Effect of bitter leaf (Vernonia amygdalina) aqueous extract on pancreatic α-amylase and intestinal α-glucosidase repressive potentials of Acarbose

Abstract

There is a continuous search for antidiabetic drugs. The available synthetic drugs, including Acarbose could only provide temporary relief with some negative effects. This has resulted in the co-administration of Acarbose with plants possessing antidiabetic potential such as bitter leaf. In Nigeria, co-administration of bitter leaf (BL) vegetable with acarbose (a synthetic inhibitor of α-amylase and α-glucosidase) in the management of Type-2 diabetes mellitus is on the increase, basically to potentiate the therapeutic value and amelioration of side effects of Acarbose. However, there is no information on the influence of BL on the effectiveness of Acarbose. This study determined the influence of BL on the α-amylase and α-glucosidase inhibitory properties of Acarbose. BL extract, acarbose and their combinations (75:25, 50:50, and 25:75) were prepared and their effect on α-amylase and α-glucosidase, and the production of Fe²⁺-induced thiobabituric reactive acid species (TBARS) in pancreas homogenate were determined. Results revealed that all the combinations exhibited the antagonistic effect except 50:50 combined ratios, which exhibited additive effects. All the samples inhibited TBARS production except 100% Acarbose. This study shows that the use of bitter leaf with Acarbose could reduce the potency of Acarbose or the bitter leaf.