Lipid peroxidation and antioxidant capacity in selected tissues of healthy black C57BL/6J mice and B16 melanoma-bearing mice

During the process of melanogenesis free radicals are generated. The aim of this study was to investigate the effects of melanogenesis in B16 melanoma on lipid peroxidation and antioxidant capacity in selected tissues of black C57BL/6J mice. The study was conducted on 24 mice: 12 healthy controls and 12 with a transplanted B16 melanoma. Two weeks after the melanoma transplant, when the average weight of the tumours was approximately 2.0 g, blood samples were taken from the orbital venous plexus. The mice were killed by dislocation of the spinal cord, and the brain, liver and lungs were removed for analysis. The level of thiobarbituric acid-reactive substances (TBARS) and of 1,1-diphenyl-2-picrylhydrazyl (DPPH) reactive substances were determined in full liver, lung and brain homogenates and in serum. The activity of superoxide dismutase (SOD) was determined only in homogenized tissue. The concentration of TBARS and the SOD activity were statistically significantly higher in all the studied tissues from mice with B16 melanoma than in tissues from healthy mice. The antioxidant capacity, however, was lower in the tissues of melanoma-bearing mice. The results obtained demonstrate an increase in oxidative stress in the tissues of mice bearing a transplanted B16 melanoma.