Antioxidant capacity and α-glucosidase inhibitor activity of Bryonia aspera extracts and its major constituent p-coumaric acid: Phytochemical analysis, biological evaluation and computational approach

This study comprehensively investigated the phenolic composition, antioxidant potential, and α-glucosidase inhibitory properties of B. aspera Steven ex Ledeb. extracts using integrated in vitro and in silico approaches. LC-MS/MS analysis identified seven major phenolic compounds, caffeic acid, chlorogenic acid, galangin, gallic acid, naringenin, p-coumaric acid, and rutin, with p-coumaric acid being the most abundant (306.71 mg/kg in aerial and 155.56 mg/kg in root extracts). Both extracts exhibited strong antioxidant and α-glucosidase inhibitory activities, particularly the aerial extract (IC50 = 0.678 and 0.173 for DPPH, ABTS, respectively and 0.022 mg/mL for α-glucosidase inhibition). Molecular docking and MM-GBSA analyses supported these findings, showing that p-coumaric acid had the strongest binding to α-glucosidase (–7.783 kcal/mol, ΔG = –47.76 kcal/mol), stabilized by key interactions with Asp-62, Arg-200, His-332, and Arg-400. A 250 ns molecular dynamics simulation confirmed the stability of the complex, and in silico ADME analysis revealed good oral absorption (67%) and compliance with Lipinski’s rule. Overall, results indicate that p-coumaric acid is the primary bioactive compound contributing to the antioxidant and α-glucosidase inhibitory activity of B. aspera, with promising potential as a natural lead for α-glucosidase inhibition.