The Inhibition Mechanisms of Three Structurally Different Salvianolic Acids on the Non-Enzymatic Glycation of Bovine Serum Albumin

The antiglycation mechanisms of three structurally different salvianolic acids (Sals) including salvianolic acid A (Sal-A), salvianolic acid B (Sal-B) and salvianolic acid C (Sal-C) were investigated using the bovine serum albumin (BSA)-fructose model. The results showed that the three compounds could inhibit the formation of glycation products, maintain protein structural stability, mitigate the development of amyloid fibrils and scavenge radicals. Notably, Sal-A possessed the highest anti-glycated activity compared with Sal-B and Sal-C. This may be related to the fact that Sal-A contained the most molecules of caffeic acid (Sal-A, Sal-B, and Sal-C possessing two, one, and zero caffeic acid units, respectively), and caffeic acid played a leading role in the antiglycation properties relative to Danshensu. Moreover, these compounds quenched the intrinsic fluorescence intensity of BSA in a static mode, with the binding constants in the order of Sal-A > Sal-B > Sal-C. Obviously, Sal-A possessed the strongest binding affinity among these compounds, which may be one of the reasons why it exhibited the optimal antiglycation capability. Furthermore, molecular docking demonstrated that the three Sals exerted protective effects on BSA by preventing glycation modification of lysine and arginine residues. These findings would provide valuable insights into the potential application of Sals for alleviating non-enzymatic glycation of protein.