Isomer distribution of hydroxyoctadecadienoates (HODE) and hydroxyeicosatetraenoates (HETE) produced in the plasma oxidation mediated by peroxyl radical, peroxynitrite, hypochlorite, 15-lipoxygenase, and singlet oxygen

• Published in: Archives of biochemistry and biophysics Vol. 635; pp. 96 - 101
• Main Authors: Umeno, Aya, Morita, Mayuko, Yoshida, Yasukazu, Naito, Yuji, Niki, Etsuo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2017
• Subjects: Animals; Arachidonate 15-Lipoxygenase - chemistry; Fatty Acids, Unsaturated - blood; Fatty Acids, Unsaturated - chemistry; Hydroxyeicosatetraenoic Acids - chemistry; Hydroxyoctadecadienoate (HODE); Hypochlorite; Hypochlorous Acid - chemistry; Lipid oxidation; Lipoxygenase; Mice; Oxidants - blood; Oxidants - chemistry; Oxidation-Reduction; Peroxides - chemistry; Peroxynitrite; Peroxynitrous Acid - chemistry; Plasma - chemistry; Singlet oxygen; Singlet Oxygen - blood; Singlet Oxygen - chemistry; Stereoisomerism; Peroxynitrite; PUFA; AAPH; NpEP; DPPP; F2-IsoP; SIN-1; Singlet oxygen; LOX; Hypochlorite; Lipid oxidation; H(p)ODE; ROS; Lipoxygenase; Hydroxyoctadecadienoate (HODE); H(p)ETE
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2017.10.023

Free and ester forms of unsaturated fatty acids and cholesterol are oxidized in vivo by multiple oxidants to give diverse products. Some lipid oxidation is mediated by enzymes to selectively give specific products, while others proceed randomly to produce mixtures of many kinds of regioisomers and stereoisomers. The efficacy of antioxidants against lipid oxidation depends on the nature of the oxidants and therefore the identification of oxidant is important for understanding the roles and effects of lipid oxidation and antioxidants in vivo. In the present study, the isomer distribution of hydro(pero)xyoctadecadienoates (H(p)ODEs) and hydro(pero)xyeicosatetraenoates (H(p)ETEs), the most abundant lipid oxidation products found in human plasma, produced in the oxidation of plasma by peroxyl radicals, peroxynitrite, hypochlorite, 15-lipoxygenase, and singlet oxygen were examined. It was shown that 9- and 13-(E,E)-HODEs, 13(S)-(Z,E)-HODE, and 10- and 12-(Z,E)-HODEs were specific lipid oxidation products by free radical, 15-lipoxygenase, and singlet oxygen, respectively. The isomer distribution of HODEs produced by peroxynitrite was similar to that by peroxyl radical, suggesting that the peroxynitrite mediated lipid oxidation proceeds by free radical mechanisms. The production of HODEs and HETEs by hypochlorite was very small. HODEs may be a better biomarker than HETEs since linoleates are oxidized by simpler mechanisms than arachidonates and all the HODEs isomers can be quantified more easily. These products may be used as specific biomarkers for the identification of responsible oxidants and for the assessment of oxidant-specific lipid oxidation levels and effects of antioxidants in vivo. [Display omitted] •HODEs and HETEs produced in the plasma oxidation by multiple oxidants were measured.•9- and 13-(E,E)-HODE were produced only by free radicals and peroxynitrite.•15-Lipoxygenase forms 13-(S)-HODE selectively and hypochlorite produces little HODE.•10- and 12-HODEs are specific biomarker for singlet oxygen oxidation.•Total HETEs and isoprostanes produced were less than HODEs.