Comparative Evaluation of Saliva’s Oxidant–Antioxidant Status in Patients with Different Clinicopathological Types of Oral Leukoplakia

OBJECTIVES: Despite advancements in the management of oral cancer, the mortality rate associated with it still remains a matter of concern. Early identification and intervention of precursor lesions such as leukoplakia have always been emphasized, as this can drastically improve the scenario. The oxidative stress has been implicated in the pathogenesis of several diseases, including oral cancer. The aim of this study was to evaluate salivary oxidant and antioxidant levels in patients with different clinicopathological stages of oral leukoplakia. MATERIALS AND METHODS: An analytical study with case–control study design was conducted. Forty newly diagnosed cases of oral leukoplakia were considered in the case group. The equal number of age- and gender-matched subjects was included in the control study group. Unstimulated whole-saliva supernatant was used to determine the levels of lipid peroxidation, glutathione S-transferase, nitrites, and uric acid using ultraviolet visible spectrophotometer. The statistical comparisons were performed by independent Student’s unpaired t test and one-way analysis of variance with post hoc analysis. Correlation analysis was performed among salivary parameters and with baseline variables. RESULTS: End products of free radical damage and nitrite levels were significantly increased in patients with oral leukoplakia compared to controls. Conversely, levels of glutathione S-transferase and uric acid were significantly decreased in the study group in comparison with healthy subjects. Similar trends were seen along the clinical stages and histopathological grades of leukoplakia. CONCLUSION: Elevated levels of reactive species with a concomitant reduction in antioxidants in leukoplakia indicate its potential as an early diagnostic marker.