Effect of antioxidants on the kinetics of chain lipid peroxidation in liposomes.

To elucidate the mechanism of action of various antioxidants, we studied the kinetics of chemiluminescence which accompanies the peroxidation of phospholipid liposomes as induced by divalent iron ions in the presence of C-525, a chemiluminescence activator. EDTA and desferal reduced the chemiluminescence latent period, probably, due to the chelation of Fe2+ ions which, thus, dropped out of chain oxidation reactions in the lipid phase. In contrast, ascorbate increased the chemiluminescence latent period, apparently, as a result of regeneration of divalent iron oxidized during lipid peroxidation. alpha-Tocopherol and rutin reduced the amplitude of the chemiluminescence slow flash and increased the duration of the latent period. beta-Carotene displayed its effect only at rather high concentrations, when the decrease in chemiluminescence intensity could be due (at least partially) to the reabsorption of chemiluminescence by this compound. The latent period remained invariable in this case.