Effect of the extract of Hua-juan tea on blood lipids and endothelial function in hypercholesterolemic rats

Objective To investigate the effect of the extract of Hua-juan tea on blood lipids and endothelial function in hypercholesterolemic rats.Methods Male SD rats were fed for 4 weeks with food containing cholesterol to induce hypercholesterolemia.The experimental group were orally treated with 3 doses of the extract of Shi-liang tea(50,100 or 200 mg·kg-1 per day)during the last 2 weeks of the experiment.At the end of the experiment,blood samples were collected to measure the plasma levels of nitric oxide(NO),asymmetric dimethylarginine(ADMA)and malondialdohyde(MDA),The thoracic aortas were isolated to determine endothelium-dependent vasodilator response.Results The extract of Shi-liang tea could dose-dependently decrease the plasma levels of total cholesterol,low-density lipoprotein and triglyceride in hypercholesterolemic rats.Such treatment could improve the endothelium-dependent vasodilator response and decrease the plasma levels of ADMA and MDA as well as increase the NO content.Conclusion The extract of shi-liang tea may lower the blood lipids and protect the endothelial function,and its effect may be related to inhibiting the peroxidation and modulating ADMA/NO system.