PROTECTION AGAINST OXIDATIVE DAMAGE OF ERYTHROCYTE-MEMBRANE BY THE FLAVONOID QUERCETIN AND ITS RELATION TO IRON-CHELATING ACTIVITY

Incubation of glutathione (GSH) depleted mouse erythrocytes with the o xidants phenylhydrazine, acrolein, divicine and isouramil resulted in the release of free iron and in lipid peroxidation and hemolysis. The addition of the flavonoid quercetin, which chelates iron and penetrate s erythrocytes, resulted in remarkable protection against lipid peroxi dation and hemolysis. The protection seems to be due to intracellular chelation of iron, since a semi-stoichiometric ratio between released iron and the amount of quercetin necessary to prevent lipid peroxidati on and hemolysis was found, Incubation of GSH depleted human erythrocy tes with divicine and isouramil did not induce lipid peroxidation and hemolysis in spite of a substantial release of iron. However, divicine and isouramil produced alterations of membrane proteins, such as spec trin and band 3, as web as formation of senescent cell antigen, The ad dition of quercetin prevented these alterations. (C) 1997 Federation o f European Biochemical Societies.