Oxidant-antioxidant status in blood and tumor tissue of oral squamous cell carcinoma patients

Background and Objective: Increased oxidative and nitrosative stress associated with disturbances in antioxidant defense system have been implicated in the pathogenesis of several diseases, most notably oral cancer. The aim of this study was to evaluate the oxidant-antioxidant status in blood samples and tumor tissue in oral squamous cell carcinoma (OSCC) patients in comparison with the healthy controls. Methods: Blood and tumor tissue samples from the diseased individuals and the normal controls were analyzed for malondialdehyde (MDA) and nitric oxide (NO) as indicators of oxidative stress and nitrosative stress respectively; superoxide dismutase (SOD) and catalase enzymes as indicators of antioxidant defense by UV visible spectrophotometer. Results: Malondialdehyde and NO levels were significantly elevated in the blood and tissue samples of OSCC patients as compared with the healthy controls. The antioxidant enzymes SOD and catalase were significantly reduced in tissue samples of OSCC group than in the control group while in the erythrocytes, catalase levels were significantly reduced and the SOD levels were higher in OSCC group in comparison with the healthy controls. Interpretation and Conclusion: Increased levels of MDA and NO indicate an increase in the oxidative stress in OSCC patients associated with a deficient antioxidant defense mechanism. This oxidant-antioxidant imbalance may be considered as one of the factors responsible for pathogenesis of cancer. Future studies regarding assessment of oxidant-antioxidant status in OSCC patients in view of selecting appropriate mode of therapy and the effectiveness of such therapy in limiting the tumor progression and recurrence is to be carried out.