What determines the antioxidant potential of yeast cells?

Reactivity which organic radicals was compared in yeast (Saccharomyces cerevisiae) strains defective in catalase and superoxide dismutase, and with a decreased level of glutathione. Yeast cell homogenates did not show considerable strain-related differences in the ability to scavenge nitroxide (TEMPO) stable free radicals and alkoxyl free radicals generated by decomposition of the free radical initiator AAPH. The "total antioxidant status" based on scavenging of ABTS free radicals showed a good correlation with the radiation resistance of the yeasts. These results point to the importance of other factors, apart from antioxidative enzymes and glutathione, in the determination of cellular resistance to ionizing radiation and other types of free-radical stress.