Hypoglycemic effect and in vitro inhibition of α-amylase and α-glucosidase by aqueous extract of Adansonia digitata seeds

Abstract

Adansonia digitata L. (Malvaceae, Baobab) is a medicinal tree with antimicrobial, antiviral, anti-inflammatory, and antioxidant properties. The leaves, fruit pulp, stem bark, and roots have been extensively studied. The aim of this study was to evaluate the glucose-lowering and in vitro antidiabetic potentials of the aqueous extract of A. digitata seed. The aqueous extract of A. digitata seed was prepared by dissolving 50g of powder seed in 500 mL of distilled water for 24 hours, filtered using Whatman filter paper, and concentrated using a rotary evaporator at 45oC. Following an oral administration of glucose (2 g/kg bwt.), distilled water, metformin (14.2 mg/kg bwt.), and A. digitata seed extracts at 500 and 1000 mg/kg bwt. respectively. Results show that the untreated mice had an average of 11.09% increase in plasma glucose concentration, while metformin, aqueous seed extract of A. digitata had an average of 17.05%, 0.99%, and 19.21% decrease in plasma glucose concentration respectively. The aqueous seed extract of A. digitata inhibited α-amylase in a concentration-dependent manner with an IC50 of 24.27±2.14 mg/mL compared with acarbose with IC50 of 22.61±1.05 mg/mL. However, the α-glucosidase inhibitory activities of the extract (IC50 34.37±1.67 mg/mL) were significantly lower compared to acarbose (IC50 53.46±2.06). The study concludes tshat aqueous seed extract of A. digitata possesses glucose-lowering properties, in vitro α-amylase and α-glucosidase inhibitory potentials.