Prevention of haemoglobin glycation by acetylsalicylic acid (ASA): A new view on old mechanism

Diabetic hyperglycemia provokes glycation of haemoglobin (Hb), an abundant protein in red blood cells (RBCs), by increasing its exposure to carbohydrates. Acetylsalicylic acid (ASA; Aspirin) is one of the first agents, which its antiglycation effect was witnessed. Although the precise molecular mechanism of action of ASA on protein glycation is not indisputably perceived, acetylation as its main molecular mechanism has been proposed. This report aims to unravel the meticulous mechanism of action of ASA by using two ASA analogues; benzoic acid (BA) and para-nitrobenzoic acid (NBA), despite their lack of acetyl group. In this regard, the inhibitory effect of these two chemicals in comparison with ASA on Hb fructation is reported. UV-visible spectroscopy, intrinsic advanced glycation end products (AGE) fluorescence spectroscopy, extrinsic thioflavin T (ThT) binding fluorescence spectroscopy, 2,4,6-trinitrobenzenesulfonic acid (TNBSA) assay, and single cell gel electrophoresis (SCGE) were used to explore the effects of BA and NBA in comparison with aforementioned chemicals in the context of protein glycation. In spite of the lack of acetyl substitution, NBA is reported as a novel agent with prominent inhibitory efficacy than ASA on the protein glycation. This fact brings up a possible new mechanism of action of ASA and reconsiders acetylation as the sole mechanism of inhibition of protein glycation.