In Vitro α-Glucosidase Inhibitory Activity of Ethanol Extract from Ficus elastica Leaves

Abstract

Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels and may lead to multiple complications. One strategy for controlling postprandial hyperglycemia is inhibition of the α-glucosidase enzyme. Although synthetic inhibitors such as acarbose are effective, they are frequently associated with gastrointestinal adverse effects, highlighting the need for alternatives derived from natural products. This study aimed to determine the in vitro α-glucosidase inhibitory activity of an ethanol extract of Ficus elastica leaves. The assay was performed spectrophotometrically using p-nitrophenyl-α-D-glucopyranoside (pNPG) as the substrate, and absorbance was measured at 405 nm with a microplate reader. Acarbose was used as the positive control. The ethanol extract showed concentration-dependent α-glucosidase inhibition. The highest inhibition was 71.437% at 400 µg/mL. The extract had an IC₅₀ value of 264.694 µg/mL, whereas acarbose had an IC₅₀ of 0.589 µg/mL. Although the inhibitory potency of the extract was substantially lower than that of acarbose, these findings indicate that Ficus elastica leaves may serve as a natural source of α-glucosidase inhibitors and support further investigation of their potential as a plant-based antidiabetic candidate.