Pesticide-Induced Alterations in Locomotor Activity, Anxiety, and Depression-like Behavior Are Mediated through Oxidative Stress-Related Autophagy: A Persistent Developmental Study in Mice.

Chlorpyrifos (CPF), dichlorvos (DDV), and cypermethrin (CP), as commonly used pesticides, have been implicated in inducing neuropsychiatric disorders, such as anxiety, depression-like behaviors, and locomotor activity impairment. However, the exact molecular mechanisms of these adverse effects, particularly in both sexes and their next-generation effects, remain unclear. In this study, we conducted behavioral analysis, along with cellular assays (monodansylcadaverine staining) and molecular investigations (qRT-PCR and western blotting of mTOR, P62, and Beclin-1) to clear the potential role of autophagy in pesticide-induced behavioral alterations. For this purpose, 42 adult female and 21 male inbred ICR mice (F0) were distributed into seven groups. Maternal mice (F0) and 112 F1 offspring were exposed to 0.5 and 1 ppm of CPF, DDV, and CP through drinking water. F1 male and female animals were studied to assess the sex-specific effects of pesticides on brain tissue. Our findings revealed pronounced anxiogenic effects and impaired locomotor activity in mice. F1 males exposed to CPF (1 ppm) exhibited significantly elevated depression-like behaviors compared to other groups. Moreover, pesticide exposure reduced mTOR and P62 levels, while enhancing the Beclin-1 gene and protein expression. These changes in autophagy signaling pathways, coupled with oxidative and neurogenic damage in the cerebral cortex and hippocampus, potentially contribute to heightened locomotor activity, anxiety, and depression-like behaviors following pesticide exposure. This study underscores the substantial impact of pesticides on both physiological and behavioral aspects, emphasizing the necessity for comprehensive assessments and regulatory considerations for pesticide use. Additionally, the identification of sex-specific responses presents a crucial dimension for pharmaceutical sciences, highlighting the need for tailored therapeutic interventions and further research in this field.

Anti-inflammatory and protective effects of Aripiprazole on TNBS-Induced colitis and associated depression in rats: Role of kynurenine pathway.

BACKGROUND: The prevalence of depression is higher in patients with inflammatory bowel disease (IBD) than in the general population. Inflammatory cytokines and the kynurenine pathway (KP) play important roles in IBD and associated depression. Aripiprazole (ARP), an atypical antipsychotic, shows various anti-inflammatory properties and may be useful in treating major depressive disorder. This study aimed to evaluate the protective effects of ARP on TNBS-induced colitis and subsequent depression in rats, highlighting the role of the KP. MATERIAL AND METHODS: Fifty-six male Wistar rats were used, and all groups except for the normal and sham groups received a single dose of intra-rectal TNBS. Three different doses of ARP and dexamethasone were injected intraperitoneally for two weeks in treatment groups. On the 15th day, behavioral tests were performed to evaluate depressive-like behaviors. Colon ulcer index and histological changes were assessed. The tissue levels of inflammatory cytokines, KP markers, lipopolysaccharide (LPS), nuclear factor-kappa-B (NF-κB), and zonula occludens (ZO-1) were evaluated in the colon and hippocampus. RESULTS: TNBS effectively induced intestinal damages and subsequent depressive-like symptoms in rats. TNBS treatment significantly elevated the intestinal content of inflammatory cytokines and NF-κB expression, dysregulated the KP markers balance in both colon and hippocampus tissues, and increased the serum levels of LPS. However, treatment with ARP for 14 days successfully reversed these alterations, particularly at higher doses. CONCLUSION: ARP could alleviate IBD-induced colon damage and associated depressive-like behaviors mainly via suppressing inflammatory cytokines activity, serum LPS concentration, and affecting the NF-κB/kynurenine pathway.

Positive Effect of 6-Gingerol on Functional Plasticity of Microglia in a rat Model of LPS-induced Depression.

Neuroinflammation has emerged as a crucial factor in the development of depression. Despite the well-known anti-inflammatory properties of 6-gingerol, its potential impact on depression remains poorly understood. This study aimed to investigate the antidepressant effects of 6-gingerol by suppressing microglial activation. In vivo experiments were conducted to evaluate the effect of 6-gingerol on lipopolysaccharide (LPS)-induced behavioral changes and neuroinflammation in rat models. In vitro studies were performed to examine the neuroprotective properties of 6-gingerol against LPS-induced microglial activation. Furthermore, a co-culture system of microglia and neurons was established to assess the influence of 6-gingerol on the expression of synaptic-related proteins, namely synaptophysin (SYP) and postsynaptic density protein 95 (PSD95), which are influenced by microglial activation. In the in vivo experiments, administration of 6-gingerol effectively alleviated LPS-induced depressive behavior in rats. Moreover, it markedly suppressed the activation of rat prefrontal cortex (PFC) microglia induced by LPS and the activation of the NF-κB/NLRP3 inflammatory pathway, while also reducing the levels of inflammatory cytokines IL-1ß and IL-18. In the in vitro experiments, 6-gingerol mitigated nuclear translocation of NF-κB p65, NLRP3 activation, and maturation of IL-1ß and IL-18, all of which were induced by LPS. Furthermore, in the co-culture system of microglia and neurons, 6-gingerol effectively restored the decreased expression of SYP and PSD95. The findings of this study demonstrate the neuroprotective effects of 6-gingerol in the context of LPS-induced depression-like behavior. These effects are attributed to the inhibition of microglial hyperactivation through the suppression of the NF-κB/NLRP3 inflammatory pathway.

Liraglutide-associated depression in a patient with type 2 diabetes: A case report and discussion.

BACKGROUND: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) like liraglutide are primarily used for managing blood sugar levels in type 2 diabetes and aiding weight loss. Typically, their adverse effects are gastrointestinal, with limited exploration into their impact on mental health. CASE PRESENTATION: This report examines a 39-year-old male with type 2 diabetes who developed depressive symptoms after starting liraglutide for glycemic control and weight reduction. Symptoms included poor mood, irritability, decreased interest and energy, progressing to sadness, low self-esteem, and physical discomfort. A clinical diagnosis of a depressive episode was made, coinciding with the initiation of liraglutide. INTERVENTION AND OUTCOME: The patient depressive symptoms significantly improved within a week after discontinuing liraglutide and starting antidepressant therapy. This suggests a possible link between liraglutide and depression, despite considering other factors like diabetes-related stress. DISCUSSION: The report explores potential mechanisms, such as GLP-1RA effects on glucose fluctuations and dopamine modulation, which might contribute to depressive symptoms. The influence on the brain reward system and the reduction in cravings for addictive substances after GLP-1RA use is also discussed as a factor in mood regulation. CONCLUSION: This case highlights the necessity of being vigilant about potential psychiatric side effects, particularly depression, associated with GLP-1RAs. The rarity of such reports calls for more research to investigate and understand these implications further.

Personality traits explain the relationship between psychedelic use and less depression in a comparative study.

Interest in psychedelics is increasing due to the potential for improved mental health and quality of life. However, adverse effects on mental health are still a concern. Personality traits have been suggested to both influence the psychedelic experience and mental health, and even be changed by psychedelic use. The present study describes for the first time a national sample of Swedish psychedelic users (n = 400) compared to a sex and age-matched control-group of non-users (n = 400) regarding mental health variables (depression, insomnia, problematic alcohol and drug use, and dissociation) and personality (Big Five). Data was collected in an online survey including individuals from 16 years of age who had at least one psychedelic experience. The main results reported psychedelic users as less depressed (Patient Health Questionnaire-9; PHQ-9) (d = - 0.29) and having more use of drugs (Drug Use Disorders Identification Test; DUDIT) (d = 1.27). In the Big Five personality traits, openness differed notably (d = 1.72), and the between-group effects in PHQ-9 were explained by lower neuroticism. Our findings reveal that psychedelic users report less depression and higher drug use, and this is partly due to personality traits. These results have implications on how we view psychedelic users and the use of psychedelic drugs.

Anabolic-androgenic steroids are linked to depression and anxiety in male bodybuilders: the hidden psychogenic side of anabolic androgenic steroids.

BACKGROUND: The prevalence of anabolic-androgenic steroids (AAS) use is on the rise among athletes and bodybuilders worldwide. In addition to the well-documented adverse effects on hepatic, renal, and reproductive functions, there is an increasing recognition of psychiatric complications associated with AAS use. This study aimed to investigate psychiatric morbidity among male bodybuilders who are AAS users. METHODS: In this cross-sectional study, 25 male bodybuilders using AAS (mean age 31.2 ± 8.9 years) were compared with a control group of 25 healthy male bodybuilders matched in age (31.3 ± 5.5 years). The demographic, hormonal, and biochemical parameters of the participants were recorded. The impact of AAS use on psychiatric morbidity was assessed using the Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI) in both groups. RESULTS: The BDI and BAI scores were significantly higher in male bodybuilders using anabolic-androgenic steroids (p < 0.0001). While the control group showed no instances of anxiety, seven individuals in the AAS user group reported mild anxiety. No participants in the control group exhibited depression, whereas seven AAS users displayed depressive symptoms (4 mild, 3 moderate). Correlations were observed between lactate dehydrogenase (LDH) levels and BAI scores, creatinine levels and both BAI and BDI scores, as well as between estradiol levels and BDI. CONCLUSION: The study concluded that AAS use among male bodybuilders is associated with elevated levels of depression and anxiety. Our findings suggest a potential correlation between anxiety and depression levels and the levels of creatinine, LDH, and estradiol in AAS users.

C3aR in the medial prefrontal cortex modulates the susceptibility to LPS-induced depressive-like behaviors through glutamatergic neuronal excitability.

Complement activation and prefrontal cortical dysfunction both contribute to the pathogenesis of major depressive disorder (MDD), but their interplay in MDD is unclear. We here studied the role of complement C3a receptor (C3aR) in the medial prefrontal cortex (mPFC) and its influence on depressive-like behaviors induced by systematic lipopolysaccharides (LPS) administration. C3aR knockout (KO) or intra-mPFC C3aR antagonism confers resilience, whereas C3aR expression in mPFC neurons makes KO mice susceptible to LPS-induced depressive-like behaviors. Importantly, the excitation and inhibition of mPFC neurons have opposing effects on depressive-like behaviors, aligning with increased and decreased excitability by C3aR deletion and activation in cortical neurons. In particular, inhibiting mPFC glutamatergic (mPFCGlu) neurons, the main neuronal subpopulation expresses C3aR, induces depressive-like behaviors in saline-treated WT and KO mice, but not in LPS-treated KO mice. Compared to hypoexcitable mPFCGlu neurons in LPS-treated WT mice, C3aR-null mPFCGlu neurons display hyperexcitability upon LPS treatment, and enhanced excitation of mPFCGlu neurons is anti-depressant, suggesting a protective role of C3aR deficiency in these circumstances. In conclusion, C3aR modulates susceptibility to LPS-induced depressive-like behaviors through mPFCGlu neuronal excitability. This study identifies C3aR as a pivotal intersection of complement activation, mPFC dysfunction, and depression and a promising therapeutic target for MDD.

Arjunolic acid ameliorates lipopolysaccharide-induced depressive behavior by inhibiting neuroinflammation via microglial SIRT1/AMPK/Notch1 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Neuroinflammation is involved in the pathogenesis of depression disorder by activating microglia cells, increasing proinflammatory cytokines, effecting serotonin synthesis and metabolism, and neuronal apoptosis and neurogenesis. Arjunolic acid (ARG) is a triterpenoid derived from the fruits of Akebia trifoliata for treating psychiatric disorders in TCM clinic, which exhibits anti-inflammatory and neuroprotective effects. However, its anti-depressive effect and underlying mechanism are unknown. AIM OF THE STUDY: The aim of this study is to explore the effect of arjunolic acid on depression and its possible mechanisms. METHODS: Intraperitoneal injection of LPS in mice and LPS stimulated-BV2 microglia were utilized to set up in vivo and in vitro models. Behavioral tests, H&E staining and ELISA were employed to evaluate the effect of arjunolic acid on depression. RT-qPCR, immunofluorescence, molecular docking and Western blot were performed to elucidate the molecular mechanisms. RESULTS: Arjunolic acid dramatically ameliorated depressive behavior in LPS-induced mice. The levels of BDNF and 5-HT in the hippocampus of the mice were increased, while the number of iNOS + IBA1+ cells in the brain were decreased and Arg1+IBA1+ positive cells were increased after arjunolic acid treatment. In addition, arjunolic acid promoted the polarization of BV2 microglia from M1 to M2 type. Notably, drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA) and molecular docking technologies identified SIRT1 as the target of arjunolic acid. Moreover, after SIRT1 inhibition by using EX-527, the effects of arjunolic acid on ameliorating LPS-induced depressive behavior in mice and promoting M2 Microglia polarization were blocked. In addition, arjunolic acid activated AMPK and decreased Notch1 expression, however, inhibition of AMPK, the effect of arjunolic acid on the downregulation of Notch1 expression were weaken. CONCLUSIONS: This study elucidates that arjunolic acid suppressed neuroinflammation through modulating the SIRT1/AMPK/Notch1 signaling pathway. Our study demonstrates that arjunolic acid might serve as a potiential anti-depressant.

Anxiety-, and depression-like behavior following short-term finasteride administration is associated with impaired synaptic plasticity and cognitive behavior in male rats.

Finasteride, a 5α-Reductase inhibitor, is used to treat male pattern baldness and benign prostatic hyperplasia. Several clinical studies show that chronic finasteride treatment induces persistent depression, suicidal thoughts and cognitive impairment and these symptoms are persistent even after its withdrawal. Previous results from our lab showed that repeated administration of finasteride for six days induces depression-like behavior. However, whether short-term finasteride administration induces anxiety-like behavior and memory impairment and alters synaptic plasticity are not known, which formed the basis of this study. Finasteride was administered to 2-2.5 months old male Wistar rats for six days and subjected to behavioral evaluation, biochemical estimation and synaptic plasticity assessment. Anxiety-like behavior was evaluated in the elevated plus maze (EPM), open field test (OFT), light/dark test (LDT), and novelty suppressed feeding test (NSFT), and learning and memory using novel object recognition test (NORT) and novel object location test (NOLT) and depression-like behavior in the sucrose preference test (SPT). Synaptic plasticity in the hippocampal Schaffer collateral-CA1 was evaluated using slice field potential recordings. Plasma corticosterone levels were estimated using ELISA. Finasteride administration induced anxiety-like behavior in the EPM, OFT, LDT and NSFT, and depression-like behavior in the SPT. Further, finasteride induced hippocampal dependent spatial learning and memory impairment in the NOLT. In addition, finasteride decreased basal synaptic plasticity and long-term potentiation (LTP) in the hippocampus. A trend of increased plasma corticosterone levels was observed following repeated finasteride administration. These results indicate the potential role of corticosterone and synaptic plasticity in finasteride-induced effects and further studies will pave way for the development of novel neurosteroid-based therapeutics in neuropsychiatric diseases.

Quercetin and Kaempferol inhibit HMC-1 activation via SOCE/NFATc2 signaling and suppress hippocampal mast cell activation in lipopolysaccharide-induced depressive mice.

OBJECTIVE AND DESIGN: Mast cells (MCs), as the fastest immune responders, play a critical role in the progression of neuroinflammation-related diseases, especially in depression. Quercetin (Que) and kaempferol (Kae), as two major diet-derived flavonoids, inhibit MC activation and exhibit significant antidepressant effect due to their anti-inflammatory capacity. The study aimed to explore the mechanisms of inhibitory effect of Que and Kae on MC activation, and whether Que and Kae suppress hippocampal mast cell activation in LPS-induced depressive mice. SUBJECTS AND TREATMENT: In vitro assays, human mast cells (HMC-1) were pretreated with Que or Kae for 1 h, then stimulated by phorbol 12-myristate 13-acetate (PMA) and 2,5-di-t-butyl-1,4-benzohydroquinone (tBHQ) for 3 h or 12 h. In vivo assays, Que or Kae was administered by oral gavage once daily for 14 days and then lipopolysaccharide (LPS) intraperitoneally injection to induce depressive behaviors. METHODS: The secretion and expression of TNF-α were determined by ELISA and Western blotting. The nuclear factor of activated T cells (NFAT) transcriptional activity was measured in HMC-1 stably expressing NFAT luciferase reporter gene. Nuclear translocation of NFATc2 was detected by nuclear protein extraction and also was fluorescently detected in HMC-1 stably expressing eGFP-NFATc2. We used Ca2+ imaging to evaluate changes of store-operated calcium entry (SOCE) in HMC-1 stably expressing fluorescent Ca2+ indicator jGCamP7s. Molecular docking was used to assess interaction between the Que or Kae and calcium release-activated calcium modulator (ORAI). The  hippocampal mast cell accumulation and activation  were detected by toluidine blue staining and immunohistochemistry with ß-tryptase. RESULTS: In vitro assays of HMC-1 activated by PtBHQ (PMA and tBHQ), Que and Kae significantly decreased expression and secretion of TNF-α. Moreover, NFAT transcriptional activity and nuclear translocation of NFATc2 were remarkably inhibited by Que and Kae. In addition, the Ca2+ influx mediated by SOCE was suppressed by Que, Kae and the YM58483 (ORAI inhibitor), respectively. Importantly, the combination of YM58483 with Que or Kae had no additive effect on the inhibition of SOCE. The molecular docking also showed that Que and Kae both exhibit high binding affinities with ORAI at the same binding site as YM58483. In vivo assays, Que and Kae significantly reversed LPS-induced depression-like behaviors in mice, and inhibited hippocampal mast cell activation  in LPS-induced depressive mice. CONCLUSIONS: Our results indicated that suppression of SOCE/NFATc2 pathway-mediated by ORAI channels may be the mechanism of inhibitory effect of Que and Kae on MC activation, and also suggested Que and Kae may exert the antidepressant effect through suppressing hippocampal mast cell activation.

Prenatal co-exposure to diisodecyl phthalate and ozone contribute to depressive behavior in offspring mice through oxidative stress and TWIST1 participation.

Exposure to diisodecyl phthalate (DIDP) during early pregnancy may be a risk factor for depressive behavior in offspring. While ozone (O3) exposure also raises the probability of depressive behavior during the preceding DIDP-induced process. In the present study, we investigated the effects of prenatal exposure to DIDP and O3 on the development of depressive-like behavior in offspring mice. The study found that prenatal exposure to both DIDP and O3 significantly increased depressive-like behavior in the offspring mice compared to either DIDP or O3 alone. Prenatal exposure to DIDP and O3 obviously increased the levels of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and cortisol, and decreased the levels of brain-derived neurotrophic factor (BDNF), 5-hydroxytryptamine (5-HT), dopamine (DA) and norepinephrine (NE) in the brain tissues of offspring mice. Transcriptome analysis further revealed significant alterations in genes related to oxidative stress and TWIST1 (a helix-loop-helix transcription factor) in response to the combined exposure to DIDP and O3. HPA axis activation, dysregulation of neurodevelopmental factors, oxidative stress and TWIST1 involvement, collectively contributed to the development of depression-like behaviors in offspring mice following prenatal exposure to DIDP and O3. Moreover, the study also verified the potential role of oxidative stress using vitamin E as an antioxidant. The findings provide valuable evidence for the relationship between co-exposure to DIDP and O3 and depression, highlighting the importance of considering the combined effects of multiple environmental pollutants in assessing their impact on mental health outcomes.

Leukotriene-modifying agents may increase the risk of depression: A cross-sectional study.

INTRODUCTION: Post-market monitoring has shown a potential link between the use of leukotriene-modifying agents (LTRAs) and an increased risk of neuropsychiatric events, such as depression. However, observational studies have produced inconsistent findings, offering no definitive conclusions. OBJECTIVE: To assess the potential correlation between LTRAs exposure and depression in US adults. METHOD: This cross-sectional study, based on population data from the National Health and Nutrition Examination Survey (NHANES) 2007-2016 cycle. The Patient Health Questionnaire-9 was used to assess depression. Multivariable regression was used to evaluate the association between LTRAs exposure and depression. Sensitivity and subgroup analyses were conducted, with the calculation of the E-value. Network pharmacology was employed to investigate the influence of LTRAs on mechanisms of depression. RESULTS: Among the 9414 participants, 595 (6.3 %) were classified as having depression. LTRAs exposure was associated with a higher prevalence of depression (16.9 % vs. 6.0 %). The multivariable logistic regression results showed that LTRAs use increased the risk of depression (OR = 1.70; 95 % CI, 1.05-2.75). An association between LTRAs exposure and depression was found in sensitivity analyses conducted regardless of multivariable linear regression with the PHQ-9 score as a continuous variable (ß = 0.97; 95 % CI, 0.44-1.50) or multivariable logistic regression with the PHQ-9 cut-off of 5 (OR = 1.52; 95 % CI, 1.08-2.14). The association between LTRAs and depression was stable in the different subgroups. CONCLUSION: LTRAs exposure is positively associated with depression in US adults. Therefore, the risk for depression in patients receiving long-term LTRAs treatment should be considered.

Short-term exposures to PM2.5, PM2.5 chemical components, and antenatal depression: Exploring the mediating roles of gut microbiota and fecal short-chain fatty acids.

BACKGROUND: PM2.5 and its chemical components increase health risks and are associated with depression and gut microbiota. However, there is still limited evidence on whether gut microbiota and short-chain fatty acids (SCFAs) mediate the association between PM2.5, PM2.5 chemical components, and antenatal depression. The purpose of this study was to investigate the mediating role of maternal gut microbiota in correlations between short-term exposure to PM2.5, short-term exposure to PM2.5 chemical components, and antenatal depression. METHODS: Demographic information and stool samples were collected from 75 pregnant women in their third trimester. Their exposure to PM2.5 and PM2.5 chemical components was measured. Participants were divided into the non-antenatal depression group or the antenatal depression group according to the cut-off of 10 points on the Edinburgh Postnatal Depression Scale (EPDS). The gut microbiota were analyzed using the 16 S rRNA-V3/V4 gene sequence, and the concentration of PM2.5 and its chemical components was calculated using the Tracking Air Pollution in China (TAP) database. Gas chromatography-mass spectrometry was used to analyze SCFAs in stool samples. In order to assess the mediating effects of gut microbiota and SCFAs, mediation models were utilized. RESULTS: There were significant differences between gut microbial composition and SCFAs concentrations between the non-antenatal depression group and the antenatal depression group. PM2.5 and its chemical components were positively associated with EPDS scores and negatively associated with genera Enterococcus and Enterobacter. Genera Candidatus_Soleaferrea (ß = -7.21, 95%CI -11.00 to -3.43, q = 0.01) and Enterococcus (ß = -2.37, 95%CI -3.87 to -0.87, q = 0.02) were negatively associated with EPDS scores, indicating their potential protective effects against antenatal depression. There was no significant association between SCFAs and EPDS scores. The mediating role of Enterococcus between different lagged periods of PM2.5, PM2.5 chemical component exposure, and antenatal depression was revealed. For instance, Enterococcus explained 29.23% (95%CI 2.16-87.13%, p = 0.04) of associations between PM2.5 exposure level at the day of sampling (lag 0) and EPDS scores. CONCLUSION: Our study highlights that Enterococcus may mediate the associations between PM2.5, PM2.5 chemical components, and antenatal depression. The mediating mechanism through which the gut microbiota influences PM2.5-induced depression in pregnant women still needs to be further studied.

20(S)-Protopanaxadiol Exerts Antidepressive Effects in Chronic Corticosterone-Induced Rodent Animal Models as an Activator of Brain-Type Creatine Kinase.

20(S)-Protopanaxadiol (PPD) is one of the bioactive ingredients in ginseng and possesses neuroprotective properties. Brain-type creatine kinase (CK-BB) is an enzyme involved in brain energy homeostasis via the phosphocreatine-creatine kinase system. We previously identified PPD as directly bound to CK-BB and activated its activity in vitro. In this study, we explored the antidepressive effects of PPD that target CK-BB. First, we conducted time course studies on brain CK-BB, behaviors, and hippocampal structural plasticity responses to corticosterone (CORT) administration. Five weeks of CORT injection reduced CK-BB activity and protein levels and induced depression-like behaviors and hippocampal structural plasticity impairment. Next, a CK inhibitor and an adeno-associated virus-targeting CKB were used to diminish CK-BB activity or its expression in the brain. The loss of CK-BB in the brain led to depressive behaviors and morphological damage to spines in the hippocampus. Then, a polyclonal antibody against PPD was used to determine the distribution of PPD in the brain tissues. PPD was detected in the hippocampus and cortex and observed in astrocytes, neurons, and vascular endotheliocytes. Finally, different PPD doses were used in the chronic CORT-induced depression model. Treatment with a high dose of PPD significantly increased the activity and expression of CK-BB after long-term CORT injection. In addition, PPD alleviated the damage to depressive-like behaviors and structural plasticity induced by repeated CORT injection. Overall, our study revealed the critical role of CK-BB in mediating structural plasticity in CORT-induced depression and identified CK-BB as a therapeutic target for PPD, allowing us to treat stress-related mood disorders.

Atractylodin ameliorates lipopolysaccharide-induced depressive-like behaviors in mice through reducing neuroinflammation and neuronal damage.

Depression is a psychiatric disorder associated with multiple factors including microglia-mediated neuroinflammation. Although atractylodin exerted a variety of biological activities, however the effect of atractylodin on neuroinflammation-related depression was still unclear. In this study, the lipopolysaccharide (LPS)-induced mouse model was used to explore the antidepressant effects and molecular mechanisms of atractylodin. The results showed that atractylodin increased sugar preference, also reduced immobility time in FST and TST. Further study showed atractylodin reduced the oxidative stress and the activation of microglia in mouse hippocampus, also inhibited the level of cytokine release, especially IL-1ß. The results of western blotting showed that atractylodin significantly inhibited the expression of NLRP3 and pro-IL1ß via inhibition of NF-κB pathway. Our studies showed that atractylodin upregulated BDNF/Akt pathway in mouse hippocampus. Therefore, this study firstly indicated that atractylodin can ameliorate lipopolysaccharide-induced depressive-like behaviors in mice through reducing neuroinflammation and neuronal damage, and its molecular mechanism may be associated with the decrease of the expression of NLRP3 inflammasome and upregulation of BDNF/Akt pathway.

Time-dependent antidepressant-like effects of reelin and ketamine in the repeated-corticosterone model of chronic stress.

There is an urgent need for novel antidepressants, given that approximately 30% of those diagnosed with depression do not respond adequately to first-line treatment. Additionally, monoaminergic-based antidepressants have a substantial therapeutic time-lag, often taking months to reach full therapeutic effect. Ketamine, an N-methyl-d-aspartate receptor (NMDAR) antagonist is the only current effective rapid-acting antidepressant, demonstrating efficacy within hours and lasting up to two weeks with an acute dose. Reelin, an extracellular matrix glycoprotein, has demonstrated rapid-acting antidepressant-like effects at 24 h, however the exact timescale of these effects has not been investigated. To determine the short and long-term effects of reelin, female Long Evans rats (n = 120) underwent a chronic corticosterone (CORT; or vehicle) paradigm (40 mg/kg, 21 days). On day 21, rats were treated with reelin (3µg; i.v.), ketamine (10 mg/kg; i.p.), both reelin and ketamine (same doses), or vehicle (saline). Behavioural and biological effects were then evaluated at 1 h, 6 h, 12 h, and 1 week after treatment. The 1-week cohort continued CORT injections to ensure the effect of chronic stress was not lost. Individually, both reelin and ketamine significantly rescued CORT-induced behaviour and hippocampal reelin expression at all timepoints. Ketamine rescued a decrease in dendritic maturity as induced by CORT. Synergistic effects of reelin and ketamine appeared at 1-week, suggesting a potential additive effect of the antidepressant-like actions. Taken together, this study provides further support for reelin-based therapeutics to develop rapid-acting antidepressant.

'Environmental standard limit concentration' arsenic exposure is associated with anxiety, depression, and autism-like changes in early-life stage zebrafish.

Arsenic is a worldwide environmental pollutant that can impair human health. Previous studies have identified mental disorders induced by arsenic, but the environmental exposure concentrations in the early life stages associated with these disorders are poorly understood. In the present study, early-life stage zebrafish were used to explore the effects on mental disorders under 'environmental standard limit concentrations' arsenic exposures of 5, 10, 50, 150, and 500 µg/L. The results showed that arsenic exposure at these concentrations changed the locomotor behavior in larval zebrafish and was further associated with anxiety, depression, and autism-like behavior in both larval and juvenile zebrafish. Changes were noted at benchmark dose limit (BMDL) concentrations as low as 0.81 µg/L. Transcriptomics showed that immediate early genes (IEGs) fosab, egr1, egr2a, ier2b, egr3, and jund were decreased after arsenic exposure in larval and juvenile zebrafish. Nervous system impairment and anxiety, depression, and autism-like behaviors in early-life stage zebrafish at 'environmental standard limit concentrations' may be attributed to the downregulation of IEGs. These findings in zebrafish provided new experimental support for an arsenic toxicity threshold for mental disorders, and they suggest that low levels of environmental chemicals may be causative developmental factors for mental disorders.

Fixed drug combination (levosulpiride and rabeprazole)-induced atypical Parkinsonian's disorders with associated anxiety and low-lying depression.

We hereby describe a rare case of levosulpiride-induced atypical parkinsonism presenting with sluggish movements, atypical kinetic tremors (tremors with voluntary movement), periorbital tremors, dystonia, difficulty in speech and coordination, postural imbalance, with additional features of difficulty in swallowing and drooling with associated recent onset psychiatric disturbances such as anxiety and low-lying depression. The dechallenge of levosulpiride and medications for associated anxiety and low-lying depression caused a complete remission of the disease within 2 ½ months.

Sildenafil, alone and in combination with imipramine or escitalopram, display antidepressant-like effects in an adrenocorticotropic hormone-induced (ACTH) rodent model of treatment-resistant depression.

BACKGROUND: Major depressive disorder (MDD) represents a challenge with high prevalence and limited effectiveness of existing treatments, particularly in cases of treatment-resistant depression (TRD). Innovative strategies and alternative drug targets are therefore necessary. Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is known to exert neuroplastic, anti-inflammatory, and antioxidant properties, and is a promising antidepressant drug candidate. AIM: To investigate whether sildenafil monotherapy or in combination with a known antidepressant, can elicit antidepressant-like effects in an adrenocorticotropic hormone (ACTH)-induced rodent model of TRD. METHODS: ACTH-naïve and ACTH-treated male Sprague-Dawley (SD) rats received various sub-acute drug treatments, followed by behavioural tests and biochemical analyses conversant with antidepressant actions. RESULTS: Sub-chronic ACTH treatment induced significant depressive-like behaviour in rats, evidenced by increased immobility during the forced swim test (FST). Sub-acute sildenafil (10 mg/kg) (SIL-10) (but not SIL-3), and combinations of imipramine (15 mg/kg) (IMI-15) and sildenafil (3 mg/kg) (SIL-3) or escitalopram (15 mg/kg) (ESC-15) and SIL-3, exhibited significant antidepressant-like effects. ACTH treatment significantly elevated hippocampal levels of brain-derived neurotrophic factor (BDNF), serotonin, norepinephrine, kynurenic acid (KYNUA), quinolinic acid (QUINA), and glutathione. The various mono- and combined treatments significantly reversed some of these changes, whereas IMI-15 + SIL-10 significantly increased glutathione disulfide levels. ESC-15 + SIL-3 significantly reduced plasma corticosterone levels. CONCLUSION: This study suggests that sildenafil shows promise as a treatment for TRD, either as a stand-alone therapy or in combination with a traditional antidepressant. The neurobiological mechanism underlying the antidepressant-like effects of the different sildenafil mono- and combination therapies reflects a multimodal action and cannot be explained in full by changes in the individually measured biomarker levels.

Single-cell RNA-sequencing of cellular heterogeneity and pathogenic mechanisms in paraquat-induced Parkinson's disease with depression.

Parkinson's disease (PD) is among the most prevalent neurodegenerative diseases, and approximately one third of patients with PD are estimated to have depression. Paraquat (PQ) exposure is an important environmental risk factor for PD. In this study, we established a mouse model of PQ-induced PD with depression to comprehensively investigate cellular heterogeneity and the mechanisms underlying the progression of depression in the context of PD. We utilized single-cell RNA-seq (scRNA-seq) to acquire the transcriptomic atlas of individual cells from model mice and characterize the gene expression profiles in each differentially expressed cell type. We identified a specific glutamatergic neuron cluster responsible for the development of heterogeneous depression-associated changes and established a comprehensive gene expression atlas. Furthermore, functional enrichment and cell trajectory analyses revealed that the mechanisms underlying the progression of PD with depression were associated with specific glutamatergic neurons. Together, our findings provide a valuable resource for deciphering the cellular heterogeneity of PD with depression. The suggested connection between intrinsic transcriptional states of neurons and the progression of depression can provide insight into potential biomarkers and specific targets for anti-depression treatment in patients with PD. SYNOPSIS: Our results obtained using model mice confirm the core effects of PQ exposure on glutamatergic neurons and their potential role in the development of PD with depression.