Evaluation of Anti-depressant, Anti-anxiety and Muscle Relaxant Activity of Hydroalcoholic Extract of Aerva javanica Roots

Aims: To evaluate anti-depressant, anti-anxiety and muscle relaxant activity of hydroalcoholic extract of Aerva javanica roots in various experimental animal models. Study Design: Animal study. Place and Duration of Study: The study was conducted in Bilwal Medchem and Research Laboratory, Jaipur from July 2021-August 2021. Methodology: The root powder of Aerva javanica was extracted with hydroalcoholic solvent (70% ethanol). The hydroalcoholic extract at three doses 100 mg/kg, 200 mg/kg, and 400 mg/kg was checked for anti-depressant and skeletal muscle relaxant activity in the experimental animal models. To determine the anti-depressant activity tail suspension test, locomotor activity, open field test, and MAO inhibitor assay were done; to determine the anti-anxiety activity hole board test was used; and to determine the skeletal muscle relaxant activity rotarod test, grip strength test, and chimney test were done. Results: In the tail suspension test, the extract at 200 mg/kg and 400 mg/kg significantly reduced the duration of immobility compared to normal control (p<0.0001). The extract at dose 400 mg/kg significantly reduced MAO-A and MAO-B activity compared to the normal control group (p<0.01 and p<0.05, respectively). The extract at 200 mg/kg and 400 mg/kg were able to decrease locomotor activity in actophotomoter and increased time spent in centre square in open field test revealing the sedative effect of the extract. In hole board test, the extract at dose 400 mg/kg and 200 mg/kg significantly increased number of head dip count (p<0.0001 and p<0.001) respectively. In the rotarod test, the extract at dose 200 and 400 mg/kg decreased the time spent on the rotating rod (p<0.0001), compared to normal control. Similarly, in the grip strength test the extract at dose 200 and 400 mg/kg decreased the time spend on suspended wire revealing the skeletal muscle relaxant property of the test extract. Conclusion: Based on the result, it can be concluded that the extract exert anti-depressant, anti-anxiety and skeletal muscle relaxant like activity in the experimental rat which was hypothesized to be attributed to the flavonoids present in the hydroalcoholic root extract of Aerva javanica.

The influence of the stereotypic forms of activity in mice behaviour in standard behavioural tests

Laboratory animals often develop abnormal repetitive (stereotypic) behaviour that can influence both physiology and behavioural test results. Such abnormal behaviours usually develop in suboptimal environment and increase over time. To explore the development of stereotypic forms of activity night home-cage behaviour of laboratory mice was analysed and collated with the behaviour in open field (OFT), hole-board (HBT) and tail suspension (TST) tests twice within 16 weeks. Mice expressed few stereotypies and their duration lessened over time from median 8.2 to 1.0 %. In contrast, grooming behaviour increased significantly from 29.5 to 49.6 %. Home-cage grooming correlated with the latency of locomotion start in OFT and with the immobility time in TST. Intensity and stability of stereotypic activity and grooming inf­luenced the duration of grooming in OFT: the mice with unstable stereotypies groomed more than others, and mice with the lowes home-cage grooming level also groomed in OFT the most. Intensity and stability of night grooming influenced the behaviour in TST: the mice with unstable level of grooming were the most mobile in this test. Abnormal home-cage activity may indicate impaired welfare, and that, in turn, may affect test activity, so researchers need to keep it in mind when planning animal behaviour experiments.

ANXIOLYTIC, ANTIDEPRESSANT AND ANTICONVULSANT ACTIVITY OF MUCUNA PRURIENS SEEDS

Behavioral models such as the elevated plus maze (EPM), light and dark method, Hole-board method, and Marble burying method were used to assess Methanolic extract of Mucuna pruriens seeds (MEMP) for anxiolytic function. MEMP in a dose of 200 and 300 mg/kg, p.o. was found to possess significant anxiolytic activity. In TST and FST, MEMP showed a substantial reduction in the time of immobility, indicating antidepressant action. MEMP significantly increased the latency for straub tail, extensor, myoclonic jerk, clonic convulsion and stupor in pentylenetetrazol (PTZ) and isoniazid-induced convulsion models. MEMP may be interfering with the level of monoamines; L-dopa, serotonin and histamine and produced antidepressant activity.

Incorporating inter-individual variability in experimental design improves the quality of results of animal experiments

Inter-individual variability in quantitative traits is believed to potentially inflate the quality of results in animal experimentation. Yet, to our knowledge this effect has not been empirically tested. Here we test whether inter-individual variability in emotional response within mouse inbred strains affects the outcome of a pharmacological experiment. Three mouse inbred strains (BALB/c, C57BL/6 and 129S2) were behaviorally characterized through repeated exposure to a mild aversive stimulus (modified Hole Board, five consecutive trials). A multivariate clustering procedure yielded two multidimensional response types which were displayed by individuals of all three strains. We show that systematic incorporation of these individual response types in the design of a pharmacological experiment produces different results from an experimental pool in which this variation was not accounted for. To our knowledge, this is the first study that empirically confirms that inter-individual variability affects the interpretation of behavioral phenotypes and may obscure experimental results in a pharmacological experiment.

Bertholletia excelsa Seeds Reduce Anxiety-Like Behavior, Lipids, and Overweight in Mice

Overweight, obesity, and psychiatric disorders are serious health problems. To evidence the anxiolytic-like effects and lipid reduction in mice receiving a high-calorie diet and Bertholletia excelsa seeds in a nonpolar extract (SBHX, 30 and 300 mg/kg), animals were assessed in open-field, hole-board, and elevated plus-maze tests. SBHX (3 and 10 mg/kg) potentiated the pentobarbital-induced hypnosis. Chronic administration of SBHX for 40 days was given to mice fed with a hypercaloric diet to determine the relationship between water and food intake vs. changes in body weight. Testes, epididymal white adipose tissue (eWAT), and liver were dissected to analyze fat content, triglycerides, cholesterol, and histological effects after administering the hypercaloric diet and SBHX. Fatty acids, such as palmitoleic acid (0.14%), palmitic acid (21.42%), linoleic acid (11.02%), oleic acid (59.97%), and stearic acid (7.44%), were identified as constituents of SBHX, producing significant anxiolytic-like effects and preventing body-weight gain in mice receiving the hypercaloric diet without altering their water or food consumption. There was also a lipid-lowering effect on the testicular tissue and eWAT and a reduction of adipocyte area in eWAT. Our data evidence beneficial properties of B. excelsa seeds influencing global health concerns such as obesity and anxiety.

Effects of Different Anxiety Levels on the Behavioral Patternings Investigated through T-pattern Analysis in Wistar Rats Tested in the Hole-Board Apparatus

The Hole-Board is an ethologically based tool for investigating the anxiety-related behavior of rats following manipulation of the central anxiety level. The present paper aims to assess behavioral patterning following pharmacological manipulation of emotional assets in Wistar rats tested in this experimental apparatus. For this purpose, the behavior of three groups of rats injected with saline, diazepam or FG7142 was evaluated using conventional quantitative and multivariate T-pattern analyses. The results demonstrate that quantitative analyses of individual components of the behavior, disjointed from the comprehensive behavioral structure, are of narrow utility in the understanding of the subject’s emotional condition. Among the components of the behavioral repertoire in rodents tested in the Hole-Board, Edge-Sniff and Head-Dip represent the most significant ones to rate anxiety level. They are characterized by a strong bivariate relationship and are also firmly part of the behavioral architecture, as revealed by the T-pattern analysis (TPA), a multivariate technique able to detect significant relationships among behavioral events over time. Edge-Sniff → Head-Dip sequences, in particular, are greatly influenced by the level of anxiety: barely detectable in control animals, they completely disappear in subjects with a reduced level of anxiety and are present in almost 25% of the total of T-patterns detected in subjects whose anxiety level increased.

Anti-depressant, anxiolytic and muscle relaxant activity of hydroalcoholic extract of Cissampelos pareira linn. Leaves

Background: The ethnopharmacological relevance suggests that the ethnic minorities of India use leaves of Cissampelos pareira L as a traditional medicine for curing various psychopharmacological disorders. Objective: To evaluate anti-depressant, anxiolytic, and muscle relaxant activity of hydroalcoholic extract of Cissampelos pareira. Results: No moribund status or mortality was observed in experimental mice up to 2000 mg/kg dose of Cissampelos pareira hydroalcoholic extract (CPHE). In the open field and actophotometer tests, CPHE 200 and 400 mg/kg treated mice with significantly abridged ambulation, a number of central squares crossed, total locomotion, and depicted less coordinated movements. While, in despair swim and tail suspension tests, CPHE 400 mg/kg treated mice significantly decreased duration of immobility and increased number of climbing, confirming its anti-depressant effect. In an elevated plus-maze test, CPHE 200 and 400 mg/kg increased the open arm exploration; in hole board test, CPHE 400 mg/kg treated rats augmented the number of head dips, depicting its anxiolytic effect. In rotarod, grip strength, and inclined plane test, CPHE 400 mg/kg treated mice decreased in fall off time on a rotating rod, suspended wire, or inclined plane. Furthermore, in the chimney test, treatment with CPHE 400 depicted less coordinated movements in mice, and mice of this group took more time to leave the cylinder, depicting its skeletal muscle relaxant effect. Conclusion: Based on the result, it can be concluded that CPHE 400 mg/kg exhibits strong anti-depressant, anxiolytic, and muscle relaxant effects, justifying its traditional uses.

Bexarotene Impairs Cognition and Produces Hypothyroidism in a Mouse Model of Down Syndrome and Alzheimer’s Disease

All individuals with Down syndrome (DS) eventually develop Alzheimer’s disease (AD) neuropathology, including neurodegeneration, increases in β-amyloid (Aβ) expression, and aggregation and neurofibrillary tangles, between the third and fourth decade of their lives. There is currently no effective treatment to prevent AD neuropathology and the associated cognitive degeneration in DS patients. Due to evidence that the accumulation of Aβ aggregates in the brain produces the neurodegenerative cascade characteristic of AD, many strategies which promote the clearance of Aβ peptides have been assessed as potential therapeutics for this disease. Bexarotene, a member of a subclass of retinoids that selectively activates retinoid receptors, modulates several pathways essential for cognitive performance and Aβ clearance. Consequently, bexarotene might be a good candidate to treat AD-associated neuropathology. However, the effects of bexarotene treatment in AD remain controversial. In the present study, we aimed to elucidate whether chronic bexarotene treatment administered to the most commonly used murine model of DS, the Ts65Dn (TS) mouse could reduce Aβ expression in their brains and improve their cognitive abilities. Chronic administration of bexarotene to aged TS mice and their CO littermates for 9 weeks diminished the reference, working, and spatial learning and memory of TS mice, and the spatial memory of CO mice in the Morris water maze. This treatment also produced marked hypoactivity in the plus maze, open field, and hole board tests in TS mice, and in the open field and hole board tests in CO mice. Administration of bexarotene reduced the expression of Aβ1-40, but not of Aβ1-42, in the hippocampi of TS mice. Finally, bexarotene increased Thyroid-stimulating hormone levels in TS mice and reduced Thyroid-stimulating hormone levels in CO mice, while animals of both karyotypes displayed reduced thyroxine levels after bexarotene administration. The bexarotene-induced hypothyroidism could be responsible for the hypoactivity of TS and CO mice and their diminished performance in the Morris water maze. Together, these results do not provide support for the use of bexarotene as a potential treatment of AD neuropathology in the DS population.