Effect of macromolecular crowding on the inhibition of non-enzymatic glycation of bovine serum albumin by cichoric acid

The inside of the cell is closely filled with diverse biological macromolecules , which will affect various physiological activities in vivo . It is known that natural products have beneficial effects against the formation of advanced glycation end products (AGEs), but their inhibitory actions in macromolecular crowding environment are still poorly understood. Therefore, to investigate the influence of macromolecular crowding environment, the inhibitory effect of cichoric acid (CA) on the non-enzymatic glycation of bovine serum albumin (BSA) in the absence and presence of crowding reagents (PEG 2000 and PEG 4000) was studied. The results demonstrated that CA could significantly inhibit the formation of AGEs than aminoguanidine in the BSA-fructose model with or without PEG, and the inhibition effect in PBS solution was better than that in macromolecular crowding environment. Moreover, CA presented strong antioxidant capacity and trapping ability of glyoxal, and could stabilize the native structure of BSA caused by the glycation modification, which might be the primary mechanisms for its anti -glycation effect. Additionally, CA tended to bind to site I of BSA mainly through hydrogen bonds and hydrophobic interactions. These findings indicated that CA could be regarded as a high potential anti -glycation inhibitor to prevent the development of diabetic complications.