title: Inhibition of lipid peroxidation by S-nitrosoglutathione and copper.
abstract: The antioxidant properties of S-nitrosoglutathione, a nitric oxide-derived product were studied in different experimental systems. By using the crocin bleaching test, S-nitrosoglutathione, in the presence of copper ions, shows an antioxidant capacity about six times higher than that of Trolox c and referable to the interception of peroxyl radicals by nitric oxide. Copper alone shows a modest inhibitory action, which is about seven times lower than that of Trolox c. S-nitrosoglutathione prevents lipid peroxidation induced by the well-known Fe2+/ascorbate system (IC50 = 450 microM) and the inhibitory effect is strongly reinforced by the presence of copper ions (IC50 = 6.5 microM). In addition, cumene hydroperoxide-induced lipid peroxidation is markedly decreased by S-nitrosoglutathione, provided that copper ions, maintained reduced by ascorbate, are present. Decomposition of S-nitrosoglutathione through metal catalysis and/or the presence of reducing agents and the consequent release of nitric oxide are of crucial importance for eliciting the antioxidant power. In this way, copper ions and/or reducing species with low antioxidant potency are able to promote the formation of an extremely strong antioxidant species such as nitric oxide.
authors.affiliation: Centro di Studio delle Biomembrane (CNR) and Dipartimento di Chimica Biologica, Università di Padova, Padova, Italy.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Rigobello
authors.forename: Guido
authors.initials: G
authors.lastname: Scutari
authors.forename: Rita
authors.initials: R
authors.lastname: Boscolo
authors.forename: Alberto
authors.initials: A
authors.lastname: Bindoli
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000737:chemistry; D001555:Benzene Derivatives / Q000494:pharmacology; D002338:Carotenoids / Q000737:chemistry; D002839:Chromans / Q000494:pharmacology; D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D005296:Ferrous Compounds / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000737:chemistry / Q000494:pharmacology; D010545:Peroxides / Q000737:chemistry; D051381:Rats; D019163:Reducing Agents / Q000494:pharmacology; D026422:S-Nitrosoglutathione / Q000737:chemistry / Q000494:pharmacology*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
chemical_list: D000975:Antioxidants; D001555:Benzene Derivatives; D002839:Chromans; D005296:Ferrous Compounds; D010545:Peroxides; D019163:Reducing Agents; D017392:Thiobarbituric Acid Reactive Substances; C049375:perhydroxyl radical; D009569:Nitric Oxide; D002338:Carotenoids; D026422:S-Nitrosoglutathione; D003300:Copper; C029036:crocin; C007164:cumene hydroperoxide; D001205:Ascorbic Acid; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid