF)、内皮素1水平,以及主动脉组织TLR4、NF-κB蛋白表达量。结果相比于正常组,模型组小鼠主动脉内有斑块形成,动脉壁不均匀增厚并发生局部钙化,有大量巨噬细胞和淋巴细胞浸润,且血清VEGF、内皮素1、三酰甘油、总胆固醇、IL-6、TNF-α、IL-8、活性氧簇水平升高,血清HDL-C、GSH-Px、SOD水平均降低,主动脉组织TLR4、NF-κB蛋白表达量均上调(均P<0.05)。相比于模型组,3个药物干预组小鼠主动脉壁增厚情况、巨噬细胞和淋巴细胞浸润现象减轻,血清VEGF、内皮素1、三酰甘油、总胆固醇、IL-6、TNF-α、IL-8、活性氧簇水平均降低,血清HDL-C、GSH-Px、SOD水平均升高,主动脉组织TLR4、NF-κB蛋白表达量均下调,且斑块易损指数、斑块内新生血管密度较低(均P<0.05);金丝桃苷高剂量组与辛伐他汀组的上述指标均优于金丝桃苷低剂量组(均P<0.05),但金丝桃苷高剂量组与辛伐他汀组的各项指标差异均无统计学意义(均P>0.05)。结论金丝桃苷能有效减轻动脉粥样硬化小鼠的炎症反应及氧化应激水平,调节血脂水平,抑制血管新生,修复血管损伤,剂量为60 mg/(kg•d)干预效果更佳。金丝桃苷的作用机制可能与抑制TLR4/NF-κB信号通路的活性有关。

Objective To investigate the intervention effect of hyperoside via Toll-like receptor 4(TLR4)/nuclear factor-κB(NF-κB)signaling pathway on mice with atherosclerosis.Methods Fifty male mice were randomly divided into normal group,model group,low-dose hyperoside group,high-dose hyperoside group,or simvastatin group,with 10 mice in each group.Except for mice in the normal group,atherosclerotic mice models were constructed in the remaining groups.After completed modeling,mice in the low-dose hyperoside group,the high-dose hyperoside group,and the simvastatin group received intragastric administration of 30 mg/(kg•d)hyperoside,60 mg/(kg•d)hyperoside,and simvastatin,respectively,and mice in the normal group and the model group received intragastric administration of normal saline with equivalent volume.All groups received intervention for 4 weeks.Pathological changes of aortic tissues in mice of various groups were observed by HE staining.Except for the normal group,the proportion of plaque component,vulnerable index of plaque,and microvasculature density of plaque were detected in mice of the remaining groups.The levels of serum triglyceride,total cholesterol,HDL-C,interleukin(IL)-6,tumor necrosis factorα(TNF-α),IL-8,glutathione peroxidase(GSH-Px),reactive oxygen species,superoxide dismutase(SOD),vascular endothelial growth factor(VEGF),and endothelin 1,as well as protein expressions of TLR4 and NF-κB in aortic tissues were detected in mice of various groups.Results Compared with the normal group,mice in the model group presented as plaque formation in aorta,artery wall uneven thickening,occurrence of local calcification,and a large number of macrophages and lymphocytes infiltration,and mice in the model group acquired elevated levels of serum VEGF,endothelin 1,triglyceride,total cholesterol,IL-6,TNF-α,IL-8,and reactive oxygen species,and decreased levels of serum HDL-C,GSH-Px,and SOD,as well as up-regulated protein expressions of TLR4 and NF-κB in aortic tissues(all P<0.05).Compared with the model group,mice in the 3 drug-intervened groups presented as aortic wall thickening,macrophages and lymphocytes infiltration relieving,and mice in these groups obtained decreased levels of serum VEGF,endothelin 1,triglyceride,total cholesterol,IL-6,TNF-α,IL-8,and reactive oxygen species,elevated levels of serum HDL-C,GSH-Px,and SOD,down-regulated protein expressions of TLR4 and NF-κB in aortic tissues,as well as lower vulnerable index of plaque and microvasculature density of plaque(all P<0.05).The aforementioned indices in the high-dose hyperoside and the simvastatin groups were superior to those in the low-dose hyperoside group(all P<0.05);however,there was no statistically significant difference in various indices between the high-dose hyperoside group and the simvastatin group(all P>0.05).Conclusion Hyperoside can effectively relieve inflammatory response and oxidative stress levels in atherosclerotic mice,modulate blood lipid levels,inhibit angiogenesis,and repair vascular damage,and the optimal intervention effect goes to 60 mg/(kg•d)dose.The mechanism of hyperoside may be related to inhibit activity of TLR4/NF-κB signaling pathway.