Screening and identifying of α-amylase inhibitors from medicine food homology plants: Insights from computational analysis and experimental studies

There is a growing interest in screening alpha-amylase inhibitors from natural products for application in the development of new antidiabetic drugs or functional foods. In this study, a structure-based virtual screening was applied to rapidly identify the alpha-amylase inhibitors from medicine food homology (MFH) plants. Similarity search, docking & scoring were used for further filter small molecules. As a result, 21 corresponding potential alpha-amylase inhibitors from MFH plants were obtained. And, six polyphenol compounds (curcumin, procyanidins, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), hesperidin, and puerarin) were highlighted for further verification after a thorough assessment of the classification of hit molecules as well as docking scores. The results of the enzyme inhibition test showed that ECG, EGCG, and procyanidins had the better binding ability of alpha-amylase among these six polyphenols. The Ki values of ECG, EGCG, and procyanidins on alpha-amylase were 0.70, 1.68, and 0.24, respectively. The CD spectra results indicated that the three polyphenols can cause conformational changes in alpha-amylase. Practical applications A structure-based virtual screening method for rapid identifying alpha-amylase inhibitors from MFH plants was developed successfully in this study. These findings suggested that natural polyphenols such as ECG, EGCG, and procyanidins may be a potential inhibitor of alpha-amylase which could be used as a nutrient supplement for the prevention of diabetes mellitus or can be further used in the development of hypoglycemic drugs. At the same time, it can provide theoretical guidance for the better utilization and development of medicine food homology plants containing these potential alpha-amylase inhibitors. Moreover, this work may provide ideas and references for the screening of other target protein inhibitors.