Anmeidan Regulates Hepatic Neurotransmitters and Circadian Rhythm in Rat Model of Insomnia via OX1R/PLCβ-1/PKCα/ERK1/2 Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore the effect and mechanism of the classic famous prescription Anmeidan （AMD） developed in the Qing Dynasty in regulating the hepatic neurotransmitters and circadian rhythm in the rat model of insomnia via the orexin-1 receptor （OX1R）/phosphatidylinositol-specific phospholipase Cβ-1 （PLCβ-1）/protein kinase Cα （PKCα）/extracellular signal-regulated kinase 1/2 （ERK1/2） signaling pathway. MethodSixty SPF-grade SD rats were randomized into blank， model， suvorexant （30 mg·kg-1·d-1）， and low-， medium-， and high-dose （4.55， 9.09， 18.09 g·kg-1·d-1， respectively） AMD groups， with 10 rats in each group. The rats in other groups except the blank group were modeled by intraperitoneal injection of p-chlorophenylalanine （PCPA） and administrated with corresponding drugs by gavage， and the blank group received an equal volume of normal saline. The general condition， body mass， and 24 h autonomic activity of each group were observed. The pathological changes of the liver tissue were observed by hematoxylin-eosin（HE）staining and Masson staining. The expression of gamma-aminobutyric acid （GABA）， 5-hydroxytryptamine （5-HT）， epinephrine （EPI）， norepinephrine （NE）， and acetylcholine （ACh） in the liver tissue was detected by enzyme-linked immunosorbent assay. The glutamate （Glu） expression in the liver tissue was detected by the biochemical method. The mRNA levels of biological clock genes Per1， Per2， Cry1， Cry2， Bmal1， and Bmal2 in the liver were determined by Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR）. The protein and mRNA levels of factors in the OX1R/PLCβ-1/PKCα/ERK1/2 signaling pathway in the liver were determined by Western blot and Real-time PCR， respectively. ResultCompared with the blank group， the modeling decreased the body mass （P<0.05， P<0.01） and caused mania and disturbed resting rhythms （P<0.01）， hepatic muscle fiber fracture， and edema with inflammatory cell infiltration. In addition， the modeling decreased the GABA， 5-HT， EPI， NE， and ACh content， increased Glu content （P<0.01）， down-regulated the mRNA levels of Per1， Per2， Cry1， and Cry2 （P<0.01）， up-regulated the mRNA levels of Bmal1 and Bmal2 （P<0.01）， and promoted the expression of OX1R， PLCβ-1， PKCα， and ERK1/2 at both protein and mRNA levels （P<0.01）. Compared with the model group， suvorexant and AMD increased the body mass （P<0.05， P<0.01）， alleviated the mania， and increased the resting time and frequency （P<0.05， P<0.01）. Moreover， the medications elevated the levels of GABA， 5-HT， EPI， NE， and ACh， lowered the Glu level， up-regulated the mRNA levels of Per1， Per2， Cry1， and Cry2 （P<0.05， P<0.01）， down-regulated the mRNA levels of Bmal1 and Bmal2， and inhibited the expression of OX1R， PLCβ-1， PKCα， and ERK1/2 at both mRNA and protein levels （P<0.05， P<0.01）. ConclusionAMD can regulate hepatic neurotransmitters and improve circadian rhythm in insomniac rats by inhibiting the OX1R/PLCβ-1/PKCα/ERK1/2 signaling pathway， and high-dose AMD demonstrated the strongest effect.