Prooxidant role of vitamin E in copper induced lipid peroxidation.
When exposed to Cu2+, alpha-tocopherol, in detergent dispersion, is rapidly oxidised. Moreover, if phospholipids and traces of their hydroperoxide derivatives are included in these dispersions, Cu2+ initiates lipid peroxidation, the rate of which is dramatically stimulated by alpha-tocopherol. The observation that the rate of alpha-tocopherol consumption is identical in the absence and in the presence of lipids undergoing peroxidation, apparently rules out any antioxidant effect. These results are consistent with a prooxidant effect of vitamin E, mediated by its capability to reduce Cu2+ to Cu+ which, in turn, produces, from lipid hydroperoxides, the highly reactive alkoxyl radicals. Present data highlight the risk of misleading results in interpreting the significance of lags in peroxidation of LDL challenged with Cu2+.
Maiorino
M
M
Zamburlini
A
A
Roveri
A
A
Ursini
F
F
D003300:Copper / Q000378:metabolism*; D007700:Kinetics; D015227:Lipid Peroxidation; D008823:Micelles; D016877:Oxidants / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism*
D008823:Micelles; D016877:Oxidants; D010743:Phospholipids; D014810:Vitamin E; D003300:Copper