Methylglyoxal and advanced glycation endproducts: new therapeutic horizons?

Advanced glycation endproducts (AGEs) are unavoidable byproducts of various metabolic pathways. They are formed by reactive metabolic intermediates such as methylglyoxal (MG), glyoxal, and 3-deoxyglucosone. These reactive intermediates bind to proteins, DNA, and other molecules and disrupt their structures and functions, which leads to different diseases such as vascular complications of diabetes, atherosclerosis, hypertension, Alzheimer's disease, and aging. In recent years, more compounds that prevent the formation of AGEs or degrade the existing AGEs have been produced and patented. They include: 1) aminoguanidine, 2) drugs used in the treatment of type 2 diabetes such as metformin and pioglitazone (patented), 3) angiotensin receptor blockers and angiotensin converting enzyme inhibitors, 4) pentoxyfylline (patented), 5) metal ion chelators desferoxamine and penicillamine, 6) antioxidants such as vitamin C or E, 7) amino group capping agents such as aspirin, 8) enzymes that cause deglycation of Amadori products, the Amadoriases, 9) compounds that mostly break alpha-dicarbonyl cross-links such as phenacylthiazolium bromide and its stable derivative ALT-711 (Alagebrium), and 10) derivatives of aryl ureido and aryl carboxaminido phenoxy isobutyric acids (patented). While some of these anti-AGE compounds are being used in clinical practice (such as metformin, pioglitazone, pentoxyfylline and aspirin) or tested in clinical trials (such as aminoguanidine and ALT-711), most of them are commonly used as experimental tools to investigate the role of AGEs in different disease conditions.