Effect of α-tocopherol on pro-oxidant and antioxidant enzyme status in radiation-treated oral squamous cell carcinoma

Objectives: The relationships between α-tocopherol, pro-oxidant and antioxidant enzyme status, and radiation toxicity were studied in stage II, III, and IVA oral squamous cell carcinoma patients. The low levels of malondialdehyde and increased activities of antioxidant enzymes were correlated with decreased oxidative stress by α-tocopherol in oral cancer patients treated with radiotherapy. The objective of the present study was to evaluate the effect of α-tocopherol on oxidant-antioxidant enzyme status in oral squamous cell carcinoma patients treated with radiotherapy.
Materials and Methods: The study included three groups with histologically confirmed oral squamous cell carcinoma patients (untreated), and they were further divided into two groups, viz., one consisting of patients who underwent radiotherapy alone (radiotherapy was given at the dosage of 6000 cGy in five fractions per week for a period of 6 weeks); and the other group treated with radiotherapy plus α-tocopherol supplementation (α-tocopherol was supplemented at a dosage of 400 IU/day) for the entire period of radiotherapy.
Results: A significant decrease ( P < 0.001) in malondialdehyde levels and increase in activities of antioxidant enzymes ( P < 0.001) in hemolysate were noticed in patients treated with radiotherapy and simultaneously supplemented with α-tocopherol when compared to radiation-treated patients.
Conclusion: It was seen that α-tocopherol played a role in protecting against the damage caused by irradiation in oral squamous cell carcinoma patients treated with radiotherapy, by enhancing the antioxidant enzyme status and reducing the pro-oxidant status.

Keywords
Glutathione-dependent enzymes, malondialdehyde, oral squamous cell carcinoma, radiotherapy, superoxide dismutase, α-tocopherol