Shen Yuan extract exerts a hypnotic effect via the tryptophan/5-hydroxytryptamine/melatonin pathway in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Sleep plays a critical role in several physiologic processes, and sleep disorders increase the risk of depression, dementia, stroke, cancer, and other diseases. Stress is one of the main causes of sleep disorders. Ginseng Radix et Rhizoma and Polygalae Radix have been reported to have effects of calming the mind and intensifying intelligence in Chinese Pharmacopoeia. Traditional Chinese medicine prescriptions composed of Ginseng Radix et Rhizoma and Polygalae Radix (Shen Yuan, SY) are commonly used to treat insomnia, depression, and other psychiatric disorders in clinical practice. Unfortunately, the underlying mechanisms of the SY extract's effect on sleep are still unknown. AIM OF THE STUDY: This study aimed to investigate the hypnotic effect of the SY extract in normal mice and mice with chronic restraint stress (CRS)-induced sleep disorders and elucidate the underlying mechanisms. MATERIALS AND METHODS: The SY extract (0.5 and 1.0 g/kg) was intragastrically administered to normal mice for 1, 14, and 28 days and to CRS-treated mice for 28 days. The open field test (OFT) and pentobarbital sodium-induced sleep test (PST) were used to evaluate the hypnotic effect of the SY extract. Liquid chromatography-tandem mass spectrometry and enzyme-linked immunosorbent assay were utilized to detect the levels of neurotransmitters and hormones. Molecular changes at the mRNA and protein levels were determined using real-time quantitative polymerase chain reaction and Western blot analysis to identify the mechanisms by which SY improves sleep disorders. RESULTS: The SY extract decreased sleep latency and increased sleep duration in normal mice. Similarly, the sleep duration of mice subjected to CRS was increased by administering SY. The SY extract increased the levels of tryptophan (Trp) and 5-hydroxytryptamine (5-HT) and the expression of tryptophan hydroxylase 2 (TPH2) in the cortex of normal mice. The SY extract increased the Trp level, transcription and expression of estrogen receptor beta and TPH2 in the cortex in mice with sleep disorders by decreasing the serum corticosterone level, which promoted the synthesis of 5-HT. Additionally, the SY extract enhanced the expression of arylalkylamine N-acetyltransferase, which increased the melatonin level and upregulated the expressions of melatonin receptor-2 (MT2) and Cryptochrome 1 (Cry1) in the hypothalamus of mice with sleep disorders. CONCLUSIONS: The SY extract exerted a hypnotic effect via the Trp/5-HT/melatonin pathway, which augmented the synthesis of 5-HT and melatonin and further increased the expressions of MT2 and Cry1.

Effects of different chronic restraint stress periods on anxiety- and depression-like behaviors and tryptophan-kynurenine metabolism along the brain-gut axis in C57BL/6N mice.

Chronic restraint stress (CRS) is a widely used stimulus to induce anxiety- and depression-like behaviors, linked to alterations in tryptophan-kynurenine (TRP-KYN) metabolism in animals. This study assessed the effects of different CRS periods on anxiety- or depression-like behaviors and TRP-KYN metabolism along brain-gut axis in C57BL/6N mice. Results showed that one-week CRS decreased the open arm entries of mice in elevated plus maze and delayed latency of feeding in novelty suppressed feeding test. Four-week CRS reduced sucrose preference, increases forced swimming immobility time, and also induced anxiety-like behaviors of mice. UPLC-MS/MS analysis revealed decreased levels of the neurotoxic 3-hydroxykynurenine (3-HK) and quinolinic acid (QA), and an increase in the neuroprotective kynurenic acid (KA) in the hippocampus of one-week CRS mice; meanwhile, four-week CRS mice displayed a reduction in KA and increases in 3-HK and QA. In the colon, both one-week and four-week CRS mice exhibited significant reductions in 3-HK and QA, with a marked increase of KA exclusively in four-week CRS mice. Briefly, one-week CRS only induced anxiety-like behaviors with hippocampal neuroprotection in TRP-KYN metabolism, whereas four-week CRS caused anxiety- and depression-like behaviors with neurotoxicity. In the colon, during both CRS periods, KYN was metabolized in the direction of NAD+ production. However, four-week CRS triggered intestinal inflammation risk with increased KA. Summarily, slightly short-term stress has beneficial effects on mice, while prolonged chronic stress can lead to pathological changes. This study offers valuable insights into stress-induced emotional disturbances.

Melatonin-related dysfunction in chronic restraint stress triggers sleep disorders in mice.

Stress may trigger sleep disorders and are also risk factors for depression. The study explored the melatonin-related mechanisms of stress-associated sleep disorders on a mouse model of chronic stress by exploring the alteration in sleep architecture, melatonin, and related small molecule levels, transcription and expression of melatonin-related genes as well as proteins. Mice undergoing chronic restraint stress modeling for 28 days showed body weight loss and reduced locomotor activity. Sleep fragmentation, circadian rhythm disorders, and insomnia exhibited in CRS-treated mice formed sleep disorders. Tryptophan and 5-hydroxytryptamine levels were increased in the hypothalamus, while melatonin level was decreased. The transcription and expression of melatonin receptors were reduced, and circadian rhythm related genes were altered. Expression of downstream effectors to melatonin receptors was also affected. These results identified sleep disorders in a mice model of chronic stress. The alteration of melatonin-related pathways was shown to trigger sleep disorders.

Sex and age differences in chronic postoperative pain among patients undergoing thoracic surgery: a retrospective cohort study.

Background: The effect of sex and age on chronic post-thoracic surgical pain (CPTP) at rest and with activity remains unclear. The main purpose of this study was to investigate the relationship between the incidence of chronic postoperative pain (at rest and with activity) and sex/age differences. Methods: This was a single-center retrospective study that included adult patients who had undergone elective thoracic surgery. Patients were divided into two groups based on sex. Demographic and perioperative data were collected, including age, sex, education level, Body Mass Index (BMI), American Society of Anesthesiologists (ASA) physical status, and medical history (hypertension, diabetes mellitus). Chronic postoperative pain data were collected by telephone follow-up. Results: Among the 3,159 patients enrolled, 1,762 were male, and 1,397 were female. After creating a matched-pairs cohort, 1,856 patients were analyzed. The incidence of CPTP at rest was 14.9% among males and 17.8% among females (p = 0.090). The incidence of CPTP with activity was 28.4% among males and 35.0% among females (p = 0.002). We analyzed three different models after propensity matching to validate the stability of the prediction model between sex and CPTP, and female sex was a significant predictor of CPTP with activity 3 months after surgery. Further analysis showed that females in the 45-55-year-old age group were more prone to develop CPTP. Conclusion: Females have a higher incidence of chronic postoperative pain with activity after thoracic surgery. Females in the 45-55-year-old age group are more prone to develop CPTP than females in other age groups.

Effects of preoperative current smoking on chronic postsurgical pain in thoracic surgery: a retrospective cohort study.

OBJECTIVE: This study aimed to investigate the effect of preoperative current smoking on chronic postsurgical pain in patients who underwent thoracic surgery. METHODS: A total of 5,395 patients aged over 18 years old who underwent thoracic surgery from January 2016 to March 2020 in Henan Provincial People's Hospital were enrolled. Patients were divided into two groups: the smoking group (SG group) and the nonsmoking group (NSG group). Propensity score matching was utilized to eliminate the influence of confounding factors, and a multivariable logistic regression model was established to determine the effect of preoperative current smoking on chronic postsurgical pain. The dose-response relationship between the smoking index (SI) and chronic postsurgical pain at rest was analyzed using a restricted cubic spline curve. RESULTS: In a matched cohort of 1028 patients, the incidence of chronic pain at rest was 13.2% in the smoking group and 19.0% in the nonsmoking group (P = 0.011). Three different models were used to verify the stability of the model between preoperative current smoking and chronic postsurgical pain. A regression model was established to determine the influence of different smoking indexes (SIs) on chronic postsurgical pain. The incidence of chronic pain at rest was lower in patients with SI ≥400 before thoracic surgery than in patients whose SI was less than 400. CONCLUSIONS: A relationship between the preoperative current smoking index and chronic postsurgical pain at rest was observed. The incidence of chronic postsurgical pain at rest was lower in patients whose SI was greater than 400.

SiO2 dust induces inflammation and pulmonary fibrosis in rat lungs through activation of ASMase/ceramide pathway.

The role of ASMase/ceramide signaling pathway in the development of silicosis needs to be verified by in vivo experiments. We investigated the role of the ASMase/ceramide signaling pathway in the progression of silicosis and the effect of desipramine (DMI) (1 mg/mL) on the development of silicosis, by establishing a silica (1 mL, 50 mg/mL) dust-contaminated rat silicosis model and administering the ASMase inhibitor, DMI, to the dust-contaminated rats. The results showed that the levels of interleukin (IL)-1ß and IL-6 were increased in the lung tissues of the rats in the dust-contaminated group at the initial stage after dusting; the inflammatory cell aggregation in the lung tissue was increased. With time progression, the hydroxyproline content in the lung tissue increased, and alpha-smooth muscle actin (α-SMA), collagen I, and vimentin substantially increased, suggesting that silicosis was formed in the lung tissue of the rats 28 days after SiO2 dust treatment. Moreover, the levels of ASMase, ceramide, and sphingosine-1-phosphate (S1P) were increased in the lung tissue of rats. The expression of ß-catenin, fibronectin, and caspase-3 protein was increased, and E-cadherin protein expression was decreased in the lung tissue of the rats in the late stage of dust contamination. The ASMase and ceramide in the lung tissues of the rats in the DMI intervention group were reduced, as were the lung tissue inflammation levels, collagen expression, and lung fibrosis. These results suggest that SiO2 dust may activate the ASMase/ceramide signaling pathway in rat lung tissue, promoting pulmonary fibrosis. DMI inhibited this activation, attenuated apoptosis, blocked epithelial-mesenchymal transition, and halted silica dust-induced silicofibrosis.

LncRNA TUG1 promotes pulmonary fibrosis progression via up-regulating CDC27 and activating PI3K/Akt/mTOR pathway.

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease with an unclear pathogenesis. This study aimed to elucidate the function and potential mechanisms of TUG1 in IPF progression. Cell viability and migration were detected by CCK-8 and transwell assays. Autophagy, fibrosis, or EMT-related proteins were measured by Western blotting. Pro-inflammatory cytokine levels were assessed by ELISA kits. The subcellular localization of TUG1 was observed by FISH assay. RIP assay detected the interaction between TUG1 and CDC27. TUG1 and CDC27 was up-regulated in TGF-ß1-induced RLE-6TN cells. TUG1 depletion suppressed pulmonary fibrosis via attenuating inflammation, EMT, inducing autophagy and inactivating PI3K/Akt/mTOR pathway in vitro and in vivo. TUG1 knockdown prevented CDC27 expression. TUG1 silencing ameliorated pulmonary fibrosis by reducing CDC27 expression and inhibiting PI3K/Akt/mTOR pathway.

Tryptophan-kynurenine metabolic characterization in the gut and brain of depressive-like rats induced by chronic restraint stress.

Accumulating evidence revealed the role of tryptophan (TRP) metabolism, especially its kynurenine pathway (KP), in the communication along the gut-brain axis. However, the underlying characterization of such interaction was not precise. In the present study, the rat depression model was induced by chronic restraint stress (CRS). After depression behavior tests, seven segments (cortex, hippocampus, striatum, hypothalamus, serum, cecum, and colon) along the gut-brain axis were collected to characterize their KP metabolism. mRNA expression of IL-1ß, IFN-γ, IL-10 and indoleamine 2,3-dioxygenase 1 (IDO1) enzyme revealed a general inflammatory response and region-specific activated IDO1 along the gut-brain axis. Determination of KP metabolites and enzymes displayed a general KP activation with region-specificity, especially in the hippocampus and colon, where the changes were more pronounced. KYN and 3-HK were increased dramatically along the gut-brain axis; hippocampal KA revealed a significant decrease while colonic KA showed a notable increase, evidenced by the same alternation trends of the corresponding enzymes. The expression of quinolinic acid phosphoribosyltransferase (QPRT), the crucial enzyme to produce NAD+ from QA, was significantly upregulated in the gut but not changed in the brain. Pearson's correlation analysis suggested that kynurenine (KYN), 3-hydroxycaninuric acid (3-HK), serotonin (5-HT), TRP and kynurenic acid (KA) significantly correlated with depressive behaviors in rats. Furthermore, western blot analysis on nod-like receptor protein 3/2 (NLRP3/NLRP2) inflammasome signaling displayed that NLRP3 and cleaved IL-1ß/caspase-1 were significantly activated in the hippocampus and colon of CRS rats. However, NLRP2 was only activated in the hippocampus. These results revealed CRS induced inflammatory responses along the brain-gut axis of rats might be controlled through the NLRP3/NLRP2 inflammasome signaling pathway, which may be the underlying regulator for CRS-induced TRP-KYN metabolic changes. This study provides a new experimental background for developing stress-related health products.

Protective effect of Gastrodia elata blume ameliorates simulated weightlessness-induced cognitive impairment in mice.

During the long-term orbital flight, exposure to microgravity negatively affects the astronauts' development of cognition, characterized by learning and memory decline. Gastrodia elata Blume (GEB) has a significant protective effect on cognitive impairment and has been used in Asia for centuries as a functional product. A previous study demonstrated that GEB could improve memory loss in mice caused by circadian rhythm disorders. However, the effects of GEB on cognitive dysfunction caused by weightless environments have not been investigated. In this study, mice received daily treatment with GEB (0.5, 1 g·kg-1d-1, i.g) and Huperzine A(Hup, 0.1 mg·kg-1d-1, i.g) orally until the end of the behavioral test (New object recognition test (NORT). Malondialdehyde (MDA) and nitric oxide (NO) levels were detected by kits, and expression of brain-derived neurotrophic factor (BDNF), protein kinase B (AKT), phosphorylated Akt (P-AKT), synaptophysin (SYN) and postsynaptic density 95(PSD95) in hippocampus were detected by western blotting. The results show that administration of GEB (0.5, 1 g·kg-1d-1, i.g) and Hup (0.1 mg·kg-1d-1, i.g) remarkably reverse HLS-induced learning and behavioral memory disorders, which were associated with significant changes in MDA and NO levels. Additionally, the protein expressions of BDNF, P-AKT/AKT, SYN, and PSD95 were significantly increased in the hippocampus. In summary, our findings will improve the reference for developing GEB as a functional product that improves memory decline.

Diagnostic Value of Metagenomic Next-Generation Sequencing for Pneumonia in Immunocompromised Patients.

Introduction: The diagnosis of pulmonary infection and the identification of pathogens are still clinical challenges in immunocompromised patients. Metagenomic next-generation sequencing (mNGS) has emerged as a promising infection diagnostic technique. However, its diagnostic value in immunocompromised patients needs further exploration. Purposes: This study was to evaluate the diagnostic value of mNGS compared with comprehensive conventional pathogen tests (CTs) in the etiology of pneumonia in immunocompromised patients and immunocompetent patients. Methods: We retrospectively reviewed 53 patients who were diagnosed with pneumonia from May 2019 to June 2021. There were 32 immunocompromised patients and 21 immunocompetent patients with pneumonia who received both mNGS and CTs. The diagnostic performance was compared between mNGS and CTs in immunocompromised patients, using the composite diagnosis as the reference standard. And, the diagnostic value of mNGS for mixed infections was further analyzed. Results: Compared to immunocompetent patients, the most commonly pathogens, followed by Cytomegalovirus, Pneumocystis jirovecii and Klebsiella pneumoniae in immunocompromised patients. Furthermore, more mixed infections were diagnosed, and bacterial-fungal-virus coinfection was the most frequent combination (43.8%). mNGS can detect more types of pathogenic microorganisms than CTs in both groups (78.1% vs. 62.5%, P = 0.016and 57.1% vs. 42.9%, P = 0.048). The overall diagnostic positive rate of mNGS for pathogens was higher in immunocompromised patients (P = 0.002). In immunocompromised patients, a comparable diagnostic accuracy of mNGS and CTs was found for bacterial, fungal, and viral infections and coinfection. mNGS had a much higher sensitivity for bacterial infections (92.9% vs. 50%, P < 0.001) and coinfections (68.8% vs. 48.3%, P < 0.05), and it had no significant advantage in the detection of fungal infections, mainly due to the high sensitivity for Pneumocystis jirovecii in both groups. Conclusion: mNGS is more valuable in immunocompromised patients and exhibits apparent advantages in detecting bacterial and mixed infections. It may be an alternative or complementary diagnostic method for the diagnosis of complicated infections in immunocompromised patients.

Effect of Radix Polygalae extract on the colonic dysfunction in rats induced by chronic restraint stress.

ETHNOPHARMACOLOGICAL RELEVANCE: Radix Polygalae, a commonly used traditional Chinese herb, has conventionally functioned in tranquilization and sedation, where anti-inflammation may be the underlying mechanism. AIM OF THE STUDY: Chronic restraint stress (CRS), a risk factor for the etiology of intestinal disorders, was used in the present study to examine whether Radix Polygalae extract (RPE) could modulate colonic dysfunction in CRS rats. MATERIALS AND METHODS: Wistar rats were exposed to 28-day CRS (6 h daily), and RPE (135 mg/kg and 270 mg/kg) was intragastrically administered 1 h before CRS. Subsequently, the gut microbiota was determined using metagenomic sequencing. Colonic proinflammatory interleukin-1ß, -6, and -18 were assayed using qRT-PCR and ELISA. Tight junction proteins were quantified by qRT-PCR and western blotting (WB), and tryptophan metabolic enzymes and metabolites were determined using qRT-PCR and UFLC-QTRAP-5500/MS. Moreover, protein expression of colonic tight junction proteins, NF-κB-NLRP3 signaling involved in the underlying mechanism of RPE were detected by WB. RESULTS: RPE significantly decreased proinflammatory cytokines and reshaped the gut microbiota, especially the probiotics, including Lactobacillus and Bacteroides. Moreover, RPE could modulate the metabolite contents and enzyme expression associated with colonic tryptophan-kynurenine (TRP-KYN) metabolism and could increase tight junction protein expression in CRS rats. Furthermore, RPE inhibited the activation of NF-κB-NLRP3 signaling in the colon of CRS rats. CONCLUSION: RPE could modulate colonic inflammation, colonic microbiota, tight junction, TRP-KYN metabolism and NF-κB-NLRP3 signaling to reach a colonic balance of CRS rats. The present study helped us to better understand and appreciate the various beneficial effects of RPE.

Fungal Inhibition of Agricultural Soil Pathogen Stimulated by Nitrogen-Reducing Fertilization.

Plant health is the fundamental of agricultural production, which is threatened by plant pathogens severely. The previous studies exhibited the effects of different pathogen control strategies (physical, chemical, and microbial methods), which resulted from bringing in exogenous additives, on microbial community structures and functions. Nevertheless, few studies focused on the potential inhibitory abilities of native microbial community in the soil, which could be activated or enhanced by different fertilization strategies. In this study, three plant diseases (TMV, TBS, and TBW) of tobacco, fungal community of tobacco rhizosphere soil, and the correlation between them were researched. The results showed that nitrogen-reducing fertilization strategies could significantly decrease the occurrence rate and the disease index of three tobacco diseases. The results of bioinformatics analyses revealed that the fungal communities of different treatments could differentiate the nitrogen-reducing fertilization group and the control group (CK). Furthermore, key genera which were responsible for the variation of fungal community were explored by LEfSe analysis. For instance, Tausonia and Trichocladium increased, while Naganishia and Fusicolla decreased under nitrogen-reducing fertilization conditions. Additionally, the correlation between tobacco diseases and key genera was verified using the Mantel test. Moreover, the causal relationship between key genera and tobacco diseases was deeply explored by PLS-PM analysis. These findings provide a theoretical basis for a nitrogen-reducing fertilization strategy against tobacco diseases without exogenous additives and make contributions to revealing the microbial mechanism of native-valued fungal key taxa against tobacco diseases, which could be stimulated by agricultural fertilization management.

Phytochemical Characterizations of Maranthes polyandra (Benth.) Prance.

Two new ursane-type triterpenoids, named Polyanside A (1) and B (2), along with eleven known compounds (3-13), were isolated and elucidated from Maranthes polyandra (Benth.) Prance. The structures of these compounds were elucidated based on chemical evidence and multiple spectroscopic data. Isolated compounds were evaluated for anti-cancer, anti-inflammatory activities, and cytotoxicity on a normal human cell line (BJ). None of them showed activity and cytotoxicity. The hexane fraction was analyzed by GC-MS, resulting in the identification of forty-one compounds. This is the first comprehensive study on the phytochemistry of M. polyandra.

Chromosome-level genome assembly of Zizania latifolia provides insights into its seed shattering and phytocassane biosynthesis.

Chinese wild rice (Zizania latifolia; family: Gramineae) is a valuable medicinal homologous grain in East and Southeast Asia. Here, using Nanopore sequencing and Hi-C scaffolding, we generated a 547.38 Mb chromosome-level genome assembly comprising 332 contigs and 164 scaffolds (contig N50 = 4.48 Mb; scaffold N50 = 32.79 Mb). The genome harbors 38,852 genes, with 52.89% of the genome comprising repetitive sequences. Phylogenetic analyses revealed close relation of Z. latifolia to Leersia perrieri and Oryza species, with a divergence time of 19.7-31.0 million years. Collinearity and transcriptome analyses revealed candidate genes related to seed shattering, providing basic information on abscission layer formation and degradation in Z. latifolia. Moreover, two genomic blocks in the Z. latifolia genome showed good synteny with the rice phytocassane biosynthetic gene cluster. The updated genome will support future studies on the genetic improvement of Chinese wild rice and comparative analyses between Z. latifolia and other plants.

Gastrodia elata blume ameliorates circadian rhythm disorder-induced mice memory impairment.

Circadian rhythm disorder (CRD) in space flight can lead to memory impairment, performance decrements and adverse health outcomes, the main manifestations of which are circadian desynchronization, sleep loss and insomnia. Sleep deprivation (SD) provide the means to evaluate these effects and the risks associated with CRD on ground. Gastrodia elata Blume (GEB) has beneficial effects on the treatment of sleep disturbances and memory loss. Fresh GEB (FG), an unprocessed raw tuber of GEB, has been used as functional health food in Asian countries for a long time. However, the research report of FG to ameliorate memory impairment caused by insomnia or lack of sleep is meager. In this study, ICR male mice were sleep-deprived continuously and water extract of FG (WFG) was orally administrated (3 and 9 g/kg/d, i.g) during the SD process lasted for 25 days, except control and model groups gavage administration with water, positive control group with modafinil (MOD, 0.1 g/kg/d, i.g). We studied the effect of WFG on CRD-induced learning and memory impairment using a set of behavioral analyses including the object location recognition test (OLRT), novel object recognition test (NORT), and the passive avoidance test (PAT). In addition, oxidative stress parameters were assessed by measuring the malondialdehyde (MDA) and superoxide dismutase (SOD) reactivity in serum and hippocampus. Our results revealed that SD decreased discrimination index (DI) in OLRT and NORT, with shorter latency into the dark chamber in PAT. Both WFG and MOD treatment can reverse these changes (P < 0.05). We concluded that WFG treatment improve CRD-induced learning and memory impairment and oxidative stress damage which makes FG a promising candidate as herbal health product of memory decline in CRD.

Chronic restraint stress induced changes in colonic homeostasis-related indexes and tryptophan-kynurenine metabolism in rats.

Chronic stressors represented risk factors for the etiology or exacerbation of several gastrointestinal diseases. The goal of the present study was to examine whether chronic restraint stress (CRS) could initiate and aggravate colonic inflammation, integrity damage and metabolic disturbance of rats. Firstly, increased inflammatory cytokines (interferon-γ (IFN-γ), tumor necrosis factor-α(TNF-α) and interleukin-10(IL-10)) and decreased tight junction (TJ) proteins (occludin and zonula occludins-1 (ZO-1)) in rat colon were observed. Secondly, untargeted metabolomics based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass (UPLC-Q-TOF/MS) revealed that TRP metabolism was the most prominently affected. Thirdly, quantification of TRP and its metabolites via prominence ultrafast liquid chromatography coupled with a QTRAP 5500 mass (UFLC-QTRAP-5500/MS) showed that TRP, kynurenine (KYN), kynurenic acid (KA) and 3-hydroxykynurenine (3-HK) were significantly increased. At the same time, 5-hydroxytryptamine (5-HT) was unchanged and 5-hydroxyindolacetic acid (5-HIAA) was significantly decreased in the colon of CRS rats. Besides, TRP metabolic enzyme changes were with the same trends as the corresponding metabolites. Thus, our data showed that CRS could initiate colonic inflammation, integrity damage and colonic metabolism disturbance, especially TRP-KYN metabolism pathway of rats, which may provide an experimental background for future research on stress-related gastrointestinal dysfunction. SIGNIFICANCE: Chronic exposure to psychological stress could induce metabolic imbalance of the body, and stressful life events were intimately correlated with frequent relapses in patients with intestinal disorders. The present study showed that chronic restraint stress (CRS) could initiate and aggravate colonic inflammation, integrity damage and metabolic disturbance, especially tryptophan-kynurenine metabolism of rats. Tryptophan-kynurenine pathway may be involved in the initiation and development of diseases induced by chronic stress. This research may shed light on future research on stress-related gastrointestinal dysfunction.

Protective effect of ginsenoside Rb1 against chronic restraint stress (CRS)-induced memory impairments in rats.

Ginsenoside Rb1 (Rb1) is one of the most active components found in ginseng and provides important benefits to the central nervous system, especially for the improvement of learning and memory. Previous studies demonstrated that Rb1 protected against scopolamine-induced amnesia and exhibited memory-enhancing effects in the SAMP8 mouse model. However, the effects of Rb1 against chronic restraint stress (CRS)-induced cognitive impairments, especially the role of Rg1 on the performance of reward directed instrumental conditioning have not been investigated. In this study, rats were subjected to CRS (6 h/day) for 28 days. Thereafter, behavioural tests including reward-directed instrumental conditioning task (RICT) and the Morris water maze (MWM) task were conducted. Administered of Rb1 (6.75 and 13.5 mg/kg, i.p.) remarkably ameliorated the memory impairments caused by CRS as evident from the results of RICT and MWM task, and this effect was accompanied by noticeable alterations in the levels of oxidative markers (superoxide dismutase, catalase, and lipid peroxidation) in the hippocampus. Additionally, Rb1 reduced the ratio of Bax:Bcl-2 and the expression of cleaved caspase-3 and cleaved caspase-9, increased the levels of synaptophysin (SYP) and postsynaptic density 95 (PSD95) and activated the BDNF/TrkB pathway in the hippocampus. In summary, the present study demonstrated that Rb1 rescues cognitive deficits induced by CRS is partially mediated by antagonizing oxidative stress and apoptosis, improving synaptic plasticity and restoring the BDNF/TrkB signalling pathway. This newly discovered effect of Rb1 sheds light on its applications in the development of therapeutic interventions to alleviate the deleterious effects of chronic stress.

The antidepressant-like effects of Shen Yuan: Dependence on hippocampal BDNF-TrkB signaling activation in chronic social defeat depression-like mice.

The Shen Yuan prescription (SY) comprises Panax ginseng (GT) and Polygala tenuifolia (YT), elicited superior antidepressant activity compared with that of GT or YT alone. The aim of this paper is to elucidate the effects of SY treatment on chronic social defeat stress (CSDS)-induced depression-like symptoms and the related mechanism. Our results indicated that SY treatment reverses the depressive-like behaviors induced by CSDS as measured by the social interaction test, sucrose preference test, forced swim test, and tail suspension test. SY decreased the serum levels of CORT and increased hippocampal neurotransmitters (5-HT, DA, and NE) in CSDS mice. Meanwhile, SY upregulated the brain-derived neurotrophic factor (BDNF) signaling pathway and reversed the decreased hippocampal neurogenesis caused by CSDS. In addition, we found that the TrkB antagonist K252a fully blocked the SY effects on behavioral improvement and eliminated the promoting effects of SY on hippocampal neurogenesis and BDNF-TrkB signaling (including the downstream ERK and Akt pathways) activation, thus further demonstrating that BDNF-TrkB signaling was necessary for the SY effects. In conclusion, our study showed that SY acted as an antidepressant in mice exhibiting CSDS-induced depression-like symptoms, and its effect was facilitated by promoting hippocampal neurogenesis and BDNF signaling pathway activation.

Cytotoxic xanthones from the plant endophytic fungus Paecilamyces sp. TE-540.

One new xanthone, chryxanthone C (1), together with four known analogues (2-5), were isolated from the cultures of Paecilamyces sp. TE-540, an endophytic fungus obtained from the leaves of Nicotiana tabacum L. The structure of 1 was elucidated by comprehensive spectral analysis including HRESIMS and 1D/2D NMR, which were confirmed by Cu Kα X-ray crystallography. Compound 1 featured an unusual dihydropyran ring fused to an aromatic ring, rather than the commonly occurring prenyl moiety. The cytotoxicity of compounds 1-5 were evaluated against five human tumour cell lines and 4 exhibited moderate to strong cytotoxicities with IC50 values ranging from 5.6 to 14.2 µM.

Human torpor: translating insights from nature into manned deep space expedition.

During a long-duration manned spaceflight mission, such as flying to Mars and beyond, all crew members will spend a long period in an independent spacecraft with closed-loop bioregenerative life-support systems. Saving resources and reducing medical risks, particularly in mental heath, are key technology gaps hampering human expedition into deep space. In the 1960s, several scientists proposed that an induced state of suppressed metabolism in humans, which mimics 'hibernation', could be an ideal solution to cope with many issues during spaceflight. In recent years, with the introduction of specific methods, it is becoming more feasible to induce an artificial hibernation-like state (synthetic torpor) in non-hibernating species. Natural torpor is a fascinating, yet enigmatic, physiological process in which metabolic rate (MR), body core temperature (Tb ) and behavioural activity are reduced to save energy during harsh seasonal conditions. It employs a complex central neural network to orchestrate a homeostatic state of hypometabolism, hypothermia and hypoactivity in response to environmental challenges. The anatomical and functional connections within the central nervous system (CNS) lie at the heart of controlling synthetic torpor. Although progress has been made, the precise mechanisms underlying the active regulation of the torpor-arousal transition, and their profound influence on neural function and behaviour, which are critical concerns for safe and reversible human torpor, remain poorly understood. In this review, we place particular emphasis on elaborating the central nervous mechanism orchestrating the torpor-arousal transition in both non-flying hibernating mammals and non-hibernating species, and aim to provide translational insights into long-duration manned spaceflight. In addition, identifying difficulties and challenges ahead will underscore important concerns in engineering synthetic torpor in humans. We believe that synthetic torpor may not be the only option for manned long-duration spaceflight, but it is the most achievable solution in the foreseeable future. Translating the available knowledge from natural torpor research will not only benefit manned spaceflight, but also many clinical settings attempting to manipulate energy metabolism and neurobehavioural functions.