Protection of superoxide dismutase by caffeine in rat liver mitochondria against gamma-irradiation

摘要

Exposure of rat liver mitochondria to high doses of 60Co gamma-rays (45-600 Gy) resulted in the loss of activity of superoxide dismutase (SOD). Presence of caffeine, even in micromolar amounts, during exposure prevented loss of SOD activity. Caffeine, at a concentration of 1 mM also showed protection against radiation-induced inhibition of 2 other mitochondrial enzymes, succinate dehydrogenase and cytochrome c oxidase. It is suggested that the radioprotective ability of caffeine is due to its ability to scavenge the reactive oxygen species generated by radiation and to inhibit radiation-induced membrane damage, as assessed by lipid peroxidation and protein oxidation.