Abstract
Food antioxidants or reductones, ascorbic acid and its derivatives, monophenolics including α-tocopherol, polyphenolics in tea leaves and red wine, SH compounds including cysteine, carotenoids including β-carotene and other reductones, can scavenge reactive oxygen species, reactive nitrogen oxide species and lipid peroxy radicals. By contrast, these antioxidants or reductones can be converted into prooxidants in the presence of oxygen or act to produce harmful compounds. Formation of heterocyclic amine mutagens in the model system is inhibited by scavenging pyrazine cation radical with monophenolics, polyphenolics, ascorbate and SH compounds, and the mutagenicity in cooked hamburger is effectively inhibited by ascorbate. Formation of nitrosamines is effectively inhibited by ascorbate, but inhibited or stimulated by polyphenolics and monophenolics. Monophenolics are converted into possibly harmful nitroso-, nitro- and diazo-compounds by reaction with N2O3. Hydroxyfuranones found in the Maillard reactions and hydroxyhydroquinone found in coffee cause DNA single strand breaks by generation of reactive oxygen species, and cause lung lipid peroxidation and increased type IV and I allergy responses by oral administration to experimental animals. On the other hand, food polyunsaturated fatty acids, which has been so far considered to give deteriorate effect, are found to be protective against oxidative stress-induced DNA damage.
