Antidiabetic potential of a novel hydroxyphenyl-bi-benzopyran-hexol compound from Cassia fistula as an α-amylase inhibitor: Integrated in silico screening and in vitro validation using a nonlinear regression model

Background Diabetes mellitus is a critically important metabolic disease, causing persistent hyperglycemia. Blood glucose levels can be effectively maintained by inhibiting the activity of α-amylase. α-amylase inhibitors manage postprandial hyperglycemia by delaying carbohydrate digestion. Objectives Identification of a potent α-amylase inhibitor from 915 bioactive compounds of Madhumukthi Kudineer Chooranum (MKC) by combining siddha knowledge with computational and experimental methods. Materials and methods Molecular docking of bioactive compounds present in MKC with α-amylase was performed, and the top ten compounds that exhibited binding affinities better than the standard inhibitor acarbose were evaluated for Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) properties, followed by Molecular Dynamics Simulations (MDS). An in vitro enzyme inhibition assay was performed for the top lead for validation of the in silico findings. Results Lead 2, Hydroxyphenyl-bi-benzopyran-hexol from Cassia fistula demonstrated the stable protein-ligand interaction with a binding energy of −69.70 ± 3.93 kJ/mol. The crude Cassia fistula stem bark extract containing Lead 2 showed 57% inhibition of α-amylase. The IC 50 values were calculated using a nonlinear regression approach based on a 4-parameter logistic (4 PL) model, yielding a lower IC 50 value of 237.25 μg/ml for the extract, compared to the IC 50 value of 264.59 μg/ml for acarbose. Conclusion By integrating traditional siddha knowledge with advanced computational screening and in vitro validation, this study proposed a novel Hydroxyphenyl-bi-benzopyran-hexol compound from Cassia fistula as a promising natural α-amylase inhibitor. However, these findings are to be validated using animal studies before clinical research leading to a novel drug.