Previous research has demonstrated the antidepressant potential of Avena sativa; however; its mode of action is still unknown. Hence, the role of the monoaminergic system in the antidepressant-like activity of A. sativa was investigated by using the tail suspension test in the present study. The mice intraperitoneally (i.p.) received the hydroalcoholic extract of A. sativa (50, 100, and 200 mg/kg) 30 min before the tail suspension test. The participation of the monoaminergic system in the antidepressant-like activity of A. sativa (200mg/kg) was assessed by administration of several receptor antagonists, 60 min before the administration of the extract in the test. Moreover, the effect of A. sativa on animals’ locomotion was examined by using open-field test. All doses of the A. sativa extract caused a significant antidepressant-like effect (p<0.001) in the tail suspension test, without any significant change in the mice locomotion in the open-field test (p>0.05). In addition, pre-treatment of the animals with sulpiride, haloperidol, SCH23390, p-chlorophenylalanine, ketanserin, WAY100135, reserpine, yohimbine, and prazosin abolished the antidepressant-like activity of A. sativa. Furthermore, the joint administration of sub-effective doses of A. sativa with fluoxetine and imipramine produced a synergistic antidepressant-like effect. Avena sativa induced an antidepressant-like effect in tail suspension test that is dependent on the monoaminergic system; however; clinical studies are required for showing the beneficial effects of the extract in humans.

DHIPC (2,4-dichloro-2´-hydroxyl-4´,6´-diisoprenyloxychalcone) is a new chalcone compound. In this study, its antidepressant-like activity of compound DHIPC was evaluated by the forced swimming test and the tail suspension test in mice. The results showed that DHIPC significantly reduced the immobility time for 2 h after treatment through the oral administration at dose of 10, 20, and 30 mg/kg in the forced swimming test and the tail suspension test, indicating a significant antidepressant-like effect. The maximal effect was obtained at 30 mg/ kg, which is similar to the positive control fluoxetine. The main monoamine neurotransmitters and their metabolites in rat brain were also simultaneously determined. It was found that DHIPC significantly increased the concentrations of the main neurotransmitters serotonin and noradrenalin, and also significantly increased 5-hydroxyindoleacetic acid contents in hippocampus, hypothalamus, and cortex in brain part. So, the probable mechanism of action of DHIPC is thought to be related to increase in serotonin and noradrenalin in the brain.

Depressive disorder is a prevalent psychiatric disorder، which affects 21% of the world population. The presently using drugs can impose a variety of side-effects including cardiac toxicity، hypopiesia، sexual dysfunction، body weight gain، and sleep disorder. During the last decade، there is a growing interest in the therapeutic effects of natural products on mental disorders. Amaranthus spinosus was investigation for antidepressant activity. Antidepressant activity of methanolic extract of Amaranthus spinosus (MEAS) was investigated by using Forced swimming test (FST) and Tail suspension test (TST) models. Escitalopram and Imipramine were used as reference standards. It has been observed from our study that both the MEAS at higher concentration showed significant (p<0. 01) reduction in immobility in tail suspension and forced swim model of depression comparable to Escitalopram and Imipramine. However further study is needed to understand mechanism of action and to identify active component responsible for antidepressant like activity.

There are several reports on immune modulating properties of chitin and chitosan microparticles. To determine the feasibility of using chitinous microparticles as an adjuvant in vaccination against Leishmania, the influence of chitin and chitosan microparticles on interferon-gama (IFN-γ) and interlkine-5 (IL-5) production by Leishmania infected cell suspension were studied.
Balb/c mice were intradermally infected with 2 × 105 stationary phase of L. major promastigotes into their base of the tail and two weeks later, leishmania infected lymph nodes cell suspensions of the mice were isolated. Small sized chitinous micro-particles ( Chitin and chitosan microparticles were caused cell proliferation, but no one has been able to stimulate the production of nitrite oxide from the Leishmania infected cell suspension. In stimulation with chitin microparticles, increase the ratio of IFN-γ/IL-5 was observed.
Chitin micro-particles are able to stimulate the production of IFN-γ in the Leishmania infected cell suspension and in the lymph nodes cell suspension can stimulate some cells to proliferation. Chitin seems to be utilized as an immunoadjuvant in Leishmania vaccine.

Spaceflight experiments in microgravity environments revealed that spaceflight affected the physiology of the testis. We used the tail-suspension model to simulate microgravity and investigated its effect on tissue and function of the testis in sexually mature male rats. Twenty-four male Wistar rats were assigned to four groups (N =6). Microgravity simulation was done by the tail hanging method; control 1) no tail traction, and tail suspension, control 2) no simulating micro angiitis just the zinc prescription and zinc was soluble in water. Groups include: 1) Just simulated microgravity, Group 2: Simulated microgravity and prescription zinc. Controls: 1: without any interventionist, 2: just used zinc. Semen, serum, and seminal plasma zinc were analyzed. LH and FSH were measured. Sample prepared from the epididymis of rats and Spermogram was performed. Data were analyzed using SPSS 22 software. The effect of microgravity on testosterone, LH, FSH, was significantly low in oligospermia, baseline sperm the concentration, total sperm count, sperm motility, length and weight of the testicles, sperm with normal morphology. FSH, LH zinc treated groups were not significantly different from other groups. The negative effects on sperm parameters were significantly reduced. Dietary restriction of zinc can affect on microgravity testicular function adversely. The effect of zinc deficiency can prevent negative effects on sperm parameters.

There are contradictions about the immune modulating properties of chitin in comparison with chitosan. To respond to these contradictions, we investigated stimulatory effects of chitin micro-particles in comparison with chitosan micro-particles on L.major infected cell suspensions. In this experimental study, Balb/c mice were intradermally infected with 2 × 105 stationary phase of L.major promastigotes into their base of the tail.Two weeks later infectivity were confirmed by PCR then leishmania infected lymph nodes cell suspensions of the mice were isolated. Chitin micro-particles were prepared by sonication and passing the filter and after size determination by mastersizer, used for cell stimulation.Finally,ELISA measured concentrations of TNF-α and IL-10 in cell culture supernatants. We observed chitin micro-particles significantly increase TNF-αand also IL-10 production (P ≤0.001) in compare with chitosan. Chitin micro-particles can stimulate production of TNF-α and IL-10 in leishmania infected cell suspensions. Chitin seems to be utilized as an immunomodulator in Leishmania vaccine or treatment.

Celastrus paniculatus seed oil, commonly known as Malkangni or Jyotishmati, was in use from time immemorial to treat brain related disorders. Celastrus paniculatus seed oil has significant antidepressant-like activity in chronic unpredictable stressed mice. The present study was undertaken to evaluate the antidepressant-like effect of Celastrus paniculatus seed oil in unstressed mice and to explore its mechanism of action. The seed oil (50, 100, and 200 mg/kg, PO) and fluoxetine per se were administered for 14 successive days to Swiss young albino mice. On the 14th day, 60 min after drug administration, animals were subjected to Tail Suspension Test (TST) and Forced Swim Test (FST). The mechanism of action was also studied. The oil significantly decreased immobility period of mice in both tail suspension test and forced swim test, indicating its significant antidepressant-like activity. The efficacy was found to be comparable to fluoxetine (P<0.0001). ED50 value of celastrus seed oil using FST and TST were 17.38 and 31.62 mg/kg, respectively. The oil did not show any significant effect on locomotor activity. It significantly inhibited brain MAO‒A activity and decreased plasma corticosterone levels. Sulpiride (selective D2-receptor antagonist), p-CPA (tryptophan hydroxylase inhibitor), and baclofen (GABAB agonist) significantly attenuated the oil-induced antidepressant-like effect, when assessed during TST. Celastrus paniculatus seed oil produced significant antidepressant-like effect in mice possibly through interaction with dopamine D2, serotonergic, and GABAB receptors; as well as inhibition of MAO‒A activity and decrease in plasma corticosterone levels.

Anxiety and depression are experienced following addicted patients durg withdrawal. This study was done to determine the effect of methadone and valproate combination on morphine withdrawal-induced anxiety and depression in male mice. In this experimental study, ninety-eight male mice were allocated into acute and chronic categories. Animals in acute chronic categories allocated into seven groups including: saline, morphine, methadone (10 mg/kg/bw), valproate (150 mg/kg/bw), three groups of valproate+methadone, in of ratio 1:1, 2:1 and 1:2. Animals were received escalating dose of morphine for 8 consecutive days except saline group. In chronic group, drugs were injected for 30 minutes before morphine administration, while in acute group; the drugs were used only at day 8. Anxiety and depression due to naloxone injection (5 mg/kg/bw) was investigated by elevated plus-maze, tail-suspension and open field tests. In the chronic group, valproate + methadone (2:1) combination therapy showed a significant increase in the percentage of open arm entries (53.86±1.9) and percentage of time spent in the open arm (58.58±4.15) compared to the morphine group, with a percentage of entering (28.12±2.03) and percentage of time (17.88±1.77) (P<0.05). In open field test, the ratio of the number to the duration of time spent in the central square, in the combination therapy groups of methadone+valproate (27±2), valproate+methadone (1:2) and valproate+methadone (2:1) were significantly increased in compare to the morphine group (P<0.05). In tail-suspension test, duration of immobility as an indicator of depression, in the treatment group of valproate+methadone (2:1) was significantly reduced (P<0.05). Valproate and methadone combination therapy particularly in ratio of 2:1 can reduce morphine withdrawal-induced anxiety and depression in animal model.

L-citrulline (L-cit) is a nonessential amino acid that interacts with the veracity of neurotransmitters in the brain and might have a positive effect on fetal growth. However, there is no information about the possible effect of L-cit on reflexive motor behavior. Thus, this study aimed to determine the effects of prenatal exposure to L-cit on reflexive motor behavior in mice offspring. Forty pregnant female mice were allocated into four groups. In the control group, mice received water, while in groups 2-4, female mice orally gavage with L-cit (25, 50, and 100 mg/kg) at 5, 8, 11, 14, and 17 days of gestation (GD). Following delivery, pups were selected, and reflexive motor behaviors were determined using ambulation, hind-limb foot angle, surface righting, hind-limb strength, grip strength, front limb suspension, and negative geotaxis tests. Also, serum Nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) were determined. Based on the findings, maternal exposure to L-cit improved ambulation score, hind-limb suspension score, grip strength, and front-limb suspension in offspring (P<0.05). Prenatal exposure to L-cit decreased surface righting, hind-limb foot angle, and negative geotaxis in offspring (P<0.05). L-cit decreased immobility time in forced swimming test (FST), tail suspension test (TST), and increased number of squares crossed in the open field test (OFT) and spending time on rotarod on postpartum mice (P<0.05). L-cit increased serum NO levels (P<0.05). L-cit decreased blood MDA and increased SOD and GPx levels in offspring (P<0.05). Findings revealed that L-cit improves postpartum behaviors in mice and reflexive motor in their pups.

Because of irnrnunotherapeutic effects of Mycobacterium vaccae (M. vaccae) by inducing Th 1 responses, we tried a heat-killed suspension of M. vaccae in rnice rnodels (C57BL/6J), which had already been challenged by turnor cell lines B 16-F 1 O. The Irnrnunization consisted of subcutaneous injection of irradiated BI6-FIO cells, as an antigen, plus M.vaccae into the tail base at two inguinal sites of rnice, which were injected by live wild type B 16-F 1 0 cells. Survival and turnor growth was recorded every three days for a period of three rnonths. Increase in survival was observed whilst decrease in turnor growth was recorded. The result indicates that the heatkilled suspension of the bacteriurn is a powerful irnrnunological adjuvant.