Phospholipid peroxidation induced by the catechol-Fe3+(Cu2+) complex: a possible mechanism of nigrostriatal cell damage

Ferric or cupric ions significantly promoted a peroxidative cleavage of unsaturated phospholipids in liposomes in vitro after coordinating with dopa and dopamine. Either alpha-tocopherol or desferrioxamine completely abolished the dopa-Fe3+ complex-induced phospholipid peroxidation, while superoxide dismutase, catalase, or sodium benzoate did not. A ferroxidase, ceruloplasmin, significantly inhibited the lipid peroxidation induced by the dopa-Fe3+ complex, indicating the importance of the reduction of the iron moiety in the complex for the lipid peroxidation. A possible mechanism of dopa-Fe3+ complex-induced phospholipid peroxidation is that oxene complexes, such as Fe(V) = O and Fe(IV) = O, produced abstract hydrogen atoms in unsaturated phospholipids to initiate lipid peroxidation.