Lipids

, Volume 27, Issue 3, pp 219–226

Redox cycling of iron and lipid peroxidation

  • Giorgio Minotti
  • Steven D. Aust
Review

Abstract

Mechanisms of iron-catalyzed lipid peroxidation depend on the presence or absence of preformed lipid hydroperoxides (LOOH). Preformed LOOH are decomposed by Fe(II) to highly reactive lipid alkoxyl radicals, which in turn promote the formation of new LOOH. However, in the absence of LOOH, both Fe2+ and Fe3+ must be available to initiate lipid peroxidation, with optimum activity occurring as the Fe2+/Fe3+ ratio approaches unity. The simultaneous availability of Fe2+ and Fe3+ can be achieved by oxidizing some Fe2+ with hydrogen peroxide or with chelators that favor autoxidation of Fe2+ by molecular oxygen. Alternatively, one can use Fe3+ and reductants like superoxide, ascorbate or thiols. In either case excess Fe2+ oxidation or Fe3+ reduction will inhibit lipid peroxidation by converting all the iron to the Fe3+ or Fe2+ form, respectively. Superoxide dismutase and catalase can affect lipid peroxidation by affecting iron reduction/oxidation and the formation of a (1∶1) Fe2+/Fe3+ ratio. Hydroxyl radical scavengers can also increase or decrease lipid peroxidation by affecting the redox cycling of iron.

Abbreviations

ADP

adenosine diphosphate

EDTA

ethylenediaminetetraacetic acid

OH

hydroxyl radical

L

lipid alkyl radical

LH

unsaturated lipids

LOOH

lipid hydroperoxides

LOO

lipid peroxyl radicals

MDA

malondialdehyde

NADPH

reduced nicotinamide adenine dinucleotide phosphate

O2−•

superoxide

SOD

superoxide dismutase

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Copyright information

© American Oil Chemists’ Society 1992

Authors and Affiliations

  • Giorgio Minotti
    • 1
  • Steven D. Aust
    • 2
  1. 1.Institute of General PathologyCatholic University School of MedicineRomeItaly
  2. 2.Biotechnology CenterUtah State UniversityLogan

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