| Abstract: | The antioxidant activity of duroquinone and hypoxen was compared with that of alpha-tocopherol and vitamin C in a model system (luminol-peroxidase-H2O2), and their influence on the level of reactive oxygen species in systems containing polymorphonuclear leukocytes of healthy and tumor-bearing animals was studied. It was shown that, in a model chemical system, the concentrations of antioxidants (the inverse of antioxidant activity) necessary to decrease twice the intensity of the chemiluminescence answer (C50%) are arranged in the following order: alpha-tocopherol > duroquinone > hypoxen > ascorbic acid. In this case, the concentrations of the hydrophobic antioxidants (C50% for alpha-tocopherol and duroquinone 10-30 mkM) should be 20-50 times higher than for hydrophilic antioxidants (C50% for vitamin C and hypoxen 0.5-0.6 mkM). It was revealed that the generation of reactive oxygen species by blood phagocytes of tumor-bearing animals is 2-2.5 times higher than by phagocytes of healthy animals. The antioxidant concentration necessary to decrease the chemiluminescence answer in the cellular system should be one order of magnitude higher than in the model chemical system. The distribution of a hydrophobic antioxidant between water/lipid phases promotes an increase in the concentration of the antioxidant necessary to decrease the level of reactive oxygen species twice. Thus, the major factor influencing the antioxidant activity is the constant of distribution of these compounds in a water/lipid system. |
