ObjectiveBased on transcriptomics， to explore the mechanism of Hei Xiaoyaosan regulating the phosphatidylinositol 3-kinase/protein kinase B （PI3K/Akt） signaling pathway to improve the learning and memory ability of insomnia rats with liver depression syndrome.MethodsSixty 8-week-old male SD rats were randomly divided into the blank group， model group， eszopiclone group （0.09 mg·kg^-1）， and low， medium， and high dose groups of Hei Xiaoyaosan （3.82， 7.65， 15.30 g·kg^-1）， with ten rats in each group. Except for the blank group， the other groups were induced insomnia rat model with liver depression by chronic restraint， tail clamping stimulation and intraperitoneal injection of p-chlorophenylalanine （PCPA）. Each treatment group received intragastric administration according to the specified dosage， once a day for 14 consecutive days. The pentobarbital sodium cooperative sleep test， open field test， and Morris water maze test were used to test the sleep quality， depressive-like behavior， and learning and memory abilities of rats. Additionally， enzyme-linked immunosorbent assay （ELISA） was used to detect the contents of 5-hydroxytryptamine （5-HT）， γ-aminobutyric acid （GABA）， brain-derived neurotrophic factor （BDNF）， glial cell line-derived neurotrophic factor （GDNF） and nitric oxide （NO） in hippocampus. Hematoxylin-eosin （HE） staining was performed to observe pathological changes of the hippocampal tissue， while terminal deoxynucleotidyl transferase deoxyuridine triphosphate （dUTP） nick end labeling （TUNEL） was used to evaluate apoptosis of hippocampal neurons. Transcriptomic sequencing technology was employed to identify differentially expressed genes in hippocampus between the model group and the blank group， as well as between the medium-dose group of Hei Xiaoyaosan and the model group. Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment analysis were performed on the intersecting genes. Subsequently， the enriched key genes and signaling pathways were analyzed and verified. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was utilized to assess the mRNA expression levels of phosphatase and tensin homolog （PTEN）， B-cell lymphoma-2 （Bcl-2）-like protein 11 （BCL2L11）， and mitogen-activated protein kinase 1 （MAPK1） in hippocampus， and Western blot was employed to evaluate the protein expressions of PI3K， phosphorylation （p）-PI3K， Akt， p-Akt， Bcl-2， Bcl-2-associated X protein （Bax）， and cleaved Caspase-3 in the same tissue.ResultsCompared with the blank group， the model group exhibited a reduction in body weight， an increase in sleep latency， and a decrease in sleep duration （P<0.01）. Additionally， rats showed obvious depression-like behavior， and their learning and memory abilities decreased. Furthermore， the contents of 5-HT， GABA， NO， BDNF and GDNF in hippocampus decreased （P<0.01）. Histological examination revealed a disorganized cell arrangement in the CA1 region of the hippocampus， characterized by irregular cell shapes， a reduced cell count， deeply stained and pyknotic nuclei， increased vacuolar degeneration， and an elevated apoptosis rate （P<0.01）. Compared with the model group， the body weight of the high and medium dose groups of Hei Xiaoyaosan increased， the sleep latency shortened and the sleep time prolonged （P<0.05， P<0.01）. Additionally， depression-like behavior and learning and memory abilities of rats were significantly improved， the levels of 5-HT， GABA， NO， BDNF and GDNF in the hippocampus increased （P<0.05， P<0.01）. These interventions also ameliorated pathological damage in the hippocampal CA1 area and reduced the apoptosis of hippocampal neurons （P<0.01）. Transcriptomic sequencing results indicated that Hei Xiaoyaosan might exert a therapeutic effect by regulating PI3K/Akt pathway through key mRNAs such as PTEN， BCL2L11， and MAPK1. The roles of these key mRNAs and proteins within PI3K/Akt pathway were further validated. In comparison to the blank group， the expression levels of PTEN， BCL2L11 and MAPK1 mRNA in the hippocampus of rats in the model group were increased （P<0.01）， while the protein expression levels of p-PI3K， p-Akt and Bcl-2 were decreased （P<0.01）， and the protein expression levels of PTEN， Bax and cleaved Caspase-3 were increased （P<0.01）. Compared with the model group， the high-dose and medium-dose groups of Hei Xiaoyaosan could down-regulate the expressions of PTEN， BCL2L11 and MAPK1 mRNAs （P<0.01）， up-regulate the expressions of p-PI3K， p-Akt and Bcl-2 proteins （P<0.01）， and down-regulate the protein expressions of PTEN， Bax and cleaved Caspase-3 （P<0.05， P<0.01）.ConclusionHei Xiaoyaosan may regulate PI3K/Akt signaling pathway by down-regulating expressions of key genes such as PTEN， BCL2L11 and MAPK1， and thus improve the learning and memory abilities of insomnia rats with liver depression syndrome.

Hei Xiaoyaosan;insomnia with liver depression syndrome;learning and memory abilities;transcriptomic sequencing;differential genes;phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway