Galangin inhibits α-glucosidase activity and formation of non-enzymatic glycation products

Inhibition of alpha-glucosidase and non-enzymatic glycation is considered as an effective approach to treat type 2 diabetes. Herein, multispectroscopic techniques and molecular docking analysis were used to investigate the inhibition of galangin on alpha-glucosidase and non-enzymatic glycation. Galangin showed a reversible inhibition on a-glucosidase activity in a mixed-type manner through a monophasic kinetic process, and induced the fluorescence quenching and conformational changes of alpha-glucosidase by forming alpha-glucosidase-galgangin complex. Molecular docking revealed that galangin primarily interacted with the amino acid residues within the active site of alpha-glucosidase, which may prevent the entrance of substrate resulting in a decrease in catalytic efficiency of alpha-glucosidase. Moreover, galangin moderately inhibited the formation of intermediates of non-enzymatic glycation, fructosamine and alpha-dicarbonyl compounds and strongly inhibited the formation of advanced glycation end products.