Inhibition of α-glucosidase by thiosulfinate as a target for glucose modulation in diabetic rats

Abstract

Postprandial hyperglycemia is a predisposing factor for vascular dysfunction and organ damage. α-glucosidase is a hydrolytic enzyme that increases the glucose absorption rate and subsequently elevates blood glucose levels. Garlic (Allium sativum L.) is a rich source of several phytonutrients, including thiosulfinate (THIO). The aim of this study was to evaluate the ability of THIO, a potent inhibitor of intestinal α-glucosidase, to reduce postprandial blood glucose. Male albino rats were randomly assigned to five different groups (n = 10 /group). Group 1 served as the control group. Groups 2-5 were injected intraperitoneally with a single dose of streptozotocin (STZ) to induce diabetes. Group 2 comprised untreated diabetic rats. Groups 3 and 4 contained diabetic rats that were given THIO orally (20 mg/kg body weight/day and 40 mg/kg body weight/day, resp.). Group 5 was the positive control having diabetic rats treated orally with acarbose (10 mg/kg body weight/day; positive control). Diabetic rats treated with THIO displayed a significant blood glucose reduction (p < 0.001 and < 0.01 by analysis of variance, resp.) and a significant elevation in insulin compared with that of untreated rats. THIO is an effective noncompetitive intestinal α-glucosidase inhibitor that promotes hypoglycemic action (p < 0.001) in STZ-injected rats. THIO is a promising agent for the management of postprandial hyperglycemia.