Effects of hypnotic active components of Cnidii Fructus on expression of hippocampal Clock genes and amino acid neurotransmitters in PCPA insomnia rats / 中草药

ABSTRACT

Objective To study the hypnotic mechanism of Cnidii Fructus hypnotic active constituent (SCZ) on the expression of clock genes and hippocampal neurotransmitters in insomnia rats. Methods The insomnia model was established by intraperitoneal injection of para-chlorophenylalanine (PCPA). SCZ at low (25 g/kg), medium (50 g/kg), and high (100 g/kg) conentrations were ig administrated respectively at the same time with diazepam as positive group, intragastric administration of PCPA was performed in insomnia rats for three days, The expression levels of Clock, Bmal1, Cry1, Cry2, Per1, Per2, and Per3 were detected by real-time PCR. The expression levels of γ-aminobutyric acid (GABA) and glutamic acid (Glu) in hippocampus dentate gyrus were detected by immunohistochemistry. The changes of contents of GABA and Glu were determinated by immunohistochemistry and high performance liquid chromatography. Results The results of immunohistochemistry showed that the expression of GABA in the dentate gyrus of the hippocampus of rats in the model group was significantly reduced compared with the control group, and the expression level of Glu was significantly increased (P < 0.05, 0.01). Compared with the model group, the expression level of GABA in SCZ medium and high dose group was significantly increased, and Glu expression was reduced significantly (P < 0.01). HPLC results showed that the GABA expression level in the hippocampus of the model group was significantly decreased compared with the control group, and the expression level of Glu was significantly increased (P < 0.05, 0.01). Compared with the model group, the expression level of Glu in hippocampus of rats in SCZ medium and high dose group was significantly decreased (P < 0.05), and the expression of GABA in rats with high and low doses of SCZ was significantly increased (P < 0.01). The results of Clock gene expression test showed that the expression of Clock and Bmal1 gene in the model group was significantly increased (P < 0.05) compared with the control group, and the expression levels of Cry1, Per1, and Per2 genes were significantly decreased (P < 0.05, 0.01). Compared with the model group, the expression of Clock and Bmal1 gene in the SCZ medium dose group was significantly decreased (P < 0.01); The expression levels of Cry1, Per1, and Per2 in the SCZ high dose group were significantly increased (P < 0.05, 0.01). The Per1 gene expression in the SCZ low-dose group was significantly increased (P < 0.01). Conclusion Cnidii Fructus hypnotic active components can increase the expression of Cry1, Per1, and Per2 gene by reducing the hypnosis of hippocampal Clock and Bmal1 expression. The increased expression of the inhibitory neurotransmitter GABA and the decreased expression of excitatory neurotransmitter Glu can inhibit the occurrence and development of insomnia, which can regulate the sleep-wake cycle for clinical treatment of insomnia.