Delayed oxidative degradation of polyunsaturated diacyl phospholipids in the presence of plasmalogen phospholipids in vitro

Abstract

The oxidative degradation of plasmalogen (alkenylacyl) phospholipids was analysed in the absence and the presence of polyunsaturated ester phospholipids by "H-NMR and by chemical determination. Brain lysoplasmenylethanolamine (lyso-P-PE), brain P-PE and erythrocyte P-PE, containing an increasing number of intrachain double bonds at sn # , were oxidized with 2,2h-azobis-(2-amidinopropane hydrochloride) (AAPH ; 2 or 10 mM) in Triton X-100 micelles (detergent\phospholipid 1 : 5, mol\mol). The formation of two peroxyl radicals was accompanied by the degradation of approx. one molecule of brain lyso-P-PE. On oxidation of brain P-PE or erythrocyte P-PE (320 nmol) with 2 mM AAPH, the (α-vinyl) methine "H signal of the enol ether decreased more rapidly than the methine proton peak of intrachain double bonds. The rate of enol ether degradation increased in the order : erythrocyte P-PE brain P-PE brain lyso-P-PE. The disappearance of the polyunsaturated ester phospholipids 1-palmitoyl-2-arachidonoyl phosphatidylcholine (16 : 0\20 : 4-PC) and 1-palmitoyl-2-linoleoyl phosphatidylcholine

Plasmalogens as endogenous antioxidants: somatic cell mutants reveal the importance of the vinyl ether

“…Saturated ethers are not particularly reactive with ROS. Finally, these results are consistent with previous studies with intact cells [37,38] and model systems [39][40][41], suggesting that plasmalogens are serving as scavengers of ROS. A number of studies have demonstrated plasmalogen-mediated protection and selective degradation of plasmalogens when lipoproteins [39,40] or cells [37] are exposed to ROS.…”

Effect of Dietary Docosahexaenoic Acid Connecting Phospholipids on the Lipid Peroxidation of the Brain in Mice

“…The function of plasmalogen is not known; however, according to recent studies, plasmalogen in the PE has an antioxidant action in lowering the oxidizability of cholesterol in the phospholipid bilayers as well as the whole membranes (31,32). In addition, it has been reported that the plasmalogen concentration in the blood plasma is significantly reduced by aging and hyperlipidemia (33). It is suggested on the basis of these studies that plasmalogen has some important functions in vivo.…”

Dysfunctional high-density lipoproteins in coronary heart disease: implications for diagnostics and therapy

“…90 Plasmalogens are a class of glycerophospholipids with anti-oxidative properties that are present in HDL only in low amounts. 78,[97][98][99] Patients with CAD had HDL relatively depleted of the plasmalogen species PC33:3, PC35:2 and PC34:2 and with a compromised ability to inhibit apoptosis of endothelial cells. 89 The finding that incorporation of the plasmalogen PC35:2 in rHDL improved its anti-apoptotic activity towards endothelial cells further underscored the potential importance of plasmalogens for the anti-apoptotic activity of HDL.…”