A ferriprotoporphyrin IX-chloroquine complex promotes membrane phospholipid peroxidation. A possible mechanism for antimalarial action.

The effect of a ferriprotoporphyrin IX-chloroquine complex on phospholipid membranes was investigated on the basis of iron-induced lipid peroxidation using microsomal phospholipid liposomes. The ferriprotoporphyrin IX-chloroquine complex remarkably promoted peroxidative cleavage of unsaturated phospholipids in liposomes, compared with ferriprotoporphyrin IX alone. Neither the combination of protoporphyrin IX with chloroquine nor the combination of Fe3+-ADP with chloroquine promoted lipid peroxidation. DL-alpha-Tocopherol completely inhibited lipid peroxidation induced by the ferriprotoporphyrin IX-chloroquine complex.