Anti-hyperglycemic and ameliorative effect of concentrated hot water-infusion of Phragmanthera incana leaves on type 2 diabetes and indices of complications in diabetic rats

Objectives: This study investigated the anti-hyperglycemic effects of concentrated hot water infusion of Phragmanthra incana leaves as well as its ameliorative effect on indices related to diabetic complications in a type 2 diabetes model of rats. Methods: Type 2 diabetes was induced by feeding 10% fructose solution ad libitum for two weeks followed by an intraperitoneal injection of streptozotocin (40 mg/kg body weight (b.w.)). Concentrated plant infusion was administered orally at a dose of 150 and 300 mg/kg b.w. to two type 2 diabetes rat groups. Diabetic rats without treatment served as a negative control while the group administered with metformin was served as a positive control. The intervention lasted for 4 weeks when a single oral dose was given daily for 5 days a week. Body weight and blood glucose were determined every week. An oral glucose tolerance test was performed in the last week of treatment. The rats were sacrificed after 4 weeks of intervention, and the blood and organs were harvested for further analysis. Results: Both dosages of the plant infusion significantly improved body weight, pancreatic β-cell function (HOMA-β), insulin secretion and reduced blood glucose, insulin resistance (HOMA-IR) with concomitant reduction in the elevated level of serum α-amylase activity, fructosamine, uric acid, urea, and liver function enzymes. The liver glycogen content was significantly improved while the activity of liver glucose-6-phosphatase was significantly reduced. Conclusion: The results demonstrate the anti-hyperglycemic ability of P. incana and its ability to delay the onset of diabetic complications which can be exploited for the anti-diabetic drug discovery.