脉抒抑制ApoE^(-/-)小鼠动脉粥样硬化形成的作用

Suppression effect of Mai Shu on formation of atherosclerotic plaque of apolipoprotein E knock-out mice

本文研究由山楂、沙棘和枸杞三味中药为主,并添加多种植物甾醇(β-谷甾醇、豆甾醇和菜油甾醇等)、β-葡聚糖和番茄红素等制备而成的天然药物组方脉抒对高脂膳食诱导ApoE^(-/-)(载脂蛋白E基因敲除)小鼠动脉粥样硬化斑块形成的影响。利用紫外液相色谱-质谱联用(LC-UV-MS)技术对脉抒的化学成分进行分析;采用特制高脂喂养建立ApoE^(-/-)动脉粥样硬化小鼠模型,观察口服不同剂量(1、2和4 g·kg^(-1)·d^(-1))脉抒10周后ApoE^(-/-)小鼠血脂水平(总胆固醇、甘油三酯及高密度脂蛋白胆固醇)的变化;分离主动脉全长,采用油红O染色,观察主动脉全长斑块形成;对主动脉根部冰冻切片分别采用油红O及天狼星红染色,观察主动脉根部斑块形成;采用动态可视化微血管观察系统,观察小鼠体内白细胞-内皮细胞黏附作用;用免疫组化方法检测主动脉根部斑块中巨噬细胞标记物CD68表达变化,观察巨噬细胞在斑块中的聚集情况。结果显示,脉抒中含有黄酮类(9.5%)、多糖类(8.9%)和植物甾醇类化合物(23.8%)等成分;模型对照组血清血脂水平较空白对照组明显升高,脉抒给药组在4 g·kg^(-1)剂量下血清总胆固醇水平较模型组显著降低,在1、2和4 g·kg^(-1)剂量下血清甘油三酯含量、斑块与内皮面积占比均较模型组显著降低;2和4 g·kg^(-1)剂量给药组主动脉根部斑块面积值、微循环中白细胞滚动速率较模型对照组显著改善;1和2 g·kg^(-1)给药组斑块胶原纤维含量明显较高,动脉根部斑块中巨噬细胞数量明显减少。上述结果提示,脉抒能降低高脂诱发动脉粥样硬化模型小鼠血脂水平,改善小鼠微循环中白细胞与内皮细胞黏附状况,说明脉抒有效抑制动脉粥样硬化模型小鼠主动脉中斑块形成的作用,可能与其减少斑块内巨噬细胞数量有关。

The research aimed to investigate the suppression effect of MaiShu which contains hawthorn, hippophae, medlar, phytosterols （β-sitosterol, stigmasterol and campesterol）, β-glucan and lycopeneon formation of atherosclerotic plaque in apolipoprotein E knock-out （ApoE-/-） mice. Liquid chromatography-ultraviolet-mass spectrometry （LC-UV-MC） methods were used to analyze the main chemical composition of MaiShu.Atherosclerotic mice models were established by high-fat diet. The mice were administrated with MaiShu （1, 2, 4 gkg-1d-1） or other contrast materials by intragastric route for 10 weeks continuously. At the end of administration, the blood of mice was collected for tests of the serum total cholesterol （TC）, total triglyceride （TG） and high density lipoprotein cholesterol （HDL-C） level. Atherosclerotic lesions in aorta and aortic root were assessed by calculating the relative area of lesions （oil red O stained）. Intravital fluorescence microscopic system was used to evaluate the leukocyte-endothelial adhesion in mesenteric artery of mice by detecting the rolling velocity of white blood cells （WBC）. Collagenous fibers and macrophages in lesions were detected by sirius red staining and immunological histological chemistry to evaluate the atherosclerotic plaque stability. Results showed that MaiShu contains various flavonoids （9.5%）, phytosterols （23.8%） and polysaccharides （8.9%）. The serum lipid level of model animals was significantly higher than the control animals. Serum TC level was decreased by MaiShu （4 gkg-1, P〈0.001） compared to the untreated model. Serum TG level was reduced by MaiShu （1, 2, 4 gkg-1） compared to model （P〈0.01）. Area of atherosclerotic lesions in aorta and aortic root was decreased in MaiShu group （aorta：1 gkg-1, P〈0.05; 2 gkg-1, P〈0.01; 4 gkg-1, P〈0.001; aortic root：2, 4 gkg-1, P〈0.01）. Rolling velocity of white blood cells of MaiShu （4 gkg-1, P〈0.001） group was increased over the untreated model. Collagenous fibers in lesions were observationally increased by MaiShu （1, 2 gkg-1） and macrophages were decreased （2, 4 gkg-1） compared to model. These results demonstrate that MaiShu can obviously decrease the serum lipid levels and the risk of leukocyte-endothelial adhesion in ApoE-/- mice. The effect of MaiShu may be associated with the decrease of macrophages in plaque.