Inhibitory Effect of Azadirachta indica A. Juss Leaf Extract on the Activities of α-Amylase and α-Glucosidase

In recent decades, there has been a drastic increase in the incidence and prevalence of diabetic mellitus. The aim of this study was to evaluate the in vitro inhibitory effect of Azadirachita indica leaf extract on the activity of alpha-amylase and alpha-glucosidase as a means of alleviating hyperglycemia and managing diabetes mellitus. Aqueous extract of Azadirachita indica exhibited most potent alpha-amylase inhibitory activity with IC50 value of 9.15 mg mL(-1) and acetone extract exhibited most potent alpha-glucosidase inhibitory activity with IC50 value of 5.00 mg mL(-1). Kinetic studies revealed both acetone and aqueous extract to exhibit mixed non-competitive inhibition for alpha-amylase and alpha-glucosidase. It can be concluded that the antidiabetic potential of Azadirachta indica may be due to its ability to inhibit both alpha-amylase and alpha-glucosidase. The presence of phytochemicals such as flavonoids, tannins and saponins in this plant may be responsible for its inhibitory activity on the two enzymes studied.