title: Protective effects of melatonin on the ionizing radiation induced DNA damage in the rat brain.
abstract: Melatonin is an endogenously produced antioxidant with radioprotective actions while ionizing radiation is a well-known cytotoxic and mutagenic agent of which the biological results are attributable to its free radical producing effects. The effect of melatonin on the DNA strand breakage and lipid peroxidation induced by ionizing radiation in the rat brain were investigated in order to clarify its radioprotective ability. The DNA strand breakage in rat brain exposed to 1000 cGy ionizing radiation was assessed by alkaline single cell gel electrophoresis and the lipid peroxidation was evaluated by measuring thiobarbituric acid reactive substances (TBARS) concentrations. A significant increase in DNA damage (p < 0.05) and TBARS concentrations (p < 0.01) was found in the radiation treated rat brain. Pre-treatment of rats with intraperitoneal doses of 100 mg/kg melatonin provided a significant decrease in the DNA strand breakage and lipid peroxidation. Our results indicate that melatonin can protect brain cells from oxidative damage induced by ionizing radiation.
authors.affiliation: Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey.
authors.forename: Ulko
authors.initials: U
authors.lastname: Undeger
authors.forename: Belma
authors.initials: B
authors.lastname: Giray
authors.forename: A Faruk
authors.initials: AF
authors.lastname: Zorlu
authors.forename: Kamil
authors.initials: K
authors.lastname: Oge
authors.forename: Nurçen
authors.initials: N
authors.lastname: Baçaran
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001921:Brain / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D005260:Female; D015227:Lipid Peroxidation / Q000187:drug effects* / Q000528:radiation effects; D008550:Melatonin / Q000494:pharmacology*; D011839:Radiation, Ionizing; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D008550:Melatonin