Total Flavonoid Content, Total Phenolic Content, and Antihyperglycemic Effect, of 70% Ethanol Extract of Neem (Azadirachta indica A. Juss) Leaves

Abstract

Diabetes mellitus is a chronic metabolic disorder characterized by impaired insulin secretion, insulin resistance, or both, leading to persistent hyperglycemia. The search for alternative antidiabetic agents has led to the exploration of medicinal plants, including neem (Azadirachta indica A. Juss), which has been used in ethnomedicine for the treatment of diabetes. This study aimed to identify the bioactive constituents of A. indica leaves and evaluate its effective dose as an antihyperglycemic agent in mice. The powdered herb and 70% ethanol extract of A. indica leaves were subjected to qualitative phytochemical screening according to standard procedures.
Total flavonoids and phenolic contents of the extract were determined spectrophotometrically. The antihyperglycemic effect was assessed through oral glucose tolerance tests. The powdered herb and extract of A. indica leaves contained alkaloids, flavonoids, saponins, tannins, phenols, and steroids. The total flavonoid and phenolic contents were 20.209 ± 0.30 mg QE/g and 43.26 ± 0.57 mg GAE/g extract, respectively. The extract demonstrated significant dose-dependent antihyperglycaemic effect with percentage blood glucose reduction of 26.57%, 32.68%, and 41.11% at 100, 300, and 500 mg/kg BW, respectively. The 300 mg/kg BW and 500 mg/kg BW doses of the extract exhibited significant (p < 0.01) higher glucose-lowering effects than that of metformin (500 mg/kg BW). These findings suggest that A. indica extract has potent postprandial glucose-lowering activity, likely due to its high phenolic, and flavonoid contents supporting its potential as a natural antidiabetic agent.