Inhibitor effect of polyamines on reduction of cytochrome C by superoxide anion

The interaction of polyamines with enzymatically generated free radicals was investigated. The superoxide anion (O-2) was generated in vitro using the xanthine oxidase-hypoxanthine system. Our results show that spermidine or spermine at different concentrations (20-200 mM) inhibit the reduction of cytochrome c; the highest levels of inhibition were obtained adding 200 mM spermidine or spermine. Putrescine (200 mM) affected the reduction of cytochrome c very little.