The effects of Eicosapentaenoic acid on the endothelium of the carotid artery of rabbits on a high-cholesterol diet

Abstract

The preventive and therapeutic effects ofEicosapentaenoic acid (EPA) on diet-inducedhyperlipidemia in rabbits have been investigated.Eighteen New Zealand rabbits were randomly dividedinto three groups of 6 subjects each; experimental group-I (EG-I) was administered a cholesterol rich diet,experimental group-II (EG-II) was treated with EPA(300 mg/kg/d) following a cholesterol-rich diet and thecontrol group (CG) had a standard diet. Blood sampleswere collected at day 0 and at the 4th and 12th weeks ofEG-II to obtain serum levels of total cholesterol (TC),high density lipid-cholesterol (HDL-C), low densitylipid-cholesterol (LDL-C) and triglyceride (TG). Fromeach group tissue samples were collected from thecarotid artery for immunohistochemistry and electronmicroscopy. Our results showed that EPA couldsignificantly lower (p<0.001) serum TC, LDL-C, HDL-C and TG levels with a reduction of 35%; 55%; 44% and51%, respectively. Scanning and transmission electronmicroscopy results revealed that endothelial damage wasmore prominent in EG-I when compared to EG-II. Theruptured endothelial lining and damaged cellular surfacewas increased in EG-I when compared to EG-II.Ultrastructural observations showed that after EPAtreatment, the degeneration and cellular surface damageon the endothelium were also decreased. These biochemical and ultrastructural results suggestthat EPA is a potential drug which significantly lowersthe serum lipid profile and partially repairs endothelialdysfunction due to hyperlipidemia