Hypolgycaemic and Hypolipidemic Effects of Nigella Sativa Seed Extract in Alloxan-Induced Diabetic Rats

Abstract

Introduction: The study investigated the hypoglycaemic and hypolipidemic activities of ethanolic leaf extract of Nigella sativa (N. sativa ) in high fat diet (HFD)– Alloxan- induced diabetic rats. Methods: The optimal hypoglycemic dose (125 mg kg−1) was determined by performing the oral glucose tolerance test (OGTT) in both normal and Alloxan -diabetic rats kept in the department of Biochemistry at Olabisi Onabanjo University. To investigate the effect of repeated administration of an ethanolic extract of N. sativa seeds, diabetic rats were treated with distilled water, N. sativa (125 mg kg−1) or metformin (500 mg kg−1) twice a day for 14 days weeks. Results: Like metformin, N. sativa significantly lowered blood glucose by 50% and blood triglyceride by 115% when compared with the distilled water. N. sativa also significantly increased the HDL-cholesterol concentrations by 60% compared with the distilled water. The concentration of ethanolic extract needed for the inhibition of hydoxyl radical scavenging were 125, 63, 118.5 and 121 μg/ml, and that for superoxide scavenging activity were found to be 20.5, 40.5, 6.5 and 12.5 μg/ml, respectively. N. sativa thus significantly increased the anti-atherogenic index and HDL-cholesterol/total cholesterol ratio. However, like metformin, N. sativa did not affect total cholesterol and LDL-cholesterol concentrations, but significantly reduced the kidney lipid peroxidation level. Conclusions: These data show that N. sativa has hypoglycemic, hypotriglyceridemic, anti-lipid peroxidative and anti-atherogenic properties in Alloxan -diabetic rats.