Glycation of β-lactoglobulin and antiglycation by genistein in different reactive carbonyl model systems

Advanced glycation end products (AGEs), which are formed in β-lactoglobulin (β-lg) glycation systems via the Maillard reaction, have been implicated in diabetes-related long-term complications. In the present study, we found that reaction conditions, including temperature, time, pH, reactant type and molar ratio of beta-lg to a sugar/MGO/GO, can significantly affect the formation of AGEs. Using SDS-PAGE, we further demonstrated that genistein, a natural isoflavone found in a number of plants including soybeans and kudzu, can efficiently inhibit cross-links of the glycated β-lg, and suppress the formation AGEs in a dose-dependent manner by trapping reactive dicarbonyl compounds. The products formed from genistein and methylglyoxal (MGO) in the β-lg-MGO assay were analyzed using LC/MS. Both mono-MGO and di-MGO adducts of genistein were detected with this method.