Effects of propolis and caffeic acid phenethyl ester on the oxidative/antioxidative status in rat brain exposed to ionising radiation

Propolis and its active component, caffeic asid phenethyl ester (CAPE), were used as antibacterial, antiinflammatory and antifungal for treatment of several diseases. Oxygen radical scavanging effects of propolis and antioxidant effects of CAPE by protecting from lipid peroxidation, and inhibiting ornitine decarboxilase, protein thyrosine kinase, lipooxygenase activities were reported. The purpose of this study was to search antioxidant effects of propolis and CAPE on the oxidative stress in rat brain exposed to total cranium irradiation. In this study, rats were divided into 6 groups: standart control (SC), control group of CAPE (CC), control group of propolis (PC), irradiated group (R), CAPE plus irradiation (C+R) and propolis plus irradiation (P+R) groups. Rats in control groups were unirradiated. Rats in R, C+R and P+R groups were exposed to total cranium irradiation of 5 Gy by single fraction. Propolis was administrated to the rats orally for ten days and first dose was given 1 hour before irradiation. CAPE was administrated to the rats intraperitoneally for ten days and first dose was given 30 minutes before irradiation. Rats were sacrified after 10 days and oxidant/antioxidant parameters such as malondialdehyde (MDA) concentrations, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities in rat brain tissues were determined. MDA levels in the R group were found to be higher than SC, P+R and C+R groups and were statistically significiant. SOD levels in R group were found to be lower than PC and C+R group and were statistically significiant. No difference was found between groups for GSH-Px activities. As results were evaluated biochemically, compared to the other groups increased oxidant and decreased antioxidant parameters in the irradiated group indicated damage of radiation by radicals. In addition, biochemical parameters showed antioxidant effects of propolis and CAPE. However, pharmocologic and toxicologic researches are needed for using propolis and CAPE as radioprotective agents against radiation-induced damage in brain.