Inhibitory effect of urate on oxidative damage induced by adriamycin-Fe3+ in the presence of H2O2.

Urate strongly inhibited DNA damage induced by adriamycin (AD)-Fe3+ in the presence of H2O2. Deoxyribose (DOR) was degraded during the interaction of Ad-Fe3+ with H2O2, and urate strongly inhibited the DOR degradation. However, hydroxyl radical (HO.) scavengers did not always prevent the DOR degradation. ESR signal of 5,5-dimethyl-1-pyroline N-oxide-hydroxyl radical adduct was detected during the interaction of Ad-Fe3+ with H2O2. Mannitol and DNA strongly diminished the ESR signal but urate only poorly did. These results suggested that inhibitory effect of urate on the H2O2-dependent AD-Fe(3+)-induced DNA damage was not always due to trap only HO.. Lipid peroxidation of erythrocyte membrane was induced by AD-Fe3+ alone and H2O2 slightly inhibited the peroxidation reaction. Urate could not inhibit the Ad-Fe(3+)-induced lipid peroxidation. These results indicate that oxygen radical species which causes the lipid peroxidation does not involve in the H2O2-dependent Ad-Fe(3+)-induced DNA damage.