Oxidative stress status and DNA damage in saliva of human subjects with oral lichen planus and oral squamous cell carcinoma.

BACKGROUND: The aim of this study was to evaluate oxidative stress status in the saliva of patients with oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC).

METHODS: Thirty-two patients with OLP, 26 patients with OSCC, and 30 non-involved subjects were enrolled in this study. The study was conducted at the Cancer Department, Clinic of Oral Medicine, Tehran University of Medical Sciences. The unstimulated whole saliva malondialdehyde (MDA), as an indicator of lipid peroxidation, the total antioxidant capacity (TAC), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were assayed by thiobarbituric acid, ferric reducing antioxidant potential (FRAP), and ELISA method, respectively. The TAC/MDA ratio was used as an index of oxidative stress status. Data were analyzed by ANOVA followed by the Tukey's post hoc test.

RESULTS AND CONCLUSION: There were no significant differences in saliva TAC and MDA levels between OLP and control, and also between OLP and OSCC patients. MDA and 8-OHdG were significantly higher but TAC was lower in OSCC patients than control. TAC/MDA ratio was significantly lower in patients with OSCC than both OLP patients and control. TAC/MDA ratio was significantly lower but 8-OHdG was higher in patients with OLP compared to control. This suggests that patients with OLP and OSCC are more susceptible to an imbalance of antioxidant-oxidative stress status.