Fig. 1.

Generation and metabolism of reactive lipid aldehydes. Increased production of superoxide anion (^•O₂⁻) leads to the production of the hydroxyl radical (^•OH) and subsequent lipid peroxidation (LOOH). This eventually results in the generation of a variety of reactive lipid aldehydes that can covalently modify proteins in a process called protein carbonylation. Under normal conditions, these lipids are detoxified by phase I and phase II antioxidant enzymes. In metabolic disease, the antioxidant milieu is depressed leading to accumulation of reactive aldehydes and protein carbonylation. SOD, superoxide dismutase; AO, alkenal/one oxidoreductase; AKR, aldo-keto reductase.