Effect of Fluoxetine on the Hippocampus of Wistar Albino Rats in Cold Restraint Stress Model

Neuroprotective Role of Selenium Nanoparticles Against Behavioral, Neurobiochemical and Histological Alterations in Rats Subjected to Chronic Restraint Stress

Chronic stress induces changes in the prefrontal cortex and hippocampus. Selenium nanoparticles (SeNPs) showed promising results in several neurological animal models. The implementation of SeNPs in chronic restraint stress (CRS) remains to be elucidated. This study was done to determine the possible protective effects of selenium nanoparticles on behavioral changes and brain oxidative stress markers in a rat model of CRS. 50 rats were divided into three groups; control group (n = 10), untreated CRS group (n = 10) and CRS-SeNPs treated group (n = 30). Restraint stress was performed 6 h./day for 21 days. Rats of CRS-SeNPs treated group received 1, 2.5 or 5 mg/kg SeNPs (10 rats each) by oral gavage for 21 days. Rats were subjected to behavioral assessments and then sacrificed for biochemical and histological analysis of the prefrontal cortex and hippocampus. Prefrontal cortical and hippocampal serotonin levels, oxidative stress markers including malondialdehyde (MDA), reduced glutathione (GSH) and glutathione peroxidase (GPx), tumor necrosis factor alpha (TNF-α) and caspase-3 were assessed. Accordingly, different doses of SeNPs showed variable effectiveness in ameliorating disease parameters, with 2.5 mg/kg dose of SeNPs showing the best improving results in all studied parameters. The present study exhibited the neuroprotective role of SeNPs in rats subjected to CRS and proposed their antioxidant, anti-inflammatory and anti-apoptotic effects as the possible mechanism for increased prefrontal cortical and hippocampal serotonin level, ameliorated anxiety-like and depressive-like behaviors and improved prefrontal cortical and hippocampal histological architecture.

The Antidepressant Activity of a Taurine-Containing Derivative of 4-Phenylpyrrolidone-2 in a Model of Chronic Unpredictable Mild Stress

This study investigates the therapeutic potential of a new compound, potassium 2-[2-(2-oxo-4-phenylpyrrolidin-1-yl) acetamido]ethanesulfonate (Compound I), in depression. Willner's chronic unpredictable mild stress model of male Wistar rats was used as a depression model. The rats were randomized into four groups, including an intact group, a Compound I group, a Fluoxetine group, and a control group with saline. Behavioral tests, such as the Porsolt forced swim test, hole-board test, elevated plus maze test, and light-dark box, were used to assess the animals' conditions. Our results demonstrated that Compound I effectively reduced the immobilization time of rats in the forced swim test, increased orientation and exploratory behavior, and decreased the latency period of going into the dark compartment compared to the control group. Hippocampal and striatal serotonin concentrations were increased in the Compound I group, and the compound also reduced the level of corticosterone in the blood plasma of rats compared to the intact animals. These results suggest that Compound I has reliable antidepressant activity, comparable to that of the reference antidepressant Fluoxetine.

Protective effects of Rosemary extract and/or Fluoxetine on Monosodium Glutamate-induced hippocampal neurotoxicity in rat

The use of Monosodium Glutamate (MSG) as a food flavor enhancer is increasing worldwide despite its neurotoxic effects. Fluoxetine (FLX) and Rosemary extract (RE) are known to have beneficial neuroprotective properties. Rats were divided into five groups: control group; MSG group, rats received 2 g/kg/day intraperitoneal (i.p.) injections of MSG for seven days; RE/MSG group, rats received 50 mg/kg/day of oral RE for 28 days starting prior to MSG; FLX/MSG group, rats received 10 mg/kg/day of oral FLX for 28 days beginning before MSG; and RE/FLX/MSG group, received combined treatments as mentioned above. Rats underwent the Barnes maze test, in addition to histopathological, immunohistochemical, morphometric and ultrastructural evaluations for their hippocampi. MSG increased the number of errors and escaped latency in the Barnes maze test that was significantly minimized in the three treatment groups. The MSG group exhibited pyramidal cell (PC) degeneration, shrunken glial cells and massive vascular dilatation that were improved with RE and/or FLX treatment. The number of glial fibrillary acidic protein (GFAP)-immunopositive cells were increased, and the number of PCs was decreased in the MSG group, while these values were significantly reversed with the three treatment groups with the most significant improvement at RE/FLX/MSG one. Ultrastructurally, PCs were shrunken with degenerated nuclei, dilated endoplasmic reticulum, swollen mitochondria, and vacuolations in the MSG group that were improved with RE and/or FLX. In conclusion, the combined RE and FLX treatment can ameliorate the toxic effect of MSG on rat hippocampus probably through its antioxidant and anti-inflammatory effects.

Biomedical Implications of Plant-Based Principles as Antidepressants: Prospects for Novel Drug Development

BACKGROUND

Depression is a most common mental disorder. The symptoms of depression include loss of energy, changes in appetite, more or less sleep, anxiety, low concentration, uncertainty, restlessness, feelings of worthlessness, guilt, or despair, and thoughts of self-harm or suicide. In order to provide safe, efficient and cost-effective medication, the plants based principles in isolation or in combination with traditional antidepressants are attracting increasing attention for depression therapy.

METHOD

The information regarding the present review and its contents such as collected from published literature materials in different international journals. We have used different search engines such as PubMed, Medline, ResearchGate Google Semantic Scholar and ScienceDirect. For this purpose, the data obtained were properly organized and suitably analyzed to include in this article.

RESULTS

Most of the phytomolecules isolated from the medicinal plants display antidepressant effect through the synaptic regulation of levels of neurotransmitters such as dopamine, serotonin, and noradrenaline in different parts of the brain. The mechanism of action of phytomolecules also involves negative regulation of the activities of monoamine oxidase (MAO) and acetylcholinesterase (AChE) and prevention of hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis. In addition, the strong antioxidative and antiinflamatory potential of these phytochemicals offer synergy to their antidepressant as well as antipsychosomatic functions.

CONCLUSION

The application of phytochemicals has proved it to be a safe, cost effective and efficient therapeutic agent to treat the patients suffering from mild to severe state of depression and other psychiatric disorders. The potential phytochemicals may be further optimized using in silico tools to develop better antidepressants and antisychotic agents in future.

Protective action of alkylglycerols under stress

The adaptogenic properties of alkylglycerols (AGs) after 1 month's treatment were investigated in a rat model of acute immobilization stress (AIS). The animals receiving AGs 157 mg/kg showed a body weight (BW) decrease in addition to a more pronounced increase in the adrenal glands index under stress conditions. Also, AGs at this dose prevented AIS-induced catalase inhibition. In addition, antiulcerative AG effects were already detected at a dose of 15 mg/kg. The data indicate that AGs promote adrenal gland activation in AIS. At the same time, AGs neutralize some of negative effects of stressful conditions, which include restoration of the oxidation-reduction balance, reduction of gastric mucosal stress lesion formation.LAY SUMMARYThe effect of alkylglycerols, ether lipids from marine organisms, was studied in stressed animals. AGs have antioxidant activity and can be useful in the complex therapy of stomach lesions.

Pro-neurogenic effect of fluoxetine in the olfactory bulb is concomitant to improvements in social memory and depressive-like behavior of socially isolated mice

Although loneliness is a human experience, it can be estimated in laboratory animals deprived from physical contact with conspecifics. Rodents under social isolation (SI) tend to develop emotional distress and cognitive impairment. However, it is still to be determined whether those conditions present a common neural mechanism. Here, we conducted a series of behavioral, morphological, and neurochemical analyses in adult mice that underwent to 1 week of SI. We observed that SI mice display a depressive-like state that can be prevented by enriched environment, and the antidepressants fluoxetine (FLX) and desipramine (DES). Interestingly, chronic administration of FLX, but not DES, was able to counteract the deleterious effect of SI on social memory. We also analyzed cell proliferation, neurogenesis, and astrogenesis after the treatment with antidepressants. Our results showed that the olfactory bulb (OB) was the neurogenic niche with the highest increase in neurogenesis after the treatment with FLX. Considering that after FLX treatment social memory was rescued and depressive-like behavior decreased, we propose neurogenesis in the OB as a possible mechanism to unify the FLX ability to counteract the deleterious effect of SI.