Study On The Sedative And Hypnotic Effect Of Somnifera Extract On Insomnia Rats

Objective:In this study,the insomnia model of rats was established by intraperitoneal injection of PCPA,and the behavior,pathological changes of hypothalamus and the content of neurotransmitters in hypothalamus and hippocampus were observed in order to comprehensively evaluate the therapeutic effect and mechanism of Menyanthes Trifoliata L.extract on rat insomnia model,so as to provide basis for further development and utilization of Menyanthes Trifoliata L.resources.Methods:Forty-eight SPF male SD rats were randomly divided into 6 groups: the blank group（CON,n=8）,the sleep deprivation model group（SDM,n=8）,the estazolam group（EST,n=8）,the low dose group（LMT,n=8）,the middle dose group（MMT,n=8）and the high dose group（HMT,n=8）.Except for the CON group,the insomnia model was established by intraperitoneal injection of PCPA suspension（350mg/kg）for two days.On the third day,the rats in the EST group were given estazolam 0.2mg/kg,the LMT group,the MMT group and the HMT group were given 200,400 and 800mg/kg Menyanthes Trifoliata L.resources,respectively,the Con group and SDM group respectively with the same volume of normal saline for seven days.The general behavior of rats in each group,the changes of body weight and sleep of rats in each group before and after modeling and after treatment were observed and recorded,the differences of each group were compared by open field test and correction test,and the pathological changes of hypothalamus were observed by H ＆ E staining.The contents of 5-HT,GABA,GLU and DA in different brain regions of hypothalamus and hippocampus were determined by enzyme-linked immunosorbent assay（ELISA）.Results:（1）The body weight increased significantly in all groups,especially in the the middle and the high dose groups.（2）In the open field experiment,the total movement distance of the low,the middle and the high dose groups increased significantly,the number of fecal particles decreased significantly,and the residence time in the central area of the middle and the high dose groups decreased significantly,and the model group had activity tracks in all areas.and frequent activity,after drug treatment,the activity track was sparse compared with the model group.（3）In the correction experiment,the sleep latency was significantly shortened and the sleep duration was significantly increased in the low,middle and high dose groups.（4）H＆E staining showed scattered pyknosis and deep staining of the nucleus of nerve cells in the blank group,a large amount of pyknosis and deep staining of the nucleus of nerve cells in the model group,and a relative decrease in the number of pyknotic nerve cells in each group.（4）In hypothalamus,the contents of 5-HT and GABA in the high dose group were significantly increased,the contents of GLU and DA and the ratio of GLU/ GABA in the low,middle and high dose groups were significantly decreased,while in hippocampus,the contents of 5-HT and GABA in the low,middle and high dose groups were significantly increased,the contents of GLU and DA were significantly decreased,and GLU/GABA was significantly decreased.Conclusion:（1）Menyanthes Trifoliata L.extract can improve the sleep condition of insomnia rats induced by PCPA and has a certain sedative and hypnotic effect.（2）The sedative and hypnotic mechanism of the extract may be related to the regulation of neurotrans-mitters such as 5-HT,GABA,GLU and DA in hypothalamus and hippocampus.