Background: Reactive oxygen species are involved in the pathogenesis of colorectal carcinoma. Clarification of oxidative/antioxidant specificities of different stages of colorectal carcinoma is of special importance.
Aim: To determine oxidative/antioxidant status in plasma of patients with different stages of colorectal carcinoma using malondialdehyde concentration, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities and distribution of superoxide dismutase isoforms.
Methods: Lipid peroxidation and antioxidant enzymes activity were estimated using spectrophotometric methods. Reverse zymography was applied for characterization of superoxide dismutase isoforms.
Results: Lipid peroxidation is increased in all groups compared to the control, but without differences between different stages of colorectal carcinoma. Total superoxide dismutase activity is lower in all colorectal carcinoma groups than in control, and there is a significant increase in tumor stage IV when compared with tumor stage II. Manganese superoxide dismutase isoform is dominant in all groups and its relative activities are significantly higher than activities of a copper/zinc isoform. Total peroxidase potential reflected in catalase and glutathione peroxidase activity is increased when compared to the control, but without any significant differences between colorectal carcinoma groups. Glutathione reductase activity is lower in all colorectal carcinoma groups than in control, and a significant decrease in glutathione reductase activity was obtained between patients in tumor stage II and III compared to tumor stage IV.
Conclusions: Colorectal carcinoma is characterized by increased oxidative stress and antioxidant disbalance. Progression of disease is followed by an increase in redox disbalance.