ABSTRACT
Citalopram and escitalopram are structurally close-related antidepressants and both forms are widely used in the world. We aimed to comparatively evaluate the anti-neuroinflammatory and neuroprotective effects of escitalopram and citalopram in Parkinson's disease (PD) mouse model. Mice were randomly divided into six groups and received 6-hydroxydopamine (6-OHDA) or vehicle administration. The mice were then treated with escitalopram, citalopram or saline for consecutive 7 days. Behaviors, neuroinflammation, neurotransmitters, and neurotoxicity were assessed. Results showed that citalopram but not escitalopram worsened body weight loss and increased freezing time in the PD mice. Both drugs had no impact on the anxiety-like behaviors but ameliorated the depressive-like behaviors as in elevated plus maze and sucrose splash tests. Escitalopram but not citalopram ameliorated motor discoordination in the PD mice as in rotarod test. In accordance, escitalopram but not citalopram attenuated the 6-OHDA-induced nigrostriatal dopaminergic loss. Further mechanistic investigations showed that both drugs mitigated activations of microglia and astrocytes and/or levels of pro-inflammatory cytokines in the PD mice, but escitalopram showed appreciably better effects in the substantia nigra. Neurotransmitter examination in the prefrontal cortex suggested that the two drugs had comparable effects on the disturbed neurotransmitters in the PD mice, but citalopram was prone to disrupt certain normal homeostasis. In conclusion, escitalopram is moderately superior than citalopram to suppress neuroinflammation and to protect against dopaminergic neuronal death and motor discoordination in the 6-OHDA-induced PD mice. Our findings imply that escitalopram shall be prescribed with priority over citalopram to treat PD patients with depression as escitalopram may meanwhile provide greater additional benefits to the patients.
Subject(s)
Citalopram , Disease Models, Animal , Escitalopram , Neuroprotective Agents , Oxidopamine , Animals , Citalopram/pharmacology , Citalopram/therapeutic use , Neuroprotective Agents/therapeutic use , Neuroprotective Agents/pharmacology , Male , Mice , Escitalopram/therapeutic use , Escitalopram/pharmacology , Neuroinflammatory Diseases/drug therapy , Neuroinflammatory Diseases/immunology , Mice, Inbred C57BL , Cytokines/metabolism , Parkinson Disease/drug therapy , Humans , Behavior, Animal/drug effects , Dopaminergic Neurons/drug effects , Dopaminergic Neurons/pathology , Anti-Inflammatory Agents/therapeutic use , Anti-Inflammatory Agents/pharmacology , Parkinsonian Disorders/drug therapy , Parkinsonian Disorders/chemically inducedABSTRACT
BACKGROUND: A more in-depth understanding of the relationship between depressive symptoms, neurocognition and suicidal behavior could provide insights into the prognosis and treatment of major depressive disorder (MDD) and suicide. We conducted a network analysis among depressed patients examining associations between history of suicide attempt (HSA), core emotional major depression disorder, and key neurocognitive domains. METHOD: Depressed patients (n = 120) aged 18-65 years were recruited from a larger randomized clinical trial conducted at the Douglas Institute in Montreal, Canada. They were randomly assigned to receive one of two antidepressant treatments (i.e., escitalopram or desvenlafaxine) for 8 weeks. Core emotional MDD and key neurocognitive domains were assessed pre-post treatment. RESULTS: At baseline, an association between history of suicide attempt (HSA) and phonemic verbal fluency (PVF) suggested that HSA patients reported lower levels of the latter. After 8 weeks of antidepressant treatment, HSA became conditionally independent from PVF. Similar results were found for both the HAM-D and the QIDS-SR core emotional MDD/neurocognitive networks. CONCLUSION: Network analysis revealed a pre-treatment relationship between a HSA and decreased phonemic VF among depressed patients, which was no longer present after 8 weeks of antidepressant treatment.
Subject(s)
Antidepressive Agents , Depressive Disorder, Major , Suicide, Attempted , Humans , Suicide, Attempted/statistics & numerical data , Suicide, Attempted/psychology , Adult , Male , Female , Middle Aged , Depressive Disorder, Major/drug therapy , Depressive Disorder, Major/psychology , Antidepressive Agents/therapeutic use , Escitalopram/therapeutic use , Escitalopram/pharmacology , Desvenlafaxine Succinate/therapeutic use , Young Adult , Aged , Adolescent , Neuropsychological Tests , Emotions/drug effectsABSTRACT
Selective serotonin reuptake inhibitors (SSRIs) are widely used for depression based on the monoamine deficiency hypothesis. However, the clinical use of these agents is controversial, in part because of their variable clinical efficacy and in part because of their delayed onset of action. Because of the complexities involved in replicating human disease and clinical dosing in animal models, the scientific community has not reached a consensus on the reasons for these phenomena. In this work, we create a theoretical hippocampal model incorporating escitalopram's pharmacokinetics, pharmacodynamics (competitive and non-competitive inhibition, and serotonin transporter (SERT) internalization), inflammation, and receptor dynamics. With this model, we simulate chronic oral escitalopram in mice showing that days to weeks are needed for serotonin levels to reach steady-state. We show escitalopram's chemical efficacy is diminished under inflammation. Our model thus offers mechanisms for how chronic escitalopram affects brain serotonin, emphasizing the importance of optimized dose and time for future antidepressant discoveries.
Subject(s)
Escitalopram , Inflammation , Selective Serotonin Reuptake Inhibitors , Serotonin Plasma Membrane Transport Proteins , Serotonin Plasma Membrane Transport Proteins/metabolism , Animals , Selective Serotonin Reuptake Inhibitors/pharmacology , Mice , Inflammation/drug therapy , Inflammation/metabolism , Escitalopram/pharmacology , Hippocampus/metabolism , Hippocampus/drug effects , Serotonin/metabolism , Humans , Citalopram/pharmacologyABSTRACT
Clinical studies of major depression (MD) generally focus on group effects, yet interindividual differences in brain function are increasingly recognized as important and may even impact effect sizes related to group effects. Here, we examine the magnitude of individual differences in relation to group differences that are commonly investigated (e.g., related to MD diagnosis and treatment response). Functional MRI data from 107 participants (63 female, 44 male) were collected at baseline, 2, and 8â weeks during which patients received pharmacotherapy (escitalopram, N = 68) and controls (Nâ =â 39) received no intervention. The unique contributions of different sources of variation were examined by calculating how much variance in functional connectivity was shared across all participants and sessions, within/across groups (patients vs controls, responders vs nonresponders, female vs male participants), recording sessions, and individuals. Individual differences and common connectivity across groups, sessions, and participants contributed most to the explained variance (>95% across analyses). Group differences related to MD diagnosis, treatment response, and biological sex made significant but small contributions (0.3-1.2%). High individual variation was present in cognitive control and attention areas, while low individual variation characterized primary sensorimotor regions. Group differences were much smaller than individual differences in the context of MD and its treatment. These results could be linked to the variable findings and difficulty translating research on MD to clinical practice. Future research should examine brain features with low and high individual variation in relation to psychiatric symptoms and treatment trajectories to explore the clinical relevance of the individual differences identified here.
Subject(s)
Antidepressive Agents , Brain , Depressive Disorder, Major , Individuality , Magnetic Resonance Imaging , Humans , Male , Depressive Disorder, Major/drug therapy , Depressive Disorder, Major/physiopathology , Depressive Disorder, Major/diagnostic imaging , Female , Adult , Brain/diagnostic imaging , Brain/physiopathology , Brain/drug effects , Antidepressive Agents/therapeutic use , Middle Aged , Escitalopram/pharmacology , Citalopram/therapeutic use , Young Adult , ConnectomeABSTRACT
BACKGROUND: Major depressive disorder (MDD) is commonly treated with selective serotonin reuptake inhibitors (SSRIs). SSRIs inhibit the serotonin transporter (5-HTT), but the downstream antidepressant mechanism of action of these drugs is poorly understood. The serotonin 1B (5-HT1B) receptor is functionally linked to 5-HTT and 5-HT1B receptor binding and 5-HT1B receptor mRNA is reduced in the raphe nuclei after SSRI administration in primates and rodents, respectively. The effect of SSRI treatment on 5-HT1B receptor binding in patients with MDD has not been examined previously. This positron emission tomography (PET) study aimed to quantify brain 5-HT1B receptor binding changes in vivo after SSRI treatment for MDD in relation to treatment effect. METHODS: Eight unmedicated patients with moderate to severe MDD underwent PET with the 5-HT1B receptor radioligand [11C]AZ10419369 before and after 3 to 4 weeks of treatment with the SSRI escitalopram 10 mg daily. Depression severity was assessed at time of PET and after 6 to 7 weeks of treatment with the Montgomery-Åsberg Depression Rating Scale. RESULTS: We observed a significant reduction in [11C]AZ10419369 binding in a dorsal brainstem (DBS) region containing the median and dorsal raphe nuclei after escitalopram treatment (P = .036). Change in DBS [11C]AZ10419369 binding correlated with Montgomery-Åsberg Depression Rating Scale reduction after 3-4 (r = 0.78, P = .021) and 6-7 (r = 0.94, P < .001) weeks' treatment. CONCLUSIONS: Our findings align with the previously reported reduction of 5-HT1B receptor binding in the raphe nuclei after SSRI administration and support future studies testing change in DBS 5-HT1B receptor binding as an SSRI treatment response marker.
Subject(s)
Depressive Disorder, Major , Escitalopram , Positron-Emission Tomography , Receptor, Serotonin, 5-HT1B , Selective Serotonin Reuptake Inhibitors , Receptor, Serotonin, 5-HT1B/metabolism , Male , Humans , Depressive Disorder, Major/drug therapy , Depressive Disorder, Major/metabolism , Depressive Disorder, Major/diagnostic imaging , Adult , Female , Middle Aged , Selective Serotonin Reuptake Inhibitors/pharmacology , Escitalopram/pharmacology , Escitalopram/metabolism , Brain/metabolism , Brain/diagnostic imaging , Brain/drug effects , Treatment Outcome , Piperazines/pharmacology , Protein Binding/drug effects , Young Adult , Citalopram/pharmacology , Benzopyrans , MorpholinesABSTRACT
Brain-derived neurotrophic factor (BDNF) dysfunction is one of the most important mechanisms underlying depression. It seems that selective serotonin reuptake inhibitors (SSRIs) improve depression via affecting BDNF level. In this systematic review, for the first time, we aimed to review the effect of three SSRIs including fluoxetine, escitalopram, and sertraline, on both depression and BDNF level in preclinical and clinical studies. PubMed electronic database was searched, and 193 articles were included in this study. After reviewing all manuscripts, only one important difference was found: subjects. We found that SSRIs induce different effects in animals vs. humans. Preclinical studies showed many controversial effects, while human studies showed only two effects: improvement of depression, with or without the improvement of BDNF. However, most studies used chronic SSRIs treatment, while acute SSRIs were not effectively used and evaluated. In conclusion, it seems that SSRIs are reliable antidepressants, and the improvement effect of SSRIs on depression is not dependent to BDNF level (at least in human studies).
Subject(s)
Brain-Derived Neurotrophic Factor , Depression , Fluoxetine , Selective Serotonin Reuptake Inhibitors , Sertraline , Humans , Brain-Derived Neurotrophic Factor/blood , Brain-Derived Neurotrophic Factor/metabolism , Sertraline/pharmacology , Sertraline/therapeutic use , Selective Serotonin Reuptake Inhibitors/pharmacology , Selective Serotonin Reuptake Inhibitors/therapeutic use , Fluoxetine/pharmacology , Animals , Depression/drug therapy , Escitalopram/pharmacology , Escitalopram/therapeutic use , Antidepressive Agents/pharmacology , Antidepressive Agents/therapeutic useABSTRACT
BACKGROUND: There is growing evidence for the therapeutic effects of the psychedelic drug psilocybin for major depression. However, due to the lack of safety data on combining psilocybin with selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) and concerns that there may be a negative interaction on efficacy, participants enrolling in psychedelic trials are usually required to discontinue SNRI/SNRIs prior to enrolling. AIMS: Using data from a recent clinical trial examining the comparative efficacy the psychedelic drug psilocybin (P) combined with approximately 20 h of psychological support to a 6-week (daily) course of the SSRI escitalopram plus matched psychological support for major depressive disorder, we explored the effects of discontinuing SSRI/SNRIs prior to study enrolment on study outcomes. METHODS: Exploratory post hoc analyses using linear mixed effects model were performed to investigate the discontinuation effect on various validated depression symptom severity scales and well-being. The impact of SSRI/SNRIs discontinuation on the acute psychedelic experience was also explored. RESULTS/OUTCOMES: In the psilocybin group, there was a reduced treatment effect on all outcome measures for SSRI/SNRIs discontinuers compared with unmedicated patients at trial entry. However, no effects of discontinuation on measures of the acute psychedelic experience were found. CONCLUSION: Discontinuation of SSRI/SNRIs before psilocybin might diminish response to treatment; however, as we did not test SSRI/SNRI continuation in our trial, we cannot infer such causation. Moreover, the exploratory nature of the analyses makes them hypothesis generating, and not confirmatory. A controlled trial of SSRI/SNRI discontinuation versus continuation prior to psilocybin is urgently required.
Subject(s)
Depressive Disorder, Major , Escitalopram , Hallucinogens , Psilocybin , Selective Serotonin Reuptake Inhibitors , Humans , Psilocybin/administration & dosage , Psilocybin/pharmacology , Psilocybin/adverse effects , Depressive Disorder, Major/drug therapy , Adult , Male , Selective Serotonin Reuptake Inhibitors/administration & dosage , Selective Serotonin Reuptake Inhibitors/adverse effects , Selective Serotonin Reuptake Inhibitors/pharmacology , Female , Hallucinogens/administration & dosage , Hallucinogens/adverse effects , Hallucinogens/pharmacology , Escitalopram/administration & dosage , Escitalopram/pharmacology , Middle Aged , Treatment Outcome , Drug Therapy, CombinationABSTRACT
Hepatocellular carcinoma (HCC) persists to be one of the most devastating and deadliest malignancies globally. Recent research into the molecular signaling networks entailed in many malignancies has given some prominent insights that can be leveraged to create molecular therapeutics for combating HCC. Therefore, in the current communication, an in-silico drug repurposing approach has been employed to target the function of PTP4A3/PRL-3 protein in HCC using antidepressants: Fluoxetine hydrochloride, Citalopram, Amitriptyline, Imipramine, and Escitalopram oxalate as the desired ligands. The density function theory (DFT) and chemical absorption, distribution, metabolism, excretion, and toxicity (ADMET) parameters for the chosen ligands were evaluated to comprehend the pharmacokinetics, drug-likeness properties, and bioreactivity of the ligands. The precise interaction mechanism was explored using computational methods such as molecular docking and molecular dynamics (MD) simulation studies to assess the inhibitory effect and the stability of the interactions against the protein of interest. Escitalopram oxalate exhibited a comparatively significant docking score (-7.4â¯kcal/mol) compared to the control JMS-053 (-6.8â¯kcal/mol) against the PRL-3 protein. The 2D interaction plots exhibited an array of hydrophobic and hydrogen bond interactions. The findings of the ADMET forecast confirmed that it adheres to Lipinski's rule of five with no violations, and DFT analysis revealed a HOMO-LUMO energy gap of -0.26778 ev, demonstrating better reactivity than the control molecule. The docked complexes were subjected to MD studies (100â¯ns) showing stable interactions. Considering all the findings, it can be concluded that Escitalopram oxalate and related therapeutics can act as potential pharmacological candidates for targeting the activity of PTP4A3/PRL-3 in HCC.
Subject(s)
Antidepressive Agents , Carcinoma, Hepatocellular , Escitalopram , Liver Neoplasms , Molecular Docking Simulation , Protein Tyrosine Phosphatases , Humans , Liver Neoplasms/drug therapy , Liver Neoplasms/metabolism , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/metabolism , Protein Tyrosine Phosphatases/antagonists & inhibitors , Protein Tyrosine Phosphatases/metabolism , Antidepressive Agents/pharmacology , Antidepressive Agents/chemistry , Escitalopram/chemistry , Escitalopram/pharmacology , Neoplasm Proteins/metabolism , Neoplasm Proteins/antagonists & inhibitors , Molecular Dynamics Simulation , Oxalates/chemistry , Oxalates/metabolism , Density Functional Theory , Molecular Structure , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistryABSTRACT
BACKGROUND: To investigate the association between pre-trial expectancy, suggestibility, and response to treatment in a trial of escitalopram and investigational drug, COMP360, psilocybin, in the treatment of major depressive disorder (ClinicalTrials.gov registration: NCT03429075). METHODS: We used data (n = 55) from our recent double-blind, parallel-group, randomized head-to-head comparison trial of escitalopram and investigational drug, COMP360, psilocybin. Mixed linear models were used to investigate the association between pre-treatment efficacy-related expectations, as well as baseline trait suggestibility and absorption, and therapeutic response to both escitalopram and COMP360 psilocybin. RESULTS: Patients had significantly higher expectancy for psilocybin relative to escitalopram; however, expectancy for escitalopram was associated with improved therapeutic outcomes to escitalopram, expectancy for psilocybin was not predictive of response to psilocybin. Separately, we found that pre-treatment trait suggestibility was associated with therapeutic response in the psilocybin arm, but not in the escitalopram arm. CONCLUSIONS: Overall, our results suggest that psychedelic therapy may be less vulnerable to expectancy biases than previously suspected. The relationship between baseline trait suggestibility and response to psilocybin therapy implies that highly suggestible individuals may be primed for response to this treatment.
Subject(s)
Depressive Disorder, Major , Escitalopram , Psilocybin , Suggestion , Humans , Psilocybin/pharmacology , Psilocybin/administration & dosage , Psilocybin/therapeutic use , Male , Adult , Female , Depressive Disorder, Major/drug therapy , Double-Blind Method , Middle Aged , Escitalopram/pharmacology , Hallucinogens/pharmacology , Hallucinogens/administration & dosage , Anticipation, Psychological/drug effects , Treatment Outcome , Citalopram/therapeutic use , Citalopram/pharmacology , Citalopram/administration & dosageABSTRACT
BACKGROUND: Newly identified multifunctional peptidergic modulators of stress responses: neuromedin U (NMU) and neuropeptide S (NPS) are involved in the wide spectrum of brain functions. However, there are no reports dealing with potential molecular relationships between the action of diverse anxiolytic or antidepressant drugs and NMU and NPS signaling in the brain. The present work was therefore focused on local expression of the aforementioned stress-related neuropeptides in the rat brain after long-term treatment with escitalopram and clonazepam. METHODS: Studies were carried out on adult, male Sprague-Dawley rats that were divided into 3 groups: animals injected with saline (control) and experimental individuals treated with escitalopram (at single dose 5 mg/kg daily), and clonazepam (at single dose 0.5 mg/kg). All individuals were sacrificed under anaesthesia and the whole brain excised. Total mRNA was isolated from homogenized samples of amygdala, hippocampus, hypothalamus, thalamus, cerebellum and brainstem. Real time-PCR method was used for estimation of related NPS, NPS receptor (NPSR), NMU, NMU and receptor 2 (NMUR2) mRNA expression. The whole brains were also sliced for general immunohistochemical assessment of the neuropeptides expression. RESULTS: Chronic administration of clonazepam resulted in an increase of NMU mRNA expression and formation of NMU-expressing fibers in the amygdala, while escitalopram produced a significant decrease in NPSR mRNA level in hypothalamus. Long-term escitalopram administration affects the local expression of examined neuropeptides mRNA in a varied manner depending on the brain structure. CONCLUSIONS: Pharmacological effects of escitalopram may be connected with local at least partially NPSR-related alterations in the NPS/NMU/NMUR2 gene expression at the level selected rat brain regions. A novel alternative mode of SSRI action can be therefore cautiously proposed.
Subject(s)
Anxiety , Brain , Clonazepam , Escitalopram , GABA Modulators , Neuropeptides , Receptors, Neuropeptide , Receptors, Neurotransmitter , Animals , Anxiety/drug therapy , Brain/drug effects , Brain/metabolism , Clonazepam/pharmacology , Clonazepam/therapeutic use , Escitalopram/pharmacology , Escitalopram/therapeutic use , GABA Modulators/pharmacology , GABA Modulators/therapeutic use , Male , Neuropeptides/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Receptors, Neuropeptide/metabolism , Receptors, Neurotransmitter/metabolismABSTRACT
Acute lung injury (ALI) is a significant cause of morbidity and mortality worldwide. To search for a new treatment for acute lung injury, we investigated the effect of escitalopram on lipopolysaccharide (LPS)-induced ALI. Our results showed that escitalopram inhibited salt-inducible kinase 2 (SIK2) activity (IC50 = 6.36 ± 0.93 µM) and triggered histone deacetylase 4 (HDAC4) dephosphorylation. Following its dephosphorylation, HDAC4 translocated into the nucleus, promoted deacetylation and cytoplasmic shuttling of p65, thus inhibited LPS-induced pro-inflammatory cytokine production. Moreover, escitalopram markedly ameliorated the inflammatory responses, reduced neutrophils infiltration and attenuated LPS-induced pulmonary injury in mice. Taken together, we identified a previously unexplored role for escitalopram in SIK2/HDAC4/NF-κB pathway, therefore escitalopram may be considered as a new treatment for ALI.
Subject(s)
Acute Lung Injury/drug therapy , Escitalopram/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Active Transport, Cell Nucleus/drug effects , Acute Lung Injury/metabolism , Acute Lung Injury/pathology , Animals , Drug Repositioning , Histone Deacetylases/metabolism , Inflammation/chemically induced , Inflammation/drug therapy , Inflammation/metabolism , Lipopolysaccharides/toxicity , Male , Mice , Mice, Inbred C57BL , NF-kappa B/metabolism , Phosphorylation/drug effects , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , RAW 264.7 Cells , Signal Transduction/drug effectsABSTRACT
We hypothesized that there is a relationship between the orexinergic system (OX) alterations and changes elicited by escitalopram or venlafaxine in adult rats subjected to maternal separation (MS). This animal model of childhood adversity induces long-lasting consequences in adult physiology and behavior. Male Wistar rats from the control and MS groups were injected with escitalopram or venlafaxine (10 mg/kg) IP from postnatal day (PND) 69-89. Adult rats were subjected to behavioral assessment, estimation of hypothalamic-pituitary-adrenal (HPA) axis activity and analysis of the OX system (quantitative PCR and immunohistochemistry) in the hypothalamus and amygdala. MS caused anxiety- and depressive-like behavior, endocrine stress-related response, and up-regulation of the OX system in the hypothalamus. Escitalopram, but not venlafaxine, increased the activity of hypothalamic OX system in the control rats and both drugs had no effect on OXs in the MS group. The disturbed signaling of the OX pathway may be significant for harmful long-term consequences of early-life stress. Our data show that the normal brain and brain altered by MS respond differently to escitalopram. Presumably, anti-anxiety and antidepressant effects of this drug do not depend on the activity of hypothalamic OX system.
Subject(s)
Escitalopram , Hypothalamus , Stress, Psychological , Animals , Male , Rats , Escitalopram/pharmacology , Hypothalamus/metabolism , Maternal Deprivation , Rats, Wistar , Stress, Psychological/metabolism , Up-RegulationABSTRACT
Human serotine transporter (hSERT) is one of the most influential drug targets, and its allosteric modulators (e.g., escitalopram) have emerged to be the next-generation medication for psychiatric disorders. However, the molecular mechanism underlying the allosteric modulation of hSERT is still elusive. Here, the simulation strategies of conventional (cMD) and steered (SMD) molecular dynamics were applied to investigate this molecular mechanism from distinct perspectives. First, cMD simulations revealed that escitalopram's binding to hSERT's allosteric site simultaneously enhanced its binding to the orthosteric site. Then, SMD simulation identified that the occupation of hSERT's allosteric site by escitalopram could also block its dissociation from the orthosteric site. Finally, by comparing the simulated structures of two hSERT-escitalopram complexes with and without allosteric modulation, a new conformational coupling between an extracellular (Arg104-Glu494) and an intracellular (Lys490-Glu494) salt bridge was identified. In summary, this study explored the mechanism underlying the allosteric modulation of hSERT by collectively applying two MD simulation strategies, which could facilitate our understanding of the allosteric modulations of not only hSERT but also other clinically important therapeutic targets.
Subject(s)
Escitalopram , Serotonin Plasma Membrane Transport Proteins , Allosteric Regulation , Allosteric Site , Antidepressive Agents/chemistry , Antidepressive Agents/pharmacology , Citalopram/pharmacology , Escitalopram/chemistry , Escitalopram/pharmacology , Humans , Molecular Dynamics Simulation , Serotonin Plasma Membrane Transport Proteins/metabolism , Selective Serotonin Reuptake Inhibitors/chemistry , Selective Serotonin Reuptake Inhibitors/pharmacologyABSTRACT
The metabotropic glutamate 2/3 (mGlu2/3) receptor antagonists are reported to produce ketamine-like rapid-acting and sustained antidepressant-like effects in rodents. In this study, we compared the effects of single administration of the new mGlu2/3 receptor antagonist TP0178894 and the selective serotonin reuptake inhibitor (SSRI) escitalopram in the chronic social defeat stress (CSDS) model of depression, a model which has been shown to be resistant to treatment with a single dose of SSRI. In the tail suspension test and forced swimming test, high dose (3.0 mg/kg) of TP0178894 significantly attenuated the increased immobility time of these tests in CSDS susceptible mice, compared with vehicle-treated mice. In contrast, low doses (0.3 and 1.0 mg/kg) of TP0178894 and escitalopram (10 mg/kg) did not alter the increased immobility time of these two tests. In the sucrose preference test, TP0178894 (3.0 mg/kg) significantly improved the reduced sucrose preference of CSDS susceptible mice, three and seven days after a single dose. In addition, Western blot analyses showed that TP0178894 (3.0 mg/kg), but not low doses of TP0178894 and escitalopram, significantly attenuated the reduced expression of synaptic proteins [α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (GluA1) and postsynaptic density protein 95 (PSD-95)] in the prefrontal cortex from CSDS susceptible mice. This study suggests that TP0178894 shows rapid-acting and sustained antidepressant-like effects in CSDS model, as ketamine does.
Subject(s)
Antidepressive Agents/pharmacology , Depression/drug therapy , Escitalopram/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Receptors, Metabotropic Glutamate/metabolism , Animals , Behavior, Animal/drug effects , Depression/metabolism , Disks Large Homolog 4 Protein/metabolism , Hindlimb Suspension/methods , Ketamine/pharmacology , Male , Mice , Mice, Inbred C57BL , Prefrontal Cortex/metabolism , Receptors, AMPA/metabolism , Selective Serotonin Reuptake Inhibitors/pharmacology , Social Defeat , Stress, Psychological/metabolismABSTRACT
Learning-induced neuroplastic changes, further modulated by content and setting, are mirrored in brain functional connectivity (FC). In animal models, selective serotonin reuptake inhibitors (SSRIs) have been shown to facilitate neuroplasticity. This is especially prominent during emotional relearning, such as fear extinction, which may translate to clinical improvements in patients. To investigate a comparable modulation of neuroplasticity in humans, 99 healthy subjects underwent three weeks of emotional (matching faces) or non-emotional learning (matching Chinese characters to unrelated German nouns). Shuffled pairings of the original content were subsequently relearned for the same time. During relearning, subjects received either a daily dose of the SSRI escitalopram or placebo. Resting-state functional magnetic resonance imaging was performed before and after the (re-)learning phases. FC changes in a network comprising Broca's area, the medial prefrontal cortex, the right inferior temporal and left lingual gyrus were modulated by escitalopram intake. More specifically, it increased the bidirectional connectivity between medial prefrontal cortex and lingual gyrus for non-emotional and the connectivity from medial prefrontal cortex to Broca's area for emotional relearning. The context dependence of these effects together with behavioral correlations supports the assumption that SSRIs in clinical practice improve neuroplasticity rather than psychiatric symptoms per se. Beyond expanding the complexities of learning, these findings emphasize the influence of external factors on human neuroplasticity.
Subject(s)
Escitalopram/pharmacology , Learning/drug effects , Magnetic Resonance Imaging/methods , Neuronal Plasticity/drug effects , Selective Serotonin Reuptake Inhibitors/pharmacology , Adult , Austria , Double-Blind Method , Emotions/drug effects , Female , Healthy Volunteers , Humans , Image Processing, Computer-Assisted , Longitudinal Studies , Male , Mental Recall/drug effects , Models, StatisticalABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Sceletium tortuosum (L.) N.E.Br. (ST) has been used by the Khoisan people of South Africa as a mood elevator. Its various pharmacological mechanisms of action suggest distinct potential as an antidepressant. Clinical studies in healthy individuals suggest beneficial effects on mood, cognition, and anxiety. AIM OF THE STUDY: To obtain a chromatographic fingerprint of a standardized extract of S. tortuosum (Zembrin®), and to evaluate the acute antidepressant-like properties of Zembrin® versus the reference antidepressant, escitalopram, in the Flinders Sensitive Line (FSL) rat, a genetic rodent model of depression. MATERIALS AND METHODS: The chemical profile of Zembrin® was determined by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) chromatogram method using alkaloid standards. Twelve saline treated FSL and six Flinders Resistant Line (FRL) control rats were used to confirm face validity of the FSL model using the forced swim test (FST). Thereafter, FSL rats (n = 10) received either 5, 10, 25, 50 or 100 mg/kg of Zembrin®, or 5, 10 or 20 mg/kg escitalopram oxalate (ESC), both via oral gavage, and subjected to the open field test (OFT) and FST. RESULTS: Four main ST alkaloids were identified and quantified in Zembrin® viz. mesembrenone, mesembrenol, mesembrine, and mesembranol (47.9%, 32%, 13.2%, and 6.8% of the total alkaloids, respectively). FSL rats showed significantly decreased swimming and climbing (coping) behaviours, and significantly increased immobility (despair), versus FRL controls. ESC 5 mg/kg and Zembrin® 25 mg/kg and 50 mg/kg showed significant dose-dependent reversal of immobility in FSL rats and variable effects on coping behaviours. Zembrin® 50 mg/kg was the most effective antidepressant dose, showing equivalence to ESC 5. CONCLUSIONS: Zembrin® (25 and 50 mg/kg) and ESC (5 mg/kg) are effective antidepressants after acute treatment in the FST, as assessed in FSL rats. Moreover, Zembrin® 50 mg/kg proved equivalent to ESC 5. Further long-term bio-behavioural studies on the antidepressant properties of Zembrin® are warranted.
Subject(s)
Antidepressive Agents/pharmacology , Depression/drug therapy , Mesembryanthemum/chemistry , Plant Extracts/pharmacology , Animals , Antidepressive Agents/administration & dosage , Antidepressive Agents/isolation & purification , Behavior, Animal/drug effects , Chromatography, High Pressure Liquid , Disease Models, Animal , Dose-Response Relationship, Drug , Escitalopram/pharmacology , Male , Mass Spectrometry , Plant Extracts/administration & dosage , Rats , South AfricaABSTRACT
Inducible nitric oxide synthase (iNOS) is an enzyme upregulated in the brain during neuroimmune stimuli which is associated with an oxidative and pro-inflammatory environment in several brain regions, including the hippocampal formation and the prefrontal cortex. The dentate gyrus of the hippocampal formation is the site of a process known as adult hippocampal neurogenesis (AHN). Although many endogenous and extrinsic factors can modulate AHN, the exact participation of specific proinflammatory mediators such as iNOS in these processes remains to be fully elucidated. Here, we investigated how the total genetic ablation of iNOS impacts the hippocampal neurogenic niche and microglial phenotype and if these changes are correlated to the behavioral alterations observed in iNOS knockout (K.O.) mice submitted or not to the chronic unpredictable stress model (CUS - 21 days protocol). Contrary to our initial hypothesis, at control conditions, iNOS K.O. mice displayed no abnormalities on microglial activation in the dentate gyrus. However, they did exhibit impaired newborn cells and immature neuron survival, which was not affected by CUS. The reduction of AHN in iNOS K.O. mice was accompanied by an increased positive coping response in the tail suspension test and facilitation of anxiety-like behaviors in the novelty suppressed feeding. Next, we investigated whether a pro-neurogenic stimulus would rescue the neurogenic capacity of iNOS K.O. mice by administering in control and CUS groups the antidepressant escitalopram (ESC). The chronic treatment with ESC could not rescue the neurogenic capacity or the behavioral changes observed in iNOS K.O. mice. Besides, in the ventromedial prefrontal (vmPFC) cortex there was no change in the expression or the chronic activation of PV neurons (evaluated by double labeling PV with FOSB) in the prelimbic (PrL) or infralimbic subregions. FOSB expression, however, increased in the PrL of iNOS K.O. mice. Our results suggest that iNOS seems essential for the survival of newborn cells and immature neurons in the hippocampus and seem to partially explain the anxiogenic-like behavior observed in iNOS K.O. mice. On the other hand, the iNOS ablation appears to result in increased activity of the PrL which could explain the antidepressant-like behaviors of iNOS K.O mice.
Subject(s)
Dentate Gyrus/cytology , Neurons/physiology , Nitric Oxide Synthase Type II/physiology , Animals , Cell Survival , Cytokines/physiology , Escitalopram/pharmacology , Male , Mice , Mice, Knockout , Microglia/physiology , Neurogenesis/drug effects , Nitric Oxide Synthase Type II/genetics , Stress, Psychological/psychologyABSTRACT
The purpose of this study was to evaluate the anxiolytic and antidepressant activity of ethanolic fruit extract of Pyrus communis (pear), in comparison with escitalopram in rodents (rats and mice). Thirty Wistar rats of about 200-250gm and albino mice of 25-30gm, male gender were divided into three groups each comprising of (n=10) animal respectively. Control group received distilled water, positive control received 10mg escitalopram & treated group received 200mg/kg/day of Pyrus communis ethanolic fruit extract orally for 30 days. They were evaluated by using the open field test, forced swim test (FST), plus maze test, light and dark test, hole poking test, stationary rod test, water maze test & cage crossing activity. Results were expressed as mean ± SD. Data was analyzed by using SPSS software (VERSION 21) one way ANOVA followed by Tukey test was used for post hoc analysis. Our result showed that fruit extract had significant antidepressant-like behavior in FST (p<0.001), open field (p<0.05), cage crossing (p<0.001) , significant anxiolytic activity in light and dark box test, plus-maze activity and significantly enhanced learning in water maze and stationary rod test when compared with control. The Pyrus communis fruit extract showed the anxiolytic and antidepressant-like profile in rats and mice. However, further studies need to be carried out in clinical trials for its use in different neuropsychological disorders.
Subject(s)
Anti-Anxiety Agents/pharmacology , Antidepressive Agents/pharmacology , Behavior, Animal/drug effects , Fruit , Memory/drug effects , Plant Extracts/pharmacology , Pyrus , Animals , Elevated Plus Maze Test , Escitalopram/pharmacology , Learning/drug effects , Mice , Morris Water Maze Test , Open Field Test , RatsABSTRACT
Many voltammetry methods have been developed to monitor brain extracellular dopamine levels. Fewer approaches have been successful in detecting serotonin in vivo. No voltammetric techniques are currently available to monitor both neurotransmitters simultaneously across timescales, even though they play integrated roles in modulating behavior. We provide proof-of-concept for rapid pulse voltammetry coupled with partial least squares regression (RPV-PLSR), an approach adapted from multi-electrode systems (i.e., electronic tongues) used to identify multiple components in complex environments. We exploited small differences in analyte redox profiles to select pulse steps for RPV waveforms. Using an intentionally designed pulse strategy combined with custom instrumentation and analysis software, we monitored basal and stimulated levels of dopamine and serotonin. In addition to faradaic currents, capacitive currents were important factors in analyte identification arguing against background subtraction. Compared to fast-scan cyclic voltammetry-principal components regression (FSCV-PCR), RPV-PLSR better differentiated and quantified basal and stimulated dopamine and serotonin associated with striatal recording electrode position, optical stimulation frequency, and serotonin reuptake inhibition. The RPV-PLSR approach can be generalized to other electrochemically active neurotransmitters and provides a feedback pipeline for future optimization of multi-analyte, fit-for-purpose waveforms and machine learning approaches to data analysis.
Subject(s)
Brain/metabolism , Dopamine/analysis , Electrochemical Techniques/methods , Serotonin/analysis , Animals , Brain/drug effects , Calibration , Carbon Fiber , Dopamine/pharmacokinetics , Electrochemical Techniques/instrumentation , Electrochemical Techniques/statistics & numerical data , Escitalopram/pharmacology , Female , Least-Squares Analysis , Machine Learning , Mice, Inbred C57BL , Microelectrodes , Neurotransmitter Agents/analysis , Serotonin/pharmacokinetics , Selective Serotonin Reuptake Inhibitors/pharmacology , Signal Processing, Computer-Assisted , SoftwareABSTRACT
AIMS: Cilostazol (CLS) has shown antidepressant effect in cardiovascular patients, post-stroke depression, and animal models through its neurotrophic and antiinflammatory activities. Consequently, we aimed to investigate its safety and efficacy in patients with MDD by conducting double-blind, randomized, placebo-controlled pilot study. METHODS: 80 participants with MDD (DSM-IV criteria) and Hamilton Depression Rating Scale (HDRS) score >20 were treated with CLS 50 mg or placebo twice daily plus escitalopram (ESC) 20 mg once daily for six weeks. Patients were evaluated by HDRS scores (weeks 0, 2, 4, and 6). Serum levels of CREB1, BDNF, 5-HT, TNF-α, NF- κB, and FAM19A5 were assessed pre- and post-treatment. RESULTS: Co-administration of CLS had markedly decreased HDRS score at all-time points compared to the placebo group (p < 0.001). Early improvement, response, and remission rates after 6 weeks were significantly higher in the CLS group (90%, 90%, 80%, respectively) than in the placebo group (25%, 65%, 50% respectively) (p < 0.001). Moreover, the CLS group was superior to the placebo group in modulation of the measured neurotrophic and inflammatory biomarkers. CONCLUSION: CLS is safe and effective short-term adjunctive therapy in patients with MDD with no other comorbid conditions. Trial registration ID:NCT04069819.