Hypoglycaemic activity of the anthocyanin enriched fraction of Lycium ruthenicum Murr. Fruits and its ingredient identification via UPLC–triple-TOF-MS/MS

Lycium ruthenicum Murr. is mainly distributed in the northwest region of China and its berries are rich in anthocyanin. This study evaluated the hypoglycaemic activity of the anthocyanin-enriched fraction (AEF) of L. ruthenicum Murr. on α-glucosidase in vivo and in vitro. Overall, 10 anthocyanins were identified via UPLC–Triple-TOF-MS/MS. The AEF exhibited strong inhibitory activity against α-glucosidase, with an IC50 value of 4.468 mg/mL. It behaved as a reversible, mixed-type inhibitor. Molecular docking and dynamic results indicated that the compounds in AEF interacted with enzymes primarily through van der Waals and hydrogen bond and the complex system was stable. The postprandial blood glucose and area under the curve of diabetic mice was significantly decreased by AEF in the carbohydrate tolerance experiments. The results indicate that the AEF from L. ruthenicum Murr. berries could be as a promising food supplement for managing blood sugar levels in patients with diabetes mellitus.