A Network Pharmacology-Based Study on Antidepressant Effect of Salicornia europaea L. Extract with Experimental Support in Chronic Unpredictable Mild Stress Model Mice / 中国结合医学杂志

OBJECTIVE@#To investigate the pharmacodynamic material basis, mechanism of actions and targeted diseases of Salicornia europaea L. (SE) based on the network pharmacology method, and to verify the antidepressant-like effect of the SE extract by pharmacological experiments.@*METHODS@#Retrieval tools including Chinese medicine (CM), PubMed, PharmMapper, MAS 3.0 and Cytoscape were used to search the components of SE, predict its targets and related therapeutic diseases, and construct the "Component-Target-Pathway" network of SE for central nervous system (CNS) diseases. Further, protein-protein interaction (PPI) network, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) function annotation of depression-related targets were analyzed to predict the antidepressant mechanism of SE. Chronic unpredictable mild stress (CUMS) model was used to construct a mouse model with depression-like symptoms. And the animals were randomly divided into 6 groups (n=10) including the normal group (nonstressed mice administered with distilled water), the CUMS group (CUMS mice administered with distilled water), the venlafaxine group (CUMS mice administered with venlafaxine 9.38 mg/kg), SE high-, medium-, and low-dose groups (CUMS mice administered with SE 1.8, 1.35 and 0.9 g/kg, respectively). Then some relevant indicators were determined for experimental verification by the forced swim test (FST), the tail suspension test (TST) and open-field test (OFT). Dopamine (DA) concentration in hippocampus and cerebral cortex, IL-2 and corticosterone (CORT) levels in blood, and nuclear factor E2 related factor 2 (Nrf2), kelch-like epichlorohydrin related protein 1 (Keap1), NAD(P) H dehydrogenase [quinone] 1 (NQO1) and heme oxygenase-1 (HO-1) levels in mice were measured by enzyme linked immunosorbent assay (ELISA) and Western blot respectively to explore the possible mechanisms.@*RESULTS@#The "target-disease" network diagram predicted by network pharmacology, showed that the potential target of SE involves a variety of CNS diseases, among which depression accounts for the majority. The experimental results showed that SE (1.8, 1.35 g/kg) significantly decreased the immobility period, compared with the CUMS group in FST and TST in mice after 3-week treatment, while SE exhibited no significant effect on exploratory behavior in OFT in mice. Compared with CUMS group, the SE group (0.9 g/kg) showed significant differences (P<0.05) in DA levels in the hippocampus and cerebral cortex. In addition, compared with CUMS control group, SE (1.8 g/kg) group showed a significant effect on decreasing the activities of CORT (P<0.05), and serum IL-2 level with no statistical significance. Finally, Western blot results showed that compared with the model group, Nrf2, Keap1, NQO1 and HO-1 protein expressions in SE group (1.8 g/kg) were up-regulated (all P<0.01).@*CONCLUSION@#The SE extract may have an antidepressant effect, which appeared to regulate Nrf2-ARE pathway and increased levels of DA and CORT in the hippocampus and cortex.

Antidepressant-like activity of ethanol extract of leaves of Caesalpinia pulcherrima in unstressed and stressed mice

In the present study, antidepressant-like activity of ethanol extract of leaves of Caesalpinia pulcherrima was evaluated in Swiss young male albino mice. Stress was induced in mice by subjecting them to unpredictable mild stress for 21 successive days. Ethanol extract of the leaves (100, 200 and 400 mg/ kg, p.o.) and fluoxetine (20 mg/kg, p.o.) were administered for 21 consecutive days to separate groups of unstressed and stressed mice. Ethanol extract (200 and 400 mg/kg) and fluoxetine significantly decreased immobility period of unstressed as well as stressed mice in tail suspension test (TST). However, the lowest dose (100 mg/kg) of the extract also significantly decreased immobility period of stressed mice in TST. The extract significantly restored reduced sucrose preference in stressed mice. There was no significant effect on locomotor activity of mice. Ethanol extract of the leaves significantly decreased plasma nitrite and corticosterone levels; brain MAO-A activity and MDA level; and increased brain reduced glutathione and catalase activity in unstressed as well as stressed mice as compared to their respective vehicle treated controls. Thus, ethanol extract of leaves of Caesalpinia pulcherrima showed significant antidepressant-like activity in unstressed and stressed mice probably through inhibition of brain MAO-Aactivity, reduction of oxidative stress and plasma corticosterone levels.

Evaluation of antidepressant activity of hydro-alcoholic extract of rhizomes of Nardostachys jatamansi DC per se and in combination with fluoxetine in wistar albino rats and swiss albino mice

Background: Depression is a common mental disorder results due to deficiency of neurotransmitter in the brain. Various medicinal properties of jatamansi are mentioned in Ayurveda. This study evaluated effect of hydro-alcoholic extract of rhizomes of Nordostachys jatamansi DC per se and in combination with fluoxetine in wistar albino rats and swiss albino mice.Methods: Animals of either sex were selected and randomly divided in test group. Jatamansi extract 10:1 and fluoxetine hydrochloride dissolved in distilled water were used. Animals were tested for forced swimming test, tail suspension test and locomotor after given test drug. Results were compared with control and analysed.Results: Nardostachys jatamansi DC, when given to rats showed dose dependent increase in number of rotation during forced swimming test in rats. During forced swimming test in glass jar statistically significant decrease in immobility was observed. Nardostachys jatamansi DC, when given to mice dose dependent statistically significant decrease in immobility time, swimming time and climbing observed. When given along with combination of fluoxetine it shows statistically significant difference in result, confirmed that it can have synergistic antidepressant activity. When used for locomotor activity in mice none of the test drugs significantly increase or decrease the locomotor activity.Conclusions: Jatamansi showed antidepressant like property in various tests conducted on rats and mice. It showed statistically significant result with increasing dose and had synergic effect when given along with fluoxetine.

Evaluation of antidepressant activity of l-methylfolate per se and its interaction with escitalopram in mice

Background: Depression is a worldwide illness in the current population. Low levels of L-methylfolate are linked to depression. Present study evaluates the anti-depressive activity of acute and chronic administration of L-methylfolate per se in forced swimming test (FST) and tail suspension test (TST) and its interaction with escitalopram in albino mice.Methods: For this 30 swiss albino mice were divided randomly into five groups (n=6) as group I (control,10ml/Kg, p.o) - 2% suspension of gum acacia, group II - escitalopram suspension (10mg/kg, p.o), group III- L-methylfolate suspension (3mg/kg, p.o), group IV- L-methylfolate (3mg/kg, p.o) plus escitalopram (5mg/kg, p.o), group V- L-methylfolate(3mg/kg, p.o) plus escitalopram(10mg/kg, p.o), for forced swimming test. In tail suspension test again, mice were divided in five groups as above except that the dose of L-methylfolate was reduced to 1.25mg/kg. The pharmacologically validated models forced swimming test and tail suspension test were performed in mice to evaluate acute and chronic antidepressant activity of L-methylfolate and its combination with escitalopram respectively, after performing an acute toxicity study.Results: L-methylfolate and L-methylfolate plus escitalopram (10mg/Kg and 5mg/Kg, p.o) showed acute and chronic antidepressant activity in albino mice in FST and TST respectively. In human L-methylfolate is only active form of folic acid that readily crosses the blood brain barrier and utilized by the CNS. It regulates the bioavailability of critical cofactor BH4, required by enzymes synthesizing monoamines whose deficiency leads to depression.Conclusions: Hence, this study suggests antidepresant activity of L-methylfolate per se and as adjuvant with escitalopram when initiated from initiation of antidepressant therapy. Also, L-methylfolate opens the possibility of reducing the dose of antidepressant when used as adjuvant.

The protective effect of L. siceraria against depression using behavioural despair animal models

Background: In recent years, the search for novel pharmacotherapy from medicinal plants for psychiatric illness was significantly progressed. The present study was performed to evaluate the antidepressant activity of ethanolic extract of Lagenaria siceraria in animal models.Methods: The antidepressant activity of ethanolic extract of the fruit of L. siceraria in rats was assessed using forced swim test and tail suspension test. Imipramine at 15 mg/kg was used as standard antidepressant drug.Results: The ethanolic extract of L. siceraria fruit (EELS) was significantly and dose-dependently reduced the duration of immobility after repeated treatment for 7 days in Forced swim test and Tail suspension Test. But combination of L. siceraria (200mg/kg) with Imipramine gave a highly significant result (p<0.001) in reduction of immobility duration and the effect of high dose (400mg/kg) with imipramine (15mg/kg) did not decrease the duration of immobility period in both animal models at end of the study. In this work the dose of 400mg/kg afforded more protection than the imipramine.Conclusions: The results obtained from this study was indicate that the antidepressant activity of L. siseraria.

Antidepressant activity of aqueous extract of Momordica charantia leaves

Background: Depression is a common debilitating illness contributing to increase in morbidity and mortality worldwide. 20% of all depressed patients are refractory to treatment with available antidepressants at adequate doses. Momordica charantia commonly known as Karela is widely used in Indian cuisine. This study was carried out to evaluate its lesser known Antidepressant activity. The objective of this study is to evaluate the Antidepressant activity of Aqueous extract of Momordica charantia leaves.Methods: This study was done in Department of Pharmacology, JNMC, AMU. Tail Suspension test and 5-Hydroxytrytophan induced Head Potentiation was evaluated in Swiss Albino mice. Forced swim test, Learned Helplessness test and Spontaneous motor activity was noted in Albino Wistar rats respectively at doses of AEMC (Aqueous extract of Momordica charantia leaves) 100mg/kg, 200mg/kg and 300mg/kg.Results: AEMC at all three doses 100mg/kg, 200mg/kg and 300mg/kg exhibited antidepressant activity by significantly decreasing the immobility time in Tail Suspension test and except 100mg/kg. In forced swim test psychostimulant activity of AEMC was ruled out in Spontaneous motor activity. Number of Escape failures was decreased in Learned Helplessness test at doses of AEMC 200mg/kg and 300 mg/kg. Increase in Head twitches was seen only with AEMC 300mg/kg in 5-Hydroxytrytophan induced Head Potentiation in mice.Conclusions: Aqueous Extract of Momordica Charantia leaves exhibits Antidepressant activity in animal models of Depression.

The effect of docosahexaenoic acid (DHA) supplementation on experimental depression in mice

Background: Depressive disorder is a prevalent psychiatric disorder, which affects 21% of the world population. Many drugs which are available as effective antidepressants produce various side effects like sedation weight gain postural hypotension etc., so there is need to develop novel compounds with minimized side effects. Hence this study was aimed to investigate the antidepressant activity of DHA, an omega-3 polyunsaturated fatty acid in albino mice.Methods: Animals were divided into four groups, consisting six mice in each group. Out of these, group I served as control (2% gum acacia), group II and III received test drug in two different doses 200mg/kg and 300mg/kg respectively and group IV received fluoxetine (20mg/kg) as standard drug. To determine the antidepressant-like activity, we used forced swim test and tail suspension test in mice. These methods are based on the observation that a mouse show alternating agitation and immobility; the immobility is indicative of a state of depression.Results: DHA produced significant antidepressant effect at all the doses, as indicated by reduction in immobility times as compared to control in both FST and TST. (P?0.05) The efficacy of DHA at dose of 300 mg/kg was comparable with that of fluoxetine. DHA at 200mg/kg dose showed significantly less antidepressant activity compared to fluoxetine. (P?0.05).Conclusions: The result specifies that compared to two doses of DHA (200mg/kg and 300mg/kg), higher dose of DHA found as an effective dose for treating depression produced due to stress.

Measurement and analysis of the behavioral changes of Rncat congenital cataract mice / 中国比较医学杂志

Objective To measure and analyze the behavioral changes of Rncat congenital cataract mice. Methods Normal BALB/c mice and KM mice were used as control group,and inbred and random mated Rncat congenital cataract mice were used as experimental group. Behavioral tests, including the open field test, coat-hanger test, forced swimming test,and tail suspension test,were conducted on the mice. Results Compared with the inbred Rncat congenital cataract mice,the residence time in the open field test,the immobility time in the forced swimming test and tail suspension test of the BALB/c mice, randomly-mated Rncat congenital cataract mice and KM mice were significantly different. Conclusions There are certain differences in behavioral performance between the Rncat congenital cataract mice and the other mice. Our findings may provide a useful reference for future researchers.

Effect of maternal separation stress on behavior of neonatal rd mice / 中国比较医学杂志

Objective To evaluate the effect of maternal separation stress on the behavior of neonatal rd mice.Methods Neonatal rd mice were divided into maternal separation (MS) group (n=9) and control group (n=9).MS-stress was induced in the MS group by 4-hour-separation per day for 28 days.Open field test,elevated plus maze test,forced swim test and tail suspension test were used to evaluate the anxiety-like and depression-like behavior of the neonatal rd mice.Results The stay time and distance travelled of MS group in the central zone were 0.88％ and 28.17±5.65 cm,respectively,significantly shorter than that of the control group (2.61％,109.9±9.79 cm.P =0.04,P =0.001).Compared with the control group,the stay time in open arms of the MS group was significantly decreased (P<0.01),while the immobility time in forced swim test and tail suspension test of the MS group were 126.5±10.22 s and 21.56±6.83 s,significantly longer than that of the control group (77.75±16.83 s,P =0.02,7.37±3.22 s,P =0.03).Conclutions The 28-day maternal separation stress can significantly increase the anxiety-like and depression-like behavior in neonatal rd mice.

Evaluation of the antidepressant activity of Moringa oleifera alone and in combination with fluoxetine.

Background: The prevalence of mental depression has increased in recent years, and has become a serious health problem in most countries of the world, including India. Due to the high cost of antidepressant synthetic drugs and their accompanying side effects, the discovery of safer antidepressant herbal remedies is on the rise. Moringa oleifera (MO) (drumstick) has been used in traditional folk medicine, and in Ayurveda, it is considered as a valuable remedy for treating nervous system disorders as well as memory enhancing agent. Objective: The present study was designed to evaluate the acute and chronic behavioral and antidepressant effects of alcoholic extracts of MO leaves in standardized mouse models of depression. Materials and Methods: Alcoholic extracts of MO (MOE) leaves were prepared, and phytoconstituents were determined using appropriate chemical analytical methods. Following preliminary dose‑finding toxicity studies, the biological activity of MOE was tested in Swiss albino mice. Animals were divided into six groups: Groups 1 and 2 served as vehicle control and fluoxetine (20 mg/kg) standard control, respectively. Groups 3 and 4 served as treatment groups and were orally administered ethanolic MOE at doses of 100 mg/kg and 200 mg/kg, respectively. Groups 5 and 6, respectively, received combination doses of MOE 100 mg/kg + 10 mg fluoxetine, and MOE 200 mg/kg + 10 mg/kg fluoxetine. Following acute and 14 days chronic treatments, all animals were tested using behavioral models of depression, such as forced swim test (FST), tail suspension test (TST), and locomotor activity test (LAT). Results: Significant changes in all tested activities (FST, TST, LAT) of chronically dosed mice were observed, especially in animals given simultaneously combined doses of 200 mg/kg/day MOE + 10 mg/kg/day fluoxetine for 14 days. The antidepressant effect of MOE may have been invoked through the noradrenergic‑serotonergic neurotransmission pathway, which is the hallmark of selective serotonin reuptake inhibitors (SSRI) class of drugs. Conclusion: The results obtained in this study suggest that combined administration of MOE with low doses of fluoxetine or other SSRI drugs seems to have promising potential.

To investigate the role of Memantine as anxiolytic in elevated plus maze test and as antidepressant in tail suspension test in Swiss albino mice.

Background: The magnitude of improvement seen with present conventional medicines for anxiety and depression remain disappointing thereby providing a scope for the study of newer drugs. In the literature, there is evidence demonstrating the modulation of N-methyl-D-aspartate (NMDA)receptors in anxiety and depression. The present study is undertaken to evaluate the antianxiety effect of memantine in elevated plus maze (EPZ) test and its antidepressant effect in tail suspension test (TST)in Swiss albino mice. Methods: Animals were divided into six groups (n=6). First group mice were given normal saline (10 ml/kg), second group were administered lorazepam (0.5 mg/kg), third group with memantine (3 mg/kg) and fourth group with memantine plus lorazepam, fi fth group was administered amitriptyline (10 mg/kg)and sixth group received memantine plus amitriptyline. All drugs were administered by intraperitoneal route daily for 7 consecutive days. Results were analyzed by one-way ANOVA followed by post-hoc Tukey’s test. Results: Memantine treated mice showed signifi cant increase (p<0.001)in time spent and number of entries in open arm and signifi cant decrease in time spent and number of entries in closed arm in EPZ when compared to control group. Duration of immobility was signifi cantly (p<0.001)reduced in animals treated with memantine when compared to the control group in TST. Conclusions: NMDA antagonist, memantine has showed signifi cant antianxiety effect in EPZ test and antidepressant effect in TST.

Spectrum-Effect Relationship of Ethyl acetate Fraction in Ethanol Extract fromXiaoyaosan(XYE-E) for Antidepressant Effect Based on1H-NMR / 世界科学技术-中医药现代化

Thearticle is aimed to find the correlation between bioactive components of XYE-E and the antidepressant efficacy, by analyzing the immovability time in tail suspension test (TST) and forced swimming test (FST). Using the method of gray relational analysis, correlation analysis and regression analysis, relating the peak area of each common peak of1H-NMR spectra with the immovability time in TST or FST, we found that there were total 14 chemical components identified in the1H-NMR spectrum of XYE-E. Among them, 8 compounds, including saikosaponin a, saikosaponin c, saikosaponin E, saikosaponin F, saikosaponin G, saikosaponin b2, atractylenolide I and atractylenolide II, had significant correlation with antidepressant efficacy.

Behavioural and neuroendocrine effects of aqueous extract of Boerhaavia diffusa Linn. in mice using tail suspension and forced swim tests – A preliminary study.

The present study was done to evaluate the effect of aqueous extract of B. diffusa on depression in mice using behavioral models such as tail suspension test (TST) and forced swim test (FST). The extract (50, 100 and 200 mg/kg, po) was administered for 14 successive days to Swiss young albino mice. On 14th day, 60 min after administration, mice were subjected to TST and FST. The administration of aqueous extract of B. diffusa (50, 100 and 200 mg/kg, po) significantly decreased immobility period in both TST and FST, indicating significant antidepressant-like activity. The lowest dose (50 mg/kg) of the extract decreased the immobility period most significantly in FST, showing most potent antidepressant-like action. The efficacy of the extract (50 mg/kg) was comparable to fluoxetine (20 mg/kg). The extract did not show any significant effect on locomotor activity. The extract showed significant monoamine oxidase -A inhibitory activity. There was no significant effect of the extract on plasma corticosterone levels. Prazosin (α1-adrenoceptor antagonist), sulpiride (selective D2-receptor antagonist), baclofen (GABAB agonist), and p-CPA (tryptophan hydroxylase inhibitor) significantly attenuated the extract-induced antidepressant-like effect, when tested in TST. The extract might produce antidepressant-like effect by interaction with α1-adrenoceptors, dopamine-D2 receptors, serotonergic, and GABAB receptors. Thus, aqueous extract of B. diffusa showed significant antidepressant-like activity in mice probably through involvement of monoaminergic and GABAergic systems.

Development and application of computer-auto-controlling and analysis system for tail suspension / 中国比较医学杂志

Objective To develop a computer-auto-controlling and analysis system for Tail suspension .Methods Combining the advantage of computer science , engineering and animal behavior into tail suspension test .The “energy”index was developed .The system was validated with antidepressants such as imipramine and paroxetine .Results The measuring principle is based on the energy developed by mice trying to escape from their suspension .During the test, the movements of the mice are analyzed in terms of force , energy and power developed over time .Each mouse issuspended by the tail using adhesive tape to a hook connected to a tail test sensor .The tail test sensor fixed to suspension bar picks up all movements of the mouse and transmits these to a signal regulation unit and transmission circuit , which amplify , filter and digitalizes the signals.The signals are displayed visually in waveform .Activity time, immobility time, energy are continuously updated .The correlation coefficient of “immobility time” collected by computer and manpower was 0.94. Using this system, both imipramine and paroxetine could decreased the immobility time and paroxetine could increased the energy induced by mice ( both P <0.01 ) .Conclusion A stable computer-auto-controlling and analysis system for Tail suspension was established and could be used to screen the antidepressants .

Antidepressant-like effect of extracts from dried root of Rehmannia glutinosa (Dihuang) / 中国药学杂志

OBJECTIVE: To investigate the antidepressant-like effect of extracts from dried root of Rehmannia glutinosa Libosch. (Dihuang) (RG).

Chronic Non-Social Stress Affects Depressive Behaviors But Not Anxiety in Mice

The etiology of most psychiatric disorders is still incompletely understood. However, growing evidence suggests that stress is a potent environmental risk factor for depression and anxiety. In rodents, various stress paradigms have been developed, but psychosocial stress paradigms have received more attention than non-social stress paradigms because psychosocial stress is more prevalent in humans. Interestingly, some recent studies suggest that chronic psychosocial stress and social isolation affects mainly anxiety-related behaviors in mice. However, it is unclear whether chronic non-social stress induces both depression- and anxiety-related phenotypes or induces one specific phenotype in mice. In the present study, we examined the behavioral consequences of three chronic non-social stress paradigms: chronic predictable (restraint) stress (CPS), chronic unpredictable stress (CUS), and repeated corticosterone-HBC complex injection (RCI). Each of the three paradigms induced mild to severe depression/despair-like behaviors in mice and resulted in increased immobility in a tail suspension test. However, anxiety-related phenotypes, thigmotaxis and explorative behaviors, were not changed by the three paradigms. These results suggest that depression- and anxiety-related phenotypes can be dissociated in mouse stress models and that social and non-social stressors might affect brain circuits and behaviors differently.

Comparative efficacy of behavioral despair models in depicting antidepressant-like effect of tramadol.

Background: Experimental evaluation of antidepressants (ADs) in diverse animal models is the need of time. There is a constant search for newer models with ease and rapid screening of AD activity. As earlier studies highlight AD effect of tramadol in animal models, the study was undertaken to compare antidepressant-like effect of tramadol in two models of behavioural despair in mice. Methods: Tramadol was administered intraperitoneally (i.p.) at two different doses of 20 and 40 mg/kg, once daily for 7 days to Swiss albino mice. The immobility period of control and drug-treated mice was recorded in tail suspension test (TST) and forced swim test (FST). The antidepressant (AD) effect of tramadol was compared with control (NS) and reference drug imipramine (10 mg/kg, p.o.), administered orally (p.o.) for seven successive days. Results: Tramadol in tail suspension test (TST) produced significant antidepressant effect at 20 and 40 mg/kg doses, as depicted by reduction in immobility period of drug-treated mice compared to control group. The efficacy of tramadol at dose of 40 mg/kg was comparable to that of imipramine treated group (p<0.001). Tramadol in forced swim test (FST) produced significant antidepressant effect only at the dose of 40 mg/kg as compared to control, while the results were insignificant as compared to imipramine treated group (p>0.05). Conclusion: The results of the present study depict antidepressant-like activity of tramadol in both the models of depression TST and FST. But TST in mice seems to be more efficacious in appraising the antidepressant like effect of tramadol.

Anti-depressant like activity of N-n-butyl-3-methoxyquinoxaline-2-carboxamide (6o) a 5-HT3 receptor antagonist.

The compound 6o (at 0.5, 1 and 2 mg/kg, ip) with optimum log P and pA2 value, was subjected to forced swim test (FST) and tail suspension test (TST). The compound 6o significantly reduced the duration of immobility in mice without affecting the base line locomotion in actophotometer. Moreover, 6o (2 mg/kg, ip), potentiated the 5-hydroxytryptophan (5-HTP)-induced head twitch responses in mice and at 1 and 2 mg/kg, ip antagonized the reserpine-induced hypothermia (RIH) in rats. In interaction studies with various standard drugs/ligands using FST, 6o (1 and 2 mg/kg, ip) potentiated the anti-depressant effect fluoxetine (5 mg/kg, ip) and reversed the depressant effect of parthenolide (1 mg/kg, ip) by reducing the duration of immobility. Furthermore, 6o (1 and 2 mg/kg, ip) potentiated the effect of bupropion (10 mg/kg, ip) in TST. The behavioural anomalies of the olfactory bulbectomised (OBX) rats were augmented by chronic 6o (1 and 2 mg/kg) treatment as observed from the modified open field test (parameters: ambulation, rearing, fecal pellet). The results suggest that compound 6o exhibited anti-depressant like effect in rodent models of depression.

Strain-dependent effects of fluoxetine on tail suspension test in mice / 中华行为医学与脑科学杂志

Objective To study the strain difference in response to the antidepressant fluoxetine in mouse tail suspension test.Methods Two outbred mouse strains (KM and ICR) and three inbred mouse strains (C57BL/6,Balb/c and DBA/2) were used in this study.They were treated with the selective serotonin reuptake inhibitor (SSRI) fluoxetine or saline and the immobility time in tail suspension test was recorded.Results There was significant difference of baseline immobility time among different stains with C57BL/6 the most immobile((145.0 ±16.8) s) and DBA/2 the least ((34.5 ± 6.1)s).Fluoxetine significantly decreased the immobility time in C57BL/6 ((116.0 ± 10.3) s vs (145.0 ± 16.8) s) of control),Balb/c ((44.3 ± 6.2) s vs (75.3 ± 10.3) s) of control) and DBA/2 mice ((16.6 ± 4.3) s vs (34.5 ± 6.1) s) of control),while the immobile time of KM and ICR mice was not influenced by fluoxetine.Conclusion The effects of fluoxetine in tail suspension test are strain dependent.Fluoxetiue exhibits antidepressant effects in C57BL/6,Balb/c and DBA/2 mice,but not in KM and ICR mice.

The influence of circadian rhythm, gender and strain on tail suspension test using Kunming, BALB/C and C57BL/6 mice / 中华行为医学与脑科学杂志

Objective To investigate the influence of circadian rhythm,gender and stain on the tail suspension test in mice.Methods The immobility time of male and female Kunming,BALB/C and C57BL/6 mice in daytime or night were analyzed.Results ① The immobility time of Kunming mice during the day ( ( 114.24 ±11.18)s) was significantly more than that at night ( (65.39 ± 19.17)s).② The immobility time of male BALB/C mice( (68.57 ± 11.27 ) s) was significantly less than that of female BALB/C mice( ( 113.33 ± 3.87 ) s).③ The immobility time of C57BL/6 mice was significant more than that of Kunming and BALB/C mice under the same condition.Conclusions Circadian rhythm,gender and strain could significantly affect the immobility time of mice in tail suspension test.To increase the sensitivity and reliability of the tail suspension test,male Kunming and female BALB/C mice should be tested during the daytime.Compared to Kunming and BALB/C mice,the results of C57BL/6 mice were more stable.