In vitro inhibition of linoleic acid peroxidation by primary S-nitrosothiols
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.
| Main Authors: | , , , |
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| Format: | Digital revista |
| Language: | English |
| Published: |
Sociedade Brasileira de Química
2010
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| Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532010001000013 |
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