Carnosine Catalyzes the Formation of the Oligo/Polymeric Products of Methylglyoxal

Background/Aims: Reactive dicarbonyl compounds, such as methylglyoxal (MG), contribute to diabetic complications. MG-scavenging capacities of carnosine and anserine, which have been shown to mitigate diabetic nephropathy, were evaluated in vitro and in vivo. Methods: MG-induced cell toxicity was characterized by MTT and MG-H1-formation, scavenging abilities by Western Blot and NMR spectroscopies, cellular carnosine transport by qPCR and microplate luminescence and carnosine concentration by HPLC. Results: In vitro, carnosine and anserine dose-dependently reduced N-carboxyethyl lysine (CEL) and advanced glycation end products (AGEs) formation. NMR studies revealed the formation of oligo/polymeric products of MG catalyzed by carnosine or anserine. MG toxicity (0.3-1 mM) was dose-dependent for podocytes, tubular and mesangial cells whereas low MG levels (0.2 mM) resulted in increased cell viability in podocytes (143±13%, p