N of lipid hydroperoxides (LOOH) derived from oxidized low-density lipoprotein (LDL). Oxidized LDL prepared by copper ion-induced oxidation contained nonesterified fatty acid hydroperoxides (FFA-OOH) and lysophosphatidylcholine (lysoPtdCho), along with cholesteryl ester hydroperoxides (CE-OOH) and phosphatidylcholine hydroperoxides (PtdCho-OOH). A plateletactivating factor-acetylhydrolase (PAF-AH) inhibitor suppressed formation of FFA-OOH and lysoPtdCho in oxidized LDL. Among LOOH species, FFA-OOH was preferentially decreased by incubating oxidized LDL with HDL. HDL exhibited selective FFA-OOH decreasing potential if it was mixed having a liposomal solution containing FFAOOH, CE-OOH and PtdCho-OOH. Two-electron reduction of your hydroperoxy group to the hydroxy group was confirmed by the formation of 13-hydroxyoctadecadienoicacid from 13-hydroperoxyoctadecadienoic acid in HPLC analyses. This decreasing effect was also found in apolipoprotein A-1 (apoA-1). FFA-OOH released from PtdChoOOH due to PAF-AH activity in oxidized LDL undergo two-electron reduction by the reducing capacity of apoA1 in HDL. This preferential reduction of FFA-OOH may take part in the mechanism from the antioxidant home of HDL. Keywords and phrases HDL ?Nonesterified fatty acid hydroperoxides ?Atherosclerosis ?Oxidized LDL ?Apolipoprotein A-1 ?Platelet activating factor-acetyl hydrolase Abbreviations LOOH FFA-OOH CE-OOH PtdCho-OOH LNA-OOHLipid hydroperoxides Nonesterified fatty acid hydroperoxides Cholesteryl ester hydroperoxides Phosphatidylcholine hydroperoxides Linoleic acid hydroperoxidesM.1021-25-6 structure Kotosai ?S. Shimada ?M. Kanda ?N. Matsuda ?T. Nakamura ?K. Murota ?Y. Kawai ?J. Terao ( ) Department of Food Science, Institute of Well being Biosciences, University of Tokushima Graduate College, Kuramoto-cho 3-18-15, Tokushima 770-8503, Japan e-mail: [email protected] K. Sekido Department of Nursing Education, Institute of Wellness Biosciences, University of Tokushima Graduate College, Kuramoto-cho 3-18-15, Tokushima 770-8503, Japan Present Address: K. Sekido Keiko Kekido, Graduate School of Health Sciences, Kobe University, Kobe 654-0142, JapanY. Shimizu ?A. Tokumura Department of Pharmaceutical Overall health Chemistry, University of Tokushima Graduate School, Kuramoto-cho 3-18-15, Tokushima 770-8503, Japan Present Address: K. Murota Kaeko Murota, Department of Life Sciences, School of Science and Engineering, Kinki University, Osaka 577-8502, Japan Present Address: Y.Indole-2-carbaldehyde Data Sheet Kawai Laboratory of Meals and Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, JapanLipids (2013) 48:569?PAF-AH apoA-1 PL-PtdCho DM-PtdCho lysoPtdCho 13-HPODE 13-HODE TMPDPlatelet activating factor-acetylhydrolase Apolipoprotein A-1 1-Palmitoyl-2-linoleoyl-sn-glycero-3phosphocholine Dimyristoyl-sn-glycero-3-phosphocholine Lysophosphatidylcholine 13-Hydroperoxyoctadecadienoic acid 13-Hydroxyoctadecadienoic acid N,N,N0 ,N0 -tetramethyl-pphenylenediamine dihydrochlorideIntroduction Plasma high-density lipoprotein (HDL) can be a complicated of proteins and lipids.PMID:24268253 In this complex, apoprotein A-1 (apoA1) may be the big protein constituent, and absolutely free cholesterol, esterified cholesterol and phospholipids are the important lipid classes [1]. HDL has been believed to act as an anti-atherosclerotic factor. The mechanism of action is thought to involve the promotion of the efflux of cholesterol from macrophage-derived foam cells within the artery wall, thereby inhibiting the progression of atherosclerosis [2].