Inflammatory bowel disease (IBD) is an idiopathic intestinal inflammatory condition with chronic and relapsing manifestations and is characterized by a disturbance in the interplay between the intestinal microbiota, the gut, and the brain. The microbiota-gut-brain axis involves interactions among the nervous system, the neuroendocrine system, the gut microbiota, and the host immune system. Increasing published data indicate that psychological stress exacerbates the severity of IBD due to its negative effects on the microbiota-gut-brain axis, including alterations in the stress response of the hypothalamic-pituitary-adrenal (HPA) axis, the balance between the sympathetic nervous system and vagus nerves, the homeostasis of the intestinal flora and metabolites, and normal intestinal immunity and permeability. Although the current evidence is insufficient, psychotropic agents, psychotherapies, and interventions targeting the microbiota-gut-brain axis show the potential to improve symptoms and quality of life in IBD patients. Therefore, further studies that translate recent findings into therapeutic approaches that improve both physical and psychological well-being are needed.
Humans ; Inflammatory Bowel Diseases/metabolism* ; Stress, Psychological/microbiology* ; Gastrointestinal Microbiome/physiology* ; Brain/metabolism* ; Hypothalamo-Hypophyseal System ; Pituitary-Adrenal System ; Animals

OBJECTIVES: To determine the pharmacological impact of hesperidin, the main component of Citri Reticulatae Pericarpium, on depressive behavior and elucidate the mechanism by which hesperidin treats depression, focusing on the gut-brain axis. METHODS: Fifty-four Sprague Dawley male rats were randomly allocated to 6 groups using a random number table, including control, model, hesperidin, probiotics, fluoxetine, and Citri Reticulatae Pericarpium groups. Except for the control group, rats in the remaining 5 groups were challenged with chronic unpredictable mild stress (CUMS) for 21 days and housed in single cages. The sucrose preference test (SPT), immobility time in the forced swim test (FST), and number in the open field test (OFT) were performed to measure the behavioral changes in the rats. Enzyme-linked immunosorbent assay was used to determine the levels of 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) in brain tissue, and the histopathology was performed to evaluate the changes of colon tissue, together with sequencing of the V3-V4 regions of 16S rRNA gene on feces to explore the changes of intestinal flora in the rats. RESULTS: Compared to the control group, the rats in the model group showed notable reductions in body weight, SPF, and number in OFT (P<0.01). Hesperidin was found to ameliorate depression induced by CUMS, as seen by improvements in body weight, SPT, immobility time in FST, and number in OFT (P<0.05 or P<0.01). Regarding neurotransmitters, it was found that at a dose of 50 mg/kg hesperidin treatment upregulated the levels of 5-HT and BDNF in depressed rats (P<0.05). Compared to the control group, the colon tissue of the model group exhibited greater inflammatory cell infiltration, with markedly reduced numbers of goblet cells and crypts and were significantly improved following treatment with hesperidin. Simultaneously, the administration of hesperidin demonstrated a positive impact on the gut microbiome of rats treated with CUMS, such as Shannon index increased and Simpson index decreased (P<0.01), while the abundance of Pseudomonadota and Bacteroidota increased in the hesperidin-treated group (P<0.05). CONCLUSION The mechanism responsible for the beneficial effects of hesperidin on depressive behavior in rats may be related to inhibition of the expressions of BDNF and 5-HT and preservation of the gut microbiota.
Animals ; Hesperidin/therapeutic use* ; Rats, Sprague-Dawley ; Depression/drug therapy* ; Male ; Stress, Psychological/drug therapy* ; Brain/metabolism* ; Brain-Derived Neurotrophic Factor/metabolism* ; Serotonin/metabolism* ; Gastrointestinal Microbiome/drug effects* ; Behavior, Animal/drug effects* ; Rats ; Brain-Gut Axis/drug effects* ; Chronic Disease ; Colon/drug effects*

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*

OBJECTIVE: To elucidate the modulation mechanism of Suanzaoren Decoction (SZRD) on basolateral amygdala (BLA) neuronal activity to alleviate chronic restraint stress (CRS)-related behavioral deficits. METHODS: The male C57BL/6J mice were assigned to 4 groups using the complete randomization method, including control (CON, n=19), CRS (n=19), SZRD (n=21), and fluoxetine (Flu, n=22) groups. Mice were restrained for 6 h per day, over a 21-d period to establish CRS models. The CON group remained in their cages without food or water during the 6-h matching period. SZRD and Flu groups received intragastric administration of SZRD (4.68 g/kg) and Flu (20 mg/kg) daily, respectively, 30 min before restraint for 21 consecutive days. The therapeutic effects of SZRD were evaluated using behavioral tests including the tail suspension test, elevated plus maze test, and forced swimming test. The cellular Fletcher B. Judson murine osteosarcoma proto-oncogene (c-Fos) expression in the BLA was measured using immunofluorescence, while action potential (AP) firing and synaptic transmission in BLA pyramidal neurons were evaluated using whole-cell patch-clamp recordings. RESULTS: SZRD administration significantly increased time spent in the open arms and open-arm entries while reducing immobility time (P<0.05 or P<0.01). It downregulated CRS-induced c-Fos expression and AP firing of pyramidal neurons in the BLA (P<0.01). Additionally, SZRD selectively attenuated excitatory (P<0.01), but not inhibitory, synaptic transmission onto BLA pyramidal neurons. CONCLUSION SZRD alleviated CRS-induced anxiety- and depression-like behaviors in mice by modulating the excitability and synaptic transmission of BLA pyramidal neurons.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Depression/complications* ; Pyramidal Cells/pathology* ; Male ; Mice, Inbred C57BL ; Basolateral Nuclear Complex/pathology* ; Restraint, Physical ; Anxiety/complications* ; Behavior, Animal/drug effects* ; Stress, Psychological/physiopathology* ; Mice ; Proto-Oncogene Proteins c-fos/metabolism* ; Action Potentials/drug effects* ; Synaptic Transmission/drug effects*

OBJECTIVES: To investigate the role of the calcium/calmodulin (CaM)-mediated activation of calcineurin (CN)-nuclear factor of activated T cells (NFAT) signaling pathway in mediating the regulatory effect of hyperforin (HY) on stress-induced depression-like disorder (DP) in mice. METHODS: C57BL/6J mice were randomly divided into control group, DP model group, and hyperforin treatment group (n=15). Behavioral changes of the mice were assessed using open field test (OFT), sucrose preference test (SPT), tail suspension test (TST), light/dark box test (LDB), and novel object suppression test (NSFT). Immunohistochemistry was used to detect tyrosine hydroxylase (TH) expression in the CA1 region of the hippocampus, and serum serotonin (5-HT) and norepinephrine (NA) levels were detected with ELISA. Western blotting was used to analyze the expressions of TNF-α, IL-1β, IL-2, and CN-NFAT pathway proteins. In cultured BV-2 microglial cells with lipopolysaccharide (LPS) stimulation, the effects of hyperforin and CN inhibitor (CNIS) on expressions of ionized calcium-binding adapter molecule 1 (IBA-1), 5-HT, NA, inflammatory cytokines and CN-NFAT pathway proteins were examined using immunofluorescence assay, ELISA or Western blotting. RESULTS: Compared with the control mice, the mice in DP group showed significantly reduced activity in OFT, decreased sucrose consumption in SPT, reduced shuttle crossing in LDB, and lowered food intake in NSFT with significantly increased immobility in TST. The mice with DP showed significantly decreased TH-positive neurons, lowered 5-HT and NA levels, and increased expressions of TNF-α, IL-1β, IL-2 and CaM-CN-NFAT pathway proteins. In cultured BV-2 cells, LPS stimulation strongly increased cellular IBA-1 expression, decreased the levels of neurotransmitters (5-HT and NA), and increased the levels of inflammatory cytokines and CN-NFAT signaling, and these changes were effectively reversed by treatment with hyperforin or CNIS. CONCLUSIONS Hyperforin improves stress-induced depression-like behaviors in mice and activated BV-2 cells by targeting the CN-NFAT signaling pathway.
Animals ; Mice, Inbred C57BL ; Mice ; Microglia/drug effects* ; Depression/etiology* ; Perylene/pharmacology* ; Calcineurin/metabolism* ; NFATC Transcription Factors/metabolism* ; Calcium Signaling/drug effects* ; Stress, Psychological ; Phloroglucinol/pharmacology* ; Signal Transduction ; Male ; Behavior, Animal/drug effects* ; Terpenes

OBJECTIVES: To investigate the mechanism by which the pyramidal neurons of the anterior cingulate cortex (ACC) modulate the effects of enriched environment (EE) for relieving anxiety-like behaviors in mice. METHODS: C57BL/6J mice were randomly divided into control group, restraint stress (RS) group, and RS+EE group (n=8). The mice in the latter two groups were subjected to RS for 2 h daily for 3 days, and those in RS+EE group were housed in an EE during modeling. Anxiety-like behaviors of the mice were evaluated using the elevated plus-maze tests (EPM) and open field test (OFT). Changes in c-Fos expression in the ACC of the mice were detected with immunofluorescence assay, and pyramidal neuron excitability in the ACC (Pyn^ACC) was measured using patch-clamp technique. The miniature excitatory and inhibitory postsynaptic currents (mEPSC and mIPSC, respectively) were analyzed to assess synaptic transmission changes. RESULTS: Behavioral tests showed obvious anxiety-like behaviors in RS mice, and such behavioral changes were significantly improved in RS+EE mice. Immunofluorescence staining revealed significantly increased c-Fos expression in the ACC in RS mice but lowered c-Fos expression in RS+EE group. Compared with the control mice, the RS mice showed increased action potential firing rate of Pyn^ACC, which was significantly reduced in RS+EE group. Compared with the RS mice, the RS+EE mice showed also decreased frequency of mEPSCs of Pyn^ACC, but the amplitude exhibited no significant changes. No obvious changes in the frequency or amplitude of mIPSCs were observed in RS+EE mice. CONCLUSIONS EE reduces excitability of Pyn^ACC to alleviate anxiety-like behaviors induced by RS in mice.
Animals ; Anxiety/physiopathology* ; Gyrus Cinguli ; Mice, Inbred C57BL ; Mice ; Pyramidal Cells/physiology* ; Restraint, Physical ; Stress, Psychological ; Proto-Oncogene Proteins c-fos/metabolism* ; Male ; Behavior, Animal ; Environment ; Excitatory Postsynaptic Potentials

OBJECTIVES: To investigate the impact of prenatal fear stress on placental amino acid transport and emotion and cognition development in offspring rats. METHODS: Thirty pregnant Wistar rats were randomized equally into control and fear stress (induced using an observational foot shock model) groups. In each group, placental and serum samples were collected from 6 dams on gestational day 20, and the remaining rats delivered naturally and the offspring rats were raised under the same conditions until 8 weeks of age. Emotional and cognitive outcomes of the offspring rats were assessed with behavioral tests, and placental structure was examined using HE staining. Bioinformatics analysis was used to identify differentially expressed placental transporter genes under fear stress. The expressions of system A and system L amino acid transporters, along with other specialized transporters, were detected using qRT-PCR and Western blotting. Fetal serum amino acid concentrations were determined by HPLC. The correlations between fetal amino acid levels and behavioral outcomes of the offspring rats were analyzed. RESULTS: The dams with fear stress showed reduced open-field activity and increased freezing behavior with significantly decreased placental weight, fetal weight, and fetal-to-placental ratio. Bioinformatics analysis revealed 28 differentially expressed transporter genes involved mainly in amino acid transport. In the fear stress group, fetal serum amino acid levels were significantly lowered and Slc38a1, Slc43a1, Slc43a2, Slc7a8, Slc6a6, Slc1a1 and Slc6a9 mRNA and protein expressions were all downregulated. The offspring rats in fear stress group exhibited decreased novel object preference and spontaneous alternation with reduced open arm exploration and increased immobility in emotional tests. Lower early-life amino acid levels was found to correlate with impaired adult cognition. CONCLUSIONS Prenatal fear stress in rats impairs placental amino acid transporter expression and reduces fetal serum amino acid levels, potentially contributing to long-term cognitive deficits in the offspring rats.
Animals ; Female ; Pregnancy ; Placenta/metabolism* ; Fear ; Rats ; Rats, Wistar ; Cognition ; Prenatal Exposure Delayed Effects ; Stress, Psychological ; Amino Acids/blood* ; Amino Acid Transport Systems/metabolism*

OBJECTIVES: To investigate the mechanisms of Modified Chaihu Guizhi Decoction (MCGD) for ameliorating anxiety- and depression-like behaviors in a mouse model of chronic unpredictable mild stress (CUMS). METHODS: The main chemical constituents of MCGD were identified through literature review, and network pharmacology analysis was performed to predict the potential pharmacological mechanisms of MCGD. For in vivo validation, male C57BL/6J mice were randomized into control group, CUMS model group, fluoxetine (FLX) treatment group, and low- and high-dose MCGD treatment groups (n=15), and in all but the control group, CUMS models were established by daily exposure to two randomized stressors for 28 consecutive days. Starting from 3 days prior to modeling, MCGD and fluoxetine treatments were administered daily via gavage and intraperitoneal injection, respectively. Depression- and anxiety-like behaviors of the mice were assessed using sucrose preference test, forced swim test, open field test and elevated plus maze test. The changes in mRNA expressions of the clock genes and inflammatory markers and expressions of the JAK2/STAT3 signaling proteins were detected using RT-qPCR and Western blotting, and immunofluorescence staining was used to detect microglia activation in the mice. RESULTS: The key active compounds in MCGD identified by network pharmacology analysis included quercetin, acacetin, formononetin, nobiletin, and baicalein. GO analysis identified 607 enriched pathways, and KEGG pathway enrichment revealed significant involvement of the JAK2/STAT3 and NF-κB signaling pathways. In the mouse models of CUMS, treatment with both fluoxetine and MCGD significantly alleviated anxiety- and depression-like behaviors. MCGD treatment significantly reduced Iba1 expression, improved the inflammatory markers, reversed the decrease in clock gene circadian rhythm amplitude, and obviously downregulated the expressions of JAK2, p-STAT3, p-NF-κB, IL-1β, and IL-6 proteins. CONCLUSIONS MCGD effectively alleviates anxiety- and depression-like behaviors in CUMS mice by modulating the inflammatory pathways and inhibiting the JAK2/STAT3 signaling pathway.
Animals ; Janus Kinase 2/metabolism* ; STAT3 Transcription Factor/metabolism* ; Signal Transduction/drug effects* ; Depression/metabolism* ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Male ; Mice, Inbred C57BL ; Anxiety/drug therapy* ; Stress, Psychological ; Disease Models, Animal

Early-life stress (ES) leads to cognitive dysfunction in female adolescents, but the underlying neural mechanisms remain elusive. Recent evidence suggests that the cell adhesion molecules NECTIN1 and NECTIN3 play a role in cognition and ES-related cognitive deficits in male rodents. In this study, we aimed to investigate whether and how nectins contribute to ES-induced cognitive dysfunction in female adolescents. Applying the well-established limited bedding and nesting material paradigm, we found that ES impairs recognition memory, suppresses prefrontal NECTIN1 and hippocampal NECTIN3 expression, and upregulates corticotropin-releasing hormone (Crh) and its receptor 1 (Crhr1) mRNA levels in the hippocampus of adolescent female mice. Genetic experiments revealed that the reduction of dorsal CA1 (dCA1) NECTIN3 mediates ES-induced object recognition memory deficits, as knocking down dCA1 NECTIN3 impaired animals' performance in the novel object recognition task, while overexpression of dCA1 NECTIN3 successfully reversed the ES-induced deficits. Notably, prefrontal NECTIN1 knockdown did not result in significant cognitive impairments. Furthermore, acute systemic administration of antalarmin, a CRHR1 antagonist, upregulated hippocampal NECTIN3 levels and rescued object and spatial memory deficits in stressed mice. Our findings underscore the critical role of dCA1 NECTIN3 in mediating ES-induced object recognition memory deficits in adolescent female mice, highlighting it as a potential therapeutic target for stress-related psychiatric disorders in women.
Animals ; Female ; Mice ; CA1 Region, Hippocampal/metabolism* ; Cell Adhesion Molecules/metabolism* ; CRF Receptor, Type 1/metabolism* ; Memory Disorders/etiology* ; Mice, Inbred C57BL ; Nectins/genetics* ; Receptors, Corticotropin-Releasing Hormone/antagonists & inhibitors* ; Recognition, Psychology/physiology* ; Stress, Psychological/complications*

Growth arrest DNA damage-inducible protein 45 β (GADD45B) has been reported to be a regulatory factor for active DNA demethylation and is implicated in the modulation of synaptic plasticity and chronic stress-related psychopathological processes. However, its precise role and mechanism of action in stress susceptibility remain elusive. In this study, we found a significant reduction in GADD45B expression specifically in the ventral, but not the dorsal hippocampal CA1 (dCA1) of stress-susceptible mice. Furthermore, we demonstrated that GADD45B negatively regulates susceptibility to social stress and NMDA receptor-dependent long-term potentiation (LTP) in the ventral hippocampal CA1 (vCA1). Importantly, through pharmacological inhibition using the NMDA receptor antagonist MK801, we provided further evidence supporting the hypothesis that GADD45B potentially modulates susceptibility to social stress by influencing NMDA receptor-mediated LTP. Collectively, these results suggested that modulation of NMDA receptor-mediated synaptic plasticity is a pivotal mechanism underlying the regulation of susceptibility to social stress by GADD45B.
Animals ; Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors* ; CA1 Region, Hippocampal/drug effects* ; Male ; Stress, Psychological/physiopathology* ; Mice ; Neuronal Plasticity/drug effects* ; Long-Term Potentiation/drug effects* ; Mice, Inbred C57BL ; Antigens, Differentiation/metabolism* ; Dizocilpine Maleate/pharmacology* ; Excitatory Amino Acid Antagonists/pharmacology* ; GADD45 Proteins