Abstract:
In this study, we established bovine serum albumin (BSA)-fructose and a BSA-methylglyoxal (MGO) model system to explore the inhibitory mechanisms of two flavonoids, naringenin and naringin, against advanced glycation end products (AGEs). The inhibitory effects of naringenin and naringin on the glycation products at different stages of the reaction and their protective effects on the protein structures were measured. Notably, the structures of the adducts formed by them and MGO were elucidated to further investigate their anti-glycation abilities. The results showed that the inhibitory rates of naringenin and naringin against AGEs increased with increasing concentration. When the naringenin and naringin concentration was 2 mg/mL, their inhibitory rates against AGEs in both the BSA-fructose and BSA-MGO systems were >80%, which was significantly higher (
P<0.05) than that of aminoguanidine. In terms of protein structure protection, they protected the microenvironment of protein fluorophores, with a fluorescence recovery rate of >40%. In addition, they increased the content of free sulfhydryl groups as well as the inhibitory rate against kynurenine, both of which reaching >95%. These increases effectively inhibited the formation of protein oxidation products. High-performance liquid chromatography-mass spectrometry (HPLC-MS) showed that both naringenin and naringin formed mono-adducts and bis-adducts after reacting with methylglyoxal (MGO). Collectively, our findings revealed that naringenin and naringin had good anti-glycation effects and inhibit AGEs through antioxidant action, thereby capturing intermediate products and chelating metal ions. These results indicate that naringenin and naringin can serve as safe and effective AGEs inhibitors with potential applications in food and medicine.