title: Oxidative damage and antioxidant response of Allium cepa meristematic and elongation cells exposed to metronidazole.
abstract: The toxicity of metronidazole (MTZ) in meristematic and elongation zones of Allium cepa roots was analyzed for 30 h of exposition. Toxic effects were evaluated by lipid peroxidation (content of thiobarbituric-reactive substances [TBARS]), reduced glutathione (GSH) levels, ascorbate acid and dehydroascorbate acid content, and enzymatic activities of superoxide dismutase and catalase. The root zones showed differentiated susceptibility to MTZ. In the elongation zone, MTZ induced an increase of TBARS content and a significant rise in GSH levels, whereas in the meristematic zone, lipid peroxidation was not observed and all antioxidant defense parameters analyzed were significantly increased. These results indicate that MTZ exposure induced oxidative stress in A. cepa roots, and that the antioxidant defenses in the meristematic zone are more efficient compared with the elongation zone, which is probably related to higher oxidative metabolism of meristematic tissue.
authors.affiliation: Department of Ecology, Genetics, and Evolution, School of Exact and Natural Sciences, University of Buenos Aires, Argentina.
authors.forename: Nancy
authors.initials: N
authors.lastname: Andrioli
authors.forename: Sebastián E
authors.initials: SE
authors.lastname: Sabatini
authors.forename: Marta D
authors.initials: MD
authors.lastname: Mudry
authors.forename: María Del Carmen
authors.initials: Mdel C
authors.lastname: Ríos de Molina
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D018519:Meristem / Q000166:cytology* / Q000187:drug effects; D008795:Metronidazole / Q000494:pharmacology*; D019697:Onions / Q000166:cytology* / Q000187:drug effects; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D059828:Plant Cells / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D008795:Metronidazole; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid