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

Abstract

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 nitrogencontaining 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.

Enhancement of Hydrophobicity of Fish Skin Gelatin via Molecular Modification with Oxidized Linoleic Acid

“…In addition, the peaks around 1160-1175 and 1238 cm −1 , associated with the stretching vibrations of the C-O in ester moiety [24] as well as 1055 cm −1 assigned to C-O bending were noticed. e absorption at around 1180 cm −1 due to C-O-O vibrations of hydroperoxides (ROOH) was also detected; this vibrational peak overlapped with C-O stretching vibrations [26]. It can be observed from the spectra that the amplitude of peaks at 1745 and 1238-1055 cm −1 increased with increasing oxidation time.…”

“…OLA might interact with gelatin molecules via ε-amino group of lysine in the gelatin [6], as shown in Scheme 2. More specifically, the reaction might involve the nucleophilic addition between the amino group of gelatin and the aldehyde carbonyl group of OLA [26]. e extent of gelatin-OLA reaction was higher by using OLA oxidized at longer time that contained a higher amount of aldehyde functional groups.…”

S‐Nitrosoglutathione Decreases Inflammation and Bone Resorption in Experimental Periodontitis in Rats

“…It may either exacerbate oxidation by reacting with superoxide forming peroxynitrite 9 or it may block the propagation of radical reactions, exerting an antioxidant effect. This later action is also displayed by NO donors such as S‐nitrosothiols (RSNOs) 10 . S‐nitrosoglutathione (GSNO) is a primary RSNO with strong vasodilator action 11 and wound‐healing properties, 12,13 which may release NO spontaneously, and is also capable of transnitrosating cysteine residues of proteins and exerting a marked microbicidal action 14,15 .…”

“…This later action is also displayed by NO donors such as S-nitrosothiols (RSNOs). 10 S-nitrosoglutathione (GSNO) is a primary RSNO with strong vasodilator action 11 and wound-healing properties, 12,13 which may release NO spontaneously, and is also capable of transnitrosating cysteine residues of proteins and exerting a marked microbicidal action. 14,15 These combined properties of GSNO, in addition to its miscibility in non-toxic pharmaceutical vehicles, such as polyvinylpyrrolidone (PVP), 16 makes GSNO/PVP formulations of interest when for investigating the effects of local NO administration in periodontitis.…”

S-nitroso-N-acetylcysteine attenuates liver fibrosis in experimental nonalcoholic steatohepatitis

“…In the second case, the formed NAC may also exert a protective effect as already described in the literature 39,40. It must be noted that although NAC is a notorious antioxidant, SNAC is already reported to have a more effective antioxidant action than NAC in in vitro15 and in vivo 14. In the last case, oral SNAC administration in an animal model of NAFLD led to a significant decrease in the concentration of hydroperoxides in the liver homogenate when compared with the control group or with the administration of NAC at a dose five times higher.…”