title: Platelet-activating factor (PAF)-like phospholipids formed during peroxidation of phosphatidylcholines from different foodstuffs.
abstract: Previously, we reported that induction of peroxidation of synthetic phosphatidylcholines (PCs) containing a polyunsaturated fatty acid by Fe(2+)-EDTA in the presence of ascorbate resulted in the formation of four types of PCs with an sn-2-oxidatively fragmented acyl group, which had platelet-aggregating activity due to interaction with platelet-activating factor (PAF) receptors. These PCs were compounds with a short-chain monocarboxylate, omega-hydroxymonocarboxylate, dicarboxylate, and dicarboxylate semialdehyde residue, respectively. In this study, we investigated the PAF-like lipids formed during peroxidation of PCs from hen egg yolk, salmon roe, sea urchin eggs, and krill in an FeSO4/EDTA/ascorbate system. The platelet-aggregating activities of these oxidized PCs were all inhibited by FR-900452, an antagonist of PAF. The activity of oxidized krill PC, which was equivalent of 89.8 +/- 8.8 pmol 16:0-PAF/mumol of starting PC, was about 5 times those of oxidized PCs from salmon roe and sea urchin eggs, and about 50 times that of oxidized hen egg yolk PC. The PAF-like phospholipids that had different combinations of long-chain alkyl or acyl groups with one of the above four types of short-chain acyl groups were identified by gas chromatography-mass spectrometry. The results indicated that foodstuffs that are rich in 1-O-alkyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine are potential sources of compounds with high PAF-like activity formed by deleterious lipid peroxidation.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Tokushima, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: Tokumura
authors.forename: H
authors.initials: H
authors.lastname: Tsukatani
mesh_terms: D000818:Animals; D003445:Crustacea / Q000378:metabolism; D004530:Egg Yolk / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D005502:Food; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D010053:Ovary / Q000737:chemistry; D010063:Ovum / Q000737:chemistry; D010084:Oxidation-Reduction; D010713:Phosphatidylcholines / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000378:metabolism*; D012474:Salmon / Q000378:metabolism; D012617:Sea Urchins / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D010713:Phosphatidylcholines; D010743:Phospholipids; D010972:Platelet Activating Factor