Antidepressant effects of Yuanzhi (Polygalae Radix) extract on chronic unpredictable mild stress-induced depression in rats: modulation of the NLRP3 inflammasome and NF-κB pathway

Objective To investigate the antidepressant effects of Yuanzhi(Polygalae Radix;PR)aqueous extract on chronic unpredictable mild stress(CUMS)-induced depression rat models and the underlying mechanisms.Methods A total of 40 male Sprague Dawley(SD)rats were randomly divided into control;model;low dose of PR(PR-L;0.5 g/kg);high dose of PR(PR-H;1 g/kg);and fluoxetine(10 mg/kg)groups;with 8 rats in each group.Except for the rats in control group;those in the other four groups underwent CUMS-induced depression modeling.PR and fluoxetine were administered intragastrically once daily;30 min prior to the CUMS procedure;for 14 consecu-tive days until the behavioral tests were performed.After CUMS modeling;the sucrose prefer-ence test(SPT);open field test(OFT);novelty-suppressed feeding test(NSFT);forced swim test(FST);and tail suspension test(TST)were employed to assess the pharmacological ef-fects of PR on the mitigation of depressive-like behaviors in rat models.Additionally;the en-zyme-linked immunosorbent assay(ELISA)was utilized to quantify the serum levels of tumor necrosis factor(TNF)-α;interleukin(IL)-6;and IL-1βin the rats.Western blot analysis was al-so conducted to evaluate the protein expression levels of nuclear factor kappa-B(NF-κB);in-ducible nitric oxide synthase(iNOS);cyclooxygenase-2(COX-2);nucleotide-binding oligomerization domain(NOD)-like receptor family pyrin domain containing 3(NLRP3);apoptosis-associated speck-like protein containing caspase recruitment domain(ASC);and caspase-1 in the hippocampal tissues of the rats.Immunofluorescence staining was per-formed to observe the morphological changes in ionized calcium-binding adapter molecule 1 positive(Iba-1+)cells in the dentate gyrus(DG)of rats with CUMS-induced depression.Results(i)Treatment with PR-H and fluoxetine resulted in significant enhancements in both the total distance and time the rats moved during tests(P<0.01 and P<0.05;respectively).Post-administration of PR-H and fluoxetine also led to statistically significant increase in su-crose preference among rats(P<0.05).Besides;PR-L;PR-H;and fluoxetine treatment markedly decreased the latency of ingestion(P<0.05;P<0.05;and P<0.01;respectively).As observed from the FST;PR-L;PR-H;and fluoxetine presented antidepressant effects on rats with CUMS-induced depression;leading to the reduction in time of their immobility(P<0.05;P<0.01;and P<0.01;respectively).The results of TST indicated reduced immobility time in rats receiving PR-H and fluoxetine treatment as well(P<0.01).(ii)Rats in model group showed an increase in the levels of Iba-1+microglia in their left and right brains in compari-son with control group(P<0.01).However;such increase was negated post PR treatment(P<0.01).Treatment with PR-L;PR-H;and fluoxetine considerably reduced the levels of inflam-matory factors(TNF-α;IL-1β;and IL-6;P<0.01).In addition;treatment of PR-L and PR-H ef-fectively counteracted the elevated levels of NLRP3;ASC;and caspase-1;and markedly down-regulated the expression levels of phosphorylated p65(p-p65);COX-2;and iNOS in rats’hip-pocampus(P<0.01).Conclusion Collectively;these findings indicate that PR exerts an antidepressant effect on rats with CUMS-induced depression partially through the modulation of the NLRP3 and NF-κB signaling pathways.

Dynamic changes of behaviors, dentate gyrus neurogenesis and hippocampal miR-124 expression in rats with depression induced by chronic unpredictable mild stress

The depression-like behavior phenotype,neurogenesis in the dentate gyrus and miR-124 expression in the hippocampus are the focus of current research on the pathogenesis of depression and antidepressant therapy.The present study aimed to clarify the dynamic changes of depression-like behavior,dentate gyrus neurogenesis and hippocampal miR-124 expression during depression induced by chronic stress to reveal pathological features at different stages of depression and to further provide insight into depression treatment.Chronic unpredictable mild stress depression models were established by exposing Sprague-Dawley rats to various mild stressors,including white noise,thermal swimming,stroboscopic illumination,soiled cages,pairing with three other stressed animals,cold swimming,tail pinch,restraint and water and food deprivation.Chronic unpredictable mild stress model rats underwent dynamic observation from 1 to 8 weeks and were compared with a control group(normal feeding without any stressors).To observe changes in the depression-like behavior phenotype during chronic unpredictable mild stress-induced depression,a sucrose preference test was used to evaluate the degree of anhedonia.An open-field test was used to evaluate locomotor activity and anxiety status.Compared with the control group,chronic unpredictable mild stress rats lost weight but did not have a depression-like behavioral phenotype at 1-4 weeks.Chronic unpredictable mild stress rats presented decreased sucrose preference and locomotor activity at 5-8 weeks.In addition,chronic unpredictable mild stress rats did not have significant anxiety-like behavior during 1-8 weeks of modeling.To observe neurogenesis dysfunctions and changes in neuronal number in the dentate gyrus during chronic unpredictable mild stress-induced depression,markers(DCX and DCX/BrdU)of neural proliferation and differentiation and the neuronal marker NeuN were assessed by immunofluorescence.Compared with the control group,neurogenesis and the neuronal number in the dentate gyrus did not change from 2 to 6 weeks;however,neural proliferation and differentiation in the dentate gyrus decreased,and the number of neurons decreased until the eighth week in the chronic unpredictable mild stress group.Real-time quantitative reverse transcription polymerase chain reaction assays and fluorescence in situ hybridization were used to measure the expression of hippocampal miR-124 during chronic unpredictable mild stress-induced depression.The results showed that the expression of hippocampal miR-124 was unchanged during the first 4 weeks but increased from 5 to 6 weeks and decreased from 7 to 8 weeks compared with the control group.These findings indicate that during chronic unpredictable mild stress-induced depression,the behavioral phenotype,miR-124 expression in the hippocampus,neurogenesis in the dentate gyrus and neuronal numbers showed dynamic changes,which suggested that various pathological changes occur at different stages of depression.All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Guangzhou University of Chinese Medicine of China in March 2015.

Optimization of food deprivation and sucrose preference test in SD rat model undergoing chronic unpredictable mild stress

Background:The chronic unpredictable mild stress(CUMS)model has long been considered the best model for exploring the pathophysiological mechanisms underlying depression.However,there are no widely recognised standards for strategies for modeling and for behavioral testing.The present study aimed to optimize the protocols for food deprivation and the sucrose preference test(SPT)for the CUMS model.Methods:We first evaluated the effects of different long periods of food deprivation on the body weight of Sprague Dawley(SD)rats by testing food deprivation for 24 hours(8:00-8:00^+),food deprivation for 12 hours during the daytime(8:00-20:00)and food deprivation for 12 hours at night(20:00-8:00^+).Next,we established a SD rat CUMS model with 15 different stimulations,and used body weight measurement,SPT,forced swim test(FST),open field test(OFT)and Morris water maze(MWM)test to verify the success of the modeling.In the SPT,consumption of sucrose and pure water within 1 and 12 hours was measured.Results:Twelve hours of food deprivation during the daytime(8:00-20:00)had no effect on body weight,while 12 hours of food deprivation at night(20:00-8:00^+)and 24 hours of food deprivation(8:00-8:00^+)significantly reduced the mean body weight of the SD rats.When SPT was used to verify the successful establishment of the CUMS rat model,sucrose consumption measured within 12 hours was less variable than that measured within 1 hour.Conclusions:Twelve hours of food deprivation in the daytime(8:00-20:00)may be considered a mild stimulus for the establishment of a CUMS rat model.Measuring sucrose consumption over 12 hours is recommended for SPT.

Effect and mechanism of LW-AFC on chronic unpredictable mild stress-induced mood and cognition impairment of mice

OBJECTIVE To explore the effect and mechanisms of LW-AFC,a new formula derived fromLiuwei Dihuang decoction,on chronic unpredictable mild stress(CUMS)-induced mood and cogni.tion impairment in mice.METHODS C57 BL/6 J mice were randomly placed into seven groups(n=10):normal control group,CUMS group,Fluoxetine(10 mg·kg^(-1),once per day) group,Liuwei Dihuang decoction group(LW,10 g·kg^(-1),once per day),and LW-AFC(0.8 g·kg^(-1),1.6 g·kg^(-1),3.2 g·kg^(-1),once per day) group.The stressed group was given CUMS for 4 weeks to set up a chronic multiple-stressed model.LW and LW-AFC was oral administered a week prior to CUMS and until the end of the study(a total of 35 d),while fluoxetine was administrated orally for 4 weeks.The anxiety behavior was analyzed using the open field test(OFT) and elevated plus maze test(EPM).The depression behavior was ana.lyzed using the sucrose preference test(SPT) and forced swimming test(FST).Spatial cognition was evaluated using Morris water maze(MWM) test and working memory was evaluated using new object recognition test(NORT).RESULTS CUMS for 28 d increased depressive-and anxiety-like behaviors.LW-AFC(1.6 g·kg^(-1)) significantly increased the numbers of entries into the open arm and time in the open arm of CUMS mice(P<0.05).LW-AFC(3.2 g·kg^(-1)) increased sucrose consumption and de.creased the immobility time of FST(P<0.01) of CUMS mice.The MWM test showed that spatial learning andmemory in CUMS mice were remarkably affected relative to controls,whereas LW-AFC(3.2 g·kg^(-1)) im.proves cognitive functions(P<0.05).CONCLUSION The mood and theability of learning and memory of thestressed group can be affected after exposure to CUS.Oral administration of LW-AFC significant.ly improved CUMS-induced impairments of mood and cognition in mice.

Shuganheweitang Ameliorates Chronic Unpredictable Mild Stress-Induced Depression-Like Behaviors in Rats through the PI3K/AKT/mTOR Pathway: Involvement of Amino Acids, Glycerophospholipids, and Energy Metabolism

Background: Depression is a typical psychosomatic disease. Shuganheweitang (SGHWT) is a clinical formula that effectively treats depression. However, the potential mechanism used by SGHWT to ameliorate depression-like behaviors is still unclear. This study investigated the effects of SGHWT on metabolic change in the liver and hypothalamus with signaling pathways involved in chronic unpredictable mild stress (CUMS)-induced depression in rats to explore the mechanism of the anti-depressive effect. Methods: A total of 52 rats were used to create a model of depression by CUMS combined with solitary rearing for 6 weeks. Open field test (OFT), sucrose preference test (SPT), forced swim test (FST), and body weight (BW) were performed to analyze the pharmacodynamic effects of SGHWT. H&E staining, Nissl staining, immunofluorescence, immunohistochemistry, and western blot were used to evaluate the mechanism of action. Untargeted metabolomics techniques by ultra-performance liquid chromatography-quantitative time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) were used to analyze all the metabolic differences in the liver and hypothalamus. Results: SGHWT improved CUMS-induced depression-like behaviors in vivo. SGHWT reduced hepatic c-Fos protein expression and increased hypothalamic c-Fos protein expression. Moreover, p-PI3K, p-AKT473, p-AKT308, and p-mTOR protein expressions were significantly downregulated in the liver and hypothalamus of CUMS rats. Notably, these alterations were reversed by the SGHWT administration. Furthermore, the metabolomic analysis identified 15 and 5 key differential SPT-associated metabolites in the liver and hypothalamus, respectively. Conclusion: This study suggests that SGHWT ameliorates chronic unpredictable mild stress-induced depression-like behaviors, by the involvement of amino acids, glycerophospholipids, energy metabolism, and the PI3K/AKT/mTOR pathway. Highlights: 1) Shuganheweitang was derived from the TCM herbal formula Sinisan. 2) SGHWT treatment reverses depression-like behaviors in CUMS-induced rats. 3) The mechanism of SGHWT on depression by the liver and hypothalamus metabolomics. 4) SGHWT regulates amino acids, glycerophospholipids, and energy metabolism. 5) SGHWT exerts antidepressant effects through the PI3K/AKT/mTOR pathway.

Jobelyn^(■), a Sorghum-Based Nutritional Supplement Attenuates Unpredictable Chronic Mild Stress-Induced Memory Deficits in Mice

The ability of an organism to adapt to aversive stressful situations or life challenging circumstances is very crucial to its state of health and survival. However, breakdown in adaptation due to persistent uncontrollable stress, leads to impairment of bodily functions and onset of a variety of pathological disorders especially memory decline. This study was designed to evaluate the effect of Jobelyn&reg;(JB), a potent antioxidant sorghum-based food supplement on unpredictable chronic mild stress (UCMS)-induced memory impairment in mice. Male Swiss mice were given JB (5 - 50 mg/kg, p.o) 30 min prior to exposure to UCMS for 14 consecutive days before testing for memory. Thereafter, the serum corticosterone level was estimated by using ELISA kits. The levels of malondialdehyde (MDA) and glutathione (GSH) as well as acetylcholinesterase activity were estimated in the brain homogenate using spectrophotometer. Histology of the brain tissues and estimation of the populations of viable neurons in the hippocampal region were done after staining with hematoxyline and eosin. Our results showed that JB reversed memory impairment and suppressed corticosterone concentrations induced by UCMS. Moreover, JB reduced oxidative stress in the brain of UCMS-mice as shown by decreased MDA levels and elevated GSH concentrations. It also decreased brain acetylcholinesterase activity when compared with chronic stress group (p < 0.05). Furthermore, JB (5 - 10 mg/kg, p.o) offered significant protection against UCMS-induced degeneration and death of neuronal cells of the cornu ammonis 3 (CA3) of the hippocampal region of the brain indicating neuroprotection. Taken together, these findings suggest that JB attenuates memory deficits induced by UCMS in mice and may be useful therapeutically for stress-related cognitive dysfunctions. The reduction in the levels of serum corticosterone, antioxidation, neuroprotection and inhibition of cholinesterase enzyme might be contributing significantly to the positive effect of JB on memory in mice exposed to unpredictable chronic mild stress.

Vitamin D_(3) attenuates anxiety-like behavior in long-term ovariectomized rats with unpredictable mild stress

The impact of various vitamin D3(VD3)doses(1.0,2.5,or 5 mg/kg,s.c.)in mitigating the negative consequences of chronic unpredictable mild stress(CUMS)was investigated.Adult female rats with long-term estrogen deficiency were assessed using the sucrose preference test(SPT),the elevated plus-maze(EPM),the light/dark test(LDT),and the open-field test(OFT)to measure anhedonia-like and anxiety-like behavior.The corticosterone(CS)and adrenocorticotrophic hormone(ACTH)concentrations in blood serum and the brain-derived neurotrophic factor(BDNF)expression in the hippocampus of long-term ovariectomized(OVX)rats were measured by ELISA kits and/or western blotting.Treatment with VD3(5.0 mg/kg),similarly to fluoxetine(10.0 mg/kg),significantly reduced the anhedonia profile in the SPT and anxiety-like behavior in the EPM and LDT,and CS and ACTH levels in blood serum.It also elevated BDNF levels in the hippocampus of long-term OVX/CUMS compared to OVX/CUMS/solvent rats.Thus,these findings suggest that VD3(5.0 mg/kg)administration might attenuate the anxiety-like profile in long-term OVX adult rats subjected to the CUMS.This might occur via activation of the BDNF signaling pathway in the hippocampus and via restoration of CS and ACTH levels in blood serum.

Increased expression level of corticotropin-releasing hormone in the amygdala and in the hypothalamus in rats exposed to chronic unpredictable mild stress

Objective Corticotropin-releasing hormone（CRH）plays an important role in neuroendocrine,autonomic and behavioral responses to stressors.In the present study,the effect of chronic unpredictable mild stress（CUMS）on CRH neurons was investigated in rat brain.Methods The rats were exposed to one of the stressors each day for 21 d.Immunostaining was performed to detect the CRH-positive neurons in the paraventricular nucleus（PVN）of the hypothalamus and in amygdala.Results After the stress protocol,the animals showed a reduction in body weight gain as well as reduced sucrose preference and locomotor activity.Interestingly,the CRH neurons in both PVN and central nucleus of the amygdala（CeA）were stimulated by CUMS.The densities of CRH-containing neurons in both PVN and CeA were significantly higher than those in control group.Conclusion The CRH systems in PVN and CeA may both contribute to depression-like behaviors during CUMS.

Citrus aurantium L. extract alleviate depression by inhibiting gut microbiota-mediated inflammation in mice

Gut microbiota plays a crucial role in the pathophysiology of depression.This study aimed to explore the antidepressant effect of mature whole Citrus aurantium fruit extract(FEMC)in the chronic unpredictable mild stress(CUMS)model.The behavioral tests were applied to assess antidepressant effect and 16S rRNA sequencing was used to analyze the changes of gut microbiota.The results showed that the major components of FEMC were naringin and neohesperidin and significantly increased the sucrose preference index of the mice.FEMC also could reduce the feeding latency in an open field test and the rest time in a novelty suppressed feeding test.In addition,FEMC could increase CUMS-induced reduction in the levels of BDNF,PSD95,and SYN in the hippocampus.Moreover,FEMC intervention slightly decreased the ratio of Firmicutes to Bacteroidota.Meanwhile,FEMC reduced the abundance of the Prevotellaceae_Ga6A1_group,[Ruminococcus]_torques_group,which have been reported to be closely related to inflammation.Bioinformatics analysis revealed that mitogen-activated protein kinase(MAPK)signaling pathway and lipopolysaccharide biosynthesis were involved in the anti-inflammatory effect of FEMC in the CUMS animal model.Finally,the ELISA results showed that FEMC could significantly reduce the expression of pro-inflammatory cytokines IL-6 and TNF-αin the serum of depressive mice.Our results suggest FEMC can am eliorate depressive behavior by i nhibiting gut microbiota-mediated inflammation in mice.

LncRNA NPTN-IT1-201 Ameliorates Depressive-like Behavior by Targeting miR-142-5p and Regulating Inflammation and Apoptosis via BDNF

Objective Long noncoding RNAs(lncRNAs)and microRNAs(miRNAs)are widely expressed in the brain and are associated with the development of neurological and neurodegenerative diseases.However,their roles and molecular mechanisms in major depressive disorder(MDD)remain largely unknown.This study aimed to identify lncRNAs and miRNAs involved in the development of MDD and elucidate their molecular mechanisms.Methods Transcriptome and bioinformatic analyses were performed to identify miRNAs and lncRNAs related to MDD.C57 mice were subjected to chronic unpredictable mild stress(CUMS)to establish a depression model.Lentiviruses containing either lncRNA NPTN-IT1-201 or miR-142-5p were microinjected into the hippocampal region of these mice.Behavioral tests including the sucrose preference test(SPT),tail suspension test(TST),and forced swim test(FST)were conducted to evaluate depressive-like behaviors.Results The results revealed that overexpression of lncRNA NPTN-IT1-201 or inhibition of miR-142-5p significantly ameliorated depressive-like behaviors in CUMS-treated mice.Dual-luciferase reporter assays confirmed interactions between miR-142-5p with both brain-derived neurotrophic factor(BDNF)and NPTN-IT1-201.ELISA analysis revealed significant alterations in relevant biomarkers in the blood samples of MDD patients compared to healthy controls.Histological analyses,including HE and Nissl staining,showed marked structural changes in brain tissues following CUMS treatment,which were partially reversed by lncRNA NPTN-IT1-201 overexpression or miR-142-5p inhibition.Immunofluorescence imaging demonstrated significant differences in the levels of BAX,Bcl2,p65,Iba1 among different treatment groups.TUNEL assays confirmed reduced apoptosis in brain tissues following these interventions.Western blotting showed the significant differences in BDNF,BAX,and Bcl2 protein levels among different treatment groups.Conclusion NPTN-IT1-201 regulates inflammation and apoptosis in MDD by targeting BDNF via miR-142-5p,making it a potential therapeutic target for MDD.

Quercetin regulates depression-like behavior in CUMS rat models via TLR4/NF-κB signaling

Background:Depression is becoming increasingly prevalent around the world,imposing a substantial burden on individuals,families,as well as society.Quercetin is known to be highly effective in treating depression.However,additional research is needed to dissect the mechanisms of its anti-depressive effects.Methods:For this study,Sprague-Dawley(SD)rats were randomized into the control,model,quercetin,or fluoxetine group.The latter three groups were exposed to chronic unpredictable mild stress(CUMS)for 42 d.The first two groups received saline solution daily via oral gavage.Meanwhile,the quercetin group was orally administered a quercetin suspension(52.08 mg/kg)every day,while the fluoxetine group was orally administered a fluoxetine solution(2.08 mg/kg).Here,fluoxetine served as the positive control drug to compare the therapeutic effects of quercetin.The experimental period was 6 weeks.Depressive behaviors in rats were assessed through various physiological and behavioral measures.Additionally,pathological changes in hippocampal tissues were examined using Nissl staining.Serum cytokines were detected using an enzymelinked immunosorbent assay(ELISA),and immunohistochemistry was employed to quantify the levels and integral optical density(IOD)values of ionized calcium binding adaptor molecule-1(Iba-1)expression in the brain.Real-time fluorescence quantitative PCR(RT-qPCR)was utilized to evaluate the mRNA levels of inflammatory indicators as well as toll-like receptor 4(TLR4),and nuclear factor-κappa B P65(NF-κB P65)in hippocampus.Western blot(WB)technique was employed to observe the protein levels of TLR4,NF-κB P65,and phospho-NF-κB P65(p-NF-κB P65).Results:After 42 d of exposure to CUMS,rats exhibited a slow increase in body weight,a reduction in food intake,an abnormal preference for sugar water,and aberrant open-field behaviors.Pathological analysis revealed the disintegration,rupture,interruption,and disorganization of hippocampal neuronal cells after CUMS exposure,along with a decrease in Nissl bodies in the CA1 region.This was accompanied by the elevated expression of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)in the serum and the upregulation of IL-1β,IL-6,and TNF-αmRNA expression in the hippocampus.Increases in Iba-1-positive cells and the IOD values of Iba-1 were detected in hippocampal microglia.Furthermore,TLR4 and NF-κB P65 mRNA and protein levels were upregulated in hippocampal tissues.Quercetin,an antidepressant,could alleviate depression-like symptoms in rats and downregulate inflammatory factors associated with the TLR4/NF-κB signaling pathway in hippocampal microglia,and its therapeutic effect was comparable to fluoxetine.Conclusion:In rat models of CUMS,quercetin may act as an antidepressant by inhibiting inflammation in hippocampal microglia via TLR4/NF-κB signaling pathway.These results offer experimental and theoretical support for applying quercetin in the clinical management of depression.

Antidepressant-like effect of essential oil of Perilla frutescens in a chronic, unpredictable, mild stress-induced depression model mice

Perilla frutescens(Perilla leaf), a garnishing vegetable in East Asian countries, as well as a plant-based medicine, has been used for centuries to treat various conditions, including depression. Several studies have demonstrated that the essential oil of P. frutescens(EOPF) attenuated the depressive-like behavior in mice. The present study was designed to test the anti-depressant effects of EOPF and the possible mechanisms in an chronic, unpredictable, mild stress(CUMS)-induced mouse model. With the exposure to stressor once daily for five consecutive weeks, EOPF(3, 6, and 9 mg·kg-1) and a positive control drug fluoxetine(20 mg·kg-1) were administered through gastric intubation to mice once daily for three consecutive weeks from the 3rd week. Open-field test, sucrose consumption test, tail suspension test(TST), and forced swimming test(FST) were used to evaluate the behavioral activity. The contents of 5-hydroxytryptamine(5-HT) and its metabolite, 5-hydroxyindoleacetic acid(5-HIAA), in mouse hippocampus were determined by HPLC–ECD. Serum interleukin(IL)-1, IL-6, and tumor necrosis factor(TNF)-α levels were evaluated by enzyme-linked immunosorbent assay(ELISA). The results showed that CUMS significantly decreased the levels of 5-HT and 5-HIAA in the hippocampus, with an increase in plasma IL-6, IL-1β, and TNF-α levels. CUMS also reduced open-field activity, sucrose consumption, as well as increased immobility duration in FST and TST. EOPF administration could effectively reverse the alterations in the concentrations of 5-HT and 5-HIAA; reduce the IL-6, IL-1β, and TNF-α levels. Moreover, EOPF could effectively reverse alterations in immobility duration, sucrose consumption, and open-field activity. However, the effect was not dose-dependent. In conclusion, EOPF administration exhibited significant antidepressant-like effects in mice with CUMS-induced depression. The antidepressant activity of EOPF might be related to the relation between alteration of serotonergic responses and anti-inflammatory effects.

Antidepressant-Like Effects of Chaihu Shugan Powder(柴胡疏肝散)on Rats Exposed to Chronic Unpredictable Mild Stress through Inhibition of Endoplasmic Reticulum Stress-Induced Apoptosis

Objective:To investigate the antidepressant-like effects of Chaihu Shugan Powder(CSP,柴胡疏肝散)and to explore its underlying mechanisms.Methods:Thirty-two Sprague-Dawley rats were randomly divided into control(CON),chronic unpredictable mild stress(CUMS),fluoxetine(FLU),and CSP groups,8 rats in each group.All of the rats except for those in the control group were subjected to 3 consecutive weeks of CUMS to establish the depression model.The open field test(OFT),forced swimming test(FST),and sucrose preference test were used to assess the anti-anxiety and antidepressant effects of CSP.Terminal deoxynucleotidyl transferase(Td T)d UTP nick-end labeling was used to determine the apoptosis rate in the hippocampal tissues.The m RNA and protein levels of glucose-regulated protein(GRP)78,spliced X-box-binding protein(XBP)-1,CCAAT/enhancerbinding protein homologous protein(CHOP),caspase-12,and c-Jun N-terminal kinase(JNK)in the hippocampus of rats were evaluated by real-time PCR and Western blot analysis,respectively.Results:Administration of CSP alleviated anxiety and depression-like behavior in CUMS rats,as revealed by enhanced time and distance in the center of the OFT(P<0.05),an increased preference for sucrose,and longer swimming time and shorter immobility time during the FST(all P<0.05).In addition,CSP treatment significantly reduced the rate of apoptosis in rat hippocampal neurons(P<0.05).The m RNA and protein expression levels of GRP78,spliced XBP-1,and CHOP were down-regulated along with the expression of caspase-12 and cleaved caspase-12 proteins(all P<0.05),whereas total and phosphorylated JNK1 protein levels did not differ significantly between control and CSP-treated rats.Conclusion:CSP can improve depression-like behavior in rats exposed to CUMS,possibly by suppressing CHOP and caspase-12 mediated apoptosis in the rat hippocampus.

GSK3β/β-catenin信号通路在运动和氟西汀改善CUMS小鼠抑郁行为中的作用机制

目的探究游泳运动和氟西汀对CUMS小鼠抑郁行为及GSK3β/β-catenin信号通路的影响。方法采用雄性C57BL/6小鼠,随机分为5组,每组8只:Con组,即普通控制组;CUMS组,实验小鼠接受7周的慢性不可预见性温和应激;CUMS+Saline组,从应激的第4周开始腹腔注射生理盐水4周;CUMS+Flu组,从应激的第4周开始腹腔注射抗抑郁药物氟西汀(Fluoxetine,Flu)4周;CUMS+Swim组,从应激的第4周开始进行游泳训练4周。实验干预结束后,所有小鼠接受行为学检测。断头处死取海马组织,采用Western blotting技术检测相关基因的蛋白表达水平。结果 (1)行为学实验显示,与Con组相比,CUMS组糖水偏好显著降低(P<0.05),强迫游泳(FST)和悬尾实验(TST)不动时间显著增加(P<0.01),开场实验(OFT)探洞次数显著减少(P<0.05);与CUMS+Saline组相比,CUMS+Flu组糖水偏好显著增加(P<0.05),FST和TST不动时间显著减少(P<0.05),OFT探洞次数显著增加(P<0.01);与CUMS组相比,CUMS+Swim组糖水偏好无显著变化,FST(P<0.05)和TST(P<0.01)不动时间显著减少,OFT探洞次数显著增加(P<0.01)。(2)Western blotting实验显示,与Con相比,CUMS组海马组织中pGSK3β(Ser9)、β-catenin的蛋白水平显著降低(P<0.05);与CUMS+Saline相比,CUMS+Flu组海马组织中β-catenin的蛋白水平显著升高(P<0.05),GSK3β、pGSK3β(Ser9)、pGSK3β(Tyr216)的蛋白水平无显著变化;与CUMS组相比,CUMS+Swim组海马组织中GSK3β(P<0.01)、pGSK3β(Ser9,P<0.05)、β-catenin(P<0.05)的蛋白水平显著升高。结论运动和氟西汀均可缓解CUMS所致的小鼠抑郁行为;慢性应激诱导抑郁行为可能涉及GSK3β/β-catenin信号通路的功能紊乱;运动和氟西汀均提高小鼠对慢性应激的耐受性从而控制抑郁病理进程,二者发挥作用的分子机制有所不同,运动缓解抑郁行为可能涉及纠正海马组织中GSK3β/β-catenin信号通路紊乱,而氟西汀缓解抑郁行为可能是非GSK3β/β-catenin依赖性的。研究论证了慢性应激期的运动干预效果媲美于抗抑郁药物氟西汀,并提出了相应的分子行为学依据。深入探究不同抑郁病理期的运动干预模式及其潜在的分子机制,将为运动抗抑郁的转化研究提供新靶向。

基于肝脏代谢组学的酸枣仁汤抗抑郁作用机制研究

采用LC-MS代谢组学技术,分析酸枣仁汤对慢性不可预知温和应激(CUMS)抑郁大鼠肝脏内源性代谢物调控作用,探索酸枣仁汤抗抑郁的作用机制。将大鼠随机分为正常组、模型组、酸枣仁汤低剂量组、酸枣仁汤高剂量组和阳性药组,采用禁食、禁水、冰水游泳、热水游泳、昼夜颠倒、夹尾、束缚等刺激,复制CUMS大鼠抑郁模型,造模与给药持续56d。观察各组大鼠行为学指标(大鼠体质量、旷场实验、糖水偏好实验和悬尾实验),收集大鼠血浆和肝脏组织,采用酶联免疫吸附测定(ELISA)检测血浆中5-羟色胺(5-HT)、多巴胺(DA)、去甲肾上腺素(NE)的含量,采用LC-MS代谢组学方法分析酸枣仁汤对CUMS模型大鼠肝脏代谢轮廓的调节作用。结果显示酸枣仁汤能显著改善CUMS模型大鼠的抑郁样行为,升高血浆中5-HT、DA、NE的神经递质水平;通过LC-MS代谢组学技术在肝脏中鉴定出24种差异代谢物,酸枣仁汤能回调其中的13种;代谢通路分析共筛选得到9条与抑郁显著相关的代谢通路,酸枣仁汤低剂量组能调节其中的4条,包括戊糖磷酸途径、嘌呤代谢、磷酸肌醇代谢、鞘脂代谢;酸枣仁汤高剂量组能调节其中的2条,包括鞘脂代谢和甘油磷脂代谢。鞘脂代谢是酸枣仁汤在不同剂量下均可调节的代谢通路,推测可能是其改善CUMS模型大鼠肝脏代谢紊乱的主要途径。

慢性应激对小鼠下丘脑食欲调节因子的影响

目的观察小鼠在慢性应激时及应激停止后下丘脑食欲调节因子的变化,并初步探索应激依赖性的食欲变化机制。方法将32只雄性C57BL/6小鼠随机分为对照(Ctrl)组及慢性不可预知温和应激(CUMS)组,每组16只。CUMS组小鼠予以CUMS(持续11周)建立应激模型,Ctrl组正常饲养。记录小鼠摄食量和体重。通过悬尾实验和强迫游泳实验验证CUMS模型是否构建成功。第12周时从两组各随机取8只小鼠收集全脑、下丘脑组织待测;两组各剩余的8只小鼠重新编组为应激停止(C-CUMS)组和应激停止对照(C-Ctrl)组,继续观察3周后,取全脑、下丘脑组织待测。通过qPCR和免疫组织化学染色方法检测小鼠下丘脑中食欲调节因子食欲素1型受体(OX1R)、瘦素受体(LEPR)和刺鼠相关蛋白(AgRP)的表达情况。结果应激第2~11周,CUMS组小鼠累积摄食量高于Ctrl组(均P<0.05),11周内两组小鼠体重差异无统计学意义(均P>0.05)。11周后CUMS组小鼠悬尾不动时间和水中漂浮时间均长于Ctrl组小鼠(均P<0.01),提示造模成功。造模成功后,CUMS组小鼠下丘脑组织中促食欲因子AgRP mRNA、OX1R mRNA表达量高于Ctrl组(均P<0.01),抑食欲因子LEPR mRNA表达量低于Ctrl组(P<0.01);CUMS组小鼠下丘脑弓状核中AgRP蛋白表达水平高于Ctrl组(P<0.05),LEPR蛋白表达水平低于Ctrl组(P<0.01)。应激停止3周后,C-CUMS组小鼠累积摄食量少于C-Ctrl组(P<0.05),体重低于C-Ctrl组(P<0.05)。C-CUMS组小鼠LEPR mRNA表达量高于C-Ctrl组(P<0.01),AgRP mRNA、OX1R mRNA表达量与C-Ctrl组相比差异无统计学意义(均P>0.05);C-CUMS组小鼠AgRP蛋白表达水平与C-Ctrl组比较差异无统计学意义(P>0.05),LEPR蛋白表达水平高于C-Ctrl组(P<0.01)。结论CUMS导致小鼠食欲增加,其机制可能与LEPR和AgRP的功能调节有关;应激停止后其食欲下降,机制可能涉及LEPR的功能调节。

心理应激相关非酒精性脂肪性肝病小鼠模型的建立及四逆散的治疗效应研究

目的建立心理应激相关非酒精性脂肪性肝病小鼠模型并探讨四逆散的治疗效应。方法40只雄性C57 BL/6J小鼠随机区分为空白组(CON)、高蔗糖富含胆固醇饮食组(CHR)、复合模型组(CS+CHR)、百洛特组(BLT)、四逆散组(SNS)。除CON组外,其余各组小鼠均给予CHR饮食,且CS+CHR组、BLT组、SNS组每天随机给予2种不同应激,共60 d。BLT组、SNS组于造模后30 d进行灌胃给药。观察小鼠行为学变化,计算肝指数、胸腺指数、脂肪指数,检测肝组织TC、TG含量,油红O、HE染色观察肝组织病理改变,检测血清皮质酮(CORT)、醛固酮(ALD)、胰岛素(INS)、胰高血糖素(GCG)含量。结果与CON组相比,CHR组脂肪指数、TC含量升高(P<0.05),CS+CHR组直立次数下降(P<0.05),脂肪指数及TC、TG、CORT、ALD、GCG含量显著增高(P<0.01);与CHR组相比,CS+CHR组直立次数下降(P<0.05),TC、TG、ALD、INS、GCG含量显著增高(P<0.01);与CS+CHR组相比,SNS散组直立次数回升(P<0.05),TG、ALD含量显著降低(P<0.01),BLT组脂肪指数、TC含量降低(P<0.05),ALD含量显著降低(P<0.01)。油红O染色结果显示,CS+CHR组可见少量脂滴,BLT组与SNS组均有减轻;而HE石蜡染色结果显示,CHR组可见少量大小不等、数量不一的圆形空泡,部分肝细胞核被挤压向肝细胞一侧,CS+CHR组可见大量大小不等、数量不一的圆形空泡,脂滴数量较多,部分肝细胞核被挤压向肝细胞一侧,而BLT组与SNS组均有减轻。结论CUMS联合CHR饮食可以更好地构建心理应激相关NAFLD小鼠模型,四逆散改善此疾病可能与其降低血清醛固酮含量相关。

Tubacin对慢性不可预见性温和应激模型大鼠的抗抑郁作用及其作用机制研究

目的探讨组蛋白去乙酰化酶6(HDAC6)选择性抑制剂tubacin对慢性不可预见性温和应激(CUMS)模型大鼠的抗抑郁作用及其可能的作用机制。方法将50只成年雄性SD大鼠随机分为五组(n=10):对照组(A组),CUMS模型组(B组),氟西汀处理组(C组),tubacin处理组(D组),氟西汀联合tubacin处理组(E组)。应用Morris水迷宫定位航行试验及空间探索试验测试大鼠的空间学习、记忆情况。采用还原型谷胱甘肽(GSH)测定试剂盒检测各组大鼠血清中GSH水平。结果 Morris水迷宫定位航行试验显示,与A组比较,B组大鼠平均逃避潜伏期显著延长(P<0.05或P<0.01);与B组比较,C、D、E组平均逃避潜伏期明显缩短(P<0.05或P<0.01),且E组平均逃避潜伏期显著短于C组和D组(P<0.05或P<0.01)。在空间探索试验中,C、D、E组大鼠在第三象限的停留时间明显长于其他三个象限(P<0.05或P<0.01),E组大鼠在第三象限的停留时间明显长于C组和D组(P<0.05或P<0.01)。B组大鼠血清GSH水平明显低于A组(P<0.05),C组血清GSH水平显著高于B组(P<0.05),E组血清GSH水平较C组进一步提高(P<0.05),并且与A组比较差异无统计学意义(P>0.05)。相关性分析发现,大鼠的空间学习、记忆能力与血清GSH水平显著相关(P<0.05)。结论 HDAC6选择性抑制剂tubacin可通过调节血清GSH水平以提高大鼠空间学习和记忆能力,从而发挥抗抑郁作用。

红笛鲷粗蛋白寡糖复合粉预防小鼠抑郁样行为及相关损伤的作用

该研究选用红笛鲷粗蛋白与低聚麦芽糖、低聚果糖和半乳低聚木糖组成的复合粉(PRSP)饲喂慢性不可预知温和应激(chronic unpredictable mild stress,CUMS)模型小鼠,探究其预防抑郁样行为及机体相关损伤的作用。将80只小鼠平均分为空白对照组(CON)、模型组(CUMS)、氟西汀对照组(FLU)、复合粉干预组(PRSP)。模型组小鼠以CUMS进行42 d造模,造模同时给予部分小鼠灌胃1.8 g/(kg·d)PRSP,以10 mg/(kg·d)氟西汀为阳性对照。饲喂结束后对各组小鼠进行行为学测试、结肠切片苏木精-伊红染色和免疫组化染色观察、血清中内毒素(lipopolysaccharides,LPS)、D-乳酸(D-lactic acid,D-LA)、肿瘤坏死因子(tumor necrosis factor-α,TNF-α)、白细胞介素6(interleukin-6,IL-6)、IL-1β和IL-10含量测定、结肠内容物样本菌群高通量测序和生物信息学分析。CUMS造模引起了小鼠行为指标异常,结肠损伤评分升高,肠上皮黏液蛋白2表达显著降低,血清中D-LA、LPS、TNF-α、IL-1β和IL-6水平显著上升,CUMS组小鼠结肠内容物特有分类单元数目显著下降,厚壁菌门(Firmicutes)与拟杆菌门(Bacteroidetes)丰度之比显著升高,CUMS小鼠结肠中毛螺菌属(Lachnospiraceae)与罗氏菌属(Oscillibacter)丰度显著下降、另枝菌属(Alistipes)丰度显著上升,菌群谷氨酸、谷氨酰胺、酪氨酸、苏氨酸、半乳糖、果糖、蔗糖、麦芽糖代谢通路基因丰度显著升高,PRSP干预后上述指标均恢复到空白对照组水平。该复合粉可以抑制慢性应激诱发的小鼠结肠菌群结构紊乱及其特定的氨基酸和糖代谢异常升高,并阻止机体系统炎症及结肠损伤的发生,对抑郁样行为起到很好的预防作用,研究结果可为高效安全预防抑郁症的食物源产品的开发提供理论支撑。

Overexpression of brain-derived neurotrophic factor in the hippocampus protects against post-stroke depression

Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor （BDNF）. In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. A BDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippo- campus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open field test in these rats as well. These findings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.