Inhibition of lipid peroxidation by S-nitrosoglutathione and copper.
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.
Rigobello
Maria Pia
MP
Centro di Studio delle Biomembrane (CNR) and Dipartimento di Chimica Biologica, Università di Padova, Padova, Italy.
Scutari
Guido
G
Boscolo
Rita
R
Bindoli
Alberto
A
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
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