Immobility Time In Tail Suspension Test Research Articles

Salidroside exerts antidepressant-like action by promoting adult hippocampal neurogenesis through SIRT1/PGC-1α signalling.

Depression is one of the major mental disorders, which seriously endangers human health, brings a serious burden to patients’ families. In this study, we intended to further explore the antidepressant-like effect and possible molecular mechanisms of Salidroside (SAL). We built corticosterone (CORT)-induced depressive mice model and used behavioural tests to evaluate depression behaviour. To explore the molecular mechanisms of SAL, we employed a variety of methods such as immunofluorescence, western blot, pharmacological interference, etc. The results demonstrated that SAL both at 25 mg/kg and 50 mg/kg can reduce immobility time in the tail suspension test (TST). At the same time, SAL treatment could restore the reduced sugar water intake preference in the sucrose preference test (SPT) in CORT-induced depressive mice and reduce the immobility time in TST and forced swimming experiments (FST). In addition, SAL treatment reversed the reduction in the number of Ki-67, BrdU, and NeuN in the hippocampus due to CORT treatment. SAL treatment also restored the expression of SIRT1, PGC-1α, brain-derived neurotrophic factor (BDNF) and other proteins in the hippocampus. In addition, after blocking SIRT1 signalling with EX527, we found that the treatment with SAL failed to reduce the immobility time in TST and FST, the level of SIRT1 and PGC-1α activity were correspondingly downregulated, and the expression of DCX and Ki-67 in the hippocampus failed to be activated. These findings suggested that SAL exerts antidepressant-like effects by promoting hippocampal neurogenesis through the SIRT1/PGC-1α signalling pathway.

Prenatal exposure to fenvalerate causes depressive-like behavior in adulthood by inhibiting brain-derived 5-HT synthesis

The developmental toxicity of fenvalerate, a representative pyrethroid insecticide, is well documented. The present study aimed to explore whether prenatal exposure to fenvalerate causes depression-like behavior in adulthood. Pregnant mice were orally administrated with either corn oil or fenvalerate (2 or 20 mg/kg) during pregnancy. Depressive-like behaviors were assessed by tail suspension test (TST), forced swim test (FST) and sucrose preference test (SPT). Immobility times in TST and FST were increased in offspring whose mothers were exposed to fenvalerate throughout pregnancy. By contrast, sugar preference index, as determined by SPT, was decreased in fenvalerate-exposed offspring. Prefrontal PSD95, a postsynaptic membrane marker, was downregulated in fenvalerate-exposed adulthood offspring. Fenvalerate-induced reduction of prefrontal PSD95 began at GD18 fetal period. Accordingly, prefrontal 5-HT, a neurotransmitter for synaptogenesis, was also reduced in fenvalerate-exposed GD18 fetuses. Tryptophan hydroxylase 2 (TPH2), a key enzyme for 5-HT synthesis, was downregulated in the midbrain of fenvalerate-exposed GD18 fetuses. Additional experiment showed that GRP78 and p-eIF2α, two endoplasmic reticulum stress-related proteins, were increased in the midbrain of fenvalerate-exposed fetal mice. The present results suggest that prenatal exposure to fenvalerate causes depressive-like behavior in adulthood, partially by inhibiting brain-derived 5-HT synthesis.

Phytochemical Properties and Antidepressant Potential of Satureja khuzestanica Jamzad Essential Oil in Mouse Models of Depression

Oxidative stress may play a pivotal role in the pathogenesis of depression. Furthermore, antioxidants are also believed to have antidepressant properties. Previous studies have reported the antioxidant effects of Satureja khuzestanica Jamzad. Therefore, this study examined the antidepressant potential of Satureja khuzestanica essential oil (SKEO) in male mice based on a forced swim test (FST) and tail suspension test (TST). The GC-MS was used to evaluate the phytochemistry of SKEO. In behavioral studies, 72 male mice were allocated to twelve groups of six and intraperitoneally received the vehicle (10 mL/kg), fluoxetine (20 mg/kg), imipramine (30 mg/kg), or SKEO (25, 50, and 100 mg/kg). Immobility time in TST and immobility, swimming, and climbing times in FST were measured. In the open-field test (OFT), the number of crossings and rearings was recorded. According to GC-MS results, carvacrol, γ-terpinene, cymene, and 2-pinene were the most abundant compounds in SKEO. In FST and TST, all doses of SKEO (except for 25 mg/kg in FST), fluoxetine, and imipramine reduced the immobility time compared to the control group. Moreover, 50 and 100 mg/kg doses of SKEO and fluoxetine increased the swimming time without significantly changing the climbing time. However, imipramine increased the climbing time without significantly changing the swimming time. None of SKEO doses caused a significant change in the number of crossings or rearings in OFT. According to our findings, the antidepressant-like effects of SKEO are similar to those of fluoxetine. While the compounds in SKEO seem to induce their effects through the serotonergic mechanism, further studies are warranted to clarify their exact mechanism of action.

Effect of Formononetin on Lipopolysaccharide-Induced Depressive-Like Behaviors and Neuroinflammation in Mice

Abstract Objective The objective of this article is to explore the effect of formononetin (FMN) on depressive-like behaviors and neuroinflammation in lipopolysaccharide (LPS)-induced mice.Methods After acclimatization, male Institute of Cancer Research mice were randomly divided into normal group, LPS group, paroxetine group (20 mg/kg), FMN low-dose group (20 mg/kg, FMN20), and FMN high-dose group (40 mg/kg, FMN40), with eight mice in each group. The depressive-like behaviors were observed by sucrose preference test, tail suspension test (TST), and open field test. The protein and mRNA levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in the hippocampus were determined by enzyme-linked immunosorbent assay and real-time quantitative polymerase chain reaction. The expression level of ionized calcium-binding adapter molecule 1 (Iba-1) in the hippocampus was observed by immunofluorescence staining to evaluate the activation level of microglia. Results Compared with the control group, the sucrose preference rate, the activity time of the central area, the distance of the central area, and the number of times of entering the central area were significantly decreased in the LPS group (p < 0.01), and the immobility time of TST was significantly prolonged (p < 0.05), the expression levels of IL-6, IL-1β, and TNF-α protein and mRNA in hippocampus were significantly increased (p < 0.01), and the fluorescence intensity of Iba-1 in CA1, CA3, and DG regions of hippocampus was significantly increased (p < 0.01). Compared with the LPS group, the sucrose preference rate, central area activity time, central area activity distance, and the number of times of entering the central area were significantly increased (p < 0.05 or p <0.01) in the FMN group, and TST immobility time was significantly shortened (p < 0.01), the expression levels of IL-6, IL-1β, and TNF-α protein and mRNA in the hippocampus were significantly decreased (p < 0.05 or p < 0.01), and the fluorescence intensity of Iba-1 in CA1, CA3, and DG regions of hippocampus was significantly decreased (p < 0.01). Conclusion FMN could inhibit LPS-induced activation of microglia, reduce hippocampal neuroinflammation, and improve depressive-like behaviors in mice.

FORMULATION AND EVALUATION OF DISPERSIBLE TABLETS OF FLAVONOID PGAL ISOLATED FROM SARACA ASOCA LEAVES

Objective: The study aimed to design and evaluate a dispersible tablet of flavonoid PGAL isolated from Saraca asoca leaves for antidepressant activity. Methods: The phytoconstituent was isolated from a methanolic extract of Saraca asoca leaves using silica gel column (60-120 mesh) chromatography. The dispersible tablets were prepared by direct compression and then evaluated for various tablet evaluation parameters and antidepressant activity, performing Tail Suspension Test (TST), Forced Swim Test (FST), Locomotion activity, Brain glutamate level and brain nitrite level. Results: Hardness of 2.85±0.13 kg/cm2 to 3.25±0.15 kg/cm2 and friability of 0.35% to 0.48% indicate that the prepared tablets were mechanically sound. Test for weight variation was also within tolerance limits, i.e. 2.04% to 4.25% difference in weight of the tablet from the average weight of 10 tablets. The tablets also passed the test for drug content uniformity, 97.35% to 100.35%, i.e. always within the prescribed limits of 95% to 105%. Disintegration time, 2 min to 2.75 min, and dispersion time, 3.25 min to 3.75 min, were also exemplary. The antidepressant activity was displayed by the optimized formulation as indicated by a significant decrease (p<0.05) in immobility time in TST as well as FST; a significant decrease (p<0.05) in the level of brain tissue glutamate as well as nitrite in PGAL formulation treated mice when compared with negative control, as did by standard drug fluoxetine. Conclusion: The formulation has been optimized based on dispersion time. The formulation with minimum dispersion time, i.e. F1, has been considered an optimized formulation. The prepared optimized formulation was found to comply with all physical parameters and antidepressant activity.

Silymarin Potentiates the Effect of Buspirone on Anxiety and Depressive-Like Behaviors Induced by Chronic Restraint Stress in Male Mice

Background: Stress and its complications such as anxiety and depression continue to be regarded as health issues in human societies. Therefore, an effective treatment strategy is highly valued for dealing with stress and related disorders. In spite of studies suggesting the neuroprotective effects of silymarin and buspirone alone, the combined effects of these treatments on chronic stress have not been elucidated yet. Thus, this study aimed to investigate the effect of silymarin and buspirone (alone or in combination) on anxiety and depressive-like behaviors and to evaluate corticosterone levels in a mice model of chronic restraint stress (RS). Methods: This study was conducted on seventy-two male BALB/c mice which were allocated in six equal groups. The animals were exposed to chronic RS (2 hours/day for 14 days) to induce a depressive-like model. An elevated plus maze (EPM) was performed to assess anxiety, while a tail suspension test (TST) was implemented to evaluate depressive-like behavior. Furthermore, the serum levels of corticosterone were measured by the enzyme-linked immunosorbent assay method. Results: Our data demonstrated that exposure to RS resulted in prolonged immobility in the TST and reduced time spent in the open arms of the EPM test. Buspirone perorally (5 mg/kg, PO) alone and combined with silymarin (200 mg/kg, PO) increased time spent in the open arms of the EPM apparatus while attenuating immobility time in TST. There was a significant decrease in the blood corticosterone level of buspirone and silymarin co-treated animals. Conclusion: These findings indicated that silymarin potentiates the beneficial effect of buspirone against chronic RS-induced anxiety and depressive-like behaviors in mice by lowering corticosterone serum levels. In this regard, further investigations should be undertaken to clarify the exact mechanism of the observed effects.

Effects of Artemisia annua L. on postmenopausal syndrome in ovariectomized mice

Ethnopharmacological relevanceArtemisia annua L. (Asteraceae) has been used as an antipyretic and anti-parasitic drug in traditional medicine for more than 2000 years. It has also been prescribed to treat symptoms caused by deficiency of Yin, which might be observed in menopausal state from the point of view of traditional medicine. Aim of the studyWe hypothesized that A. annua might be useful for treating menopausal disorders with less adverse effects than hormone replacement therapy. Thus, the aim of the present study was to investigate effects of A. annua on postmenopausal symptoms of ovariectomized (OVX) mice. Materials and methodsOVX mice were employed as a model for postmenopausal disorders. Mice were treated with a water extract of A. annua (EAA; 30, 100 or 300 mg/kg, p.o.) or 17β-estradiol (E2; 0.5 mg/kg, s.c.) for 8 weeks. Open field test (OFT), novel object recognition task (NOR), Y-maze test, elevated plus maze test (EPM), splash test and tail suspension test (TST) were conducted to determine whether EAA could ameliorate postmenopausal symptoms. Phosphorylated levels of extracellular signal-regulated kinase (ERK), protein kinase B (Akt), and glycogen synthase kinase-3β (GSK-3β), β-catenin and expression level of synaptophysin in the cortex and hippocampus were evaluated by Western blot analysis. ResultsEAA treatment significantly increased the discrimination index in NOR, decreased the time in closed arm than in open arm in EPM, increased grooming time in splash test, and decreased immobility time in TST, as did E2 treatment. In addition, decreased phosphorylation levels of ERK, Akt, GSK-3β, and β-catenin and expression levels of synaptophysin in the cortex and hippocampus after OVX were reversed by administration of EAA and E2. ConclusionThese results suggest that A. annua can ameliorate postmenopausal symptoms such as cognitive dysfunction, anxiety, anhedonia, and depression by activating ERK, Akt, and GSK-3β/β-catenin signaling pathway and hippocampal synaptic plasticity, and that A. annua would be a novel treatment for postmenopausal symptoms.

Essential role of microglia in the fast antidepressant action of ketamine and hypidone hydrochloride (YL-0919).

Introduction: Intracerebral microglia play a vital role in mediating central immune response, neuronal repair and synaptic pruning, but its precise role and mechanism in fast action of antidepressants have remained unknown. In this study, we identified that the microglia contributed to the rapid action of antidepressants ketamine and YL-0919. Methods: The depletion of microglia was achieved with the diet containing the colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 in mice. The tail suspension test (TST), forced swimming test (FST) and novelty suppressed feeding test (NSFT) were employed to evaluate the rapid acting antidepressant behavior of ketamine and YL-0919 in the microglia depletion model. The number of microglia in the prefrontal cortex (PFC) was assayed by the immunofluorescence staining. The expressions of synaptic proteins (synapsin-1, PSD-95, GluA1) and brain-derived neurotrophic factor (BDNF) in the PFC were tested by Western blot. Results: The immobility duration in FST and the latency to feed in NSFT were shortened 24h after an intraperitoneal (i.p.) injection of ketamine (10mg/kg). The microglial depletion of PLX3397 blocked the rapid antidepressant-like effect of ketamine in mice. In addition, the immobility time in TST and FST as well as latency to feed in NSFT were reduced 24h after the intragastric (i.g.) administration of YL-0919 (2.5mg/kg), and the rapid antidepressant effect of YL-0919 was also blocked by the microglial depletion using PLX5622. About 92% of microglia in the prefrontal cortex was depleted in PLX5622 diet-fed mice, while both ketamine and YL-0919 promoted proliferation on the remaining microglia. YL-0919 significantly increased the protein expressions of synapsin-1, PSD-95, GluA1 and BDNF in the PFC, all of which could be blocked by PLX5622. Conclusion: These results suggested the microglia underlying the rapid antidepressant-like effect of ketamine and YL-0919, and microglia would likely constitute in the rapid enhancing impact of synaptic plasticity in the prefrontal cortex by YL-0919.

Once-Daily Subcutaneous Irisin Administration Mitigates Depression- and Anxiety-like Behavior in Young Mice

Major depression is one of the most common psychiatric disorders worldwide, usually associated with anxiety. The multi-etiological nature of depression has increased the search for new antidepressant molecules, including irisin, for which, in a previous study, we tested its effect in young mice when administered intraperitoneally in a long-term intermittent manner. Here, we evaluated the effect of subcutaneous short-term irisin administration (100 µg/Kg/day/5 days) in male and female mice subjected to behavioral paradigms: Tail Suspension Test (TST), Forced Swim Test (FST), Elevated Plus Maze (EPM), and Y Maze (YM). Moreover, a qRT-PCR assay was performed to analyze the impact of irisin treatment on Pgc-1α/FNDC5 expression in the brain. A significant reduction in immobility time in TST and FST was observed in irisin-treated mice. Furthermore, irisin treatment significantly increased the number of entries and time spent in open arms, demonstrating its anxiolytic effect. Memory-enhancing effects were not reported in YM. Interestingly, no gender differences were observed in all behavioral tests. Overall, these results suggest that short-term subcutaneous irisin administration can exert an antidepressant and anxiolytic role, probably due to the activation of the Pgc-1α/FNDC5 system in the brain. Further investigation could lead to the identification of irisin as a new agent for the treatment of psychiatric disorders.

Mechanism of essential oil from Schizonepeta tenuifolia in treatment of depression based on network pharmacology and experimental verification

This paper aimed to explore the antidepressant effect of the essential oil from Schizonepeta tenuifolia Briq.(EOST) on the treatment of depression and its mechanism by using a combination of network pharmacology and the mouse model of lipopolysaccharide(LPS)-induced depression. The chemical components in EOST were identified using gas chromatography-mass spectrometer(GC-MS), and 12 active components were selected as the study objects. The targets related to EOST were obtained by Traditional Chinese Medicines Systems Pharmacology(TCMSP) and SwissTargetPrediction database. The targets related to depression were screened out through GeneCards, Therapeutic Target Database(TTD), and Online Mendelian Inheritance in Man(OMIM) database. The Venny 2.1 was applied to screen out the common targets of EOST and depression. The targets were imported into Cytoscape 3.7.2 to generate "drug-active component-diease-target" network diagram. The protein-protein interaction(PPI) network was constructed using STRING 11.5 database and Cytoscape 3.7.2, and the core targets were screened out. DAVID 6.8 database was used for Gene Ontology(GO) func-tional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis, and subsequently the enrichment results were visualized through the bioinformatics platform. The mouse model of depression was induced by intraperitoneally injecting with LPS in mice. Before modeling, mice were administrated orally with EOST. The antidepressant effect of EOST was evalua-ted by tail suspension test(TST), forced swimming test(FST), and novelty suppressed feeding test(NSFT) after modeling. The content of interleukin(IL)-1β was determined by enzyme-linked immunosorbent assay(ELISA), and the protein expression levels of IL-1β and pro IL-1β in the hippocampus were determined by Western blot. There were 12 main components and 179 targets in EOAT, of which, 116 targets were related to depression, mainly involved in neuroactive ligand-receptor interaction, calcium signaling pathway, and cyclic adenosine monophosphate(cAMP) signaling pathway. Biological processes such as synaptic signal transduction, G-protein coupled receptor signaling pathway, and chemical synaptic transmission were involved. Molecular functions such as neurotransmitter receptor activity, RNA polymerase Ⅱ transcription factor activity, and heme binding were involved. In mice experiments, the results showed that EOST at 100 mg·kg~(-1) and 50 mg·kg~(-1) significantly shortened the immobility time in TST and FST as well as the feeding latency in NSFT compared with the model group, decreased the levels of serum IL-1β and NO, and reduced the protein expression levels of IL-1β and pro IL-1β in the hippocampus. In conclusion, EOST shows a good antidepressant effect in a multi-component, multi-target, and multi-pathway manner. The mechanism may be attributed to the fact that EOST can down-regulate the protein expression levels of IL-1β and pro IL-1β, decrease the release of inflammatory factors, and reduce neuroinflammation response.

Involvement of monoaminergic system in the antidepressant effect of 3-substituted thietane-1,1-dioxide derivative

Introduction: The aim of the study was to assess the involvement of the monoaminergic system in the antidepressant effect of a new 3-substituted thietane-1,1-dioxide derivative (N-199/1) using tests with several pharmacological antag­onists and agonists. Materials and methods: We conducted 3 sets of experiments in white outbred male mice. In Experiment 1, we as­sessed the antidepressant effect of N-199/1 in the forced swimming test (FST) and tail suspension test (TST) when administered repeatedly for 2 weeks intraperitoneally (i.p.). In Experiment 2, we evaluated the antidepressant effect of N-199/1 in FST and TST when co-administered with 5HT1A- (WAY100635, 0.1 mg/kg), 5HT2A/2C- (ketanserin, 5 mg/kg), 5HT3- (ondansetron, 1 mg/kg) serotonergic and α2-adrenergic (yohimbine, 1 mg/kg) receptors antagonists. In Experiment 3, we assessed the effect of N-199/1 on the hypothermia induced by i.p. injection of α2-adrenergic recep­tors agonist clonidine (0.3 mg/kg). Results and discussion: N-199/1 reduced immobility time (IT) and index of depression (ID) in FST, and did not affect IT in TST, either when administered repeatedly in Experiment 1, or acutely in Experiment 2. In Experiment 2, ketanse­rin enhanced the effect of N-199/1, decreasing ID by 36%, while WAY100635 and yohimbine antagonized it, increasing ID by 27% and IT by 115%, respectively, in comparison with N-199/1. N-199/1 attenuated the effect of ondansetron, increasing IT by 36%. In Experiment, 3 N-199/1 reduced clonidine-induced hypothermia 1 h after the injection of clonidine. N-199/1 exhibited pronounced antidepressant properties in FST, an agonism to 5HT1A-receptors and an antagonism to 5HT2A/2C- and α2-receptors in tests of neuropharmacological interaction, which indicates an atypical mechanism of its antidepressant action. Conclusion: The antidepressant effect of N-199/1 is due to the stimulation of 5HT1A-receptors and blockade of 5HT2A/2C- and α2-receptors. Graphical abstract:

Antidepressant effect of Jujuboside A on corticosterone-induced depression in mice

ObjectiveThe aim of this study was to investigate the antidepressant effect of Jujuboside A (JuA) on corticosterone (CORT)-induced depression in mice and explore the underlying mechanisms. MethodsThe mice models were submitted to CORT and treated with JuA (10 and 30 mg/kg) for three weeks. Experiments were also performed on mice with brain-derived neurotrophic factor knockdown (BDNF (±)) as control subjects. Behavioral tests, including the open field test (OFT), tail suspension test (TST), forced swimming test (FST) and Morris water maze (MWM), were then performed to evaluate the antidepressant effect of JuA. The expression levels of BDNF, tyrosine kinase receptor B (TrkB), and cyclic AMP response element binding protein (CREB) in the hippocampi of mice were examined by immunohistochemistry (IHC) and Western blot. The effect of JuA on the viability of mouse hippocampal cells (HT22) was also assessed by CCK-8 assay. ResultsJuA significantly decreased the OFT and TST immobility time of the mice, the total distance travelled and the time spent in the central area also effectively increased in the OFT. In the MWM, the escape latencies of the mice decreased remarkably, while the number of times the mice crossed the platform and the target quadrant increased significantly after treatment with JuA. In addition, the BDNF, TrkB, and CREB expression levels were significantly increased in the hippocampi of the mice treated with JuA. Furthermore, JuA clearly attenuated CORT-induced cell injury, as evidenced by the increased viability of the HT22 cells. ConclusionThese findings demonstrated that JuA may exhibit potential antidepressant effect in mice by increasing protein expression levels of BDNF, TrkB, CREB, and improving the viability of the hippocampal cells.

The Role of Banana (Musa balbisiana Colla) Peel Floss as Functional Food Matrix to Alleviate Chronic Stress

BACKGROUND: Banana peel (Musa balbisiana Colla) already has a diverse variety of nutritional benefits, but its perishable nature necessitates additional food processing, one of which is banana peel floss.
 AIM: The objective of this study was to examine the antidepressant effects of banana peel floss in experimental animals subjected to chronic mild stress (CMS) for 6 weeks.
 METHODS: Animals were randomly assigned into five groups. The first group was fed a control diet without CMS as a negative control. The other four groups were exposed to CMS and fed a control diet as a positive control, with three of the five groups fed a control diet supplemented with 15%, 30%, and 60% banana peel floss. The tail suspension test (TST) and the Morris water maze were used as behavioral parameters in this study (MWM). Cortisol and serotonin levels were measured in two stages: after CMS exposure or before banana peel floss intervention, and after 4 weeks of banana peel floss intervention.
 RESULTS: The results showed that the immobility time in TST and escape latency in the MWM test were significantly reduced in the groups supplemented with 15% and 30% banana peel floss, respectively. Furthermore, we observed a significant association between serotonin and cortisol levels and also between the duration of immobility time in TST and serotonin levels.
 CONCLUSIONS: The administration of banana peel floss caused significant changes in plasma serotonin concentrations, implying that the presence of dietary fiber, tryptophan, and bioactive components in banana peel floss can reduce stress-induced depression by regulating cortisol levels and increasing serotonin levels.

The Rapid and Long-Lasting Antidepressant Effects of Iridoid Fraction in Gardenia Jasminoides J.Ellis Are Dependent on Activating PKA-CREB Signaling Pathway.

Lag periods of therapeutic efficacy cause poor compliance of patients, which has made solutions for rapid antidepressants the most urgent need in the depression study field at present. We have identified through our previous studies the rapid antidepressant effects of the traditional herb Gardenia jasminoides J.Ellis [Rubiaceae] (GJ) and its standardized fractions. Through screening different fractions of GJ, we decided to place our focus on the iridoid fraction of GJ (GJ-IF). Methods: 1. Tail suspension test (TST), forced swimming test (FST), and novelty suppressed-feeding test (NSFT) were performed in sequence on mice after GJ-IF administration. 2. Mice in the model group were under chronic unpredictable mild stress (CUMS) for 3 w. After GJ-IF treatment, mice were placed in an open field test (OFT), Sucrose preference test (SPT), NSFT, TST, and FST. 3. Western Blot was performed to examine the expression of brain-derived neurotrophic factor (BDNF), Synapsin 1, cyclic-AMP dependent protein kinase A (PKA), phosphorylated cyclic-AMP responsive element-binding protein (p-CREB), and cAMP response element-binding protein (CREB). 4. Mice in the test group were administrated with GJ-IF after intraperitoneal injection of PKA blocker H89. Results: 1. GJ-IF treatment significantly reduced the immobility time of TST at 1 d and FST at 26 h. 2. GJ-IF reversed the deficits induced by 3 w CUMS in SPT, TST, FST, and NSFT at 1 d and 26 h. The antidepressant effects of a single dose of iridoid fraction could also last for at least 14 d. 3. The results of molecule studies suggested that a single dose of GJ-IF activated p-CREB at 2 h and the PKA-CREB pathway at 1 d. The expression of BDNF did not significantly change from 30 min to 1 d after GJ-IF administration. 4. Blockade of PKA-CREB signaling pathway reversed the antidepressant effects of GJ-IF at 1 d, but not 30 min and 2 h. Conclusion: GJ-IF is the crucial component in the rapid antidepressant of GJ. Rapid and sustained antidepressant effects of GJ-IF were dependent on activating the PKA-CREB signaling pathway.

Antidepressant-like Effects of Renin Inhibitor Aliskiren in an Inflammatory Mouse Model of Depression.

Depression is considered a neuropsychic disease that has global prevalence and is associated with disability. The pathophysiology of depression is not well understood; however, emerging evidence has indicated that neuroinflammation could contribute to developing depression symptoms. One of the factors that have a role in the development of neuroinflammation is the renin–angiotensin system. Therefore, the goal of the current study is to determine the antidepressant-like effects of Aliskiren, a renin inhibitor, against lipopolysaccharide (LPS)-induced depressive-like behavior in mice, glial cell activation, and the upregulation of proinflammatory cytokines in the prefrontal cortex. For behavioral studies, the open field test (OFT), tail suspension test (TST), forced swim test (FST), and sucrose preference test (SPT) were used. Inflammatory markers were assessed using real-time polymerase chain reaction (RT-PCR). LPS administration (0.5 mg/kg, intraperitoneal injection (i.p.)) sufficiently reduced the number of crossings in OFT, whereas Aliskiren pretreatment (10 mg/kg, i.p.) attenuated the LPS effect for two hours after LPS injection. The treatments did not show effects on locomotor activity in OFT 24 h after LPS administration. LPS increased the immobility time in TST and FST or reduced sucrose consumption in SPT after 24 h. Aliskiren reversed the effects induced by LPS in TST, FST, and SPT. CD11 b mRNA, a microglial marker, GFAP mRNA, an astroglial marker, and proinflammatory cytokines genes (TNF-α, IL-1β, and IL-6) were upregulated in the prefrontal cortex in LPS exposed animals. However, Aliskiren reduced LPS-induced inflammatory genes in the prefrontal cortex. Hence, the outcomes conclude that Aliskiren prevents depressive illness associated with neuroinflammation in humans.

Effect of wheat-grain moxibustion on the expression of 5-HT and cortisol in the serum, and MR and GR in the hippocampus in rats with hypothyroidism complicated with depression

To observe the effect of wheat-grain moxibustion on behavior, 5-hydroxytryptamine (5-HT) and cortisol in the serum, mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) in the hippocampus in rats with hypothyroidism complicated with depression, and to explore the possible mechanism of wheat-grain moxibustion on improving depression in rats with hypothyroidism. A total of 32 SPF SD rats were randomly divided into a blank group, a model group, a medication group and a wheat-grain moxibustion group, 8 rats in each group. Except for the blank group, the rats in the remaining groups were treated with intragastric administration of 0.1% propylthiouracil (PTU) suspension at 1 mL/100 g, once a day for 4 weeks to establish the rat model of hypothyroidism, and whether the rats were accompanied with depression-like behavior determined through behavioristics evaluation. The rats in the medication group were intervened with euthyrox at 0.9 mL/100 g, once a day, for 4 weeks; the rats in the wheat-grain moxibustion group were treated with wheat-grain moxibustion at "Dazhui" (GV 14), "Mingmen" (GV 4), "Shenshu" (BL 23) and "Pishu" (BL 20), 7 cones each acupoint, once a day, six times a week for 4 weeks. After the intervention, the depression status was observed by behavioristics test; the contents of thyroid stimulating hormone (TSH), total thyroxine (TT4), 5-HT and cortisol in the serum were detected by ELISA; the protein expressions of MR and GR in hippocampus were detected by Western blot; the expressions of MR mRNA and GR mRNA in the hippocampus were detected by real-time PCR. Before the intervention, compared with the blank group, the scores of open field test (OFT) were decreased and the immobility time of tail suspension test (TST) was prolonged (P<0.05); the serum TSH contents were increased and TT4 contents were decreased (P<0.01) in the other three groups. After the intervention, compared with the model group, the vertical score of OFT was increased and the immobility time of forced swimming test (FST) was prolonged in the medication group (P<0.05), while the scores of three items of OFT were increased (P<0.05, P<0.01), and the immobility time of FST and TST was shortened in the wheat-grain moxibustion group (P<0.01, P<0.05). Compared with the medication group, the immobility time of TST and FST in the wheat-grain moxibustion group was shorter (P<0.05, P<0.01). Compared with the blank group, in the model group, the contents of serum TSH and cortisol were increased (P<0.01, P<0.001), while the contents of serum TT4 and 5-HT were decreased (P<0.01, P<0.001). Compared with the model group, the contents of serum TT4 and 5-HT were increased, while the contents of serum TSH and cortisol were decreased in the medication group and wheat-grain moxibustion group (P<0.01, P<0.05). Compared with the blank group, the protein and mRNA expression of MR, GR in the hippocampus in the model group was decreased (P<0.01, P<0.05, P<0.001); compared with the model group, the protein and mRNA expression of MR in the hippocampus in the medication group were increased (P<0.05), and the protein expression of MR, GR and mRNA expression of MR in the hippocampus in the wheat-grain moxibustion group were increased (P<0.05, P<0.01). Compared with the medication group, the expression of MR mRNA in the wheat-grain moxibustion group was increased (P<0.05). Wheat-grain moxibustion could significantly improve thyroid function and depression in rats with hypothyroidism. Its mechanism may be related to up-regulating the protein and mRNA expression of MR and GR in the hippocampus, and then affecting the expression of serum cortisol and 5-HT.

Swimming exercise reverses chronic unpredictable mild stress-induced depression-like behaviors and alleviates neuroinflammation and collapsing response mediator protein-2-mediated neuroplasticity injury in adult male mice.

ObjectiveImpaired neuroplasticity and neuroinflammation are vital in the mechanisms of depression. Exercise alleviates depressive symptoms and ameliorates body functions. Swimming is one of the most common exercises; however, whether swimming alters depressive behaviors and the underlying mechanism has not been fully elucidated.MethodsMale C57/BL6J mice were exposed to chronic unpredictable mild stress (CUMS) for 6 weeks and then were subjected to a 5-week swimming program. Behavioral test, including sucrose preference test (SPT), open field test (OFT), elevated plus-maze (EPM) test, and tail suspension test (TST), was conducted to assess the anxiety-like and depressive behaviors. Western blotting and immunofluorescence staining were carried out after tissue collection.ResultsThis study showed that CUMS-induced depressive behaviors but swimming exercise increased sucrose preference in SPT, increased time and velocity in the center on OFT, decreased time in the closed arm, increased time in the open arm in EPM, and decreased immobility time in TST. We further found swimming exercise increased hippocampal collapsing response mediator protein-2 (CRMP2) expression and decreased p-CRMP2 expression in CUMS mice. CUMS inhibited the levels of α-tubulin and CRMP2, and the expression of ionized calcium-binding adaptor molecule 1 and caspase-1, whereas swimming reversed them in CUMS-exercised mice.ConclusionOur study confirmed that swimming exercise reverses CUMS-induced depressive behaviors, and neuroinflammation and CRMP2-mediated neuroplasticity are involved, which may provide a new insight into the antidepression therapy of exercise.

The Banana (Musa balbisiana Colla) Peels Flour Modulates HTR2B Receptor Expression in the Liver Diabetic Rats

Uncontrolled diabetes mellitus (DM) has been linked to depression and lipid metabolism impairment. Serotonin (5-HT) has been known to improve lipid metabolism and affect mood. The 5-Hydroxytryptophan (5-HTP) in banana peel flour (BPF) is a precursor to synthesize 5-HT in the body, which is linked to initiating liver regeneration via HTR2B receptors. The impact of 5-HTP in the diet on HTR2B receptor expression has yet to be thoroughly investigated. We aimed to elucidate the correlation between serum lipid profile and immobility time in Tail Suspension Test (TST) as depressive-like behavior and compare the expression of HTR2B receptor in healthy and diabetic rats. Male Wistar (Rattus norvegicus) rats were assigned to the control and treatment groups in a DM model with streptozotocin (60 mg/kg) injected intraperitoneally, then either fed standard diet or BPF 10% supplemented standard diet for 21 days. Immunohistochemical staining was used to examine the expression of 5-HT, HTR2B receptors. We determined that diabetic rats fed the standard diet supplemented 10% BPF group showed significantly lower concentrations of total cholesterol and triglycerides compared to diabetic rats fed a standard diet and it was positively correlated between total cholesterol and LDL with the duration of immobility time in TST. The average immunoreactivity score in diabetic rats fed 10% BPF was the highest among the other groups, indicating that the available BPF dose is sufficient for HTR2B activation, which will support the liver cell regeneration process, and should be investigated further.

NEUROPHARMACOLOGICAL SCREENING, ANTI-STRESS ACTIVITY, AND TOXICITY STUDIES OF STANDARDIZED EXTRACT OF THE SEEDS OF CELASTRUS PANICULATUS WILLD

Objective: Celastrus paniculatus Willd, family Celastraceae is an important medicinal plant distributed all over India. Due to the presence of antioxidative polyphenols in C. paniculatus Willd have received much attention for health-promoting properties by scavenging the free radicals, the purpose of this study is to understand neuropharmacological, anti-stress activity, and toxicity studies of standardized seeds extract of “C. paniculatus Willd. Methods: The sun dried C. paniculatus Willd seeds were collected and extracted with ethanol by maceration. Then, the ethanolic extract was subjected to phytochemical screening. The acute toxicity of the ethanolic extract of C. paniculatus was observed as per the Organization for Economic Co-operation and Development guideline no. 423. Neuropharmacological and anti-stress effects were analyzed and evaluated by using physical stress models such as Swimming endurance test, Anoxic tolerance test, Tail suspension test (TST), and Elevated plus maze test. For this study, Swiss albino mice (20–30 g) were divided into five groups of six animals each. Distilled water administered as vehicle in control group and standard group received Withania somnifera (100 mg/kg) while C. paniculatus Willd ethanolic extract (100, 200, and 400 mg/kg) was given orally for 7 days. Results and Discussion: Change in immobility time in swim endurance, first clonic convulsion produced in anoxic tolerance test, immobility time in TST and open arms entry in elevated plus maze test was recorded as parameters. The ethanolic extracts of C. paniculatus Willd significantly reduces the immobility timing along with increases the swimming endurance time, and clonic convulsion timing in anoxic tolerance test in comparison of control group. In tail suspension significant decrease in immobility time and increased open arm entry in elevated plus maze were observed as compare to control group. Conclusion: C. paniculatus Willd has potential as a medicinal plant and it showed protective effect for the stress prevention as the alkaloids are present as main constituents.

Putative Role of Monoaminergic Systems in Antidepressant and Anxiolytic Effects of Naringin in Mice: An Interaction Study with Receptor Antagonists

Aim: Stress-related disorders like depression and anxiety represent one of the greatest therapeutic challenges globally. Although previous studies have revealed the antidepressant-like potentials of naringin, the neurotransmitter receptor interaction mechanisms of action have not been studied, hence, this study was carried out to evaluate the role of neurotransmitter-receptor antagonists in the antidepressant-like effects of naringin in mice.&#x0D; Method: Male Swiss mice were subjected to chronic unpredictable mild stress (CUMS) apart from mice in the control group. The mice were then pretreated with different neurotransmitter antagonists; metergoline (4 mg /kg i.p.), a 5-HT1 - and 5-HT2 -receptor antagonist; propranolol; (0.2 mg/kg i.p.), β1,2-noradrenoceptor antagonist or haloperidol (0.2 mg/kg i.p.), D 2 -dopaminergic receptor antagonists prior to the administration of naringin or vehicle (10 mL/kg). The antidepressant-like and anxiolytic effects of naringin were evaluated 30 min later using the tail suspension test (TST), open-field test (OFT), sucrose preference test (SPT) and elevated plus maze (EPM) tests paradigms.&#x0D; Results: Administration of naringin following CUMS significantly decrease immobility time and locomotion activity in TST and OFT respectively, relative to control while increasing preference to sucrose in SPT, open arm entries as well as time spent in open arm in EPM, relative to control suggesting antidepressant-like property. Pretreatment with metergoline, propranolol, and haloperidol following CUMS increased immobility time in TST, locomotor activity in OFT and IOAA in the EPM. Reduced preference for sucrose in SPT, open arm entry and duration in EPM relative to control (p &lt; 0.05), however, these effects were attenuated by naringin.&#x0D; Conclusion: These findings suggest that the antidepressant-like activity exhibited by naringin might be mediated via interactions with 5-HTergic, noradrenergic, and dopaminergic receptors, while the anxiolytic effect might involve interaction with both 5-HTergic and noradrenergic receptors.