An investigation of oxidative stress and coenzyme Q10 levels in patients with head and neck squamous cell carcinomas.

Objective: The purpose of this study was to determine the oxidative states of head and neck squamous cell carcinoma (HNSCC) patients by measuring their plasma levels of malondialdehyde (MDA), an indicator of lipid peroxidation, 3-nitrotyrosine (3-NT), an indicator of protein oxidation, and the coenzyme Q10 (CoQ10), an important antioxidant, and compare them with healthy individuals.

Materials And Methods: The plasma MDA, 3-NT and CoQ10 levels of 35 patients and 20 healthy individuals were measured with the high-performance liquid chromatography (HPLC) method. By comparing the patients' smoking habits, stage of the disease, size of the primary tumor and the presence of lymph nodes and the values of healthy individuals, the oxidative stress load of HNSCC patients was determined.

Results: The mean plasma MDA levels of carcinoma patients were two times higher than those of healthy individuals (p < 0.001). When the mean plasma 3-NT levels of patients and healthy individuals were compared, no significant difference was found (p > 0.05). The mean plasma CoQ10 level of patients was low when compared with healthy individuals; however, no significant difference was detected (p > 0.05). In addition, as the stage and tumor size increased in HNSCC patients, their non-enzymatic antioxidant levels significantly decreased (p < 0.05).

Conclusions: In HNSCC patients, lipo-oxidative damage increased while nitrosative stress did not change; however, antioxidant activity decreased which in turn increased both lipid peroxidation and oxidative stress. These findings support the contention that oxidative stress strongly reflects the health status of HNSCC patients.