Effect of partially purified angiotensin converting enzyme inhibitory proteins from Moringa oliefera leaves on alloxaninduced diabetic rats

Abstract

This study evaluated the effect of partially-purified angiotensin converting enzyme (ACE) inhibitory proteins obtained from the leaves of Moringa oleifera on blood glucose, serum ACE activity and lipid profile of alloxaninduced diabetic rats. Twenty-five apparently healthy male albino rats were divided into five groups of five rats each. Groups II, III, IV and V were given 100 mg/kg alloxan intraperitoneally to induce diabetes. Rats in group I served as control, group II (diabetic control), groups III, IV and V were orally administered with glucophage (36.43mg/kg), enalapril (3mg/kg) and partially-purified proteins from Moringa oleifera leaves (5mg/kg), respectively, for fourteen days. The blood glucose concentration of rats given alloxan was determined 48 hours after administration of alloxan to confirm diabetes (glucose concentration ≥180mg/dl), after which treatment began. The blood glucose concentration of rats in all groups was determined on the 7th and 14th day of treatment. On the fourteenth day, the rats were sacrificed and blood collected for lipid profile and ACE analysis. Results obtained shows blood glucose level of rats given glucophage, enalapril and the partially-purified proteins from Moringa oleifera leaves (5mg/kg) was significantly (p<0.05) lower than rats in the diabetic control group. There was no significant difference (p>0.05) when serum glucose of treated rats was compared to the control group. The serum ACE activity of diabetic control rats (group II) increased significantly (p<0.05) compared to control rats. However, treatment given to rats in groups III, IV and V decreased ACE activity significantly (p<0.05). The serum levels of total cholesterol (TC), triglyceride and low density lipoprotein (LDL) cholesterol increased significantly (p<0.05), while high density lipoprotein (HDL) cholesterol decreased significantly (p<0.05) in diabetic rats compared to rats in control group and those given glucophage and enalapril. It is concluded from the results of this study that the partially-purified proteins from Moringa oleifera leaves possess hypoglycemic, hypolipidemic and ACE inhibitory activity in vivo.

Keywords: Moringa oleifera, partially-purified ACE inhibitory proteins, diabetes, angiotensin converting enzyme, lipid profile