Inhibition of α‐glucosidase activity by curcumin loaded on ZnO@rGO nanocarrier for potential treatment of diabetes mellitus

Abstract

Curcumin (Cur) is an acidic polyphenol with some effects on α‐glucosidase (α‐Glu), but Cur has disadvantages such as being a weak target, lacking passing the blood–brain barrier and having low bioavailability. To enhance the curative effect of Cur, the hybrid composed of ZnO nanoparticles decorated on rGO was used to load Cur (ZnO@rGO‐Cur). The use of the multispectral method and enzyme inhibition kinetics analysis certify the inhibitory effect and interaction mechanism of ZnO@rGO‐Cur with α‐Glu. The static quenching of α‐Glu with both Cur and ZnO@rGO‐Cur is primarily driven by hydrogen bond and van der Waals interactions. The conformation‐changing ability by binding to the neighbouring phenolic hydroxyl group of Cur increased their ability to alter the secondary structure of α‐Glu, resulting in the inhibition of enzyme activity. The inhibition constant (Ki, Cur > Kis,ZnO@rGO‐Cur) showed that the inhibition effect of ZnO@rGO‐Cur on α‐Glu was larger than that of Cur. The CCK‐8 experiments proved that ZnO@rGO nanocomposites have good biocompatibility. These results suggest that the therapeutic potential of ZnO@rGO‐Cur composite is an emerging nanocarrier platform for drug delivery systems for the potential treatment of diabetes mellitus.