Involvement of the GABAA Receptor in the Antidepressant-Like Effects Produced by Low and High Doses of the Flavonoid Chrysin in the Rat: A Longitudinal Study.

BACKGROUND: The flavonoid chrysin produces rapid and long-lasting anxiolytic- and antidepressant-like effects in rats. However, it is not known whether low and high doses of chrysin produce differential anti-immobility effects through the Gamma-Aminobutyric Acid sub-type A (GABAA) receptor. The goal of this work was therefore to compare low and high doses of chrysin for their effects on depression-like behavior in a longitudinal study. Moreover, chrysin was compared with the serotonergic fluoxetine and Gamma-Aminobutyric Acid (GABA)ergic allopregnanolone, and its involvement with the GABAA receptor after chronic treatment was also investigated. METHODS: Male Wistar rats were assigned to five groups (n = 8 each): vehicle, 1 mg/kg chrysin, 5 mg/kg chrysin, 1 mg/kg fluoxetine, and 1 mg/kg allopregnanolone. In the first experiment, treatments were injected daily and the effects on locomotor activity and the forced swim test were evaluated at 0, 1, 14, and 28 days of treatment, and 48 h after the final treatment. In the second experiment, similar groups were treated for 28 days with injection of 1 mg/kg picrotoxin to investigate the role of the GABAA receptor. Depending on the experimental design, one- and two-way analysis of variance (ANOVA) tests were used for statistical analysis, with p < 0.05 set as the criteria for significance. RESULTS: In both experiments, the treatments did not alter locomotor activity. However, low and high doses of chrysin, allopregnanolone, and fluoxetine gradually produced antidepressant-like effects in the forced swim test, and maintained this effect for 48 h post-treatment, except with low dose chrysin. Picrotoxin blocked the antidepressant-like effects produced by low dose chrysin, but did not affect those produced by high dose chrysin, allopregnanolone, or fluoxetine. CONCLUSIONS: The differential antidepressant-like effects caused by low and high doses of chrysin are time-dependent. Low dose chrysin produces a rapid antidepressant-like effect, whereas high dose chrysin produces a delayed but sustained the effect, even 48 h after withdrawal. The effect with high dose chrysin was similar to that observed with allopregnanolone and fluoxetine. The mechanism for the antidepressant-like effect of low chrysin appears to be GABAergic, whereas the effect of high dose chrysin may involve other neurotransmission and neuromodulation systems related to the serotonergic system.

Co-catalpol alleviates fluoxetine-induced main toxicity: Involvement of ATF3/FSP1 signaling-mediated inhibition of ferroptosis.

BACKGROUND: Fluoxetine is often used as a well-known first-line antidepressant. However, it is accompanied with hepatogenic injury as its main organ toxicity, thereby limiting its application despite its superior efficacy. Fluoxetine is commonly traditionally used combined with some Chinese antidepressant prescriptions containing Rehmannia glutinosa (Dihuang) for depression therapy and hepatoprotection. Our previous experiments showed that co-Dihuang can alleviate fluoxetine-induced liver injury while efficiencies, and catalpol may be the key ingredient to characterize the toxicity-reducing and synergistic effects. However, whether co-catalpol can alleviate fluoxetine-induced liver injury and its toxicity-reducing mechanism remain unclear. PURPOSE: On the basis of the first recognition of the dose and duration at which pre-fluoxetine caused hepatic injury, co-catalpol's alleviation of fluoxetine-induced hepatic injury and its pathway was comprehensively elucidated. METHOD AND RESULTS: The hepatoprotection of co-catalpol was evaluated by serum biochemical indexes sensitive to hepatic injury and multiple staining techniques for hepatic pathologic analysis. Subsequently, the pathway by which catalpol alleviated fluoxetine-induced hepatic injury was predicted by network pharmacology to be predominantly the inhibition of ferroptosis. These were validated and confirmed in subsequent experiments with key technologies and diagnostic reagents related to ferroptosis. Further molecular docking showed that activating transcription factor 3 (ATF3) and ferroptosis suppressor protein 1 (FSP1) were the the most prospective molecules for catalpol and fluoxetine among many ferroptosis-related molecules. The critical role of ATF3/FSP1 signaling was further observed by surface plasmon resonance, diagnostic reagents, transmission electron microscopy, Western blot, real-time PCR, immunofluorescence, and immunohistochemistry. Results showed that fluoxetine directly bound to ATF3 and FSP1; agonisting ATF3 or blocking FSP1 abolished the alleviation of catalpol on fluoxetine-induced liver injury, and both exacerbated ferroptosis. Moreover, co-catalpol significantly enhanced the antidepressant efficacy of fluoxetine against depressive behaviours in mice. CONCLUSION: The hepatic impairment properties of fluoxetine were largely dependent on ATF3/FSP1 target-mediated ferroptosis. Co-catalpol alleviated fluoxetine-induced hepatic injury while enhancing its antidepressant efficacy, and that ATF3/FSP1 signaling-mediated inhibition of ferroptosis was involved in its co-administration detoxification mechanism. This study was the first to reveal the hepatotoxicity characteristics, targets, and mechanisms of fluoxetine; provide a detoxification and efficiency regimen by co-catalpol; and elucidate the detoxification mechanism.

The antidepressive mechanism of Longya Lilium combined with Fluoxetine in mice with depression-like behaviors.

Traditional Chinese medicine is one of the most commonly used complementary and alternative medicine therapies for depression. Integrated Chinese-western therapies have been extensively applied in numerous diseases due to their superior efficiency in individual treatment. We used the meta-analysis, network pharmacology, and bioinformatics studies to identify the putative role of Longya Lilium combined with Fluoxetine in depression. Depression-like behaviors were mimicked in mice after exposure to the chronic unpredictable mild stress (CUMS). The underlying potential mechanism of this combination therapy was further explored based on in vitro and in vivo experiments to analyze the expression of COX-2, PGE2, and IL-22, activation of microglial cells, and neuron viability and apoptosis in the hippocampus. The antidepressant effect was noted for the combination of Longya Lilium with Fluoxetine in mice compared to a single treatment. COX-2 was mainly expressed in hippocampal CA1 areas. Longya Lilium combined with Fluoxetine reduced the expression of COX-2 and thus alleviated depression-like behavior and neuroinflammation in mice. A decrease of COX-2 curtailed BV-2 microglial cell activation, inflammation, and neuron apoptosis by blunting the PGE2/IL-22 axis. Therefore, a combination of Longya Lilium with Fluoxetine inactivates the COX-2/PGE2/IL-22 axis, consequently relieving the neuroinflammatory response and the resultant depression.

(2-Cyclohexyl-1-methylpropyl) cyclohexane isolated from garlic extract exhibits antidepressant-like activity: extraction, docking, drug-like properties, molecular dynamics simulations and MM/GBSA studies.

Depressive disorders are among most common psychiatric diseases and second most common form of psychiatric illness globally. Commonly available chemical drugs used for treatment of nervous system disorders exert undesirable effects. Therefore, there is a growing need towards exploring novel antidepressants of herbal origin. Earlier, the antidepressant effect of methanolic extract of garlic has been shown. In this study, the ethanolic extract of garlic was prepared and chemically analysed using Gas Chromatography - Mass Spectrometry (GC-MS) screening. A total of 35 compounds were found to be present, which might act as antidepressant. Using computational analyses, these compounds were screened as potential inhibitors (selective serotonin reuptake inhibitor (SSRI)) against serotonin transporter (SERT)/leucine receptor (LEUT). In silico docking studies and other physicochemical, bioactivity and ADMET studies resulted in the selection of compound 1 ((2-Cyclohexyl-1-methylpropyl) cyclohexane) as potential SSRI (binding energy -8.1 kcal/mol) compared to known reference SSRI fluoxetine (binding energy -8.0 kcal/mol). Analysis of conformational stability, residue flexibility, compactness, binding interactions, solvent accessible surface area (SASA), dynamic correlation, and binding free energy predicted from molecular mechanics (MD) with generalised Born and surface area solvation (MM/GBSA) studies revealed formation of a more stable SSRI like complex with compound 1 having strong inhibitory interaction compared to known SSRI fluoxetine/reference complex. Thus, compound 1 may act as an active SSRI leading to discovery of potential antidepressant drug.Communicated by Ramaswamy H. Sarma.

Dietary Co-supplements attenuate the chronic unpredictable mild stress-induced depression in mice.

Does it make a difference what we eat when it comes to our mental health? Food and nutrients are essential not only for human biology and physical appearance but also for mental and emotional well-being. There has been a significant increase in the favourable effects of dietary supplements in the treatment of depressive state in the latest days. Co-supplements which can be a great contribution in the management of depression from the future perspective and might help to reduce standard anti-depressant drug doses, which can be a strategic way to reduce the side effect of standard anti-depressants drugs. This study was designed to evaluate and compare the anti-depressant effects of cholecalciferol-D3 (V.D3), n-3 polyunsaturated fatty acid (PUFA), and a combination of V.D3 + n-3 PUFA with fluoxetine treatment in chronic unpredictable mild stress (CUMS) induced depression in the mice model. We established CUMS depressant mice model and treated CUMS mice with V.D3, n-3 PUFA, and a combination of V.D3 + n-3 PUFA with fluoxetine. Behavioral changes were measured by the forced swim and tail suspension test. Oxidative stress markers and anti-depressant activity were assessed through parameters such as superoxide dismutase, reduced glutathione, lipid peroxidation, and serum corticosterone levels. Additionally, we measured the levels of neurotransmitters dopamine and serotonin. CUMS induced mice displayed depressive-like behaviours. Moreover, cholecalciferol-D3, n-3 PUFA, and a combination of Cholecalciferol-D3 + n-3 PUFA with fluoxetine treatment attenuated the depressive-like behaviour in CUMS mice accompanied with suppression of oxidative stress markers by up-regulated the expression of an antioxidant signalling pathway. The results suggested that treatment of cholecalciferol-D3, n-3 PUFA, and a combination of Cholecalciferol-D3 + n-3 PUFA with fluoxetine significantly ameliorated depressive-like behaviours in CUMS induced depression in mice. To delve further into the implications of these findings, future studies could explore the specific molecular mechanisms underlying the observed effects on oxidative stress markers and the antioxidant signaling pathway. This could provide valuable insights into the potential of dietary supplements in the management of depression and help in reducing the reliance on conventional antidepressant medications, thus improving the overall quality of treatment for this prevalent mental health condition.

Acori Tatarinowii Rhizoma prevents the fluoxetine-induced multiple-drug resistance of Escherichia coli against antibiotics.

BACKGROUND: In treating depression, the residual anti-depressant in gut interacts with the microbiome, leading to the appearance of multiple drug resistant (MDR) mutants, which poses a challenge for the treatment of infectious complications. Strategy is needed to combat this issue. Acori Tatarinowii Rhizoma (ATR, rhizome of Acorus tatarinowii Schott, Araceae), a traditional Chinese medicine, has been widely used for treatment of neurological disorders and gastrointestinal digestive disease in China. Here, ATR was demonstrated an excellent MDR-preventing effect in fluoxetine-induced Escherichia coli (E. coli). AIM OF THE STUDY: This study aimed to reveal the effective role of ATR and its signaling cascades involved in preventing fluoxetine-induced MDR. MATERIALS AND METHODS: The water extract of ATR was co-applied with sub-minimum inhibitory concentration (100 mg/l) of fluoxetine in E. coli to evaluate its anti-MDR potential. Formation of reactive oxygen species (ROS) and expression of MDR-related genes in bacteria were measured by dichloro-dihydro-fluorescein diacetate assay and real-time PCR, respectively. Two fluorescent dyes, 1-N-phenylnapthylamine and 3,3'-dipropylthiadicarbocyanine were used to analyze the outer membrane permeability and inner membrane depolarization of E. coli. The accumulation of fluoxetine in the treated E. coli was determined via HPLC. The active fraction of ATR was identified. RESULTS: The water extract of ATR significantly decreased the number of MDR mutants induced by fluoxetine and had half effective concentrations (EC50) of 55.5 µg/ml and 16.8 µg/ml for chloramphenicol and tetracycline, respectively. ATR robustly reversed the fluoxetine-induced superoxide response and membrane damage in E. coli. In addition, the inclusion of ATR significantly reduced the accumulation of fluoxetine in E. coli. After further fractionation, the polysaccharide of ATR was demonstrated as the fraction with the most significant anti-MDR activity. CONCLUSIONS: This is the first report to investigate the MDR-preventing effect of ATR. The results of this study proposed ATR as an excellent herbal product to prevent MDR issues, as induced by fluoxetine, with the potential to reduce the side effects during the drug therapy of depression.

Acupuncture alleviates CUMS-induced depression-like behaviors of rats by regulating oxidative stress, neuroinflammation and ferroptosis.

BACKGROUND: The treatment of depression with acupuncture has been documented. The mechanism behind acupuncture's curative and preventative effects is still unknown. METHODS: The current study examined the effects of acupuncture on depression-like behaviors in a rat model of chronic unpredictable mild stress (CUMS), while also exploring its potential mechanisms. A total of six groups of rats were randomly assigned: control, CUMS, acupuncture, fluoxetine, acupoint catgut embedding and sham acupoint catgut embedding. Fluoxetine (2.1 mg/kg) and acupoint catgut embedding were used for comparative research to acupuncture. The modelling evaluation is measured by body weight and behavior tests. Western blotting and reverse transcription-polymerase chain reaction were used to detect the proteins and mRNA expression of Silent information regulator 1 (Sirt1)/ nuclear factor-erythroid 2-related factor 2 (Nrf2)/ heme oxygenase-1 (HO-1)/ Glutathione peroxidase 4 (GPX4) pathway in the hippocampus. The expression of oxidative stress (OS)-related proteins and inflammatory cytokines in the serum was detected with ELISA. Immunofluorescence showed microglia and astrocytes activity in the hippocampus. RESULTS: Acupuncture and fluoxetine could alleviate CUMS-induced depression-like behaviors. Acupuncture was also found to effectively reverse the levels of MDA, SOD, GSH, GSH-PX and T-AOC, IL-1ß, IL-6 and TNF-α in the serum of CUMS-induced rats. Rats with CUMS showed decreased levels of Sirt1, Nrf2, HO-1 and GPX4 in the hippocampus, while acupuncture treatment could partly reverse the diminished effects. In addition, acupuncture treatment significantly reduced the activation of hippocampal microglia and astrocytes in CUMS-induced rats. CONCLUSION: The study's findings indicate that acupuncture has the potential to mitigate depression-like behaviors in rats induced with CUMS by mitigating OS and reducing neuroinflammation.

Electroacupuncture ameliorates chronic unpredictable mild stress-induced depression-like behavior and cognitive impairment through suppressing oxidative stress and neuroinflammation in rats.

BACKGROUND: Depression is associated with lowered mood, anxiety, anhedonia, cognitive impairments, and even suicidal tendencies in severe cases. Yet few studies have directed acupuncture's mechanism toward enhancing axonal repair correlated with synaptic plasticity and anti-inflammatory effects related to oxidative stress in the hippocampus. METHODS: Male Sprague-Dawley (SD) rats were randomly divided into control group (CON), chronic unpredictable mild stress (CUMS) group, CUMS + electroacupuncture group (EA), and CUMS + fluoxetine group (FLX) (n = 10/group). Rats were given a 28-day treatment at the Shangxing (GV23) and Fengfu (GV16) acupoints with electroacupuncture or fluoxetine (2.1 mg/kg). RESULTS: Rats exposed to CUMS induced depression-like behaviors and spatial learning-memory impairment, changed the ionized calcium binding adaptor molecule 1 (IBA-1), Vglut1, myelin basic protein (MBP), and postsynaptic density protein 95 (PSD95) level of hippocampal, increased the Nod-like receptor protein 3 (NLRP3), atypical squamous cell (ASC), Caspase level and hippocampal reactive oxygen species (ROS), and prompted the activation of Epha4-mediated signaling and an inflammatory response. Conversely, electroacupuncture administration reduced these changes and prevented depression-like behaviors and cognitive impairment. Electroacupuncture also promoted hippocampal expression of Sirtuin1(SIRT1), Nuclear factor erythroid 2-like (Nrf2), Heme oxygenase-1 (HO-1); reduced the expression of interleukin-1ß (IL-1ß), interleukin-18 (IL-18), and tumor necrosis factor-alpha (TNF-α); and prevented neural damage, particularly the synaptic myelin sheath, and neuroinflammation by regulating Eph receptor A4 (EphA4) in the hippocampal. CONCLUSION: These results indicate that electroacupuncture prevents depression-like behaviors with cognitive impairment and synaptic and neuronal damage, probably by reducing EphA4, which mediates ROS hyperfunction and the inflammatory response.

Serotonin is a common thread linking different classes of antidepressants.

Depression pathology remains elusive. The monoamine hypothesis has placed much focus on serotonin, but due to the variable clinical efficacy of monoamine reuptake inhibitors, the community is looking for alternative therapies such as ketamine (neurogenesis theory of antidepressant action). There is evidence that different classes of antidepressants may affect serotonin levels; a notion we test here. We measure hippocampal serotonin in mice with voltammetry and study the effects of acute challenges of escitalopram, fluoxetine, reboxetine, and ketamine. We find that pseudo-equivalent doses of these drugs similarly raise ambient serotonin levels, despite their differing pharmacodynamics because of differences in Uptake 1 and 2, rapid SERT trafficking, and modulation of serotonin by histamine. These antidepressants have different pharmacodynamics but have strikingly similar effects on extracellular serotonin. Our findings suggest that serotonin is a common thread that links clinically effective antidepressants, synergizing different theories of depression (synaptic plasticity, neurogenesis, and the monoamine hypothesis).

Prophylactic Effects of Hemp Seed Oil on Perimenopausal Depression: A Role of HPA Axis.

Hemp seed, the dried fruit of Cannabis sativa L. (Moraceae), has been extensively documented as a folk source of food due to its nutritional and functional value. This study evaluated the antidepressant effect of hemp seed oil (HSO) during its estrogen-like effect in Perimenopausal depression (PMD) rats induced by ovariectomy combined with chronic unpredictable mild stress (OVX-CUMS). Female SD rats (SPF, 10 weeks, sham operated group, ovariectomy (OVX) model group, ovariectomy - chronic unpredictable mild stress (OVX-CUMS) group, HSO + OVX-CUMS group, fluoxetine (FLU) + OVX-CUMS group, n=8) were subjected to treatment with HSO (4.32 g/kg) or fluoxetine (10 mg/kg) for 28 days (20 mL/kg by ig). Sucrose preference test (SPT), forced swimming test (FST), open field test (OFT), estrogen receptor α (ERα) and estrogen receptor ß (ERß) expression, estradiol (E2), follicle stimulating hormone (FSH), luteinizing hormone (LH), cortisol (CORT), adrenocorticotropic hormone (ACTH), corticotropin releasing hormone (CRH), norepinephrine (NE), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5HIAA) levels are measured to evaluate the function of the hypothalamic-pituitary-ovarian (HPO) and hypothalamic-pituitary-adrenal (HPA) axis. The results showed that OVX-CUMS significantly decrease sucrose preference rate in SPT, increase immobility time in FST and OFT, and decrease movement distance and stand-up times in OFT. HSO treatment significantly improves depression-like behaviors, upregulates the expression of ERα and ERß, improves HPO axis function by increasing E2 levels and decreasing FSH and LH levels, reverses HPA axis hyperactivation by decreasing CORT, ACTH, and CRH levels, and upregulates NE, 5-HT, and 5HIAA levels in model rats. The findings suggested that HSO could improve depression-like behavior in OVX-CUMS rats by regulating HPO/HPA axis function and neurotransmitter disturbance.

Saffron carotenoids reversed the UCMS-induced depression and anxiety in rats: Behavioral and biochemical parameters, and hippocampal BDNF/ERK/CREB and NR2B signaling markers.

BACKGROUND: Depression is a debilitating condition that affects the mind and the individual's body. The improving effects of saffron on depression and anxiety have long been discussed, with limited information about the molecular mechanism of action. HYPOTHESIS/PURPOSE: Investigating the effect of saffron carotenoids, Crocin and Crocetin, on depression and anxiety in rats by emphasizing some signaling pathways involved. STUDY DESIGN: Depression and anxiety were induced in rats via unpredictable chronic mild stress (UCMS). Then different rat groups were treated with Crocin, Crocetin, Fluoxetine, and vehicle. Behavioral tests were done before and after treatment. METHODS: The serum Serotonin and Corticosterone and the expression of some hippocampal signaling proteins were studied. Furthermore, bioinformatics tools were used to predict the interactions of Crocin/ Crocetin with the Serotonin transporter and NMDA receptor subunit NR2B. Then, the patch-clamp was used to study the interaction of Crocetin with the NMDA receptor. RESULTS: Various behavioral tests confirmed the induction of depression and the improvement of depression by these natural carotenoids. In addition, Crocin/ Crocetin significantly increased the decreased serum Serotonin and reduced the increased serum Corticosterone in the depressed groups. They also increased or caused a trend of increase in the CREB, ERK, BAD, BDNF, p11, and 5-HT1B expression in the hippocampus of the depressed groups. In addition, there were an increase or a trend in p-CREB/CREB, p-ERK1/2 /ERK1/2, and p-BAD/BAD ratios in the Crocin/ Crocetin treated depressed groups. However, the NR2B and FOXO3a expression showed a trend of decrease in depressed groups after treatment. The bioinformatics data indicated that Crocin/ Crocetin could bind to the Serotonin transporter (SLC6A4) and NR2B subunit of the NMDA receptor. Both carotenoids bind to the same site as Fluoxetine in the SLC6A4. However, they bound to different sites on the NR2B. So, Crocetin binds to NR2B at the same site as Ifenprodil. But Crocin bound to another site. The whole cell patch-clamp recording on the normal rat hippocampus revealed a significant decrease in the NMDA peak amplitude after Crocetin treatment, indicating its inhibitory effect on this receptor. CONCLUSION: The antidepressant activities of Crocin/ Crocetin are possibly due to their effects on Serotonin and Corticosterone serum concentrations, NR2B expression, and the downstream signaling pathways. Furthermore, these natural carotenoids, like Fluoxetine, induced an increasing tendency in p11 and 5HT1B in depressed rats.

Antidepressant evaluation of Andrographis paniculata Nees extract and andrographolide in chronic unpredictable stress zebrafish model.

Andrographis paniculata (A. paniculata) showed an anti-depressive effect in rodent models. Zebrafish has recently emerged as a worthy complementary translational model for antidepressant drug discovery study. This study investigates the anti-depressive effect of A. paniculata extract and andrographolide in the chronic unpredictable stress (CUS)- zebrafish model. Four groups of zebrafish (n = 10/group), i.e. control, CUS (stressed, untreated), CUS + A. paniculata (100 mg/L) and CUS + fluoxetine (0.01 mg/L) were assessed in open-field and social interaction tests, 24 h after treatment. After extract screening, behavioural and cortisol analysis of andrographolide (5, 25 and 50 mg/kg, i.p.) and fluoxetine (10 mg/kg, i.p.) were evaluated. Before the behavioural study, acute toxicity and characterization of A. paniculata extract using UHPLC-ESI-MS/MS were performed. A significant reduction in freezing duration was found in A. paniculata- (t-test, p = 0.0234) and fluoxetine-treated groups (t-test, p < 0.0001) compared to the CUS group. A significant increase in total distance travelled, and contact duration was observed only in the fluoxetine-treated group (t-test, p = 0.0007) and (t-test, p = 0.0207), respectively. A significant increase in highly mobile duration was observed in both treatment groups. Andrographolide (50 mg/kg, i.p.) acute treatment showed a significant reduction in freezing duration (p = 0.0042), duration in a dark area (p = 0.0338) and cortisol level (p = 0.0156) and increased total distance travelled (p = 0.0144). Twenty-six compounds were tentatively characterized by LC-MS/MS method, and andrographolide content is 0.042 µg/g. According to cortisol analysis, A. paniculata's LC50 is 627.99 mg/L, while andrographolide's EC50 was determined as 26.915 mg/kg. Further assessment of the cellular and molecular underpinnings of the anti-depressive effect of andrographolide is strongly recommended to evaluate the potential as an antidepressant.

14-3-3ζ Plays a key role in the modulation of neuroplasticity underlying the antidepressant-like effects of Zhi-Zi-Chi-Tang.

BACKGROUND: Zhi-Zi-Chi-Tang (ZZCT) is an effective traditional Chinese medicinal formula. ZZCT has been used for the treatment of depression for centuries. Its clinical efficacy in relieving depression has been confirmed. However, the molecular mechanisms of ZZCT regarding neuroplasticity in the pathogenesis of depression have not yet been elucidated. PURPOSE: The present study aimed to examine the effects of ZZCT on neuroplasticity in mice exposed to chronic unpredictable mild stress (CUMS), and to explore the underlying molecular mechanisms. METHODS: For this purpose, a murine model of depression was established using the CUMS procedure. Following the intragastric administration of ZZCT or fluoxetine, classic behavioral experiments were performed to observe the efficacy of ZZCT as an antidepressant. Immunofluorescence was used to label and quantify microtubule-associated protein (MAP2) and postsynaptic density protein (PSD95) in the hippocampus. Golgi staining was applied to visualize the dendritic spine density of neurons in the hippocampi. Isolated hippocampal slices were prepared to induce long-term potentiation (LTP) in the CA1 area. The hippocampal protein expression levels of glycogen synthase kinase-3ß (GSK-3ß), p-GSK-3ß (Ser9), cAMP response element binding protein (CREB), p-CREB (Ser133), brain-derived neurotrophic factor (BDNF) and 14-3-3ζ were detected using western blot analysis. The interaction of 14-3-3ζ and p-GSK-3ß (Ser9) was examined using co-immunoprecipitation. LV-shRNA was used to knockdown 14-3-3ζ by an intracerebroventricular injection. RESULTS: ZZCT (6 g/kg) and fluoxetine (20 mg/kg) alleviated depressive-like behavior, restored hippocampal MAP2+ PSD95+ intensity, and reversed the dendritic spine density of hippocampal neurons and LTP in the CA1 region of mice exposed to CUMS. Both low and high doses of ZZCT (3 and 6 g/kg) significantly promoted the binding of 14-3-3ζ to p-GSK-3ß (Ser9) in the hippocampus, and ZZCT (6 g/kg) significantly promoted the phosphorylation of GSK-3ß Ser9 and CREB Ser133 in the hippocampus. ZZCT (3 and 6 g/kg) upregulated hippocampal BDNF expression in mice exposed to CUMS. LV-sh14-3-3ξ reduced the antidepressant effects of ZZCT. CONCLUSION: ZZCT exerted antidepressant effects against CUMS-stimulated depressive-like behavior mice. The knockdown of 14-3-3ζ using lentivirus confirmed that 14-3-3ζ was involved in the ZZCT-mediated antidepressant effects through GSK-3ß/CREB/BDNF signaling. On the whole, these results suggest that the antidepressant effects of ZZCT are attributed to restoring damage by neuroplasticity enhancement via the 14-3-3ζ/GSK-3ß/CREB/BDNF signaling pathway.

The effects of acupuncture on depression by regulating BDNF-related balance via lateral habenular nucleus BDNF/TrkB/CREB signaling pathway in rats.

Depression is a major mental disease worldwide, causing dysfunction of Lateral Habenular (LHb). As a non-invasive alternative, acupuncture (AP) has been widely used to treat depression in clinic, yet few basic studies have been focused on the effects and mechanism of acupuncture on synaptic plasticity in LHb. Therefore, this study aimed to explore the potential mechanism of the antidepressant effect of acupuncture. Male Sprague-Dawley (SD) rats were randomly divided into control, chronic unpredictable mild stress (CUMS), AP, fluoxetine (FLX), acupoint catgut embedding (ACE), sham-ACE groups (n = 9/group). Rats were given a 28-day treatment at the Shangxing (GV23) and Fengfu (GV16) acupoints with acupuncture, ACE, sham-ACE or fluoxetine (2.1 mg/kg). The results showed that AP, FLX and ACE suppressed the behavioral deficits, increased the level of the 5-hydroxytryptamine and FNDC5/IRISIN in serum, also reduced the expression of pro-BDNF impacted by CUMS. Both AP and FLX ameliorated the %area of IBA-1, GFAP, BrdU and DCX in the LHb and increased the expression of BDNF/TrkB/CREB, with non-significant difference between the two groups These findings suggest that AP therapy relieves depression-related manifestations in depressed rats, suggesting a potential mechanism via the BDNF/TrkB/CREB pathway in LHb.

Acupuncture Alleviates CUMS-Induced Depression-Like Behaviors by Restoring Prefrontal Cortex Neuroplasticity.

Purpose: To explore the therapeutic efficiency of acupuncture and the related molecular mechanism of neural plasticity in depression. Methods: Chronic unpredictable mild stress- (CUMS-) induced rats were established for the depression animal model. There were a total of four rat groups, including the control group, the CUMS group, the CUMS+acupuncture group, and the CUMS+fluoxetine group. The acupuncture group and the fluoxetine group were given a 3-week treatment after the modeling intervention. The researcher performed the open-field, elevated plus maze, and sucrose preference tests to evaluate depressive behaviors. The number of nerve cells, dendrites' length, and the prefrontal cortex's spine density were detected using Golgi staining. The prefrontal cortex expression, such as BDNF, PSD95, SYN, and PKMZ protein, was detected using the western blot and RT-PCR. Results: Acupuncture could alleviate depressive-like behaviors and promote the recovery of the neural plasticity functions in the prefrontal cortex, showing the increasing cell numbers, prolonging the length of the dendrites, and enhancing the spine density. The neural plasticity-related proteins in the prefrontal cortex, including BDNF, PSD95, SYN, and PKMZ, were all downregulated in the CUMS-induced group; however, these effects could be partly reversed after being treated by acupuncture and fluoxetine (P < 0.05). Conclusion: Acupuncture can ameliorate depressive-like behaviors by promoting the recovery of neural plasticity functions and neural plasticity-related protein upregulation in the prefrontal cortex of CUMS-induced depressed rats. Our study provides new insights into the antidepressant approach, and further studies are warranted to elucidate the mechanisms of acupuncture involved in depression treatment.

Effects of fluoxetine withdrawal in the brainstem and hypothalamus of overnourished rats: Chronic modulation on oxidative stress levels.

Poor nutritional quality in the early stages of development is associated with neurological diseases in adulthood. Studies showed that obesity-induced oxidative stress contributes to the genesis of neurological diseases through dysregulation of the brainstem and hypothalamus. Fluoxetine (Fx) is an antidepressant member in the family of selective serotonin reuptake inhibitors (SSRI) that can induce positive effects by reducing oxidative damage in brain tissues. We aimed to evaluate the late effect of Fx in the brainstem and hypothalamus of overnourished rats during development. Male Wistar rats, after birth, were randomly divided into the normal-nourished group (N, n = 9) and the overnourished group (O, n = 3). On the 39th day of life, the groups were subdivided into normofed, and the overnourished group treated or not with fluoxetine (10 mg/kg daily) (NF, NV, OF, and OV). All groups were treated from the 39th to the 59th day of life, and within 90 days, the tissues were collected for oxidative stress analysis. Briefly, our results showed that Fx treatment induced a tissue-dependent long-lasting effect in overfed animals, increasing the enzymatic defense (i.e., CAT and GST activity) in the hypothalamus, but more intensive, increasing the non-enzymatic defense (i.e., Total Thiols and GSH levels) in the brainstem. Overall, our study suggests that serotonin modulation at the final stage of brain development causes a long-lasting impact on brain structures in overfed rats at a different mode.

Effect of Bromelain on Chronic Unpredictable Stress-induced Behavioral, Biochemical, and Monoamine Changes in Wistar Albino Rat Model of Depression.

BACKGROUND: Bromelain is a complex mixture of protease enzyme extract from the fruit or stem of the pineapple plant and it has a history of folk medicine use. It is known to have a wide range of biological actions and it is most commonly used as an anti-inflammatory agent, though scientists have also discovered its potential as an anticancer and antimicrobial agent, it has been reported to have positive effects on the respiratory, digestive, circulatory systems and potentially on the immune system. OBJECTIVE: This study was designed to investigate the antidepressant potential of Bromelain in the chronic unpredictable stress (CUS) model of depression. METHODS: We studied the antioxidant activity, and neuroprotective effect of Bromelain by analyzing the fear and anxiety behavior, antioxidants, and neurotransmitter levels, and also by analyzing the histopathological changes. Adult male Wistar albino rats were divided into 5 groups, Control; Bromelain; CUS; CUS + Bromelain, CUS + fluoxetine. Animals of the CUS group, CUS + Bromelain group, and CUS + Fluoxetine group were exposed to CUS for 30 days. Animals of the Bromelain group and CUS + Bromelain group were treated orally with 40 mg/kg Bromelain throughout the period of CUS whereas, the positive control group was treated with fluoxetine. RESULTS: Results showed a significant decrease in oxidative stress marker (lipid peroxidation), and the stress hormone cortisol, in Bromelain-treated CUS-induced depression. Bromelain treatment in CUS has also resulted in a significant increase in neurotransmitter levels, which indicates the efficacy of Bromelain to counteract the monamine neurotransmitter changes in depression by increasing their synthesis and reducing their metabolism. In addition, the antioxidant activity of Bromelain prevented oxidative stress in depressed rats. Also, hematoxylin and eosin staining of hippocampus sections has revealed that Bromelain treatment has protected the degeneration of nerve cells by chronic unpredictable stress exposure. CONCLUSION: This data provides evidence for the antidepressant-like action of Bromelain by preventing neurobehavioral, biochemical, and monoamine alterations.

Pairing with Enriched Sound Exposure Restores Auditory Processing Degraded by an Antidepressant.

Antidepressants, while effective in treating depression and anxiety disorders, also induce deficits in sensory (particularly auditory) processing, which in turn may exacerbate psychiatric symptoms. How antidepressants cause auditory signature deficits remains largely unknown. Here, we found that fluoxetine-treated adult female rats were significantly less accurate when performing a tone-frequency discrimination task compared with age-matched control rats. Their cortical neurons also responded less selectively to sound frequencies. The degraded behavioral and cortical processing was accompanied by decreased cortical perineuronal nets, particularly those wrapped around parvalbumin-expressing inhibitory interneurons. Furthermore, fluoxetine induced critical period-like plasticity in their already mature auditory cortices; therefore, a brief rearing of these drug-treated rats under an enriched acoustic environment renormalized auditory processing degraded by fluoxetine. The altered cortical expression of perineuronal nets was also reversed as a result of enriched sound exposure. These findings suggest that the adverse effects of antidepressants on auditory processing, possibly because of a reduction in intracortical inhibition, can be substantially alleviated by simply pairing drug treatment with passive, enriched sound exposure. They have important implications for understanding the neurobiological basis of antidepressant effects on hearing and for designing novel pharmacological treatment strategies for psychiatric disorders.SIGNIFICANCE STATEMENT Clinical experience suggests that antidepressants adversely affect sensory (particularly auditory) processing, which can exacerbate patients' psychiatric symptoms. Here, we show that the antidepressant fluoxetine reduces cortical inhibition in adult rats, leading to degraded behavioral and cortical spectral processing of sound. Importantly, fluoxetine induces a critical period-like state of plasticity in the mature cortex; therefore, a brief rearing under an enriched acoustic environment is sufficient to reverse the changes in auditory processing caused by the administration of fluoxetine. These results provide a putative neurobiological basis for the effects of antidepressants on hearing and indicate that antidepressant treatment combined with enriched sensory experiences could optimize clinical outcomes.

Antidepressant Potential of a Functionalized 3-Selanyl Benzo[b]Furan Compound in Mice: Focus on the Serotonergic System.

The present study investigated the antidepressant-like potential of a functionalized 3-selanyl benzo[b]furan (SeBZF) in male Swiss mice. To evaluate possible antidepressant-like actions, the compounds SeBZF1-5 (50 mg/kg, intragastric, i.g., route) were acutely screened in the tail suspension tests (TSTs). The compound 3-((4-methoxyphenyl)selanyl)-2-phenylbenzofuran (SeBZF3) was then selected. Dose-response and time-response curves revealed that SeBFZ3 exerts antidepressant-like effects in the TST (5-50 mg/kg) and forced swimming test (FST; 50 mg/kg). Additional tests demonstrated that pretreatment with receptor antagonists WAY100635 (5-HT1A; 0.1 mg/kg, subcutaneous route), ketanserin (5-HT2A/C; 1 mg/kg, intraperitoneal, i.p.), or ondansetron (5-HT3; 1 mg/kg, i.p.) blocked the SeBZF3 antidepressant-like effects (50 mg/kg) in the TST. In addition, the coadministration of subeffective doses of SeBZF3 (1 mg/kg, i.g.) and fluoxetine (a selective serotonin reuptake inhibitor; 5 mg/kg, i.p.) produced synergistic action. A high dose of SeBZF3 (300 mg/kg) did not produce oral acute toxicity. The present results provide evidence for the antidepressant-like action of SeBZF3 and its relative safety, as well as predict the possible interactions with the serotonergic system, aiding in the development of novel options to alleviate psychiatric disabilities.

Fast-onset effects of Pseudospondias microcarpa (A. Rich) Engl. (Anacardiaceae) hydroethanolic leaf extract on behavioral alterations induced by chronic mild stress in mice.

INTRODUCTION: Pseudospondias microcarpa (Anacardiaceae) is a plant widely used traditionally for treating various central nervous system disorders. A previous study in our laboratory confirmed that the hydroethanolic leaf extract (PME) of the plant produces an antidepressant-like effect in rodent models of behavioral despair. However, its effect on depressive-like behavior induced by chronic mild stress (CMS) and its time course of action are still unknown. In this context, the long-term effects of PME on cognitive function and depressive- and anxiety-like behavior caused by CMS were assessed. METHODS: Male ICR mice were exposed to CMS for nine weeks and anhedonia was evaluated by monitoring sucrose intake (SIT) weekly. PME (30, 100, or 300 mg kg-1) or fluoxetine (FLX) (3, 10, or 30 mg kg-1) was administered to the mice during the last six weeks of CMS. Behavioral tests-coat state, splash test, forced swimming test (FST), tail suspension test (TST), elevated plus maze (EPM), open field test (OFT), novelty suppressed feeding (NSF), EPM transfer latency, and Morris water maze (MWM)-were performed after the nine-week CMS period. RESULTS: When the mice were exposed to CMS, their SIT and grooming behavior reduced (splash test), their coat status was poor, they became more immobile (FST and TST), more anxious (OFT, EPM, and NSF), and their cognitive function was compromised (EPM transfer latency and MWM tests). Chronic PME treatment, however, was able to counteract these effects. Additionally, following two (2) weeks of treatment, PME significantly boosted SIT in stressed mice (30 mg kg-1, P<0.05; 100 mg kg-1, P<0.05; and 300 mg kg-1, P<0.001), as compared to four (4) weeks of treatment with FLX. CONCLUSION: The present findings demonstrate that PME produces a rapid and sustained antidepressant-like action and reverses behavioral changes induced by chronic exposure to mild stressors.