Abstract: Objective To study the curative effect of Hawthorn flavones on brain damage in Wistar rats induced by microwave radiation and to clarify the treatment effect of Hawthorn flavones on non-heat effect and heat effect induced by microwave radiation.Methods 36 Wistar rats were randomly divided into normal control group,radiation model group and radiation administration group.The rats  in  the last two groups were given  200 mW.cm^-2  microwave radiation for 5 min.After microwave radiation,the rats in radiation administration group were given 40 mg.kg^-1 Hawthorn flavones once a day,the rats in the other two groups were renderedthe same amount of saline by the same way.The whole process lasted for  14 d.Then the  learning and memory capacities of the rats in 10,11,12,13 and 14 d respectively were detected by Morris Water Maze.The other day after stopping given the Hawthorn flavones,the rats were killed and the brains were removed,then the changes of the brain structures were observed by optical microscope.Results  Compared with normal control group,the target quadrant time,platform residence time,times of crossing platform and times of crossing coverage area of rats in radiation model group and radiation administration group were decreased after 200 mW.cm^-2 microwave radiation (P<0.05);meanwhile the indexes mentioned above in radiation administration group were higher than those in radiation model group (P<0.05).After  200 mW.cm^-2 microwave radiation,the  rat hippocampus and cerebellum neurons appeared nuclear pyknosis and  deep dyeing,and in  radiation administration group  the injury of rat hippocampus neurons was decreased,and restored,without significant changes in cerebellum neurons and blood vessels.Conclusion The learning and memory capacities and the brain structure of the rats can be damaged by microwave radiation with dosage of 200 mW.cm^－2 and Hawthorn flavones has curative effecton brain damage of rats induced by microwave radiation.

Key words: Hawthorn flavones, microwave radiation, brain damage