RESUMO
BACKGROUND: The role of oxidative stress in the genesis of various types of cancers is well established. Several chemical, cell culture and animal studies also indicate that antioxidants may slow or even prevent the development of cancer. Brain is considered abnormally sensitive to oxidative damage as brain tissue has high rate of oxygen consumption, high lipid content and relatively low antioxidant defenses, compared to other tissues. MATERIALS AND METHODS: The study design chosen for the present study was cross sectional. The biochemical parameters that were estimated in saliva manually using spectrophotometric methods were ferric reducing antioxidant power (FRAP) assay--a direct measure of total antioxidant activity of biological fluids and protein thiols. The physical parameters of saliva that were also assessed were salivary flow rate, pH of the saliva and the osmolality of the saliva. RESULTS: The mean values of salivary flow rate and pH were significantly decreased among malignant and benign tumor patients whereas the salivary osmolality was significantly increased in both the groups of patients. The mean values of salivary FRAP were significantly reduced among malignant and benign tumor patients. However, the salivary protein thiols were significantly increased in these patients. CONCLUSION: Hence with these observations it can be concluded that in saliva, besides the physical characteristics, salivary FRAP and protein thiol levels are appropriate indicators of the antioxidant status in brain tumor patients.
