Forced Swimming Test In Mice Research Articles

5-HT1B receptor activation produces rapid antidepressant-like effects in rodents

Ketamine is noted for its rapid onset antidepressant response and effectiveness in patients with treatment resistant depression. While most research has focused on glutamatergic mechanisms, recent studies show that antidepressant-like effects in rodents are dependent upon the serotonergic (5-HT) system and suggest a potential contribution of the 5-HT1B receptor. In this study we utilized CP-94253 to examine whether 5-HT1B receptor agonism produces rapid and sustained antidepressant-like effects, focusing on rodent models and treatment approaches commonly used to demonstrate the differentiated response to ketamine. We first confirmed that CP-94253 is a potent 5-HT1B agonist in vitro and that CP-94253 occupies brain 5-HT1B receptors at the doses tested. CP-94253 reduced immobility in the mouse forced swim test (FST) and exhibited a prominent antidepressant signature in the mouse-behavior phenotyping platform SmartCube®. When examined 24 h after acute treatment, CP-94253 reduced FST immobility in both naïve rats and in rats receiving chronic interferon alpha treatment. Ex vivo hippocampal long-term potentiation was also enhanced in naïve rats receiving acute CP-94253 treatment, 24 h prior to the recordings. In mice exposed to chronic social defeat stress, antidepressant-like effects in the tail suspension and sucrose preference tests were seen 1 h and 24 h after acute treatment, respectively. Finally, whole brain c-fos imaging in mice showed that CP-94253 modulates neuronal activity in discrete brain regions including the lateral habenula circuit implicated in depression and the ketamine treatment response. Collectively these results support the further investigation of 5-HT1B agonism as a novel treatment approach for major depressive disorder.

Discovery of Multi-functional Lead Compounds Originating from Traditional Chinese Medicine for Developing Anti-depressive Agents via Virtual Screening

Background: The increasing prevalence of depression has become a global health issue. Currently approved anti-depressive including 5-hydroxytryptamine (5-HT), dopamine (DA), norepinephrine (NE), triple reuptake inhibitors (TRIs) and glutamate N-methyl-D-aspartate (NMDA) receptor antagonists have limited effects because of their insufficient efficacy and/or slow onset of action. Developing multifunctional antidepressants that can modulate 5-HT, DA, NE, and NMDA simultaneously can potentially overcome the current drug defects. Objective: This study aimed to explore leads for the development of multi-functional anti-depressive agents that simultaneous triple reuptake inhibitory and NMDA-GluN2B receptor antagonistic activities. Methods: Potential leads were screened virtually from the TCMSP database based on the 3DPharmacophore model of TRIs followed by the molecular docking into NMDA-GluN2B receptor, BBB score, and the in silico toxicity evaluation. The biological activities of discovered leads on 5-HT, NE, and DA reuptake and their effect on the NMDA-GluN2B receptor were evaluated via radio-labeled neurotransmitters and competition radio-ligand binding experiment with [3H] ifenprodil, respectively. Lastly, the antidepressant effect of these potential leads was determined in vivo through the forced swim test in mice. Results: Two compounds were attained as potential leads after the aforementioned experiments. Further in vitro biological evaluation identified Hit-2 as a promising lead that exerted favorable triple 5- HT/DA/NE reuptake inhibitory activity (66.98% inhibition rate at 10 μM against hNET, 73.01% inhibition rate at 1 μM against hDAT and 86.27% inhibition rate at 1 μM against hSERT), as well as potent NMDA-GluN2B receptor antagonistic activity (Ki=115.73 ± 3.54 nM). The antidepressant activity of Hit- 2 was confirmed through in vivo experiments Conclusion: Hit-2 not only simultaneously inhibited the reuptake of 5-HT, DA, and NE, and acted as an NMDA-GluN2B receptor antagonist in vitro but also showed in vivo antidepressant activity. These findings may serve as a structural basis for the further development of multi-functional anti-depressive agents.

Antidepressant effects of selective adenosine receptor antagonists targeting the A1 and A2A receptors administered jointly with NMDA receptor ligands: behavioral, biochemical and molecular investigations in mice

BackgroundThe objective of the study was to ascertain the antidepressant potential of the co-administration of NMDA receptor ligands and selective adenosine A1 and A2A receptor antagonists.MethodsThe forced swim test (FST) and spontaneous locomotor activity test were carried out in adult male naïve mice. Before the behavioral testing, animals received DPCPX (a selective adenosine A1 receptor antagonist, 1 mg/kg) or istradefylline (a selective adenosine A2A receptor antagonist, 0.5 mg/kg) in combination with L–701,324 (a potent NMDA receptor antagonist, 1 mg/kg), D–cycloserine (a partial agonist at the glycine recognition site of NMDA receptor, 2.5 mg/kg), CGP 37849 (a competitive NMDA receptor antagonist, 0.3 mg/kg) or MK–801 (a non-competitive NMDA receptor antagonist, 0.05 mg/kg). Additionally, serum BDNF level and the mRNA level of the Adora1, Comt, and Slc6a15 genes in the murine prefrontal cortex were determined.ResultsThe obtained results showed that DPCPX and istradefylline administered jointly with NMDA receptor ligands (except for DPCPX + D–cycloserine combination) produced an antidepressant effect in the FST in mice without enhancement in spontaneous motility of animals. An elevation in BDNF concentration was noted in the D–cycloserine-treated group. Adora1 expression increased with L–701,324, DPCPX + D–cycloserine, and DPCPX + CGP 37849, while D–cycloserine, CGP 37849, and MK–801 led to a decrease. Comt mRNA levels dropped with DPCPX + L–701,324, istradefylline + L–701,324/CGP 37849 but increased with D–cycloserine, MK–801, CGP 37849 and DPCPX + MK–801/ CGP 37849. Slc6a15 levels were reduced by D–cycloserine, DPCPX + L–701,324 but rose with DPCPX + CGP 37849/MK–801 and istradefylline + D–cycloserine/MK–801/CGP 37849.ConclusionOur study suggests that selective antagonists of adenosine receptors may enhance the antidepressant efficacy of NMDA receptor ligands highlighting a potential synergistic interaction between the adenosinergic and glutamatergic systems. Wherein, A2A receptor antagonists are seen as more promising candidates in this context. Given the intricate nature of changes in BDNF levels and the expression of Adora1, Comt, and Slc6a15 seen after drug combinations exerting antidepressant properties, further research and integrative approaches are crucial understand better the mechanisms underlying their antidepressant action.

Antidepressant-like effects of Cimicifuga dahurica (Turcz.) Maxim. via modulation of monoamine regulatory pathways

Sheng-ma is recorded in the Compendium of Materia Medica and mainly originates from the rhizomes of Cimicifuga dahurica (Turcz.) Maxim. (CD), Cimicifuga heracleifolia Kom. and Cimicifuga foetida L. The alcoholic extract of Cimicifuga foetida L. (Brand name: Ximingting®) has been approved for the treatment of perimenopausal symptoms accompanying hot flash, depression and anxiety in China. However, there's no further study about the antidepressant-like effects of C. dahurica (CD). The aim of this study is to investigate the antidepressant-like effect of CD extracted by 75% ethanol and its possible mechanisms.The neuro-protective effects of CD on injured PC12 cells induced by corticosterone was measured firstly. Then, forced swim test (FST), tail suspension test (TST), reserpine-induced hypothermia, 5-hydroxytryptophan (5-HTP) induced head twitch response in mice and chronic unpredictable mild stress (CUMS) on sucrose preference tests were executed. Moreover, the potential mechanisms were explored by measuring levels of monoamine neurotransmitter in mice frontal cortex and hippocampus, testing monoamine oxidase enzyme A (MAO-A) activities in the brains of CUMS-exposed mice. Results showed that CD (60, 120 mg/kg) can significantly decreased the immobility period in FST and TST in mice without affecting locomotor activity. CD (30 mg/kg, 60 mg/kg, 120 mg/kg) could significantly counteracted reserpine-induced hypothermia and increased the number of head-twitches in 5-HTP induced head twitch response. It was also found that the monoamine neurotransmitter levels in the hippocampus and frontal cortex were significantly increased in 60 mg/kg and 120 mg/kg CD treated mice. In addition, CD (60 and 120 mg/kg) significantly inhibited MAO-A after 6-week CUMS exposure. CD can effectively produce an antidepressant-like effect, which involved with modulation of monoamine regulatory pathways.

Comparative Study of The Chemical Composition and Pharmacological Activity of Three Chemotypes of Peppermint

The aim of the work was to study the composition of the alcohol extract, antioxidant activity and pharmacological properties of peppermint leaves of three forms - menthol, linalool and carvone. Materials and methods: Chromatography-mass-spectrometric analysis was performed on an Agilent Technologies device. For the model evaluation of antioxidant activity, the aerometric method for measuring the total antioxidant activity was used, implemented in the TsvetYauza-01-AA device. Tonic activity was studied in terms of the duration of swimming of laboratory animal (male mice) with a load of 7% of the animal's body weight until complete fatigue - "The mouse forced swim test". The discussion of the results. When studying the chemical composition of medicinal plant raw materials of peppermint leaves of menthol, linalool, carvone types, more than 50 compounds were identified. A comparative analysis showed that the content of menthol in peppermint leaves of the menthol type can exceed the content of menthol in other chemotypes by ten or more times. At the same time, the tonic effect of an aqueous extract from peppermint leaves is mostly associated with the menthol. It should be taken into account when using this type of raw material in the manufacturing. Findings. The raw material of peppermint leaves may have a different degree of pharmacological activity depending on the chemotype, which should be taken into consideration when using this type of raw material.

Neuroprotective effect of Dark Chocolate on ketamine-induced animal model of psychosis through the reversal of behavioral, biochemical and histopathological changes

The present study was designed to evaluate the antipsychotic-like activity of dark chocolate against Ketamine-induced psychosis in animals and to explore the possible underlying mechanisms for this activity. Dark chocolate (200, 400 mg/kg, along with diet), haloperidol (1mg/kg, i.p.), and olanzapine (5mg/kg, i.p) were administered daily to different groups of mice and rats; after 30 min Ketamine was injected for 21 successive days. The antipsychotic- like activity was assessed using an actophotometer, stereotypic behaviors, forced swim test (FST), and passive avoidance test. Dark Chocolate (DC) and olanzapine remarkably decreased the immobility period of Ketamine-treated mice in FST, indicating the beneficial effect of DC against depressive or negative symptoms of psychosis. There was no significant effect on the locomotor activity of the mice with the administration of DC, while it showed a reducing impact against stereotypic behaviors. Furthermore, DC significantly reduced the time taken by the rats to climb the pole, showing the effect of DC on cognition. In addition, acetylcholinesterase (AChE) activity, malondialdehyde (MDA), and tissue necrosis factor (TNF-α) levels were markedly decreased and increased GABA and enhanced reduced glutathione (GSH) levels with the treatment of DC. Furthermore, DC was also effective in reducing the ketamine induced hyperchromatic nuclei, perinuclear vacuolization, and dilated vascular channels in the cortex part of the brain. Behavioral, biochemical, and histopathological studies suggest the protective effect of DC against Ketamine induced psychosis.

The effect of vine tea (Ampelopsis grossedentata) extract on fatigue alleviation via improving muscle mass

Ethnopharmacological relevanceVine Tea (VT, Ampelopsis grossedentata), boasts a venerable tradition in China, with a recorded consumption history exceeding 1200 years. Predominantly utilized by ethnic groups in southwest China, this herbal tea is celebrated for its multifaceted therapeutic attributes. Traditionally, VT has been employed to alleviate heat and remove toxins, exhibit anti-inflammatory properties, soothe sore throats, lower blood pressure, and fortify bones and muscles. In the realm of functional foods derived from plant resources, VT has garnered attention for its potential in crafting anti-fatigue beverages or foods, attributed to its promising efficacy and minimal side effects. Currently, in accordance with the Food Safety Standards set forth by the Monitoring and Evaluation Department of the National Health and Family Planning Commission in China, VT serves as a raw material in various beverages. Aim of the studyVT has an anti-fatigue or similar effect in folk. However, the underlying molecular mechanisms contributing to VT's anti-fatigue effects remain elusive. This study endeavors to investigate the influence of Vine Tea Aqueous Extract (VTE) on fatigue mitigation and to elucidate its operative mechanisms, with the objective of developing VTE as a functional beverage. Materials and methodsThe preparation of VTE involved heat extraction and freeze-drying processes, followed by the identification of its metabolites using UPLC-QTOF-MS to ascertain the chemical composition of VTE. A fatigue model was established using a forced swimming test in mice. Potential molecular targets were identified through network pharmacology, transcriptome analysis, and molecular docking. Furthermore, RT-PCR and Western blot techniques were employed to assess mRNA and protein expressions related to the AMPK and FoxO pathways. ResultsVTE significantly prolonged the duration of swimming time in an exhaustive swimming test in a dose-dependent manner, while simultaneously reducing the concentrations of blood lactic acid (LA), lactate dehydrogenase (LDH), serum urea nitrogen (SUN), and creatine kinase (CK). Notably, the performance of the high-dose VTE group surpassed that of the well-recognized ginsenoside. VTE demonstrated a regulatory effect akin to ginsenoside on the AMPK energy metabolism pathway and induced downregulation in the expression of Gadd45α, Cdkn1a, FOXO1, and Fbxo32 genes, suggesting an enhancement in skeletal muscle mass. These findings indicate that VTE can improve energy metabolism and muscle mass concurrently. ConclusionsVTE exhibits significant anti-fatigue effects, and its mechanism is intricately linked to the modulation of the AMPK and FoxO pathways. Crucially, no caffeine or other addictive substances with known side effects were detected in VTE. Consequently, vine tea shows substantial promise as a natural resource for the development of anti-fatigue beverages within the food industry.

Inhaled Litsea glaucescens K. (Lauraceae) leaves’ essential oil has anxiolytic and antidepressant-like activity in mice by BDNF pathway activation.

Ethnopharmacological relevanceLitsea glaucescens K. (Lauraceae) is a small tree from the Mexican and Central American temperate forests, named as “Laurel”. Its aromatic leaves are ordinarily consumed as condiments, but also are important in Mexican Traditional Medicine, and among the most important non wood forest products in this area. The leaves are currently used in a decoction for the relief of sadness by the Mazahua ethnic group. Interestingly, “Laurel” has a long history. It was named as “Ehecapahtli” (wind medicine) in pre-Columbian times and applied to heal maladies correlated to the Central Nervous System, among them depression, according to botanical texts written in the American Continent almost five centuries ago. Aim of the studyDepression is the first cause of incapacity in the world, and society demands alternative treatments, including aromatherapy. We have previously demonstrated the antidepressant-like activity of L. glaucescens leaves’ essential oil (LEO), as well as their monoterpenes linalool, and beta-pinene by intraperitoneal route in a mice behavioral model. Here we now examined if LEO and linalool exhibit this property and anxiolytic activity when administered to mice by inhalation. We also investigated if these effects occur by BDNF pathway activation in the brain. Materials and methodsThe LEO was prepared by distillation with water steam and analyzed by gas chromatography-mass spectrometry (GC-MS). The monoterpenes linalool, eucalyptol and β-pinene were identified and quantified. Antidepressant type properties were determined with the Forced Swim Test (FST) on mice previously exposed to LEO or linalool in an inhalation chamber. The spontaneous locomotor activity and the sedative effect were assessed with the Open Field Test (OFT), and the Exploratory Cylinder (EC), respectively. The anxiolytic properties were investigated with the Elevated Plus Maze Apparatus (EPM) and the Hole Board Test (HBT). All experiments were video documented. The mice were subjected to euthanasia, and the brain hippocampus and prefrontal cortex were dissected. ResultsThe L. glaucescens essential oil (LEO) contains 31 compounds according to GC/MS, including eucalyptol, linalool and beta-pinene. The LEO has anxiolytic effect by inhalation in mice, as well as linalool, and β-pinene, as indicated by OFT and EC tests. The LEO and imipramine have antidepressant like activity in mice as revealed by the FST; however, linalool and ketamine treatments didn't modify the time of immobility. The BDNF was increased in FST in mice treated with LEO in both areas of the brain as revealed by Western blot; but did not decrease the level of corticosterone in plasma. The OFT indicated that LEO and imipramine didn't reduce the spontaneous motor activity, while linalool and ketamine caused a significant decrease. ConclusionHere we report by the first time that L. glaucescens leaves essential oil has anxiolytic effect by inhalation in mice, as well as linalool, and β-pinene. This oil also maintains its antidepressant-like activity by this administration way, similarly to the previously determined intraperitoneally. Since inhalation is a common administration route for humans, our results suggest L. glaucescens essential oil deserve future investigation due to its potential application in aromatherapy.

Antidepressant activity of the pyrrolo[1,2a][1,4]diazepine GMAL-24 in a forced swimming test in mice

The antidepressant activity of pyrrolo[1,2a][1,4]diazepines (GMAL-24, GMAL-27, GMAL-31, GMAL-32 and GMAL-33) synthesized at the V.V. Zakusov Research Institute of Pharmacology in a forced swimming test on male outbred mice was studied. The compounds were tested in the dose range from 1.5 mg/kg to 20 mg/kg, the reference group received tricyclic antidepressant amitriptyline at a dose of 10 mg/kg, and the control group received 0.5 ml of saline solution. All injections were performed intraperitoneally. After GMAL-27 administration immobilization time was decreased of 1.78, 1.64 and 1.74 times, respectively, compared with the control in all three studied doses (1.5 mg/kg, 5 mg/kg and 10 mg/kg), without significant differences from the control (p = 0.1340; p = 0.2748; p = 0.2214, respectively). The compound GMAL-31 in doses from 1.5 mg/kg to 20 mg/kg had no effect on the duration of immobilization compared to the control group of mice. It was established that the compound GMAL-24 at doses of 5 mg/kg and 10 mg/kg significantly reduced the periods of immobilization compared to the control group and did not differ in this parameter from the comparison drug, which indicates an antidepressant effect comparable to the effect of amitriptyline.

Design and synthesis of a novel dipeptide mimetic of the 4th loop of neurotrophin-3 and its pharmacological effects

A novel neurotrophin-3 loop 4 dipeptide mimetic, bis(N-γ-hydroxybutyryl-L-glutamyl-L-asparagine) hexamethylenedi-amide (GTS-302), was designed and synthesized. Compound GTS-302 activated the tyrosine kinase receptors TrkC and TrkB, exhibited cytoprotective activity (10-8–10-5 M) in oxidative stress model in HT-22 cells and in 6-hydroxy-dopamine-induced SH-SY5Y cell damage. It also demon- strated an antidepressant-like activity in the forced swim test in mice (0.5–10.0 mg kg–1, intraperitoneally).

Protective effects of curcumin on desipramine-induced islet β-cell damage via AKAP150/PKA/PP2B complex.

Tricyclic antidepressants (TCAs) are widely used to treat depression and anxiety-related mood disorders. But evidence shows that TCAs elevate blood glucose levels and inhibit insulin secretion, suggesting that TCAs are a risk factor, particularly for individuals with diabetes. Curcumin is a bioactive molecule from the rhizome of the Curcuma longa plant, which has shown both antidepressant and anti-diabetic activities. In the present study, we investigated the protective effect of curcumin against desipramine-induced apoptosis in β cells and the underlying molecular mechanisms. In the mouse forced swimming test (FST), we found that lower doses of desipramine (5 and 10 mg/kg) or curcumin (2.5 mg/kg) alone did not affect the immobility time, whereas combined treatment with curcumin (2.5 mg/kg) and desipramine (5, 10 mg/kg) significantly decreased the immobility time. Furthermore, desipramine dose-dependently inhibited insulin secretion and elevated blood glucose levels, whereas the combined treatment normalized insulin secretion and blood glucose levels. In RIN-m5F pancreatic β-cells, desipramine (10 μM) significantly reduced the cell viability, whereas desipramine combined with curcumin dose-dependently prevented the desipramine-induced impairment in glucose-induced insulin release, most effectively with curcumin (1 and 10 μM). We demonstrated that desipramine treatment promoted the cleavage and activation of Caspase 3 in RIN-m5F cells. Curcumin treatment inhibited desipramine-induced apoptosis, increased mitochondrial membrane potential and Bcl-2/Bax ratio. Desipramine increased the generation of reactive oxygen species, which was reversed by curcumin treatment. Curcumin also inhibited the translocation of forkhead box protein O1 (FOXO1) from the cytoplasm to the nucleus and suppressed the binding of A-kinase anchor protein 150 (AKAP150) to protein phosphatase 2B (PP2B, known as calcineurin) that was induced by desipramine. These results suggest that curcumin protects RIN-m5F pancreatic β-cells against desipramine-induced apoptosis by inhibiting the phosphoinositide 3-kinase/AKT/FOXO1 pathway and the AKAP150/PKA/PP2B interaction. This study suggests that curcumin may have therapeutic potential as an adjunct to antidepressant treatment.

Engeletin alleviates depression-like phenotype by increasing synaptic plasticity via the BDNF-TrkB-mTORC1 signalling pathway.

Major depressive disorder (MDD) is a severe mental disorder associated with high rates of morbidity and mortality. Current first-line pharmacotherapies for MDD are based on enhancement of monoaminergic neurotransmission, but these antidepressants are still insufficient and produce significant side-effects. Consequently, the development of novel antidepressants and therapeutic targets is desired. Engeletin, a natural Smilax glabra rhizomilax derivative, is a compound with proven efficacy in treating ischemic stroke, yet its therapeutic effects and mechanisms for depression remain unexplored. The effects of engeletin were assessed in the forced swimming test (FST) and tail suspension test (TST) in mice. Engeletin was also investigated in the chronic restraint stress (CRS) mouse model of depression with fluoxetine (FLX) as the positive control. Changes in prefrontal cortex (PFC) spine density, synaptic plasticity-linked protein expressions and the brain-derived neurotrophic factor (BDNF)-tyrosine kinase B (TrkB)- mammalian target of rapamycin complex 1 (mTORC1) signalling pathway after chronic stress and engeletin treatment were then investigated. The TrkB and mTORC1 selective inhibitors, ANA-12 and rapamycin, respectively, were utilized to assess the engeletin's antidepressive mechanisms. Our data shows that engeletin exhibited antidepressant-like activity in the FST and TST in mice without affecting locomotor activity. Furthermore, it exhibited efficiency against the depression of CRS model. Moreover, it enhanced the BDNF-TrkB-mTORC1 pathway in the PFC during CRS and altered the reduction in dendritic spine density and levels of synaptic plasticity-linked protein induced by CRS. In conclusion, engeletin has antidepressant activity via activation of the BDNF-TrkB-mTORC1 signalling pathway and upregulation of PFC synaptic plasticity.

The study of the spectrum of pharmacological activity of the new original NT-3 mimetic dipeptide GTS-302

BACKGROUND: The association of the pathogenesis of neurodegenerative diseases, depression, anxiety, and cognitive disorders with the deficit of neurotrophin-3 determines the prospect of creating drugs with a similar mechanism of action. Since the use of full-size neurotrophin-3 is limited by unsatisfactory pharmacokinetic properties, it is relevant to create low-molecular-weight mimetics of neurotrophin-3 that are active when administered systemically. A dimeric dipeptide mimetic of the 4th loop of neurotrophin-3, hexamethylenediamide bis(N--oxibutyryl-L-glutamyl-L-asparagine) GTS-302, which activates TrkC and TrkB receptors, has been developed at the V.V. Zakusov Research Institute of Pharmacology.
 AIM: The aim of this study was to investigate the spectrum of pharmacological activity of GTS-302.
 MATERIALS AND МETHODS: The pharmacological effects of GTS-302 were investigated following its intraperitoneal administration. The antidepressant-like activity of GTS-302 was studied in the forced swim test in mice after acute and 7-day administration. The anxiolytic and cognitive activity of the dipeptide were studied in the elevated plus maze test in mice and the novel object recognition test in rats after acute administration, respectively. The effect of GTS-302 on pain sensitivity was studied in the hot plate test in mice after acute administration.
 RESULTS: It was found that GTS-302 exhibits antidepressant-like activity after acute administration at doses of 0.5, 1.0, 5.0 and 10 mg/kg. After 7-day administration, the antidepressant-like activity of GTS-302 was more pronounced in terms of effect size and statistical significance. The dipeptide GTS-302 at doses of 1.0, 5.0 and 10.0 mg/kg showed anxiolytic and cognitive activity and did not affect pain sensitivity.
 CONCLUSIONS: The pharmacological spectrum of the low-molecular-weight mimetic of neurotrophin-3, dipeptide GTS-302, revealed upon systemic administration includes a number of neuropsychotropic effects characteristic of the full-sized neurotrophin. This allows us to consider GTS-302 as a potential neuropsychotropic drug.

(099) Dual Effect of a Serotonin and Dopamine Reuptake Inhibitor (IP2018), and the Search for a Depressive Rat Model with Erectile Dysfunction

Abstract Introduction In patients with major depressive disorder, up to 68% present with comorbid sexual dysfunction, which resolves in only 5% to 30% of patients treated with antidepressants. Several groups of antidepressants negatively affect sexual function. Objective The present study investigated whether a newly developed amine transport inhibitor, IP2018, improves depression and erectile function in the same dose range. Methods The dose-dependent effect of IP2018 in two different mouse models for depression, the mouse forced swim test (mFST) and mouse tail suspension test (mTST), is reported. In male Wistar, Sprague Dawley and the depressive rats (Flinders Sensitive Line (FSL) and Flinders Resistant Line (FRL)), increases in intracavernosal pressure (ICP) and mean arterial pressure (MAP) were measured, and the ratio ICP/MAP was used as a measure of erectile function. We investigated whether IP2018 induces changes in ICP or flow and whether IP2018 facilitates suboptimal increases in ICP induced by cavernosal nerve electrical stimulation. The late IP2018 procedure was performed in the rest of the rats to evaluate their erectile function. Results We found that infusion of IP2018 dose-dependently improved mFST and was more potent than citalopram. At the same time, higher doses of IP2018 were required to obtain effect in the mTST model, and IP2018 was equipotent to citalopram. Infusion of low doses of IP2018 dose-dependently increased the number and the duration of spontaneous erections. At the highest dose of IP2018, the increases in the number and duration of spontaneous erections were similar to the effect of the lowest dose, and the increases in flow were 5 times higher. IP2018 (1-30 μM) caused small relaxations in isolated corpus cavernosum strips. FSL and FRL rats showed a diminished ICP/MAP compared to Sprague Dawley control rats. Conclusions IP2018 is more potent or has a similar effect to the well-known antidepressant drug citalopram in mouse models for depression. The potent effect of IP2018 on erectile function in anaesthetized rats suggests that IP2018 in the same dose range has positive effects on both depression and erectile function. FSL/FRL rats appear to allow the study of drug effects on both depression and sexual function in one animal model. Disclosure Yes, this is sponsored by industry/sponsor: Initiator Pharma A/S Clarification Industry funding only - investigator initiated and executed study Any of the authors act as a consultant, employee or shareholder of an industry for: Initiator Pharma A/S

The Effect of Dayak Onion Extract on Lactic Acid Levels in Mice with FST Model

Intense physical exercise can increase lactic acid levels in the blood as a result of the anaerobic metabolism that occurs at that time. The impact of increased levels of lactic acid includes the occurrence of acidosis, damage to body cells, and fatigue which reduces muscle performance. Antioxidants can play a role in preventing body fatigue caused by oxidative stress. Onion Dayak (Eleutherine palmifolia) is a type of medicinal plant that is useful for health. The high content of antioxidants in Dayak onions can be used as an alternative anti-fatigue ingredient. This study aimed to look at the effect of the dose and duration of Dayak onion extract on lactic acid levels and physical activity in mice forced swimming test models. Type of Research Randomized Pre and Post-Test Control Group Design. Male White Mice (Sprague Dawley) 2 months old (weight 150-200g). Divided into 5 groups K- (the experimental group was not given Dayak onion extract, they were still given FST), K+ (the experimental group was given xanthine and FST), P1 (given Dayak onion extract at a dose of 50mg/200gBW), P2 (given the extract onion Dayak dose of 100mg/200gBB), P3 (given onion extract dose of 200mg/200gBW). Dayak onion extract was given for 28 days and given the forced swimming test, then the changes in lactic acid and physical activity endurance in swimming were observed.

Antidepressant effect of 4-Butyl-alpha-agarofuran via HPA axis and serotonin system

Depression is a leading cause of disability worldwide and the psychiatric diagnosis most commonly associated with suicide. 4-Butyl-alpha-agarofuran (AF-5), a derivative of agarwood furan, is currently in phase III clinical trials for generalized anxiety disorder. Herein, we explored the antidepressant effect and its possible neurobiological mechanisms in animal models. In present study, AF-5 administration markedly decreased the immobility time in mouse forced swim test and tail suspension test. In the sub-chronic reserpine-induced depressive rats, AF-5 treatment markedly increased the rectal temperature and decreased the immobility time of model rats. In addition, chronic AF-5 treatment markedly reversed the depressive-like behaviors in chronic unpredictable mild stress (CUMS) rats by reducing immobility time of forced swim test. Single treatment with AF-5 also potentiated the mouse head-twitch response induced by 5-hydroxytryptophan (5-HTP, a metabolic precursor to serotonin), and antagonized the ptosis and motor ability triggered by reserpine. However, AF-5 had no effect on yohimbine toxicity in mice. These results indicated that acute treatment with AF-5 produced serotonergic, but not noradrenergic activation. Furthermore, AF-5 reduced adrenocorticotropic hormone (ACTH) level in serum and normalized the neurotransmitter changes, including the decreased serotonin (5-HT) in hippocampus of CUMS rats. Moreover, AF-5 affected the expressions of CRFR1 and 5-HT2C receptor in CUMS rats. These findings confirm the antidepressant effect of AF-5 in animal models, which may be primarily related to CRFR1 and 5-HT2C receptor. AF-5 appears to be promising as a novel dual target drug for depression treatment.

Antidepressant-like Properties of Melatonin and Atorvastatin Combination following the Restraint Stress in Mice: A Study of Oxidative Stress Factors.

Antidepressant properties of melatonin and atorvastatin have been reported by clinical and experimental studies. Since both melatonin and atorvastatin possess antioxidant properties and considering the involvement of oxidative stress factors in depression, the aim of the present investigation was to study the possible role of oxidative stress factors in the antidepressant- like effect of melatonin and atorvastatin combination in mice forced swimming test. Following the induction of restraint stress, mice were randomly divided into eight groups including the non-stressed and stressed vehicle-treated groups, melatonin- and atorvastatintreated groups, a combination of melatonin and atorvastatin-treated group, and fluoxetineadministrated group. The open field test (OFT) and forced swimming test (FST) were carried out, and the hippocampus and prefrontal cortex were removed for the measurement of oxidative stress factors. Induction of restraint stress increased the immobility time in FST, and melatonin (10 mg/kg) significantly reduced it. Atorvastatin at both doses of 1 and 10 mg/kg could not alter the immobility time, significantly. Co-administration of melatonin and atorvastatin (10 mg/kg) exerted a significant antidepressant-like response and decreased the immobility time compared with melatonin or atorvastatin (10 mg/kg), alone. Induction of restraint stress elevated the malondialdehyde (MDA) levels in mice's hippocampus, while pretreatment of animals with atorvastatin (10 mg/kg) could reverse it. The co-administration of melatonin and atorvastatin (10 mg/kg) increased the cortical superoxide dismutase (SOD) activity compared with atorvastatin alone, but could not alter the catalase (CAT) activity. It is concluded that atorvastatin might augment the antidepressant-like properties of melatonin in FST.

The role of GPR39 zinc receptor in the modulation of glutamatergic and GABAergic transmission

BackgroundDespite our poor understanding of the pathophysiology of depression, a growing body of evidence indicates the role of both glutamate and gamma-aminobutyric acid (GABA) signaling behind the effects of rapid-acting antidepressants (RAADs). GPR39 is a zinc-sensing receptor whose activation leads to a prolonged antidepressant-like response in mice. Both GPR39 and zinc can modulate glutamatergic and GABAergic neurotransmission, however, exact molecular mechanisms are still elusive. In this study, we aimed to research the role of glutamatergic and GABAergic system activation in TC-G 1008 antidepressant-like effects and the disruptions in this effect caused by a low-zinc diet.MethodsIn the first part of our study, we investigated the role of joint administration of the GPR39 agonist (TC-G 1008) and ligands of the glutamatergic or GABAergic systems, in antidepressant-like response. To evaluate animal behaviour we used the forced swim test in mice. In the second part of the study, we assessed the effectiveness of TC-G 1008-induced antidepressant-like response in conditions of decreased dietary zinc intake and its molecular underpinning by conducting a Western Blot analysis of selected proteins involved in glutamatergic and GABAergic neurotransmission.ResultsThe TC-G 1008-induced effect was blocked by the administration of NMDA or picrotoxin. The joint administration of TC-G 1008 along with muscimol or SCH50911 showed a trend toward decreased immobility time. Zinc-deficient diet resulted in dysregulation of GluN1, PSD95, and KCC2 protein expression.ConclusionsOur findings indicate the important role of glutamate/GABA signaling in the antidepressant-like effect of TC-G 1008 and imply that GPR39 regulates the balance between excitatory and inhibitory activity in the brain. Thus, we suggest the zinc-sensing receptor be considered an interesting new target for the development of novel antidepressants.

Screening of anti-fatigue active ingredients of Eleutherococcus senticosus via spectrum-effect relationship based on factor analysis and LC-MS/MS

ES contains compounds known to have significant anti-fatigue activity. In recent years, it has received extensive attention because it is efficient. However, its active ingredients on antifatigue effect are still unclear. This study attempts to establish the spectrum-effect relationship of ES antifatigue activity to screen the effective components. The results showed that the similarity of 15 ES fingerprints obtained by LC-MS/MS was 0.533–0.992, and the chemical structures of 22 common peaks were identified. The anti-fatigue activity of 15 batches of ES was characterized by forced swimming test of mice and quantified by CAFI, among which S4, S1 and S5 had better activity. 9 components (caffeic acid, 5-(4-O-β-D-glucosylferoyl)-quinic acid, (±)13-HODE, isofraxidin, eleutheroside E, syringin, pinoresinol diglucoside or its isomer, 7,8-dihydrodehydrocarbinol alcohol-4-O-β-D-glucoside, secoisolariciresinol-4-O-β-D-glucoside) highly related to anti-fatigue activity may be the effective components of ES.

Synergistic anti-depressive effect of combination treatment of Brexpiprazole and selective serotonin reuptake inhibitors on forced swimming test in mice.

Selective serotonin reuptake inhibitors (SSRIs) are used to treat major depressive disorder (MDD) and other psychiatric disorders (e.g., obsessive compulsive disorder, social anxiety disorder, and panic disorder). In MDD treatment, SSRIs do not show remission in approximately 30% of patients, indicating a need for a better treatment option. Forced swimming test (FST) is a behavioral assay to evaluate depression-like behavior and antidepressant efficacy in rodents. In the present study, we evaluated the combination effect of brexpiprazole with SSRIs on FST in mice, in order to investigate their synergistic effect. Brexpiprazole (0.003 mg/kg) was intraperitoneally injected to mice 15min before testing. Escitalopram (10mg/kg), fluoxetine (75 mg/kg), paroxetine (10mg/kg), or sertraline (15 mg/kg) were orally administered to mice 60min before testing. Then, the mice were placed in water and immobility time was measured. Data from animals treated with escitalopram, fluoxetine, paroxetine, and sertraline were pooled as SSRI-treated group data. Combination treatment of brexpiprazole with SSRIs reduced immobility time in FST more than vehicle or each single treatment. A significant interaction effect was confirmed in the combination of brexpiprazole and SSRIs (p=0.0411). Efficacy of adjunctive brexpiprazole has already been demonstrated in clinical trials in MDD patients not adequately responding to antidepressants including escitalopram, fluoxetine, paroxetine, and sertraline. The synergistic antidepressant-like effect of brexpiprazole with SSRIs found in this study supports the already known clinical findings.