Alpha-glucosidase inhibitory activities of astilbin contained in Bauhinia strychnifolia Craib. stems: an investigation by in silico and in vitro studies

Abstract

Abstract Introduction Bioactive compounds from traditional medicines are good alternatives to standard diabetes therapies and may lead to new therapeutic discoveries. The stems of Bauhinia strychnifolia Craib. (BC) have a possible antihyperglycemic effect; However, the extraction of astilbin from BC has never been recorded in alpha-glucosidase inhibitory activities. Methods Using liquid chromatography–mass spectrometry (LC–MS/MS), 32 compounds were detected in the BC extract. The screening was based on peak area. Seven compounds found. PASS recognized all seven compounds as potential alpha-glucosidase (AG) inhibitors. Astilbin and quercetin 3-rhamnoside were the most likely inhibitors of AG. Arguslab, AutoDock, and AutoDock Vina investigated the binding of the two compounds and AG. The binding stability was confirmed by molecular dynamics (MD). In addition, the optimum solvent extraction was studied via CosmoQuick, and extracts were examined with 1H-NMR prior to testing with AG. Results All three software programs demonstrated that both compounds inhibit AG more effectively than acarbose. According to the sigma profile, THF is recommended for astilbin extraction. The BC extract with THF showed outstanding AG inhibitory action with an IC50 of 158 ± 1.30 µg mL-1, which was much lower than that of the positive control acarbose (IC50 = 190 ± 6.97 µg mL-1). In addition, astilbin from BC was found to inhibit AG strongly, IC50 = 22.51 ± 0.70 µg mL-1 through the extraction method of large-scale astilbin with THF has the best extraction capacity compared to other solvents, hence the initial stage of extraction employs THF to extract and precipitate them with ethyl acetate and water. Conclusion In silico and in vitro studies reveal that astilbin inhibits AG and is superior to acarbose, validating its promise as an AG inhibitor. Overall, astilbin was the most bioactive component of BC for antidiabetic action.

Keywords

• Bauhinia strychnifolia Craib.
• Astilbin
• Alpha-glucosidase
• Antihyperglycemic effect