Methanol Leaf Extract of Persea americana Protects Rats against Cholesterol-Induced Hyperlipidemia

Abstract

Aim: To investigate anti-hyperlipidemic activity of methanol leaf extract of Persea americana (MEPA) in cholesterol-induced hyperlipidemic rats. Methodology: The animals were randomly divided into five groups of 5 rats each. Group1 served as the normal control (NC) and received distilled water. Group 2, the cholesterol-induced hyperlipidemic control (CHOL) was given cholesterol diet (20% groundnut oil, 1% cholesterol and 0.5% cholic acid mixed with rat pellet) orally. Groups 3 and 4 received oral administration of cholesterol diet and MEPA at a dose of 20 and 40 mg/kg body weight respectively, while group 5 was treated orally with cholesterol diet and cholestyramine (0.26g/kg body weight). Cholesterol diet, MEPA and cholestyramine were administered daily for a period of eight weeks. Results: The changes observed in the plasma levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL) and high density lipoprotein (HDL) of hyperlipidemic control rats were reversed by MEPA in a dose-dependent manner. At 20 mg/kg body weight, MEPA significantly (p<0.05) reduced TC, TG and LDL plasma levels by 54.2%, 46.2% and 65.6% respectively, and increased HDL plasma level by 60.0%. At a higher dose of 40 mg/kg, MEPA reduced TC, TG and LDL levels by 60.4%, 69.2% and 87.5% respectively while HDL was increased by 80.0%. There was a significant increase of change in body weight of hyperlipidemic rats compared to the change in normal control. MEPA caused a reduction of change in body weight to nearly that of the normal control. MEPA also dose-dependently caused significant reduction (p<0.05) of plasma lipid peroxidation in the rats. The anti-hyperlipidemic effect of MEPA was comparable to that of the standard drug, cholestyramine. Conclusion: The results of this study showed that Persea americana could be a source of good alternative remedy for hyperlipidemia. Further studies are needed to fully understand the mechanism of action of the plant.