Inhibition of lipid peroxidation and nonlipid oxidative damage by carnosine

The antioxidant effects of carnosine on lipids and nonlipids, including liposomes, carbohydrates, and proteins, were investigated. Carnosine exhibited a remarkable antioxidant effect in liposome and deoxyribose model systems. Carnosine at high amounts (50 mg/mL) was effective in protecting protein against oxidation. The correlation coefficients between reducing ability and the inhibition of liposome, albumin, and deoxyribose oxidation were r=0.92, 0.83, and 0.41, respectively. Carnosine exhibited metal-binding ability and scavenging ability for hydroxyl radicals generated by photolysis of H₂O₂ with UV light. The correlation coefficients between hydroxyl radical scavenging and the inhibitory effect on deoxyribose, liposome, and albumin oxidative damage were r=0.97, 0.60, and 0.29, respectively. These properties may explain how carnosine protects lipids and non-lipids against oxidative damage.