Role of Carbonyl Stress in Aging and Age-Related Diseases

Summary The browning of proteins via the Maillard reaction in vivo involves nonenzymatic autoxidation and/or enzyme-catalysed oxidation of carbohydrates, lipids and amino acids. Carbohydrates also contribute to non-oxidative browning of proteins by rearrangement and elimination pathways which generate deoxydicarbonyl compounds, such as deoxyglucosone and methylglyoxal. A common feature of both the oxidative and non-oxidative reactions is the formation of reactive carbonyl compounds, suggesting that carbonyl stress, as well as oxidative stress, is involved in chemical modifications of proteins during the Maillard reaction. Oxidative stress may enhance the damage produced by carbonyl stress, both by providing an additional source of carbonyls and by limiting the rate of their detoxification.