The Efficacy Study on Si Ni San Freeze-Dried Powder on Sleep Phase in Insomniac and Normal Rats

Objectives. To investigate the effect of Si Ni San freeze-dried powder (SNSP) on sleep phase in insomniac and normal rats, to identify its mode of action in improving sleep, and to provide a reliable method for determining pharmacodynamic material basis of Si-Ni-San on improving sleep. Methods. Rats were deprived of sleep by using the footplate electrical stimulator to record the rats' electroencephalogram (EEG) and electromyogram (EMG) by using polysomnography (PSG) and copy insomnia model by the method of electric stimulation. Analysis on EEG and EMG was carried out to observe the effects of SNSP on the sleep phase of insomniac and normal rats. Results. Rats were treated by intragastric administration (i.g.) consecutively for seven days. The results showed that the total sleep time was extended; meanwhile, SWS2 (P < 0.01) and REMS (P < 0.05) were mainly prolonged for both insomniac and normal rats. The dates implied SNSP could significantly improve sleep. Conclusions. SNSP could prolong SWS2 and REMS, the experimental reproducibility is good, and the dates indicate that SNSP has the sedative function. Study on the effects of SNSP on sleep phases provided a basis for the further studies on effective constituents and the pharmacodynamic mechanism of SNSP.