Mechanism of ochratoxin A stimulated lipid peroxidation.

Lipid peroxidation, measured as malondialdehyde formation or by oxygen uptake, was stimulated markedly by the mycotoxin ochratoxin A (OTA) in a reconstituted system consisting of phospholipid vesicles, the flavoprotein NADPH-cytochrome P450 reductase, Fe3+, EDTA and NADPH. Deletion of EDTA lowered the extent of lipid peroxidation but did not eliminate it. Fluorometric and spectrophotometric studies demonstrated the formation of a 1:1 Fe3(+)-OTA complex.