Neuroprotective effects of erythropoietin against oxidant injury following brain irradiation: an experimental study

INTRODUCTION: Radiation therapy (RT) is a major treatment modality, and the central nervous system is a dose-limiting organ in clinical RT. This experimental study aims to present the evaluation of the neuroprotective effects of erythropoietin (EPO) against oxidant injury following brain irradiation in rats. MATERIAL AND METHODS: Forty Wistar rats were randomly assigned to four groups (n = 10 each). In group 1 the rats received no EPO and underwent sham RT. The rats in groups 2 and 3 received EPO. In group 2 rats underwent sham RT, while in group 3 rats received RT. The rats in group 4 received no EPO and underwent RT. Rats were irradiated using a Cobalt-60 teletherapy machine using a single fraction of 20 Gy covering the whole brain. Cervical dislocation euthanasia was performed. The nitrite and malondialdehyde (MDA) levels and the superoxide dismutase (SOD) and glutathione peroxidase (GSHPX) activities were evaluated in dissected brain tissues. RESULTS: The nitrite and MDA levels were higher in the RT group (2.10 ±0.62 ppm, 26.02 ±2.16 nmol/ml; p < 0.05) and lower in the EPO + RT group (1.45 ±0.12 ppm, 25.49 ±1.90 nmol/ml; p < 0.05). The SOD and GSHPX activity was higher in the EPO + RT group (2.62 ±0.49 U/mg, 1.75 ±0.25 U/mg, p < 0.05). CONCLUSIONS: This study supports the probable neuroprotective effects of EPO against oxidant injury following brain irradiation in a rat model, presumably through decreasing free radical production and increasing expression of antioxidant enzymes.