Phytochemical composition, acute toxicity, hypoglycemic and hypolipidemic effects of ethanol extract of Allium sativum (garlic) bulb in male Wistar rats

Allium sativum (garlic) has been used in traditional medicine in Nigeria in the treatment of various ailments such as cold, cough, and microbial infections; and there have been various claims about its pharmacological activities including anti-inflammatory, antimicrobial, hypoglycemic, hypolipidemic, antioxidant, antidiabetic, and anticancer properties. However, there are insufficient data to back up these claims. It is against this backdrop, this study evaluated the phytochemical composition, acute toxicity, hypoglycaemic and hypolipidemic potentials of ethanol extract of A. sativum bulb in male Wistar rats in order to validate its therapeutic use as hypoglycaemic and hypolipidemic agent. Twenty adult male Wistar rats were randomly divided into four groups of five rats each where group 1 (control) received normal saline while group 2-4 received the extract at the doses of 200, 400, and 1000mg/kg b.w respectively for fourteen days. T-test and one-way ANOVA were used to test for significant (p<0.05) differences among the groups. Qualitative and quantitative phytochemical screening of the extract indicated the presence of flavonoids (17.59±0.01), saponins (13.55±0.01), alkaloids (2.06±0.06), tannins (0.04±0.00), phenols (0.01±0.00), phlobatanin, phytosterols and terpenoids whereas steroids, anthraquinones and glycosides were not detected. The administration of the extract produced a significant (P<0.05) decrease in the blood glucose concentration in the treatment groups compared to the control group, whereas a significant (P<0.05) decrease was observed in the total cholesterol concentration of group 4 only relative to the control. Furthermore, there was a significant (P<0.05) increase in the HDL concentrations and a significant (P<0.05) decrease in the triglycerides and LDL concentrations respectively in all treatment groups compared to the control group. From these findings therefore, we conclude that A. sativum offers both hypoglycemic and hypolipidemic effects in male Wistar rats.