title: Melatonin alleviates lung damage induced by the chemical warfare agent nitrogen mustard.
abstract: The cytotoxic mechanism of mustards has not been fully elucidated; recently, we reported that reactive oxygen species, nitric oxide [produced by inducible nitric oxide synthase (iNOS)] and peroxynitrite are involved in the pathogenesis and responsible for mustard-induced toxicity. Melatonin, a potent antioxidant molecule, acts as an iNOS inhibitor and a peroxynitrite scavenger. Using the prototypic nitrogen mustard (mechlorethamine/HN2) as a model and based on its known cytotoxic mechanisms, the present study was performed to test melatonin for its capability in protecting the lungs of injured male Wistar rats. Lung mustard toxicity was induced via an intratracheally injection of HN2 (0.5mg/kg) dissolved in saline (100microl). Control animals were injected the same amount of saline only. Melatonin was administered intraperitoneally with two different doses (20mg/kg or 40mg/kg) beginning 1h before HN2 application and continued every 12h for six replications. Forty-eight hours after the last melatonin injection, the animals were sacrificed and their lungs were taken for further assay, i.e., malondialdehyde (MDA) levels, and superoxide dismutase (SOD), glutathione peroxidase (GPx) and iNOS activity. Additionally their urine was collected for nitrite-nitrate (NO(x)) analysis. HN2 injection caused increased iNOS activity and MDA levels in lung tissue and NO(x) values in urine; lung GPx activity was significantly depressed. Melatonin restored all of these oxidative and nitrosative stress markers in a dose-dependent manner. In conclusion, the results of study provide evidence that melatonin may have the ability to reduce mustard-induced toxicity in the lungs.
authors.affiliation: Department of Public Health, Gülhane Military Medical Academy, Ankara, Turkey.
authors.forename: Muharrem
authors.initials: M
authors.lastname: Ucar
authors.forename: Ahmet
authors.initials: A
authors.lastname: Korkmaz
authors.forename: Russel J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: Hakan
authors.initials: H
authors.lastname: Yaren
authors.forename: Sükrü
authors.initials: S
authors.lastname: Oter
authors.forename: Bülent
authors.initials: B
authors.lastname: Kurt
authors.forename: Turgut
authors.initials: T
authors.lastname: Topal
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology* / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism / Q000652:urine; D002619:Chemical Warfare Agents; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005979:Glutathione Peroxidase / Q000378:metabolism; D008168:Lung / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D008171:Lung Diseases / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008466:Mechlorethamine; D008550:Melatonin / Q000494:pharmacology* / Q000627:therapeutic use; D009566:Nitrates / Q000652:urine; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D009573:Nitrites / Q000652:urine; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D002619:Chemical Warfare Agents; D009566:Nitrates; D009573:Nitrites; D008315:Malondialdehyde; D008466:Mechlorethamine; D005979:Glutathione Peroxidase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D013482:Superoxide Dismutase; D008550:Melatonin