Discovery of the Underlying Mechanism of Ginger Juice Processed Ziziphi Spinosae Semen for Its Sedative‐Hypnotic Effect on Insomnia Mice via Regulation of HPA Axis and cAMP/PKA Signaling Pathway

Based on Traditional Chinese Medicine (TCM) theory, the efficacy and mechanism of Ginger juice processed Ziziphi Spinosae Semen (GJPZSS) for treating insomnia, particularly stress-related types, were investigated to provide empirical evidence. An insomnia model was induced in mice by DL-4-chlorophenylalanine (PCPA) and chronic tail clamping. The sedative effect was evaluated by behavioral tests. Serum components from GJPZSS were analyzed by UHPLC-Q-TOF-MS/MS, and 64 potential targets were identified. The cAMP signaling pathway was enriched as the core pathway by Kyoto Encyclopedia of genes and genomes (KEGG) analysis and was validated by molecular docking. GJPZSS was demonstrated to prolong sleep time, reduce immobility time, increase 5-hydroxytryptamine (5-HT) and gamma-aminobutyric acid (GABA) levels, decrease hypothalamic-pituitary-adrenal (HPA) axis levels, and suppress neuronal death. The reduction of the cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), cAMP-response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in the brain was also significantly inhibited. It was concluded that the sleep-improving effect of GJPZSS was mediated through the regulation of the HPA axis and the cAMP/PKA/CREB/BDNF signaling pathway.