The protective role of plasmalogens in iron-induced lipid peroxidation

The role of plasmalogens in iron-induced lipid peroxidation was investigate d in two liposomal systems. The first consisted of total brain phospholipid s with and without plasmalogens, and the second of phosphatidylethanolamine /phosphatidylcholine liposomes with either diacyl- or alkenylacyl-phosphati dylethanolamine. By measuring thiobarbituric acid reactive substances, oxyg en consumption, fatty acids and aldehydes, we show that plasmalogens effect ively protect polyunsaturated fatty acids from oxidative damage, and that t he vinyl ether function of plasmalogens is consumed simultaneously. Further more, the lack of lag phase, the increased antioxidant efficiency with time , and the experiments with lipid- and water-soluble azo compounds, indicate that plasmalogens probably interfere with the propagation rather than the initiation of lipid peroxidation, and that the antioxidative effect cannot be related to iron chelation. (C) 1998 Elsevier Science Inc.