Duration Of Immobility In Forced Swim Test Research Articles

Protective effects of a novel 5-HT3 receptor antagonist, N-n-butyl-3-methoxy quinoxaline-2-carboxamide (6o) against chronic unpredictable mild stress-induced behavioral changes and biochemical alterations

Stimulation of high oxidative stress in the brain is considered as an important factor for neurotoxicity towards the pathophysiology of chronic stress-induced depression disorder. In the present research, a potential 5-HT3 receptor antagonist N-n-butyl-3-methoxy quinoxaline-2-carboxamide (6o) having good Log P (2.60) and pA2 (7.7) values was examined for its effect on the behavioral and biochemical changes induced by the chronic unpredictable mild stress (CUMS) model. In the current investigation mice were introduced to different stress procedures daily for a period of 28days to induce a depressive-like behavior. The results show that CUMS caused a depression-like behavior in mice, as indicated by the significant decrease in sucrose consumption and locomotor activity and increase in immobility in the forced swim test (FST). Moreover, it was found that oxidative stress markers such as lipid peroxide and nitrite levels were significantly increased, whereas, antioxidant enzymes such as glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) levels were decreased in the brain tissue of CUMS-subjected mice. “Compound 6o” (1 and 2mg/kg, p.o.) and fluoxetine treatment (20mg/kg, p.o.) for a period of 21days altered the CUMS-induced behavioral (increased immobility period, reduced sucrose preference and decreased locomotor activity) and biochemical (increased lipid peroxide, increased brain nitrite; decreased GSH, SOD and CAT levels) alterations. Moreover normal mice treated with “compound 6o” (2mg/kg, p.o.) showed a significant decrease in the duration of immobility in FST as compared to normal vehicle treated mice. In conclusion, “compound 6o” produced antidepressant-like effects in behavioral despair paradigm in chronically stressed mice by restoring antioxidant enzyme activity.

Antidepressant effects of insulin in streptozotocin induced diabetic mice: Modulation of brain serotonin system

Diabetes is a persistent metabolic disorder, which often leads to depression as a result of the impaired neurotransmitter function. Insulin is believed to have antidepressant effects in depression associated with diabetes; however, the mechanism underlying the postulated effect is poorly understood. In the present study, it is hypothesized that insulin mediates an antidepressant effect in streptozotocin (STZ) induced diabetes in mice through modulation of the serotonin system in the brain. Therefore, the current study investigated the antidepressant effect of insulin in STZ induced diabetes in mice and insulin mediated modulation in the brain serotonin system. In addition, the possible pathways that lead to altered serotonin levels as a result of insulin administration were examined. Experimentally, Swiss albino mice of either sex were rendered diabetic by a single intraperitoneal (i.p.) injection of STZ. After one week, diabetic mice received a single dose of either insulin or saline or escitalopram for 14days. Thereafter, behavioral studies were conducted to test the behavioral despair effects using forced swim test (FST) and tail suspension test (TST), followed by biochemical estimations of serotonin concentrations and monoamine oxidase (MAO) activity in the whole brain content. The results demonstrated that, STZ treated diabetic mice exhibited an increased duration of immobility in FST and TST as compared to non-diabetic mice, while insulin treatment significantly reversed the effect. Biochemical assays revealed that administration of insulin attenuated STZ treated diabetes induced neurochemical alterations as indicated by elevated serotonin levels and decreased MAO-A and MAO-B activities in the brain. Collectively, the data indicate that insulin exhibits antidepressant effects in depression associated with STZ induced diabetes in mice through the elevation of the brain serotonin levels.

Antidepressant activity of brahmi in albino mice.

In traditional system of medicine brahmi has been used to enhance memory. Recently it has been reported to have action in psychiatric disorders. With these backgrounds the work has been undertaken to study antidepressant activity of brahmi in albino mice. To evaluate antidepressant activity of brahmi in experimental models. The antidepressant activity was studied in albino mice using forced swimming test (FST), tail suspension test (TST) and shock induced depression (SID). Imipramine (10mg/kg), fluoxetine (30mg/kg) were used as standard drugs and brahmi (10, 20, 30mg/kg) was used as test drug. Brahmi exhibited significant decrease in duration of immobility in FST and reduced the shock induced decrease in activity in SID models. It didn't show any activity in the TST model. Brahmi has shown antidepressant activity in FST and SID.

Antidepressant-like effects of tea polyphenols on mouse model of chronic unpredictable mild stress

Tea polyphenols (TPs), which are the natural compounds extracted from tea leaves, possess a number of beneficial properties, such as reducing the risks of cancer and heart diseases, alleviating cognitive impairments and showing antidepressant-like activity in the forced swim test (FST) and tail suspension test (TST). The present study was designed to investigate the protective effect of TPs on the chronic unpredictable mild stress (CUMS)-induced depression model in mice and to elucidate the related underlying mechanisms. With the daily exposure to stressor for 5 consecutive weeks, TPs were administered in mice at a daily dose of 25mg/kg or 50mg/kg by gavage for 3 consecutive weeks from the 3rd week. Our results showed that CUMS significantly decreased the levels of serum serotonin (5-HT) and norepinephrine (NE) in the hippocampus, the prefrontal cortex and serum, and the activities of superoxide dismutase (SOD) and catalase (CAT), with an increase in lipid peroxidation level as well as a reduction in glutathione (GSH) level and an elevation in the production of malondialdehyde (MDA) in the hippocampus and the prefrontal cortex. CUMS also reduced open-field activity, sucrose consumption, as well as increased immobility duration in FST and TST. TPs administration could effectively reverse the alterations in the concentrations of 5-HT and NE, elevate the activities of SOD and CAT as well as the level of GSH, reduce the MDA level and inhibit lipid peroxidation. Moreover, TPs could effectively reverse alterations in immobility duration, sucrose consumption and open-field activity. In conclusion, TPs administration has exhibited significant antidepressant-like effects in mice with CUMS-induced depression. The antidepressant activity of TPs might be related to the alteration of monoaminergic responses and antioxidant defenses.

Effect of aqueous extract and fractions of Zhi-Zi-Hou-Pu decoction against depression in inescapable stressed mice: Restoration of monoamine neurotransmitters in discrete brain regions

Context: Zhi-Zi-Hou-Pu decoction (ZZHPD) is a traditional prescription which has been used to treat “Yu-syndrome” (depression and melancholia) in Chinese herbal medication.Objective: To evaluate antidepressant activities of ZZHPD, its fractions and possible mechanism(s) of action.Materials and methods: ZZHPD (1241, 2482 and 4964 mg/kg), n-butanol fraction (ZH-BA, 1454 mg/kg), cyclohexane fraction (ZH-CH, 17 mg/kg) and aqueous fraction (ZH-AQ, 3493 mg/kg) were administered orally to different groups of mice for seven consecutive days. Forced Swimming Test (FST) and Tail Suspension Test (TST) were conducted 60 min after the last administration to evaluate the antidepressant effect. Norepinephrine, dopamine and 5-hydroxytryptamine levels in discrete brain parts were determined by HPLC-FD immediately after behavioral tests. Results: ZZHPD at 2482, 4964 mg/kg, ZH-BA (1454 mg/kg), ZH-CH (17 mg/kg) or clomipramine hydrochloride (20 mg/kg) significantly (p < 0.05) reduced the duration of immobility in FST and TST without affecting locomotor activities in the Open Field Test. Observed from score plot of Principle Component Analysis of monoamine levels in different groups, the monoamine profile of ZZHPD-treated mice were similar to that of the normal control mice. HPLC-UV analysis indicated that iridoid glycosides, flavones and neolignans might be the active chemicals.Discussion and conclusion: The results demonstrated significant antidepressant-like effect of ZZHPD in mice which was related to monoaminergic system, ZH-BA and ZH-CH could be the active fractions responsible for the antidepressant effect of ZZHPD.

Antidepressant-like effects of the extract from Cimicifuga foetida L.

Ethnopharmacological relevance: Cimicifuga foetida L., a traditional Chinese medicine, has been developed for the treatment of perimenopausal symptoms including depression in China (Brand name: XIMINGTING®, XMT). The primary active constituents are believed to be the triterpene glycosides. Nevertheless, there are no studies about the antidepressant-like effects of XMT in rodents. Aims of the studyThe present study aimed to evaluate antidepressant-like effects of XMT. Materials and methodsAntidepressant-like activity of XMT was studied using forced swimming test (FST) and tail suspension test (TST) in female mice, as well as chronic mild stress (CMS) procedure in female rats. In addition, 5-hydroxytryptophan (5-HTP)-induced head-twitch test and yohimbine toxicity potentiation test in female mice were conducted to propose the possible serotonergic or noradrenergic mechanisms in the antidepressant-like effects of XMT. In mice, XMT was administrated acutely and for 7 consecutive days (20, 40 and 80mg/kg/day, p.o.); and in rats for 28 consecutive days (10, 20 and 40mg/kg/day, p.o.). ResultsXMT significantly reduced immobility duration in FST and TST without affecting locomotor activity, increased swimming and climbing durations in FST, and enhanced 5-HTP-induced head-twitch response while did not affect yohimbine-induced lethality in female mice. XMT also normalized the inhibition of sucrose intake and decreased the levels of plasma adrenocorticotropic hormone and serum corticosterone and adrenal gland weight in CMS-treated female rats. ConclusionsThese data indicate XMT processes antidepressant-like properties in rodents, which could be related to its serotonergic and noradrenergic activation and normalization of the hypothalamic-pituitary-adrenal axis.

Antidepressant Potential of 5-HT3 Receptor Antagonist, N-n- propyl-3-ethoxyquinoxaline-2-carboxamide (6n)

The present study was designed to evaluate the antidepressant potential of 5-HT3 receptor antagonist N-n-propyl-3-ethoxyquinoxaline-2-carboxamide (6n). The compound ‘6n’ with optimum log P and pA2 value identified from a series of compounds synthesized in our laboratory was subjected to forced Swim Test (FST) (1, 2, and 4 mg/kg, i.p) and Tail Suspension Test (TST) (1, 2, and 4 mg/kg, i.p.). The compound ‘6n’ significantly reduced the duration of immobility in mice without affecting the baseline locomotion. Moreover, ‘6n’ (2 mg/kg, i.p.) potentiated the 5-hydroxytryptophan (5-HTP)-induced head twitch responses in mice and ‘6n’ at tested dose (1 and 2 mg/kg, i.p.) reversed the reserpine-induced hypothermia in rats. In interaction studies of ‘6n’ with various standard drugs/ligands using FST, ‘6n’ (1 mg/kg, i.p.) potentiated the antidepressant effect of venlafaxine (4 and 8 mg/kg, i.p.) and fluoxetine (10 and 20 mg/kg, i.p.). Additionally, ‘6n’ (1 and 2 mg/kg, i.p.) influenced the effect of harmane (5 mg/ kg, i.p.) as well as reversed the effect of parthenolide (1 mg/kg, i.p.) by reducing the duration of immobility in FST. Furthermore, ‘6n’ (1 mg/kg, i.p.) potentiated the effect of bupropion (10 and 20 mg/kg, i.p.) in TST. Chronic ‘6n’ (1 and 2 mg/kg, i.p.) treatment attenuated the behavioral abnormalities in olfactory bulbectomized rats. In conclusion, these various findings reiterated the antidepressant-like effects of ‘6n’ in behavioral models of depression.

Ketamine-enhanced immobility in forced swim test: A possible animal model for the negative symptoms of schizophrenia

Schizophrenia is a chronic and highly complex psychiatric disorder characterised by cognitive dysfunctions, negative and positive symptoms. The major challenge in schizophrenia research is lack of suitable animal models that mimic the core behavioural aspects and symptoms of this devastating psychiatric disorder. In this study, we used classical and atypical antipsychotic drugs to examine the predictive validity of ketamine-enhanced immobility in forced swim test (FST) as a possible animal model for the negative symptoms of schizophrenia. We also evaluated the effects of a selective serotonin reuptake inhibitor (SSRI) on the ketamine-enhanced immobility in FST. Repeated administration of a subanaesthetic dose of ketamine (30 mg kg(-1), i.p., daily for 5 days) enhanced the duration of immobility in FST 24 h after the final injection. The effect, which persisted for at least 21 days after withdrawal of the drug, was neither observed by single treatment with ketamine (30 mg kg(-1) i.p.) nor repeated treatment with amphetamine (1 and 2 mg kg(-1) i.p., daily for 5 days). The enhancing effects of ketamine (30 mg kg(-1) day(-1) i.p.) on the duration of immobility in the FST were attenuated by clozapine (1, 5 and 10 mg kg(-1) i.p.), risperidone (0.25 and 0.5 mg kg(-1) i.p.) and paroxetine (1 and 5 mg kg(-1) i.p.). Haloperidol (0.25 and 0.50 mg kg(-1) day(-1) i.p.) failed to attenuate the ketamine-enhanced immobility in the FST. The repeated ketamine administration neither affects locomotor activity nor motor coordination in rats under the same treatment conditions with the FST, suggesting that the effects of ketamine on the duration of immobility in this study was neither due to motor dysfunction nor peripheral neuromuscular blockade. Our results suggest that repeated treatment with subanaesthetic doses of ketamine enhance the duration of immobility in FST, which might be a useful animal model for the negative symptoms (particularly the depressive features) of schizophrenia.

Antidepressant-like effect of genipin in mice

The present study aimed to investigate the antidepressant potential of genipin and its possible mechanisms. Mouse models of depression including the forced swimming test (FST) and the tail suspension test (TST) were used to evaluate the effects of genipin. A possible mechanism was explored in the test of antagonism of reserpine-induced ptosis and hypothermia in mice. The contents of monoamine neurotransmitters and their metabolites including epinephrine (NE), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in mice hippocampi were determined by HPLC–ECD. The results showed that intra-gastric administration of genipin at 50, 100, 200 mg/kg or fluoxetine at 7.5 mg/kg for 7 days significantly reduced the duration of immobility in FST and TST, while it did not affect the locomotor activity in the open field test (OFT). However, the effect was not dose-dependent. When the mice were treated with genipin or fluoxetine for 7 days, both of them could antagonize reserpine-induced ptosis and hypothermia. The 5-HT and NE contents in mice hippocampi were decreased after the peritoneal injection of reserpine at 2.0 mg/kg. The pre-treatment with genipin at 50, 100, 200 mg/kg or fluoxetine at 7.5 mg/kg for 7 days could elevate the contents of NE and 5-HT in mice hippocampi significantly. The results suggest that compared with fluoxetine, genipin exerts antidepressant-like effects significantly. A possible mechanism, at least in part, is the regulation of the 5-HT and NE levels in the hippocampus.

Depressive-like behavior in mice recently recovered from motor disorders after 3-nitropropionic acid intoxication

Striatum may be involved in depressive disorders according to the neuroimaging analysis and clinical data. However, no animal model at present supported the possible role of striatum in the pathogenesis of depression. In the present study, we have investigated the depressive-like behavior in mice recently intoxicated with 3-nitropropionic acid (3-NP), a widely known toxin that selectively damages the striatum in the brain. Mouse model was made with subacute systemic 3-NP treatment, and the depressive-like behavior was measured using the duration of immobility during forced swimming test (FST). When the mice at day 15 post-intoxication just totally recovered from motor deficits, the duration of immobility in FST was significantly longer than that in controls. The depressive-like behavior was not due to the fatigue or general sickness following 3-NP intoxication and could be reversed by the antidepressant, desipramine hydrochloride. In two successive FST in 24 h interval, the depressive-like behavior could be observed again in subsequent FST (at day 16 post-intoxication), and the mice presented a normal "learned helplessness". A novel depression animal model could be established in mice during the initial period of recovery from 3-NP intoxication. The depression-like behavior might occur independently without involvement of cognitive defects, and the striatal lesions may underlie the depression-like behavior attributable to 3-NP intoxication.