Purpose: This study investigated the potential neuroprotective effect of epigallocatechin-3-gallate (EGCG) on radiation-induced cell death and damage in the hippocampus.
Materials and methods: Adult male Wister rats received oral treatment with EGCG at doses of 2.5 and 5 mg/kg/d for 3 d before 4 Gy γ irradiation.
Results: The pretreatment of irradiated rats with EGCG significantly ameliorated the increased plasma levels of homocysteine, amyloid β, TNF-α and IL-6 levels and the decrease of dopamine and serotonin. Pretreatment with EGCG also significantly ameliorated the irradiation-induced increase in the 4-HNE and protein carbonyl levels and the decreased antioxidants including glutathione level, and the activities of glutathione peroxidase and glutathione reductase in the hippocampus. EGCG treatment prior to radiation exposure protected against DNA damage and apoptosis in the hippocampus. The increase in the levels of p53, Cytochrome-c, Bax and caspases 3 and 9 in the hippocampus were significantly ameliorated with a significant increase in Bcl-2. These changes were supported by marked protection of the dentate gyrus that exhibited a similar histological structure of the control animals.
Conclusions: EGCG can attenuate the severity of radiation-induced damage and cell death in hippocampus recommending polyphenols as successful option for protecting against radiation-induced hippocampal damage.
Keywords: Brain; Ionizing radiation; apoptosis; glutathione; green tea; oxidative stress.