Inhibition of Key Digestive Enzymes Linked to Type 2 Diabetes Mellitus by Piper betle L. Leaf Extracts to Manage Diabetes in an Alternative Way

Abstract

Background: Diabetes mellitus is a chronic metabolic disorder. The therapeutic approaches for treating diabetes are to decrease the absorption of glucose through the inhibition of carbohydrate hydrolyzing enzymes like α-amylase and α-glucosidase or to use medications for lowering the blood glucose level. Objective: The current study aimed to investigate the inhibitory potentials of the key digestive enzymes, α-amylase and α-glucosidase, by betel leaf extracts and blood glucose lowering activities using diabetic mice. Methods: In vitro inhibitory potentials of the key enzymes linked to type 2 diabetes mellitus (viz. α-amylase and α-glucosidase) by the betel leaf (Piper betle) extracts, including the study on the mode of enzyme inhibition, were evaluated spectrophotometrically and in vivo blood glucose lowering activities were assessed using alloxan-induced diabetic mice. Results: Betel leaf extracts showed potential α-amylase and α-glucosidase inhibition activities and blood glucose lowering activities. Among the extracts, young deshi betel leaf extract demonstrated the highest α-amylase inhibition activity, while young khasia betel leaf extract exhibited the lowest α-amylase inhibition activity. Young khasia betel leaf extract showed the maximum α-glucosidase inhibition activity. However, the lowest α-glucosidase inhibition activity was found with deshi betel leaf extracts. Betel leaf extract inhibited α-amylase and α-glucosidase activities through competitive inhibition. In vivo study revealed that among the extracts, young deshi and khasia leaf extract reduced blood glucose levels in all doses. Young deshi leaf extract exhibited significant (p<0.05) antidiabetic activity to reduce blood glucose level ˂ 6.9 mmol/L at a lower concentration. Conclusion: This study would open a new window for the researcher to find new antidiabetic bioactive compounds that would be cost-effective and without any adverse effects.