十两茶提取物抗高脂诱导家兔动脉粥样硬化形成涉及调节ADMA/NO通路

目的：观察十两茶提取物对高脂诱导家兔动脉粥样硬化的影响。方法：家兔高脂饲料喂养4周后,分别灌胃给予不同剂量的十两茶提取物（25、50和100mg/kg）,共4周。实验结束后,颈动脉取血检测红细胞变形能力,测定血脂、NO、非对称二甲基精氨酸（ADMA）和丙二醛（MDA）含量;分离胸主动脉检测脂质斑块面积和血管内皮依赖性舒张功能。结果：十两茶提取物能剂量依赖性地降低高脂饲养家兔血清总胆固醇和低密度脂蛋白水平,同时显著减少主动脉粥样斑块面积和改善血管内皮舒张功能及红细胞变形能力。十两茶提取物显著降低血清MDA和ADMA含量和增加NO水平,且呈剂量依赖性。结论：十两茶提取物具有抗动脉粥样硬化作用,其机制与抑制脂质过氧化、调节ADMA/NO系统,改善血管内皮功能和红细胞变形能力有关。

Involvement of ADMA/NO pathway in antiatherosclerotic properties of the extract of shi-liang cha in hypercholesterolemic diet-fed rabbits

AIM： To investigate the effects of the extract of shi-liang cha on atherogenesis in hypereholesterolemic diet-fed rabbits. METHODS： Male rabbits were fed with food containing cholesterol for 8 weeks to induce atherosclerosis. For drug treatment, the animals were orally treated with different doses of the extract of shi-liang cha （25, 50 or 100 mg/kg per day） during the last four-week period of the experiment. At the end of the experiment, blood samples were collected to measure the plasma levels of nitric ox- ide （NO）, asymmetric dimethylarginine （ADMA） and malondialdohyde （MDA）, and the aortas were isolated to determine endothelium-dependent vasodilator response and lesion area. RESULTS. The extract of shiliang cha could dose-dependently decrease plasma lev-els of total cholesterol, low-density lipoprotein and lesion area in atherosclerotic rabbits. Moreover, such treatment could improve endothelium-dependent vasodilator response and erythrocyte deformability, decrease the plasma levels of ADMA and MDA and increase NO content. CONCLUSION： The extract of shi-liang cha lowers blood lipids and inhibits atherogenesis, which may be related to improving endothelial function and erythrocyte deformability via inhibiting lipid peroxidation and modulating ADMA/NO system.