Protective Effects Of Propolis On Rats Exposed To Radiation

Objective:To study the protective effects of propolis in rats exposed to ⁶⁰Co–γrays and radon inhalation .Metheods: (1)Male Wistar rats were randomly divided into 3 groups with 6 rats in each group,i.e.,irradiation group, prevention group and therapy group.The prevention group was given propolis per day before irradiation at the dose of 0.2mg/kg in 3 consecutive days.The therapy group was given propolis after irradiation at the same dose in 7 consecutive days.The experimental groups were exposed ⁶⁰Co-γrays at the dose of 3.0Gy and dose rate of 1.0Gy/min. (2)Twenty-eight male Wistar rats were randomly divided into 7 groups,one control group,three groups of radon exposure(the cumulative doses up to 30,67 and 111WLM, respectively) and three groups of propolis prevention.The prevention groups were given propolis at the dose of 0.2mg/kg before daily radon exposure. (3)The activity of SOD(superoxide dismutase) and the content of MDA(malondialdehyde)in blood and lung tissue were detected. Pathological sections were used to identify the lung damage induced by radon. DNA damage of BALF(bronchoalveolar lavage fluid) cells and WBC(white blood cell) were detected by SCGE(single cell gel electrophoresis). The propolis effects on the peripheral blood cells were also observed .Results: (1) The activity of SOD in rats treated with propolis after exposure to ⁶⁰Co-γrays was higher and the content of MDA was lower than those in irradiation group. The activity of SOD in blood and lung tissue was significantly decreased and the level of MDA increased in radon-inhald rats compare to the control group.The activity of SOD was increased and the content of MDA was reduced in the propolis prevention groups. Inflammatory reaction was observed in lung tissues after radon exposure. (2) The length of commet tail and the DNA% content in BALF cells and WBC increased after exposure to ⁶⁰Co-γrays and radon irradiation,but decreased after treatment with propolis.(3) The number of WBC in rats treated with propolis increased significantly.