Anxiolytic and anxiogenic drug effects on male and female gerbils in the black-white box

Anxiolytic, antioxidant, and neuroprotective effects of goji berry polysaccharides in ovariectomized rats: experimental evidence from behavioral, biochemical, and immunohistochemical analyses

Recent studies have indicated that polysaccharides, the main component of the Lycium barbarum L. fruit, have beneficial effects (e.g., anxiolytic, antioxidant, and neuroprotective) on humans and rodents. However, the effects of different dosages of such polysaccharides on ovariectomized rats and their underlying mechanisms in the brain have not been evaluated in the literature. Here, we aimed to evaluate the effects of the high and low doses of polysaccharides obtained from Lycium barbarum fruits (HD-LBP and LD-LBP, respectively) on anxious behaviors via behavioral (using the OFT and EPM), biochemical (using ELISA), and immunohistochemical (using immunohistochemical staining) measures in detail. Two weeks after ovariectomy, the rats were randomly assigned to either the treatment conditions [control (DW, 3 mL/kg, p.o., per day), LD-LBP (20 mg/kg, 3 mL/kg, p.o., per day), HD-LBP (200 mg/kg, 3 mL/kg, p.o., per day), 17 β-ES (1 mg/kg, 3 mL/kg, p.o., per day), DZ(1 mg/kg, 3 mL/kg, p.o., per day)] or operation type [SHAM (pseudo-ovariectomized) and OVX (ovariectomized)]. The treatments were applied for 30 consecutive days, and then serum and brain tissue samples of all rats were collected. Biochemical (SOD, CAT, GPX, MDA, and 17 β-ES) and immunohistochemical (BDNF, SER, and apoptosis) analyses of the samples were performed as well. The rats administered HD-LBP and LD-LBP were less anxious than the control groups. The HD-LBP-treated rats had high levels of SOD and low levels of MDA in their serum samples. Moreover, HD-LBP and drug-treated groups had a high number of SER receptors and BDNF-positive cells and a low number of TUNEL-positive cells in their hippocampal brain tissues. The HD-LBP treatments decrease anxious behavior by increasing antioxidant enzyme activities, hippocampal SER and BDNF neurotransmitter levels and decreasing the TUNEL-positive cell count of ovariectomized rats. Given these findings, we suggest that menopause-induced symptoms of anxiety can be reduced by polysaccharides obtained from goji berry fruits, and that these findings will be beneficial for the production studies of natural herbal-origin antianxiety (anxiolytic) drugs in the future.

Diazepam Reduces Escape and Increases Closed-Arms Exploration in Gerbils After 5 min in the Elevated Plus-Maze

Despite the wide implementation of the elevated plus-maze (EPM) test to assess anxiety-related behaviors in rodents, the interpretation of these measures in gerbils has received limited attention. Here, male gerbils were treated with vehicle or diazepam, followed by a 20-min EPM session. EPM data were subjected to minute-by-minute, 5-min bins and factor analyses. During the first 5-min, gerbils avoided the closed arms in favor of the open arms and diazepam increased open-arms entries; furthermore, a single factor (escape behavior) explained all the analyzed measures. Only after 5-min, gerbils reduced open-arms exploration and three independent factors emerged for each subsequent 5-min bin. These findings suggest that EPM data from gerbils should be analyzed in at least two 5-min bins. Measures from the standard 5-min session seem to be related to an escape response from the EPM through the open arms. Once habituated, measures from the second 5-min bin seem to be related to a conflictive situation: keep trying to escape unsuccessfully (due to open-arms height) or seek protection in the closed arms (unsafe places). Diazepam seems to reduce this conflict by mitigating the escape response (Factor 1 - Anxiety) and increasing closed-arms approach (Factor 2) and risk assessment (Factor 3). Unlike mice and rats, a decrease in open-arms exploration and an increase in risk assessment could be interpreted as an anxiolytic-like effect in gerbils.

Leaves of Spondias mombin L. a traditional anxiolytic and antidepressant: Pharmacological evaluation on zebrafish (Danio rerio)

ETHNOBOTANICAL RELEVANCE

Spondias mombin L. is a plant dispersed throughout the tropical regions of South America, Africa, and Asia, being found mainly in the North and Northeast of Brazil, where the leaves are used in preparations for neuropsychiatric disorders. Therefore, it is of great importance to carry out studies in different pharmacological models that can prove the traditional use of this plant species.

MATERIALS AND METHODS

the hydroethanolic extract from S. mombin leaves (HELSm) was evaluated by oral administration (25 mg/kg) and by immersion (25 mg/l) in scototaxis test in zebrafish (Danio rerio). For this study, caffeine (100 mg/kg) and buspirone (25 mg/kg) were used as standard drugs. The antidepressant action of the HELSm was evaluated assessed in the novel tank diving test (NTDT). In this study, a group with 1% ethanol, one with unpredictable chronic mild stress (UCMS), and another with developmental, social isolation (DSI) were used as induction groups for depression-like behavior and fluoxetine (20 mg/kg) as a drug pattern.

RESULTS

by the HPLC-UV fingerprint analysis, the HELSm presented several derivatives of polyphenolic compounds and flavonoids and identified ellagic acid and isoquercitrin, and by the gas-chromatographic, the majority of the identified compounds were fatty acids, esters, and alcohols. By immersion, the LC₅₀ was 49.86 mg/l and by oral via the LD₅₀ in 48 h, was 4.515 g/kg in zebrafish. For all spatiotemporal and behavioral variables (time spent, white compartment, latency, toggle, erratic swimming, freezing duration, thigmotaxis, and risk assessment), the treatment with HELSm produced a similar effect to buspirone and was significant when compared to the caffeine and control group (p < 0.01, Tukey-Kramer test). For all spatiotemporal and behavioral variables evaluated (time spent at the top of the apparatus, crossed quadrants, erratic swimming, and duration of freezing), treatment with HELSm produced a change in the depression-like behavior in the groups tested, with a similar effect to fluoxetine, both with a significant difference when compared to the control groups (p < 0.01).

CONCLUSIONS

Our results suggest that the acute administration of the HELSm in the scototaxis and NTDT tests in a zebrafish model (Danio rerio) produced anxiolytic and antidepressant effects, devoid of hypnotic and sedative actions by immersion, and this action was improved when administered by oral via. Possibly, the presence of isoquercitrin in the leaves of Spondias mombin participates in the anxiolytic and antidepressant effects.

Nucleus incertus contributes to an anxiogenic effect of buspirone in rats: Involvement of 5-HT1A receptors

The nucleus incertus (NI), a brainstem structure with diverse anatomical connections, is implicated in anxiety, arousal, hippocampal theta modulation, and stress responses. It expresses a variety of neurotransmitters, neuropeptides and receptors such as 5-HT1A, D2 and CRF1 receptors. We hypothesized that the NI may play a role in the neuropharmacology of buspirone, a clinical anxiolytic which is a 5-HT1A receptor partial agonist and a D2 receptor antagonist. Several preclinical studies have reported a biphasic anxiety-modulating effect of buspirone but the precise mechanism and structures underlying this effect are not well-understood. The present study implicates the NI in the anxiogenic effects of a high dose of buspirone. Systemic buspirone (3 mg/kg) induced anxiogenic effects in elevated plus maze, light-dark box and open field exploration paradigms in rats and strongly activated the NI, as reflected by c-Fos expression. This anxiogenic effect was reproduced by direct infusion of buspirone (5 μg) into the NI, but was abolished in NI-CRF-saporin-lesioned rats, indicating that the NI is present in neural circuits driving anxiogenic behaviour. Pharmacological studies with NAD 299, a selective 5-HT1A antagonist, or quinpirole, a D2/D3 agonist, were conducted to examine the receptor system in the NI involved in this anxiogenic effect. Opposing the 5-HT1A agonism but not the D2 antagonism of buspirone in the NI attenuated the anxiogenic effects of systemic buspirone. In conclusion, 5-HT1A receptors in the NI contribute to the anxiogenic effect of an acute high dose of buspirone in rats and may be functionally relevant to physiological anxiety.

Effect of Beta vulgaris Linn. Leaves Extract on Anxiety- and Depressive-like Behavior and Oxidative Stress in Mice after Acute Restraint Stress

BACKGROUND

Stress plays a significant role in the pathogenesis of neuropsychiatric disorders such as anxiety and depression. Beta vulgaris is commonly known as "beet root" possessing antioxidant, anticancer, hepatoprotective, nephroprotective, wound healing, and anti-inflammatory properties.

OBJECTIVE

To study the protective effect of Beta vulgaris Linn. ethanolic extract (BVEE) of leaves against acute restraint stress (ARS)-induced anxiety- and depressive-like behavior and oxidative stress in mice.

MATERIALS AND METHODS

Mice (n = 6) were pretreated with BVEE (100 and 200 mg/kg, p. o.) for 7 days and subjected to ARS for 6 h to induce behavioral and biochemical changes. Anxiety- and depressive-like behavior were measured by using different behavioral paradigms such as open field test (OFT), elevated plus maze (EPM), forced swim test (FST), and tail suspension test (TST) 40 min postARS. Brain homogenate was used to analyze oxidative stress parameters, that is, malondialdehyde (MDA) and reduced glutathione (GSH) level.

RESULTS

BVEE pretreatment significantly (P < 0.05) reversed the ARS-induced reduction in EPM parameters, that is, percentage entries and time spent in open arms and in OFT parameters, that is, line crossings, and rearings in mice. ARS-induced increase in the immobility time in FST and TST was attenuated significantly (P < 0.05) by BVEE pretreatment at both the dosage. An increase in MDA and depletion of GSH level postARS was prevented significantly (P < 0.05) with BVEE pretreatment at both the dosage (100 and 200 mg/kg).

CONCLUSION

BVEE exhibits anxiolytic and antidepressant activity in stressed mice along with good antioxidant property suggesting its therapeutic potential in the treatment of stress-related psychiatric disorders.

SUMMARY

Stress plays major role in the pathogenesis of anxiety and depressionARS-induced anxiety- and depressive-like behavior through oxidative damage in miceBVEE pretreatment reversed ARS-induced behavioral changes, that is, anxiety and depressionARS-induced oxidative stress was prevented by BVEE pretreatment in mice. Abbreviations Used:

ANOVA

Analysis of variance, ARS: Acute restraint stress, BVEE: Beta vulgaris ethanolic extract, BV: Beta vulgaris, CMC: Carboxymethylcellulose, CNS: Central nervous system, CPCSEA: Committee for the purpose of control and supervision of experiments on animals, cms: Centimeter, DNA: Deoxyribose nucleic acid, EPM: Elevated plus maze, FST: Forced swim test, GSH: Reduced glutathione, g: Gram, h: Hour, IAEC: Institutional Animal Ethics Committee, mg: Milligram, μM: Microgram, MDA: Malondialdehyde, SEM: Standard error of mean, TST: Tail suspension test, UV: Ultraviolet, w/v: Weight by volume.

A Methodological Discussion of Caffeine Research and Animal Avoidance Behavior

Introduction: We present a review of the methodological aspects of caffeine research within animal tests of escape and avoidance behavior in the presence of aversive stimuli. Method: We highlight species, methods of caffeine administration, dosage, dependent measures, and research designs commonly used in this research. Results: Typical subjects were rodents and zebrafish, with species-specific vehicles of caffeine administration and dependent measures. Behavioral tests for escape and avoidance as a function of caffeine consumption were conceptually similar across species, although the arrangement of measures was necessarily adapted to the physiological contingencies of the different species. Discussion and Conclusions: Caffeine administration preceding the presentation of aversive stimuli generally, but not exclusively, enhanced the effect of escape and avoidance of aversive stimuli. The many commonalities in methods and results across species suggest similar methods may be relevant to human subjects as well.

Changes in retinal morphology, electroretinogram and visual behavior after transient global ischemia in adult rats

The retina is a light-sensitive tissue of the central nervous system that is vulnerable to ischemia. The pathological mechanism underlying retinal ischemic injury is not fully understood. The purpose of this study was to investigate structural and functional changes of different types of rat retinal neurons and visual behavior following transient global ischemia. Retinal ischemia was induced using a 4-vessel occlusion model. Compared with the normal group, the number of βIII-tubulin positive retinal ganglion cells and calretinin positive amacrine cells were reduced from 6 h to 48 h following ischemia. The number of recoverin positive cone bipolar cells transiently decreased at 6 h and 12 h after ischemia. However, the fluorescence intensity of rhodopsin positive rod cells and fluorescent peanut agglutinin positive cone cells did not change after reperfusion. An electroretinogram recording showed that the a-wave, b-wave, oscillatory potentials and the photopic negative response were completely lost during ischemia. The amplitudes of the a- and b-waves were partially recovered at 1 h after ischemia, and returned to the control level at 48 h after reperfusion. However, the amplitudes of oscillatory potentials and the photopic negative response were still reduced at 48 h following reperfusion. Visual behavior detection showed there was no significant change in the time spent in the dark chamber between the control and 48 h group, but the distance moved, mean velocity in the black and white chambers and intercompartmental crosses were reduced at 48 h after ischemia. These results indicate that transient global ischemia induces dysfunction of retinal ganglion cells and amacrine cells at molecular and ERG levels. However, transient global ischemia in a 17 minute duration does not appear to affect photoreceptors.

Coumarins from Angelica archangelica Linn. and their effects on anxiety-like behavior

TRADITIONAL RELEVANCE: Angelica archangelica Linn. (Apiaceae) is an herb distributed in tropical and subtropical regions of the world. Both in Chinese and Indian system of medicine, it is used for nervous disorders including anxiety, anorexia, migraine and other cerebral diseases.

AIM OF STUDY

To evaluate the anxiolytic potential of non polar coumarins isolated from A. archangelica Linn.

METHODS AND RESULTS

A. archangelica Linn. (1 kg) was subjected to extraction in a soxhlet apparatus with petroleum ether (40-60 °C), yield 6.9% w/w. The extract of petroleum ether produced a yellow colored precipitate (YP) which was evaluated for anxiolytic like effect using EPM test and was found significant (**P<0.01) in doses of 5 and 10 mg/kg, po. The precipitate was shown to be a mixture of seven constituents in HPTLC and six on the TLC plate which were further subjected to separation by preparative TLC. Non polar coumarins were isolated namely imperatorin (IM) and isoimperatorin (IIM). YP, IM, IIM were tested for anxiolytic like effects in a dose of 5mg/kg, po along with DZ (1mg/kg, po) using EPM, Light & dark arena and hole board models in rats. All the test drugs were found to have significant (*P<0.05, **P<0.01) activity. IM and IIM have the potential to reduce anxiety but yellow precipitate showed the most promising activity as compared to isolated coumarins. This effect may be due to the synergistic action of all compounds present in the YP or by multiple mechanism of action. The test drugs may have the potential for different receptors.

CONCLUSION

The mixture of coumarins isolated from A. archangelica and its constituents imperatorin and isoimperatorin have the potential to reduce anxiety but it is the mixture which have more significant activity as compared to its individual components.

Pharmacological modulation of anxiety-like phenotypes in adult zebrafish behavioral models

Zebrafish (Danio rerio) are becoming increasingly popular in neurobehavioral research. Here, we summarize recent data on behavioral responses of adult zebrafish to a wide spectrum of putative anxiolytic and anxiogenic agents. Using the novel tank test as a sensitive and efficient behavioral assay, zebrafish anxiety-like behavior can be bi-directionally modulated by drugs affecting the gamma-aminobutyric acid, monoaminergic, cholinergic, glutamatergic and opioidergic systems. Complementing human and rodent data, zebrafish drug-evoked phenotypes obtained in this test support this species as a useful model for neurobehavioral and psychopharmacological research.