OBJECTIVE: To investigate the antidepressant effects of Xiaoyao Pill (XYP) by exploring its interactions with gut microbiota and tryptophan metabolism. METHODS: Utilizing network pharmacology, the functional substance groups, key targets, and pathways of XYP in the treatment of depression were identified. The chronic unpredictable mild stress (CUMS) protocol was implemented in male Sprague-Dawley rats to establish depression model. Thirty rats were randomly divided into 3 groups according to their body weight (10 for each): control, CUMS and XYP groups (1.8 g/kg). After 28-day interventions, behavioral phenotyping including sucrose preference test (SPT) and open field test (OFT) were performed. Biochemical validation encompassed enzyme-linked immunosorbent assay for serum cortisol, hematoxylin-eosin histopathology, and immunohistochemistry. Liquid chromatography-mass spectrometry was utilized to profile serum metabolites, while fecal samples underwent metagenomic sequencing for gut microbiota characterization. RESULTS: Network pharmacology studies predicted that key components can protect the nervous system by regulating inflammatory pathways through the blood-brain barrier. SPT and OFT showed that XYP treatment significantly ameliorated depressive-like behaviors (all P<0.05). XYP treatment also restored hippocampal neuronal density, increased serum neurotransmitter levels of neurotransmitters such as 5-hydroxytryptamine and vasoactive intestinal peptide, and while suppressing inflammatory markers such as tumor necrosis factor-alpha, interleukin-1 beta (IL-1 β), and IL-6 (all P<0.05). Metagenomics revealed significant restructuring of gut microbiota, notably the regulation of Parabacteroides distasonis (P<0.05). Non-targeted metabolomics analysis showed that the level of metabolites in the tryptophan and kynurenine pathway significantly changed (variable importance in the projection >1, P<0.05), and the change of metabolic flux was significantly correlated with behavioral improvement (P<0.05). CONCLUSIONS XYP exerts antidepressant effects by increasing neurotransmitter levels, reducing inflammatory makers and modulating Parabacteroides distasonis. Through further exploration of metabolomics, we found that XYP may play a protective role in depression by regulating tryptophan metabolism.
Animals ; Tryptophan/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Gastrointestinal Microbiome/drug effects* ; Rats, Sprague-Dawley ; Depression/blood* ; Male ; Stress, Psychological/drug therapy* ; Behavior, Animal/drug effects* ; Rats ; Chronic Disease ; Hippocampus/drug effects*

OBJECTIVES: The neurotoxicity of carbon monoxide (CO) to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Our previous study found that retinoic acid (RA) can suppress the neurotoxic effects of CO. This study further explores, in vivo and in vitro, the molecular mechanisms by which RA alleviates CO-induced central nervous system damage. METHODS: A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO, and a DEACMP animal model was established in adult Kunming mice. Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin V/propidium iodide (PI) double staining. The transcriptional and protein expression of each gene was detected using real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Long noncoding RNA (lncRNA) SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes. In DEACMP mice, SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression. RESULTS: RA at 10 and 20 μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes, downregulation of SNHG15 and LINGO-1, and upregulation of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) (all P<0.05). Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity (all P<0.05). Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels (all P<0.05). Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP (all P<0.05). CONCLUSIONS RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes, thereby reducing central nervous system injury and exerting neuroprotective effects. LncRNA SNHG15 and LINGO-1 are key molecules mediating RA-induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway. These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
Animals ; RNA, Long Noncoding/physiology* ; Brain-Derived Neurotrophic Factor/genetics* ; Carbon Monoxide Poisoning/complications* ; Mice ; Tretinoin/pharmacology* ; Nerve Tissue Proteins/metabolism* ; Membrane Proteins/metabolism* ; Apoptosis/drug effects* ; Hippocampus/cytology* ; Receptor, trkB/metabolism* ; Neurons/drug effects* ; Male ; Brain Diseases/etiology* ; Oligodendroglia/drug effects* ; Signal Transduction ; Cell Line

OBJECTIVES: The integrated endoplasmic reticulum stress inhibitor (ISRIB) is a selective inhibitor of the protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway within endoplasmic reticulum stress (ERS) and can improve spatial and working memory in aged mice. Although ERS and oxidative stress are tightly interconnected, it remains unclear whether ISRIB alleviates cognitive impairment by restoring the balance between ERS and oxidative stress. This study aims to investigate the effects and mechanisms of ISRIB on lipopolysaccharide (LPS)-induced cognitive impairment in mice. METHODS: Eight-week-old male ICR mice were randomly divided into 3 groups: Normal saline (NS) group, LPS group, and ISRIB+LPS group. NS and LPS groups received daily intraperitoneal injections of normal saline for 7 days; on day 7, LPS group mice received intraperitoneal LPS (0.83 mg/kg) to establish a cognitive impairment model. ISRIB+LPS group received ISRIB (0.25 mg/kg) intraperitoneally for 7 days, with LPS injected 30 minutes after ISRIB on day 7. Cognitive ability was evaluated by the novel place recognition test (NPRT). Real-time fluorogenic quantitative PCR (RT-qPCR) was used to detect changes in nitric oxide synthase (NOS), superoxide dismutase-1 (SOD-1), and catalase (CAT) gene expression in the hippocampus and prefrontal cortex. Oxidative stress markers malondialdehyde (MDA), glutathione (GSH), and oxidized glutathione (GSSG), were measured in hippocampal and prefrontal cortex tissues. RESULTS: Compared with the NS group, mice in LPS group showed a significant reduction in novel place recognition ratio, upregulation of hippocampal NOS-1 and NOS-2 mRNA, downregulation of SOD-1 and CAT mRNA, increased MDA and GSSG, decreased GSH, and reduced GSH/GSSG ratio (all P<0.05). Compared with the LPS group, mice in ISRIB+LPS group exhibited significantly improved novel place recognition, downregulated NOS-1 and NOS-2 mRNA, upregulated SOD-1 and CAT mRNA, decreased MDA and GSSG, increased GSH, and an elevated GSH/GSSG ratio in the hippocampus (all P<0.05). No significant changes were observed in the prefrontal cortex. CONCLUSIONS ISRIB improves LPS-induced cognitive impairment in mice by restoring the oxidative/antioxidant balance in the hippocampus.
Animals ; Lipopolysaccharides ; Male ; Mice, Inbred ICR ; Cognitive Dysfunction/drug therapy* ; Mice ; Oxidative Stress/drug effects* ; Endoplasmic Reticulum Stress/drug effects* ; Hippocampus/drug effects* ; Nitric Oxide Synthase Type II/genetics* ; Guanidines/pharmacology* ; eIF-2 Kinase/antagonists & inhibitors* ; Signal Transduction/drug effects* ; Superoxide Dismutase/metabolism*

OBJECTIVES: To explore the molecular mechanism by which miR-124 affects cognitive function of sleep-deprived rats. METHODS: Fifty-four adult male SD rats were randomized into 6 groups (n=9), including a normal control group, a sleep deprivation (SD) model group, and 4 intracerebral microinjection groups in which the rats were subjected to stereotactic injection of miR-124 agomir, miR-124 agomir NC, miR-124 antagomir, or miR-124 antagomir into the lateral ventricle 7 days before SD modeling. The cognitive functions of the rats were evaluated with Morris water maze test, and pathological changes in the hippocampus were observed using HE staining. The expression level of miR-124 in hippocampal tissues of the rats was detected with qRT-PCR, and the expression level of apoptosis-related proteins and signaling pathway proteins were determined using Western blotting. RESULTS: In Morris water maze test, the SD rat models treated with miR-124 agomir showed a significantly shorter escape latency and fewer platform crossings with increased percentage of time and swimming distance in the fourth quadrant as compared with those in SD model group, while the rats treated with miR-124 antagomir exhibited worsened performance in the test. In the SD rat models, treatment with miR-124 agomir obviously lessened pathological changes in the hippocampus, while treatment with miR-124 antagomir significantly worsened the pathological changes. Compared with those in SD model group, the miR-124 agomir-treated rats showed an increased hippocampal expression of miR-124 with upregulated protein expressions of PI3K, p-AKT/AKT, and Bcl-2 and downregulated expressions of Bax and caspase-3 proteins, while rats treated with miR-124 antagomir showed significantly decreased hippocampal expression of miR-124 with lowered expressions of PI3K, p-AKT/AKT and Bcl-2 proteins and increased Bax and caspase-3 protein expressions. CONCLUSIONS High expression of miR-124 alleviates SD-induced cognitive decline and neuronal apoptosis in rats by activating the PI3K/AKT signaling pathway.
Animals ; MicroRNAs/metabolism* ; Signal Transduction ; Proto-Oncogene Proteins c-akt/metabolism* ; Male ; Rats, Sprague-Dawley ; Hippocampus/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Cognition ; Rats ; Sleep Deprivation/metabolism* ; Apoptosis ; Maze Learning

OBJECTIVES: To explore the bioactive components in Jiawei Xiaoyao Pills (JWXYP) and their mechanisms for alleviating depression-like behaviors. METHODS: The active compounds, key targets, and pathways of JWXYP were identified using TCMSP and TCMIP databases. Thirty-six SD rats were randomized equally into 6 groups including a control group and 5 chronic unpredictable mild stress (CUMS)-induced depression groups. After modeling, the 5 model groups were treated with daily gavage of normal saline, 1.8 mg/kg fluoxetine hydrochloride (positive control drug), or JWXYP at 1.44, 2.88, and 4.32 g/kg. The depression-like behaviors of the rats were evaluated using behavioral tests, and pathological changes in the liver and hippocampus were examined with HE staining. The biochemical indicators in the serum and brain tissues were detected using ELISA. Serum metabolomics analysis was performed to identify the differential metabolites using OPLS-DA, and gut microbiota changes were analyzed using 16S rDNA sequencing. RESULTS: Network pharmacology revealed that menthone and paeonol in JWXYP were capable of penetrating the blood-brain barrier to regulate inflammatory pathways and protect the nervous system. In the rat models subjected to CUMS, treatment with JWXYP significantly improved body weight loss, sucrose preference and open field activities, reduced liver inflammation, alleviated structural changes in the hippocampal neurons, decreased serum levels of TNF‑α, IL-1β, IL-6 and LBP, and increased 5-HT and VIP concentrations in the serum and brain tissue, and these effects were the most pronounced in the high-dose group. Metabolomics analysis showed changes in such metabolites as indole-3-acetamide and acetyl-L-carnitine in JWXYP-treated rats, involving the pathways for bile acid biosynthesis and amino acid metabolism. 16S rDNA analysis demonstrated increased gut microbiota diversity and increased abundance of Lactobacillus species in JWXYP-treated rats. CONCLUSIONS JWXYP alleviates depression-like symptoms in rats by regulating the neurotransmitters, inhibiting inflammation and oxidation, and modulating gut microbiota.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Gastrointestinal Microbiome/drug effects* ; Rats, Sprague-Dawley ; Depression/drug therapy* ; Neurotransmitter Agents/metabolism* ; Rats ; Inflammation ; Male ; Hippocampus ; Behavior, Animal/drug effects*

OBJECTIVES: To explore the correlation of hypertension with postoperative cognitive dysfunction and its possible mechanism. METHODS: Twelve-week-old spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) rats were both randomized into control group and surgical group (n=8). In the latter group, the rats received carotid artery exposure surgery under sevoflurane anesthesia to establish models of postoperative learning and memory impairment. Postoperative cognitive function changes of the rats were evaluated using behavioral tests. The hippocampus of the rats were collected for determining ATP level and mitochondrial membrane potential (MMP) and for detecting expressions of UCP2 and astrocyte markers (GFAP and NOX4) using Western blotting and immunofluorescence staining. Serum levels of ROS, IL-6, IL-1β and TNF‑α were detected using ELISA. Nissl staining was used to examine hippocampal neuronal loss in the CA1 region. RESULTS: The SHRs exhibited exacerbated learning and memory deficits following the surgery as shown by significantly reduced performance in novel object recognition tests and context-related and tone-related fear conditioning experiments. Compared with WKY rats, the SHRs had significantly decreased mitochondrial UCP2 expression and MMP in the hippocampus, increased hippocampal ATP level, and markedly increased serum levels of ROS and inflammatory factors, showing also increased activation of hippocampal astrocytes and microglia and reduced number of neurons positive for Nissl staining. CONCLUSIONS Hypertension can exacerbate major postoperative learning and memory impairment in rats possibly as a result of UCP2-mediated mitochondrial dysfunction and oxidative stress damage, which further leads to astrocyte overactivation and neuronal damage.
Animals ; Rats, Inbred SHR ; Rats ; Uncoupling Protein 2 ; Rats, Inbred WKY ; Hypertension/physiopathology* ; Hippocampus/metabolism* ; Mitochondria/metabolism* ; Down-Regulation ; Male ; Memory Disorders/etiology* ; Mitochondrial Proteins/metabolism*

OBJECTIVES: To observe the effect of 4-(arylethynyl)-pyrrolo[2,3-d] pyrimidine (10b) on post-traumatic stress disorder (PTSD)-like behaviors and ERK1/2-SGK1 signaling pathway in mice. METHODS: C57BL/6 mouse models exposed to single prolonged stress (SPS) were treated with daily gavage of saline, 10b at low, moderate and high doses, or paroxetine for 14 days. The changes in PTSD-like behaviors of SPS mice with different treatments were observed using behavioral tests. Western blotting and immunofluorescence assay were used to detect the protein expression levels of mGluR5, p-ERK, and SGK1 in the hippocampus of the mice. Pathological changes in the liver and kidney tissues of the mice were examined using HE staining. Molecular docking and molecular dynamics analyses were employed to evaluate the binding stability between the compound 10b and mGluR5. RESULTS: Compared to the normal control mice, the SPS mice exhibited obvious PTSD-like behaviors with increased hippocampal expressions of mGluR5 and p-ERK proteins and decreased SGK1 protein expression. Compound 10b significantly ameliorated behavioral abnormalities in SPS mice, inhibited mGluR5 expression, and reversed the dysregulation of p-ERK and SGK1. No obvious liver or kidney toxicity was observed after 10b treatment. Molecular docking and dynamics studies demonstrated a stable interaction between 10b and mGluR5. CONCLUSIONS The compound 10b ameliorates PTSD-like behaviors induced by SPS in mice possibly by inhibiting mGluR5 expression to modulate the ERK1/2-SGK1 signaling pathway.
Animals ; Stress Disorders, Post-Traumatic/drug therapy* ; Receptor, Metabotropic Glutamate 5/metabolism* ; Mice, Inbred C57BL ; Mice ; Protein Serine-Threonine Kinases/metabolism* ; Pyrimidines/pharmacology* ; Immediate-Early Proteins/metabolism* ; Signal Transduction/drug effects* ; MAP Kinase Signaling System/drug effects* ; Male ; Molecular Docking Simulation ; Hippocampus/metabolism*

OBJECTIVES: To explore whether the antioxidant axis Nrf2/HO-1 is involved in the regulation of hippocampus injury induced by cypermethrin and its underlying mechanism. METHODS: Ten-week-old C57BL/6 mice were randomly divided into control group and cypermethrin exposure groups with low, medium, and high exposure levels. After 21 days of oral gavage of corn oil (control) or cypermethrin, the levels of MDA, T-SOD, GSH-Px and CAT in the hippocampus of the mice were examined to evaluate the oxidative stress levels. HE staining was used to observe morphological changes of the hippocampal neurons. Western blotting, immunofluorescence staining and RT-qPCR were employed to detect the protein expressions and mRNA expression of Nrf2 and HO-1 and HO-1. RESULTS: Subacute oral exposure to cypermethrin significantly increased MDA level, decreased the activities of antioxidant enzymes T-SOD, GSH-Px and CAT, and induced neuronal damage in the CA1 and CA3 regions in the hippocampus of C57BL/6 mice. Cypermethrin exposure also caused Nrf2 protein translocation from the cytoplasm to the nucleus, accompanied by upregulated expression levels of the key antioxidant factor Nrf2 and its downstream target kinase HO-1. CONCLUSIONS Cypermethrin exposure dose-dependently causes oxidative damage in the hippocampus of C57BL/6 mice, which is regulated by the Nrf2/HO-1 antioxidant pathway.
Animals ; Pyrethrins/toxicity* ; NF-E2-Related Factor 2/metabolism* ; Hippocampus/cytology* ; Mice, Inbred C57BL ; Mice ; Oxidative Stress/drug effects* ; Neurons/pathology* ; Heme Oxygenase-1/metabolism* ; Signal Transduction ; Membrane Proteins

OBJECTIVES: To explore the therapeutic mechanism of Chaihu Shugan (CHSG) Decoction for improving cognitive impairment in rats with epilepsy induced by lithium chloride and pilocarpine. METHODS: Male SD rat models of cognitive impairment model after epilepsy induced by intraperitoneal injection with lithium chloride and pilocarpine were randomly divided into 5 groups (n=12) for treatment with daily gavage of saline, donepezil (90 mg/kg), or CHSG Decoction at 2.5, 5.0, 10, 20 and 40 g/kg for 4 consecutive weeks, with 10 rats with intraperitoneal injection with saline as the blank control group. Morris water maze test was used to evaluate cognitive and behavioral changes of the rats after treatment. The mRNA and protein expressions of ASIC1, NR1, NR2A and NR2B in the hippocampus of rats were detected using RT-qPCR and Western blotting. RESULTS: Compared with those with saline treatment, the rat models treated with CHSG Decoction at 5 and 10 g/kg showed significantly shortened escape latency and prolonged stay in the target quadrant with increased number of platform crossings in Morris water maze test. CHSG Decoction treatment at the two doses significantly increased ASIC1, NR1, NR2A and NR2B protein expressions in the hippocampus of the rat models, and their mRNA expression levels were all increased significantly after the treatment at the doses above 2.5 g/kg. CONCLUSIONS CHSG Decoction can improve cognitive impairment in rats after epilepsy possibly by regulating the expression and channel activity of NMDAR protein and its subunit protein via upregulating ASIC1 to modulate neuronal excitability and synaptic plasticity in the hippocampus.
Animals ; Hippocampus/drug effects* ; Receptors, N-Methyl-D-Aspartate/metabolism* ; Acid Sensing Ion Channels/metabolism* ; Rats, Sprague-Dawley ; Male ; Rats ; Epilepsy/complications* ; Cognitive Dysfunction/drug therapy* ; Drugs, Chinese Herbal/therapeutic use* ; Up-Regulation ; Maze Learning

OBJECTIVES: To exple the mechanism of Qixiong Zuogui Granules (QXZG) for enhancing synaptic plasticity in aging rats. METHODS: Forty SD rats were randomized into control group, aging model group, donepezil treatment group, and QXZG treatment group (n=10). Except for the control rats, all the rats were subjected to daily intraperitoneal injection of D-galactose for 8 consecutive weeks to induce brain aging, and donepezil hydrochloride and QXZG suspension were administered by gavage during modeling. After the interventions, the rats were evaluated for general conditions, behavioral changes, oxidative stress indicators, hippocampal pathologies, and expressions of the brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) pathway, p16, and synaptic plasticity-associated proteins. RESULTS: The rats in the model group exhibited obvious aging phenotypes such as yellowing of the teeth and hair, body weight loss, and impaired learning and memory abilities, with decreased serum SOD and GSH-Px activities and increased serum MDA level. The rat models also showed obvious pathological changes, reduced Nissl bodies, and elevated p16 protein expression in the hippocampal CA1 region, with significantly decreased expression levels of BDNF, TrkB, CREB and synaptic plasticity proteins SYN, GAP43, and PSD95. Treatment with QXZG alleviated the aging phenotypes in the rat models, improved their learning and memory abilities and pathological changes in the hippocampal CA1 region, reduced oxidative stress and p16 protein expression, and promoted the expressions of the BDNF/TrkB pathway proteins and synaptic plasticity proteins. CONCLUSIONS QXZG enhances synaptic plasticity and reduces oxidative stress in aging rats possibly by upregulating the BDNF/TrkB signaling pathway proteins, thereby delaying brain aging and improving learning and memory abilities of the rats.
Animals ; Brain-Derived Neurotrophic Factor/metabolism* ; Neuronal Plasticity/drug effects* ; Signal Transduction/drug effects* ; Rats, Sprague-Dawley ; Receptor, trkB/metabolism* ; Rats ; Aging ; Drugs, Chinese Herbal/pharmacology* ; Male ; Oxidative Stress ; Hippocampus/metabolism*