Abstract
The biological antioxidant activities of bromophenols (5-bromo-3, 4-dihydroxy benzaldehyde and 5-bromo-3, 4-dihydroxy benzylalcohol), protocatechualdehyde and vanillyl octadecanamide were compared with α-tocopherol in vitro and in vivo. All of these antioxidants significantly inhibited the lipid peroxidation in microsomal suspensions induced by ascorbate/Fe(II) or NADPH. By removing the non-binding free antioxidants from the suspensions, the inhibitory activities markedly decreased in antioxidants other than α-tocopherol; however, considerable activity was still observed. The effects of orally administered antioxidants on the symptoms of vitamin E deficiency were examined using rats fed with a vitamin E-free diet and supplemented with oxidized oils. As a result and contrary to the effects in vitro, all of the antioxidants were much less effective in liver. However, some of the vitamin E-deficient symptoms such as organic solvent-soluble fluorescent materials in the heart and lung, and oxidative hemolysis were significantly suppressed by some antioxidants.
