title: Melatonin prevents methotrexate-induced hepatorenal oxidative injury in rats.
abstract: Regarding the mechanisms of methotrexate (MTX) hepatotoxicity and nephrotoxicity, several hypotheses have been put forward, among which oxidative stress (including depletion of glutathione) is likely. This investigation elucidates the role of free radicals in MTX-induced toxicity and the protection by melatonin. Wistar albino rats were injected with MTX intraperitoneally. Following a single dose of MTX (20 mg/kg), either saline (MTX group) or melatonin (10 mg/kg, MTX + Mel group) was administered for 5 days. In other rats, physiologic saline (control group) or melatonin (10 mg/kg, Mel group) was injected for 5 days, following a single injection of saline. On the sixth day, rats were killed to obtain blood, liver, and kidney tissue samples. Malondialdehyde (MDA), an end product of lipid peroxidation, and glutathione (GSH), a key antioxidant, levels were evaluated in blood and tissue homogenates. Reactive oxygen metabolite-induced inflammatory changes in kidney and liver tissues were evaluated by measuring myeloperoxidase (MPO) activity, an index of neutrophil infiltration. MTX administration resulted in increased MDA levels and MPO activity and decreased GSH levels in the blood, liver, and kidney whereas melatonin reversed these effects. When melatonin was administered alone, no significant changes in biochemical parameters were noted. In conclusion, the present study suggests that melatonin may be of therapeutic benefit when used with MTX.
authors.affiliation: Department of Physiology, School of Medicine; Department of Pharmacology, School of Pharmacy, Marmara University, Istanbul, Turkey.
authors.forename: Nermina
authors.initials: N
authors.lastname: Jahovic
authors.forename: Hülya
authors.initials: H
authors.lastname: Cevik
authors.forename: A Ozer
authors.initials: AO
authors.lastname: Sehirli
authors.forename: Berrak C
authors.initials: BC
authors.lastname: Yeğen
authors.forename: Göksel
authors.initials: G
authors.lastname: Sener
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D005260:Female; D005978:Glutathione / Q000378:metabolism; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology*; D008727:Methotrexate / Q000009:adverse effects*; D018384:Oxidative Stress / Q000187:drug effects; D009195:Peroxidase / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D008315:Malondialdehyde; D009195:Peroxidase; D005978:Glutathione; D008550:Melatonin; D008727:Methotrexate