Background: Many chemotherapeutic regimens used in the treatment of cancer generate free radicals that may be a part of their beneficial effects. The aim of this study was to assess the oxidative status in patients undergoing chemotherapy for acute myeloid leukemia (AML).

Methods: Thirty-eight patients with AML (17 female and 21 male patients) with a mean age 34.05±12.49 years were included in the study. All the patients received cytarabine and daunorubicin as their standard induction therapy. Serum levels of malondialdehyde (MDA), total antioxidant capacity (TAC), and also the erythrocyte superoxide dismutase and glutathione peroxidase activities were measured before and 14 days after chemotherapy.

Results: Plasma malondialdehyde concentrations increased significantly (from a former 2.68±0.89 nmol/ml to 3.14±1.29 nmol/ml) 14 days post chemotherapy (p=0.04). Moreover, the total plasma antioxidant capacity changed from 1.09±0.15 mmol/L to 1.02±0.14 mmol/L (p=0.005). Erythrocyte superoxide dismutase and glutathione peroxidase activity decreased over time from 1157.24±543.61 U/gHb to 984.01±419.09 U/gHb (p=0.04) and 46.96±13.70 U/gHb to 41.40±6.44 U/gHb (p=0.02), respectively.

Conclusion: In this study, an increase in malondialdehyde levels and a decrease in the levels of antioxidant enzymes and total antioxidant capacity were observed. It seems that chemotherapy by cytarabine and daunorubicin generates enormous amounts of free radicals in patients undergoing the treatment for AML. Use of antioxidant supplementation during chemotherapy i is discouraged as it may interfere with the generation of free radicals that may be a part of the therapeutic efficacy of these drugs.