Enhanced α-glycosidase inhibition through synergistic interactions: A comprehensive analysis of dihydromyricetin and acarbose in vine tea extracts

Summary α-Glycosidase, a critical therapeutic target in type 2 diabetes mellitus (T2DM), can be modulated by inhibitors to reduce postprandial blood glucose levels. This study investigated the inhibitory effects of vine tea ( Ampelopsis grossedentata ) and its key compounds on α-glycosidase. The results demonstrated that fifteen varieties of vine tea extracts inhibited α-glycosidase in a dose-dependent manner, with IC 50 values ranging from 5.25 to 35.8 μg mL −1 . HPLC analysis revealed dihydromyricetin (DHM) as the main compound in vine tea, with an IC 50 value of 262.50 μM. Notably, the synergistic combination of DHM and the antidiabetic drug acarbose (ABS) significantly enhanced inhibitory effectiveness, with the optimal ratio (1:125) yielding a potentiation index (CI) of 0.09. Fluorescence and molecular docking analyses supported the hypothesis that DHM enhanced ABS's inhibitory effect through complex formation and specific interactions, offering a promising option for safer and more effective diabetes therapy.