Exploring the α-Glucosidase Inhibitory Activity of Bioactive Compounds from Persicaria odorata (Lour.) Extracts via Integrated In Vitro and In Silico Studies.

Persicaria odorata (Lour.) contains considerable amounts of phytochemicals, including phenolics and essential oils, which have been reported to inhibit α-glucosidase activity. However, which bioactive compounds play a key role in inhibiting the α-glucosidase activity is unclear. To address this issue, the methanolic extract of P. odorata was assayed via in vitro studies, and forty-four compounds in P. odorata extracts were elucidated using in silico studies. The extract strongly inhibited yeast α-glucosidase with an IC50 value of 0.31 µg/mL, which was 450-fold more potent than acarbose (IC50 = 139.47 µg/mL), under experimental conditions. The Lineweaver-Burk plots indicated that the inhibition type of the extract on α-glucosidase is a noncompetitive inhibitor. Molecular docking demonstrated that procyanidin B (P9) and rutin (P19), which belong to the flavonoids, were predicted by computational approaches to be bioactive compounds that have more favorable binding interactions to yeast α-glucosidase residues compared to forty-four other compounds and acarbose. Molecular dynamics simulations revealed that P9 and P19 complexes with yeast α-glucosidase remained stable during the 500 ns simulations. Moreover, both P9 and P19 were predicted to qualify as α-glucosidase inhibitors with low toxicity. These findings suggest that P. odorata could be used as an alternative edible plant to manage postprandial hyperglycemia in T2DM, and could serve as basic scientific data. Further experimental studies of the pure bioactive compounds are necessary to support these findings.