title: An advanced Electron Spin Resonance (ESR) spin-trapping and LC/(ESR)/MS technique for the study of lipid peroxidation.
abstract: There are two types of nutritionally important polyunsaturated fatty acids (PUFAs), namely &#969;-6s and &#969;-3s. PUFAs and their metabolites generated from lipid peroxidation via cyclooxygenase (COX) and lipoxygenase (LOX) are believed to be involved in a variety of physiological and pathological processes in the human body. Both COX- and LOX-catalyzed PUFA peroxidation are complex events that generate a series of radicals, which may then bind proteins, target DNA/RNA, and lead to a number of biological changes. However, due to the lack of an appropriate method, it was not possible until recently to identify the short-lived PUFA-derived radicals in COX-/LOX-catalyzed peroxidation. Failure to characterize free radicals during peroxidation has greatly restricted our knowledge about COX/LOX biology in human health. Here we review the development and refinement of combined ESR spin trapping and LC/ESR/MS to characterize PUFA-derived radicals formed from in vitro (cell-free) peroxidation. We also present the most recent approach for studying peroxidation in cells which allows us to directly assess the potential bioactivity of PUFA-derived free radicals. This advanced technique has resulted in a major breakthrough in radical structural characterization, as well as assessment of free radical-associated cell growth response, thereby greatly improving our knowledge of PUFAs, COX-/LOX-catalyzed lipid peroxidation, and their related biological consequences.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, Nursing and Allied Sciences,  North Dakota State University, Fargo, ND 58108, USA. steven.qian@ndsu.edu.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: Gu
authors.forename: Steven Y
authors.initials: SY
authors.lastname: Qian
mesh_terms: D002853:Chromatography, Liquid; D004578:Electron Spin Resonance Spectroscopy; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000378:metabolism*; D005609:Free Radicals / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation; D013058:Mass Spectrometry; D055432:Metabolomics
chemical_list: D005231:Fatty Acids, Unsaturated; D005609:Free Radicals