Study on the Effect of Ziziphi spinosae Semen Poria cocos Powder and Soybean Peptide Powder on Improving Sleep in Insomnia Model Mice

Objective: To study the sleep-improving effect of Ziziphi spinosae Semen Poria cocos powder and soybean peptide powder on insomnia model mice induced by p-chlorophenylalanine (PCPA). Methods: One hundred eighty SPF male BALB/c mice were purchased. First, ninety of them were randomly divided into six groups (normal control group, model control group, low, medium and high dose groups of Ziziphi spinosae Semen Poria cocos powder, soybean peptide powder group) for the pentobarbital sodium-induced sleep test. The remaining 90 mice were randomly divided into six groups (same group as above) for the open field test, the contents of hypothalamic 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) and norepinephrine (NE) in the hypothalamus were measured and the contents of γ-aminobutyric acid (GABA) and glutamic acid (Glu) in the hippocampus were measured. The normal control group and the model control group were administered with sterile water while the low, medium and high dose groups of Ziziphi spinosae Semen Poria cocos powder were administered with 0.67, 1.33, 4.00 g/kg BW solution and the soybean peptide powder groupwas administered with 1.15 g/kg BW solution. The gavage volume of rats was 20 mL/kg BW. The sleep test lasted for 36 days and the open field test lasted for 37 days. On the 29th and 30th day, except the normal control group, the other mice were given intraperitoneal injection of PCPA (350 mg/kg BW) to construct an insomnia model and then continued to be administered for 6, 7 d. Results: Compared with the model control group, Ziziphi spinosae Semen Poria cocos powder could significantly shorten the sleep latency induced by pentobarbital sodium, prolong sleep time, reduce horizontal score, vertical score and modified score, significantly increase the contents of 5-HT and 5-HIAA in the hypothalamus, reducing NE content, reduce Glu content in the hippocampus, improve the hippocampal GABA content, regulate the Glu/GABA ratio and maintain Glu/GABA balance in the hippocampus. Soybean peptide powder could significantly prolong sleep time and maintain Glu/GABA balance. Conclusion: Ziziphi spinosae Semen Poria cocos powder has a certain ameliorative effect on sleep in insomnia model mice by elevating monoamine neurotransmitter 5-HT content and reducing NE content in the hypothalamic of insomnia mice, promoting the sleep wake state of insomnia mice toward normal recovery. It also can regulate Glu and GABA content in the hippocampal and maintain the homeostatic balance of Glu and GABA.