Membrane-protective properties of isobornylphenols-a new class of antioxidants

The membrane protective and membrane active properties and the antioxidative activity of new semisynthetic antioxidants—isobornylphenols were studied. The presence of oxidant and cytotoxic properties of the compounds were evaluated considering the degree of hemolysis of erythrocytes, either spontaneous or induced by hydrogen peroxide. All the studied compounds were found to have significant antioxidative activity in certain conditions. But their capacity to protect membrane erythrocytes from oxidative stress substantially depended on the structure and concentration of the compound. The highest membrane protective activity was observed for 2,6-diisobornyl-4-methylphenol, which has isobornyl in both of its ortho-positions. Scanning electron microscopy of blood erythrocyte surface architectonics confirmed the ability of the studied compounds to interact with the cell membrane and to change its structure. A relationship between erythrocyte morphological transformation according to bilayer-couple hypothesis depending on isobornylphenols membrane behavior and the cytotoxic effect of certain compound high concentrations reflected in low membrane protective activity in the model cell system was shown. The data obtained allow us to conclude that the biological activity of isobornylphenols is due to both their antioxidative properties and their ability to interact with the cell membranes.