Prophylactic effects of magnesium and vitamin E in rat spinal cord radiation damage: evaluation based on lipid peroxidation levels Selc ßuk Peker a, * , Ufuk Abacioglu b , Ibrahim Sun a , Deniz Konya a , Meral Yu ¨ksel c , Necmettin M. Pamir a a Department of Neurosurgery, Marmara University School of Medicine, Istanbul 34662, Turkey b Department of Radiation Oncology, Marmara University School of Medicine, Istanbul 34662, Turkey c Department of Biochemistry, Marmara University School of Medicine, Istanbul 34662, Turkey Received 23 February 2004; accepted 13 May 2004 Abstract This study investigated the neuroprotective effects of magnesium sulfate prophylaxis and vitamin E prophylaxis in a rat model of spinal cord radiation injury. Groups were subjected to different treatment conditions for 5 days prior to irradiation, and outcomes were evaluated on the basis of lipid peroxidation levels in cord tissue. Four groups of rats were investigated: no radiation/treatment (n = 4), intraperitoneal (i.p.) saline 1 ml/day (n = 6), i.p. vitamin E 100 mg/kg/day (n = 6), and i.p. magnesium sulfate 600 mg/kg/day (n = 6). The thoracic cord of each non-control rat was exposed to 20 Gy radiation in a LINAC system using 6 MV x-rays, and malondialdehyde (MDA) levels (reflecting lipid peroxidation level) were determined 24 hours post-irradiation. The MDA levels in thoracic cord segments from the control rats were used to determine baseline lipid peroxidation. The mean levels in the control, saline-only, vitamin E, and magnesium sulfate groups were 12.12 F 0.63, 27.0 F 2.81, 17.71 F 0.44, and 14.40 F 0.47 nmol/mg tissue, respectively. The MDA levels in the saline-only group were significantly higher than baseline, and the levels in the vitamin E group were significantly lower than those in the saline group ( P < 0.05 for both). The levels in the magnesium sulfate group were dramatically lower than those in the saline group ( P < 0.001). The results indicate that i.p. magnesium sulfate has a marked neuroprotective effect against radiation-induced oxidative stress in the rat spinal cord. D 2004 Elsevier Inc. All rights reserved. Keywords: Lipid peroxidation; Magnesium; Myelopathy; Prophylaxis; Radiation; Spinal cord; Vitamin E 0024-3205/$ - see front matter D 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.lfs.2004.05.003 * Corresponding author. Tel.: +1-90-216-3264559; fax: +1-90-216-3057961. E-mail address: peker@atlas.net.tr (S. Peker). www.elsevier.com/locate/lifescie Life Sciences 75 (2004) 1523 – 1530