Presence of Isorhamnetin-3-O-Rutinoside Enhances Interaction of Acarbose With α-Amylase/α-Glucosidase

Studies indicated that some active flavonoids combined with acarbose could reduce the side effects of acarbose and enhance its efficacy. Isorhamnetin-3-O-rutinoside (IOR) is a flavonoid found in many edible herbs. In this work, the synergistic effects of IOR and acarbose on α -amylase/α-glucosidase (PA/AG) were evaluated using ZIP score analysis. In the presence of IOR, the binding constant K b values of acarbose with PA/AG were significantly improved, indicating that IOR exhibited synergistic effect with acarbose by increasing its K b values. Furthermore, in the presence of IOR, acarbose resulted in greater changes in microenvironment and secondary structure of PA/AG. The docking analysis confirmed that IOR and acarbose bound to the different sites of PA/AG. Compared with pure enzyme, the complexes formed by IOR/acarbose with two enzymes were more stable based on dynamics simulations. This study suggested that IOR might be used as a potential synergistic inhibitor of acarbose.