In vitro inhibition of linoleic acid peroxidation by primary S-nitrosothiols

Journal of the Brazilian Chemical Society

Fernanda I. Simplicio¹  Amedea B. Seabra¹  Gabriela F. P. De Souza¹  Marcelo G. De Oliveira¹ 

[1] ,Universidade Estadual de Campinas Instituto de Química Campinas SP ,Brazil

关键词: nitric oxide;    S-nitrosothiols;    lipid peroxidation;    linoleic acid;    lipoxygenase;   

DOI  :  10.1590/S0103-50532010001000013

来源: SciELO

【 摘 要 】

Nitric oxide (•NO) is an effective chain-breaking antioxidant in the inhibition of lipid peroxidation and circulates in vivo mainly as primary S-nitrosothiols (RSNOs). In this work, the in vitro peroxidation of linoleic acid-SDS comicelles (LA-SDS) catalyzed by soybean lipoxygenase (SLO) and FeII ions was monitored in the presence and absence of three primary RSNOs: S-nitrosocysteine, S-nitroso-N-acetylcysteyne and S-nitrosoglutathione. Kinetic measurements based on the formation of conjugated double bonds and fluorescent oxidized LA-lysine adducts, showed that RSNOs are more potent antioxidants than their corresponding free thiols (RSHs) in equimolar conditions. These results are consistent with the blocking of LA-SDS peroxidation by RSNOs through the inactivation of peroxyl/alkoxyl (LOO•/LO•) radicals, leading to nitrogen-containing products of oxidized LA, which release free •NO. These results indicate that endogenous RSNOs may play a major role in the blocking of lipid peroxidation in vivo, through the primary inactivation of alkoxyl/peroxyl radicals and also of preformed lipid hydroperoxides.

【 授权许可】

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