[Therapeutic effect of Ziziphi Spinosae Semen extracts on chronic unpredictable mild stress-induced depression and insomnia-like behavior in mice].

This paper aims to study the effect of Ziziphi Spinosae Semen extracts on chronic unpredictable mild stress(CUMS)-induced depression-like and insomnia behavior models of mice. The CUMS-induced depression-like and insomnia behavior model of mice was established by CUMS treatment for three weeks. The mice were randomly divided into control group, model group, positive drug diazepam group(2 mg·kg~(-1)), as well as low-dose group(1.95 g·kg~(-1)), medium-dose group(3.9 g·kg~(-1)), and high-dose group(7.8 g·kg~(-1)) of Ziziphi Spinosae Semen extracts, with 18 mice in each group. On the 15th day of modeling, the drug was administered intragastrically once a day for one week. Then, the pentobarbital sodium cooperative righting experiment, open field experiment, and elevated plus maze experiment were carried out, respectively. The contents of neurotransmitters 5-hydroxytryptamine(5-HT) and 5-hydroxyindoleacetic acid(5-HIAA) in serum and thalamus of mice, as well as the levels of corticotropin releasing hormone(CRH), adrenocorticotropic hormone(ACTH), and corticosterone(CORT) in serum, were determined by enzyme-linked immunosorbent assay(ELISA). The neuron damage in the hippocampus of mice was observed by hematoxylin-eosin(HE) staining and Nissl staining. Western blot was used to detect the expressions of tryptophan hydroxylase 2(TPH2), serotonin transporter(SERT), monoamine oxidase A(MAOA), five prime repressors under dual repression binding protein 1(Freud1), synaptic plasticity-related proteins [cellular gene FOS(C-FOS), postsynaptic density protein 95(PSD95), synapsin 1(SYN1), and activity-regulated cytoskeleton-associated gene(ARC)], blood-brain barrier(BBB) permeability-related proteins [zonula occludens 1(ZO-1), occludin, and claudin 1], inflammatory factors [NOD-, LRR-and pyrin domain-containing protein 3(NLRP3), apoptosis-associated speck-like protein(ASC), gasdermin D(GSDMD), caspase-3, and caspase-8], and antioxidant factors [nuclear factor erythroid 2-related factor 2(NRF2) and heme oxygenase 1(HO1)] in thalamic tissue of mice. The results indicated that compared with that in the model group, the sleep latency was significantly shortened, and the sleep duration was significantly prolonged in each dose group of Ziziphi Spinosae Semen extracts. The number of visits to the central area of the open field and the distance and time of visits were significantly increased in each dose group of Ziziphi Spinosae Semen extracts. In addition, the proportion of distance and time of entering the open arm area of the elevated plus maze was significantly increased in each dose group of Ziziphi Spinosae Semen extracts. The contents of 5-HT and 5-HIAA in serum and thalamus of mice increased to varying degrees in each dose group of Ziziphi Spinosae Semen extracts; the contents of CRH, ACTH, and CORT in serum of mice were significantly decreased. The protein expression of TPH2 was significantly increased. The protein expression of MAOA, SERT, and Freud1 was significantly decreased. Ziziphi Spinosae Semen extracts could also significantly reduce the protein expression of C-FOS but significantly increase the protein expression of PSD95, ARC, and SYN1. They could reduce the pathological damage of the hippocampus in mice and significantly increase the protein expression of ZO-1, occluding, and claudin 1. The protein expression of NLRP3, GSDMD, ASC, caspase-3, and caspase-8 in the thalamic tissue of mice was significantly decreased, and the protein expression of HO1 and NRF2 was significantly increased. In conclusion, Ziziphi Spinosae Semen extracts could effectively improve sleep disorders and depression-like behaviors in CUMS-induced model mice, which may be related to regulating the 5-HT anabolism process and hypothalamic-pituitary-adrenal(HPA) axis-related hormone levels, reducing pathological damage in the hippocampus, improving synaptic plasticity, repairing BBB integrity, and alleviating inflammatory response and oxidative stress damage.