Level Of Anxiety In Animals Research Articles

Evaluation of safety and biomedical potential of water-soluble oat lignin Avena sativa L.

The study of the value of lignin for biomedical use is generating growing interest. For the first time, the safety and biological efficacy of lignin from the stems of the oat Avena sativa L. were studied, necessary for a preliminary assessment of its biomedical potential, have been studied. In vitro experiments, a sample of oat lignin exhibited cytotoxicity to the HeLa, A549, and HT-29 cancer cell lines, depending on the concentration. At maximum concentrations 125 and 150 μg/ml, it reduced their survival and increased the level of reactive oxygen species. In vivo experiments, a sample of oat lignin, with acute (from 5 to 250 mg/kg body weight) and chronic (300, 1200 and 2000 mg/kg body weight) administration, did not have a toxic or genotoxic effect on the organs of mice. The biological efficacy of the oat lignin was manifested in activation of repair processes in bone marrow and thyroid gland, a decrease in the level of abnormal spermatozoa in males, stimulation of reproductive performance of females and in increase in research activity and a decrease in the level of anxiety in animals. The results indicate the prospects for further study of the medical and biological potential lignin of the oat.

The Study of TRPV1 Channels of the Central Nervous System and Their Effect on Anxiety in ICR Mice.

The TRPV1 channel is actively involved in various neuronal processes and is found in various structures of the nervous system, including peripheral and central neurons, sensory ganglia, spinal cord, and various parts of the brain. Due to its ability to respond to various stimuli, TRPV1 can have a significant impact on the body's responses to stress. Studies indicate the involvement of TRPV1 in the regulation of anxiety behavior. Suppression of TRPV1 activity leads to a decrease in the level of anxiety in animals, which indicates the importance of this channel in psychoemotional regulation. A promising compound for inhibiting this channel is the APHC3 peptide, which is a selective receptor antagonist. The results obtained this study show that this peptide has a pronounced anxiolytic effect, reducing the level of anxiety in the studied animals.

Изучение влияния пептидов продуктов пчеловодства на поведение крыс в условиях хронического стресса

Chronic stress is one of the causes of depression. Various daily factors, accumulating, can lead to the formation of a constant state of stress and anxiety. In this study, we measured the ability of peptides of royal jelly, drone brood, and bee honey up to 5 kDa to reduce anxiety under chronic stress conditions in male Wistar rats. To do this, the animals of the control and experimental groups were subjected to random stress factors for 14 days (2 factors per day), while simultaneously receiving 0.9% NaCl solution (control group) or aqueous solutions of the corresponding peptides intranasally at a concentration of 300 μg/kg of body weight (peptides were obtained by a combination of ultrafiltration, ion exchange chromatography and gel-filtration). After 14 days, the level of anxiety in animals of all groups was measured using such behavioral tests as “Open field”, “Forced swimming” and “Light-dark box”. It was found that in the OF test, animals treated with royal jelly and drone brood peptides show shorter freezing time, higher horizontal and vertical locomotor activity, spend more time on research activities and grooming; in the FST animals of the same groups spent more time actively swimming; in the LDB test animals of the same groups spent more time in the illuminated part of the experimental setup and crossed the border between the dark and light parts more times. The results indicate that rats treated with royal jelly and drone brood peptides have lower levels of stress and anxiety compared to animals that received 0.9% NaCl solution (control group) or a solution of bee honey peptides. After conducting behavioral tests, the animals were withdrawn from the experiment and the concentration of corticosterone and ACTH was determined in the blood serum. It was found that there is no any changes in hormone concentrations between rats from control or experimental groups. Probably, the peptides of drone brood and royal jelly have an anxiolytic effect, without affecting the work of the hypothalamic-pituitary-adrenal axis, but acting through intracerebral molecular targets.

Folic Acid Preconditioning Alleviated Radiation-Induced Ovarian Dysfunction in Female Mice.

Radiological therapy/examination is the primary source of artificial radiation exposure in humans. While its application has contributed to major advances in disease diagnosis and treatment, ionizing radiation exposure is associated with ovarian damage. The use of natural products, either alone or as an adjunct, has become increasingly common for reducing the side effects of radiological therapy during disease treatment. Herein, we explored the protective effect of folic acid (FA), a widely used B vitamin, against radiation-induced ovarian injury and its mechanism of action. Female mice with normal ovarian function were randomly divided into control, FA, radiation, and radiation + FA groups. The intervention strategy included daily intragastric administration of FA (5 mg/kg) for 3 weeks prior to radiation exposure. Mice in the radiation and radiation + FA groups received a single dose of 5 Gy X-ray irradiation. Changes in the estrous cycle were then recorded, and ovarian tissues were collected. Pathophysiological changes as well as reproductive and endocrine-related indexes were determined via H&E staining, immunohistochemistry, Western blot, and ELISA. The reproductive performance and emotional symptoms of animals were also monitored. Our results indicated that FA intervention effectively alleviated ovarian damage, leading to more regular estrous cycles, lesser impairment of follicular morphology and endocrine status, as well as greater germ cell preservation. Reduced levels of oxidative stress, inflammation, and enhanced DNA repair were associated these changes. FA pre-administration improved the reproductive performance, leading to higher pregnancy rates and greater litter sizes. Further, the anxiety levels of animals were significantly reduced. Our results indicate that FA pre-administration significantly alleviates radiation-induced ovarian damage in rodents, highlighting its potential as a protective strategy against radiation exposure in the female population.

Novel Multitarget Hydroxamic Acids with a Natural Origin CAP Group against Alzheimer's Disease: Synthesis, Docking and Biological Evaluation.

Hydroxamic acids are one of the most promising and actively studied classes of chemical compounds in medicinal chemistry. In this study, we describe the directed synthesis and effects of HDAC6 inhibitors. Fragments of adamantane and natural terpenes camphane and fenchane, combined with linkers of various nature with an amide group, were used as the CAP groups. Accordingly, 11 original target compounds were developed, synthesized, and exposed to in vitro and in vivo biological evaluations, including in silico methods. In silico studies showed that all synthesized compounds were drug-like and could penetrate through the blood–brain barrier. According to the in vitro testing, hydroxamic acids 15 and 25, which effectively inhibited HDAC6 and exhibited anti-aggregation properties against β-amyloid peptides, were chosen as the most promising substances to study their neuroprotective activities in vivo. All in vivo studies were performed using 5xFAD transgenic mice simulating Alzheimer’s disease. In these animals, the Novel Object Recognition and Morris Water Maze Test showed that the formation of hippocampus-dependent long-term episodic and spatial memory was deteriorated. Hydroxamic acid 15 restored normal memory functions to the level observed in control wild-type animals. Notably, this effect was precisely associated with the ability to restore lost cognitive functions, but not with the effect on motor and exploratory activities or on the level of anxiety in animals. Conclusively, hydroxamic acid 15 containing an adamantane fragment linked by an amide bond to a hydrocarbon linker is a possible potential multitarget agent against Alzheimer’s disease.

Alkaloids of Peganum harmala L. and their Pharmacological Activity

Peganum harmala L. contains 17 alkaloids of quinazoline and indole structure types. Of these, harmaline, harmine, harmalol and L-peganin (vazicin) are pharmacologically active. It was established that of the alkaloids contained in the seeds, 50-95% is dominated by harmaline, harmine is dominated in the roots (67-74% of the total of extractive substances), and in the aerial part, the main mass is peganin (up to 78% of the total of alkaloids). Beta-carboline alkaloids of Peganum harmala L. inhibit monoamine oxidase, thereby exerting a neuroprotective effect.
 This article is devoted to the results of studies of the neurotropic action of harmine hydrochloride, when compared with the activity of the reference drug “Amitriptyline”. It was shown that the use of harmine hydrochloride helps to reduce the level of anxiety in animals under conditions of experimental psychoemotional chronic stress with prolonged administration. In the study of acute and chronic toxicity, it was determined that harmine hydrochloride belongs to the category of moderately toxic substances (hazard class II). According to the results of molecular docking, the presence of strong bonds in harmine hydrochloride with the serotonin 5-HT2C receptor, dopamine D2 receptor, as well as monoamine oxidase A and B was revealed, which indicates the implementation of the mechanism of neurotropic action of harmine hydrochloride at the level of synaptic neurotransmission of monoamines (dopamine, serotonin and others). It was also established that harmine hydrochloride eliminates haloperidol-induced catalepsy in rats, reduces oligokinesia and rigidity in the Parkinson’s test, has antihypoxic activity in the hypobaric hypoxia test, and exhibits pronounced antidepressant activity in the Porsolt’s test. In the course of the study of pharmacokinetics and bioavailability, it was revealed that with the administration of harmine hydrochloride, the quantitative content is quickly achieved and the concentration of the active substance in the blood significantly increases. The relative bioavailability of harmine hydrochloride is 112.7%.

EFFECTS OF MELANOCORTINSON THE BEHAVIOR OF RATSIN THETEST OFELEVATED CRUCIFORM MAZE AND EXPERIMENTALLY INDUCED OFSOCIALS

— In this study we have investigated the effects of melanocortins (group analogs of neuropeptides) on the psychoemotional state of rats under conditions of experimental social stress. The study was carried out on male rats which were injected intraperitoneally for 20 days with the neuropeptide drugs Semax and ACTH(6-9)-ProGly-Pro at a dose of 100 μg/kg/day starting from the 1st day of stress exposure. The psychoemotional state of the animals was evaluated by means of the behavioral test of elevated cruciform maze. It was found that intraperitoneal administration of neuropeptides (Semax, ACTH(6-9)- Pro-Gly-Pro) helps to reduce high anxiety levels in animals both with aggressive and submissive types of behavior under conditions of experimental social stress via their psychomodulatory effects.

Electrophysiological effects of polyethylene glycol modified gold nanoparticles on mouse hippocampal neurons

Gold nanoparticles (AuNPs) can cross the blood brain barrier, thus can be used as nanocarriers in brain drug delivery. However, the effect of bare and polyethylene glycol-modified (PEGylated) AuNPs on normal neural function has not been extensively investigated. In this study, bioelectrical properties of neuronal functions of male BALB/c mice were explored ex vivo and in vivo by using 5 nm bare AuNPs and PEGylated AuNPs. Electrophysiological properties of neurons from hippocampal CA1 region sections were recorded by patch clamp method. Ex vivo, firing rate of action and membrane potentials in response to negative current stimuli significantly altered only after bare AuNP exposure compared to control (p < 0.05). After in vivo injections, anxiety levels of animals were similar. Amplitude of action potentials reduced only in bare AuNP group (p < 0.05). In conclusion, excitability of hippocampal neurons is increasing with bare AuNP exposure, and PEGylation might be more biocompatible for medical applications.

The impact of bilberry fruits polyphenols, sorbed on buckwheat flour, on the induced disorders of carbohydrate metabolism of male C57BL/6c mice

The hypoglycemic properties of polyphenolic compounds of plant origin are confirmed by the results of numerous preclinical and clinical studies. However, the biological effects of these compounds are limited by their low bioavailability. This makes it urgent to develop methods for its increasing due to new methods of entering polyphenols into the organism, for example, by extracting them from natural sources in the form of extracts and concentrating extracts on food polymer matrices for subsequent use as a functional food ingredient (FFI). The aim of this study was to evaluate in vivo the possible effect of consumption of the obtained FFI in the form of a food matrix - buckwheat flour enriched with bilberry polyphenols - on carbohydrate metabolism disorders induced by a high-fat diet with a high content of easily digestible carbohydrates (sucrose) and anxiety level of male C57Bl/6c mice. Material and methods. The food matrix was obtained by sorption of the bilberry fruits polyphenol extract on buckwheat flour. The total polyphenol content in the composition of food matrix was 8.9±0.7 mg-eq gallic acid/g flour. Total anthocyanin content in the composition of food matrix was 4.6±0.1 mg/g flour. The experiment was conducted for 150 days using 48 male C57Bl/6c mice (weaners). The animals were divided into 3 groups: the control group K1 (n=16, the mice received a standard semi-synthetic diet (22.5% protein, 10% fat, 58% carbohydrates as starch, 362 kcal/100 g), the control group K2 (n=14) and the experimental group G3 (n=18). Disorders of carbohydrate and lipid metabolism in animals of groups K2 and G3 were modeled by feeding an iso-nitrogenous high-fat diet with a high content of easily digestible carbohydrates (HFHC-diet: 22.5% protein, 30% fat, 18% carbohydrates in the form of starch, 20% sucrose, 493 kcal/100 g). FFI, a food matrix in the amount of 6.6 g/100 g of feed, was introduced into the diet of animals of the experimental group G3, which corresponded to the amount of polyphenols equal to 58.7 mg-eq gallic acid/100 g of feed and the content of anthocyanins 30.4 mg/100 g of feed. Once every three weeks, the level of glucose in the blood of animals was monitored. On days 60 and 114 of the experiment, animals were tested on an elevated plus maze. Animals were decapitated under light ether anesthesia at the end of experiment. The content of glycated hemoglobin was determined in the blood. Results and discussion. Animals of both groups treated with HFHC-diet consumed significantly less feed compared with animals of the control group K1 (2.91±0.05 g/day per mouse). Moreover, animals of the experimental group G3 consumed significantly more food (2.51±0.04 g/day per mouse) compared with animals of the control group K2 (2.36±0.04 g/day per mouse). In contrast, the energy consumption of animals of both groups fed HFHC-diet was significantly higher compared to the K1 group (10.5±0.2 kcal/ day per mouse). Energy consumption by animals of group G3 (12.3±0.2 kcal/day per mouse) was significantly higher compared to animals of the control group K2 (11.5±0.2 kcal/day per mouse). The data obtained indicate that the consumption of FFI in the form of polyphenols adsorbed on the food matrix can contribute to increased appetite in animals treated with the high-fat diet. The results of the Elevated Plus Maze test indicated the absence of the effect of polyphenols in the composition of the food matrix on the anxiety level of animals. Starting from day 42 until the end of the experiment, the glucose level in animals of group G3 was significantly lower than the corresponding indicator for animals of the control group K2. Conclusion. In accordance with the results obtained, further studies of the safety and clinical efficacy of including the developed FFI in the form of a food matrix with polyphenols into the composition of specialized foods for the prevention of carbohydrate metabolism disorders are advisable.

The neurogenic effects of rosmarinic acid in a mouse model of type 2 diabetes mellitus

There is emerging evidence for a dysregulation of insulin signaling in the brains of patients with Alzheimer’s disease (AD) with overlapping molecular features to Type 2 Diabetes Mellitus (T2DM). In addition, T2DM is a known risk factor of AD. The goal of this study was to investigate the neurogenic and neuroprotective potential of rosmarinic acid (RA) in a streptozotocin (STZ)-induced combined with high fat diet (HFD) mouse model of diabetes. Animals were divided into four experimental groups (control, diabetic, diabetic + RA, RA only). Behavioral analysis was performed to assess spatial learning and anxiety levels of animals, whereas quantitative real time PCR was carried out to assess the gene expression levels of neuronal markers of neurogenesis (Ki67, DCX and NeuN). A significant decrease in memory and spatial learning was observed in the diabetic mice, which was substantially improved by RA treatment. RA also increased the gene expression of NeuN, DCX and Ki67, which were dysregulated in the diabetic model. This study proposes RA as a potential therapeutic agent to mitigate neuronal dysfunction associated with T2DM by promoting adult hippocampal neurogenesis.

Magnetic resonance spectroscopy of hippocampal and striatal neurometabolites in experimental PTSD rat modeling

The spectrum of the metabolites in the dorsal region of the hippocampus and striatum was studied using the method of 1H magnetic resonance spectroscopy at experimental modeling of the posttraumatic stress disorder syndrome (PTSD) in rats. PTSD was reproduced by exposure of the cat cue to rats daily along 10 day by 10 minutes at once. The anxiety level of animals was estimated 12 days later after the end of the experimental series of stress. Based on the anxiety index, the rats were divided into 3 phenotypes. The animals with an anxiety index &gt; 0.8 (group 1) had lower plasma corticosterone compared with rats form the control group. In animals with an anxiety index in the range 0.7–0.8 (group 2), an elevated corticosterone level was noted. The rats with an anxiety index &lt; 0.7 (group 3) had a lower plasma corticosterone level compared with animals from the control group. Rats of group 2 were characterized by an increased level of GABA in the hippocampus compared with controls. In the remaining groups, the percentages of GABA in the hippocampus and striatum did not differ significantly from the control. The distribution of NAA differed form that of GABA. The highest level of NAA was found in the striatum for rats from group 1, whereas NAA in animals form groups 1 or 3 did not differ from the control. The NAA level in the hippocampus was similar between all groups, including the control. The results obtained indicate that multiple exposures to psychological stress associated with the sense of proximity of a natural enemy in some animals cause an anxiolytic reaction. These animals are characterized by a stable corticosterone level and a stable level of neurometabolites in the studied structures of the brain. For rats with the highest level of anxiety, a lowered level of corticosterone with a constant level of neurometabolites in the hippocampus and striatum is characteristic. And only in rats with an intermediate level of anxiety, synchronization was observed between the increase in plasma corticosterone and the increase in hippocampal GABA content. The results obtained are in good agreement with the ideas of the protective action of glucocorticoids under PTSD manifested in restraining violations of the psycho-physiological status. The mate rials allow the neurobiological mechanisms of the protective action of glucocorticoids to be detailed.

Adaptation Effect of Repeated Xenon Application

Objective: to investigate the effect of xenon addition to oxygen mixtures. Materials and methods. The repeated use of a xenon-oxygen gas mixture containing 50% xenon, 40% oxygen, and 10% nitrogen versus an oxygen mixture containing 40% oxygen on behavioral parameters characterizing orientativeexploratory activity, stress, and anxiety in Wistar rats, as well as the level of free radical oxidation and urgent protection proteins was comparatively analyzed. Results. Repeated exposure to the hyperoxic mixture increases the level of anxiety in animals and enhances the intensity of free radical processes and the activity of liver antioxidant protection enzymes; incorporation of xenon into the oxygen gas mixture levels off the multiple action of hyperoxia. Conclusion. The findings are suggestive of the lower level of anxiety in animals and the adaptation effect of repeated application of xenon incorporated into oxygen mixtures.

Targeted Inactivation of the Gene Encoding Gamma-Synuclein Affects Anxiety Levels and Investigative Activity in Mice

Gamma (γ) synuclein is a member of the family of synucleins, which are cytoplasmic, predominantly, neuronal, proteins found only in vertebrates. Significant quantities of γ-synuclein are found in the axons and presynaptic terminals of neurons located in brain areas responsible for forming emotions and memory. However, the involvement of γ-synucleins in controlling neuronal and synaptic processes underlying various types of behavior in humans and animals have not yet been studied. We provide the first demonstration that the absence of γ-synuclein increases orientational-investigative activity in a novel context and decreases the level of situational anxiety in animals.

Effects of opioidergic systems upon anxiolytic-like behaviors induced in cholestatic rats

Cholestasis is associated with endotoxinemia and elevated serum levels of bile acids, cholesterol, bile salts and opioids. Opioid systems have been reported to modulate anxiety. In the present study, the possible involvement of opioidergic system on anxiolytic-like behaviors induced by cholestasis was investigated. Cholestasis was induced in male Wistar rats by ligation of the main bile duct using two ligatures and transecting the duct at the midpoint between them. A standard elevated plus-maze was used to determine anxiety levels in animals. The data indicated that there is an increase, 13 days (but not 10 days) after bile duct ligation, in the percentage of open arm time (%OAT) and open arm entries (%OAE) but not locomotor activity, grooming, rearing and defecation, showing anxiolytic-like effects of cholestasis. Intraperitoneal (i.p.) injection of a subthreshold dose of morphine (4 mg/kg), 15 min before testing 10 days after bile duct ligation, showed an increase in %OAT and %OAE, suggesting an anxiolytic-like effect for the drug. Furthermore, injection of subthreshold doses of naloxone (0.4 and 0.6 mg/kg, i.p.), 15 min before testing 13 days after bile duct ligation, decreased %OAT and %OAE. This indicates that naloxone blocks anxiolytic-like behaviors induced by cholestasis. Also, injection of a subthreshold dose of naloxone (0.4 mg/kg, i.p.), 15 min before the injection of a subthreshold dose of morphine (4 mg/kg, i.p.), 10 days after bile duct ligation, decreased %OAT and %OAE but not other behaviors. In conclusion, the results show the involvement of opioidergic system in anxiolytic-like behaviors induced by cholestasis.