A Comparative Study of Ferulic Acid on Different Monosaccharide-Mediated Protein Glycation and Oxidative Damage in Bovine Serum Albumin

Three dietary monosaccharides, (glucose, fructose, and ribose), have different rates of protein glycation that accelerates the production of advanced glycation end-products (AGEs). The present work was conducted to investigate the effect of ferulic acid (FA) on the three monosaccharide-mediated protein glycations and oxidation of BSA. Comparing the percentage reduction, FA (1–5 mM) reduced the level of fluorescence AGEs (F-AGEs) and N(ε)-(carboxymethyl) lysine (N(ε)-CML) in glucose-glycated BSA (F-AGEs = 12.61%–36.49%; N(ε)-CML = 33.61%–66.51%), fructose-glycated BSA (F-AGEs = 25.28%–56.42%; N(ε)-CML = 40.21%–62.91%), and ribose-glycated BSA (F-AGEs = 25.63%–51.18%; N(ε)-CML = 26.64%–64.08%). In addition, the percentages of FA reduction of fructosamine (Frc) and amyloid cross β-structure (Amy) were Frc = 20.45%–43.81%; Amy = 17.84%–34.54% in glucose-glycated BSA, Frc = 25.17%–36.92%; Amy = 27.25%–39.51% in fructose-glycated BSA, and Frc = 17.34%–29.71%; Amy = 8.26%–59.92% in ribose-glycated BSA. FA also induced a reduction in protein carbonyl content (PC) and loss of protein thiol groups (TO) in glucose-glycated BSA (PC = 37.78%–56.03%; TO = 6.75%–13.41%), fructose-glycated BSA (PC = 36.72%–52.74%; TO = 6.18%–20.08%), and ribose-glycated BSA (PC = 25.58%–33.46%; TO = 20.50%–39.07%). Interestingly, the decrease in fluorescence AGEs by FA correlated with the level of N(ε)-CML, fructosamine, amyloid cross β-structure, and protein carbonyl content. Therefore, FA could potentially be used to inhibit protein glycation and oxidative damage caused by monosaccharides, suggesting that it might prevent AGEs-mediated pathologies during diabetic complications.