In Vitro Antidiabetic and Anti-Glycation Potential of the Ethanolic Root Extract of Marsdenia tenacissima: Enzyme Inhibition and Molecular Docking Studies

ABSTRACTBackground: Regulation of postprandial hyperglycemia through inhibition of carbohydratedigesting enzymes and prevention of advanced glycation end product formation represents animportant pharmacological approach in diabetes mellitus. Marsdenia tenacissima is amedicinal plant rich in steroidal and phenolic constituents, but its antidiabetic potential hasnot been adequately characterised.Objectives: The present study evaluated the in vitro α-amylase, α-glucosidase, and antiglycation activities of the ethanolic root extract of M. tenacissima (EEMT) and exploredpossible interactions of selected phytoconstituents with human maltase-glucoamylase usingmolecular docking.Materials and Methods: Roots of M. tenacissima were shade-dried, powdered, andextracted with 95% ethanol using Soxhlet extraction. Preliminary phytochemical screeningwas performed. α-Amylase inhibition was evaluated by the DNSA method, α-glucosidaseinhibition by the p-nitrophenyl-α-D-glucopyranoside method, and anti-glycation activityusing a BSA-glucose fluorescence model. IC₅₀ values were determined from concentrationresponse relationships. Selected phytoconstituents were docked against the N-terminalcatalytic domain of human maltase-glucoamylase (PDB ID: 3L4Y).Results: EEMT yielded 13.2% w/w extract. The extract produced concentration-dependent α-amylase inhibition with an IC₅₀ of 183.62 µg/mL compared with 96.41 µg/mL for acarbose.α-Glucosidase inhibition was stronger, with an IC₅₀ of 142.87 µg/mL compared with 78.35µg/mL for acarbose. Anti-glycation activity demonstrated an IC₅₀ of 206.74 µg/mL comparedwith 118.29 µg/mL for aminoguanidine. Molecular docking showed predicted binding scoresof -9.8, -8.9, and -8.6 kcal/mol for tenacigenin B, quercetin, and kaempferol, respectively.Conclusion: EEMT demonstrated concentration-dependent inhibition of carbohydratedigesting enzymes and protein glycation. Molecular docking provided computational supportfor possible interactions of selected phytoconstituents with human maltase-glucoamylase. Further fractionation, mechanistic, cellular, and in vivo studies are required to establish thepharmacological significance of these findings.