eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2026-10-10 23 3 59930 article Vardhana Janakiraman 1 Spriha Bairagi 1 Department of Biotechnology, School of Life Sciences, Vels Institute of Science, Technology, And Advanced Studies (VISTAS), Chennai, India The Diabetes mellitus is characterized by persistent hyperglycemia and associated metabolic complications. Pomegranate (Punica granatum) peel is rich in polyphenolic and flavonoid compounds and has reported biological activity. The present study investigated the green synthesis and characterization of iron-containing nanoparticles using aqueous pomegranate peel extract and evaluated their in vitro α-amylase inhibitory activity. Aqueous pomegranate peel extract was reacted with ferric chloride, followed by characterization using UV–Vis spectroscopy, FTIR, XRD, SEM, EDS, and DLS. A change in color from pale yellow to black and an absorption maximum at approximately 268 nm were observed after synthesis. FTIR indicated hydroxyl, carbonyl and Fe–O-associated bands. SEM showed predominantly spherical particles with primary particle diameters of 17.18–27.76 nm, whereas DLS showed hydrodynamic size distributions of approximately 250–600 nm, consistent with aggregation and/or a phytochemical-associated hydration layer. The aqueous peel extract and the synthesized FeONPs showed concentration-dependent α-amylase inhibitory activity. At the highest tested sample volume, the extract showed 89.61% inhibition and the FeONPs showed 80.34% inhibition. These findings demonstrate in vitro α-amylase inhibitory activity of both the pomegranate peel extract and the synthesized iron-containing material; however, therapeutic antidiabetic efficacy, safety, mechanism, and in vivo effectiveness remain to be established. https://www.biotech-asia.org/vol23no3/invitro-antidiabetic-evaluation-of-biogenic-iron-oxide-nanoparticles-derived-from-punica-granatum-peel-extract/ Amylase Inhibition; Antidiabetic Activity; Diabetes Mellitus; Green Synthesis; Iron Oxide Nanoparticles; Punica granatum