245 - The Radioprotective Effects of Propolis and Caffeic Acid Phenethyl Ester on Radiation-Induced Oxidative/nitrosative Stress in Brain Tissue

Abstract

Head and neck cancer patients treated with radiotherapy suffer severe side effects during and following their treatment. Efforts to decrease toxicity of irradiation to normal tissue, organs and cells have led to searching for cytoprotective agent. Investigations for effective and non-toxic compounds with radioprotective capability led to increasing interest in antioxidant such as Propolis and Caffeic acid phenethyl ester (CAPE). The aim of this study was to evaluate the antioxidant and radioprotective effects of Propolis and CAPE on radiation-induced oxidative/nitrosative stress in the brain tissue. Fourty Sprague-Dawley rats were randomly divided into five groups. Group 1 (Irradiation (IR) + Propolis) received total cranium irradiation and propolis was given orally through an orogastric tube daily. Group 2 (IR+CAPE) received total cranium irradiation plus CAPE, was dissolved in dimethyl sulfoxide (DMSO) just before giving to the rats, intraperitoneally (IP) every day. Group 3 (IR) received 5 Gy of gamma irradiation as a single dose to total cranium plus 1 ml saline daily. Group 4 received daily plain DMSO. Group 5 received daily plain saline. At the end of the 10 day time period, xanthine oxidase (XO), nitric oxide synthase (NOS) activities, nitric oxide (NO●) and peroxynitrite (ONOO–) levels were significantly higher in IR group compared to all other groups. In conclusion, the results suggest the radioprotective ability of Propolis and CAPE involving prevention of radiation-induced oxidative/nitrosative damage.