Protective Effect of Fisetin (3,7,3′,4′-Tetrahydroxyflavone) against γ-Irradiation-Induced Oxidative Stress and Cell Damage

Ionizing radiation can induce cellular oxidative stress through the generation of reactive oxygen species, resulting in cell damage and cell death. The aim of this study was to determine whether the antioxidant effects of the flavonoid fisetin (3,7,3',4'-tetrahydroxyflavone) included the radioprotection of cells exposed to gamma-irradiation. Fisetin reduced the levels of intracellular reactive oxygen species generated by gamma-irradiation and thereby protected cells against gamma-irradiation-induced membrane lipid peroxidation, DNA damage, and protein carbonylation. In addition, fisetin maintained the viability of irradiated cells by partially inhibiting gamma-irradiation-induced apoptosis and restoring mitochondrial membrane potential. These effects suggest that the cellular protective effects of fisetin against gamma-irradiation are mainly due to its inhibition of reactive oxygen species generation.