Protective effect of ashwagandha (Withania somnifera) against neurotoxicity induced by aluminum chloride in rats

Objective: To evaluate the neuroprotective effect of ashwagandha extract against aluminum chloride-induced neurotoxicity in rats. Methods: Rats were divided into control, aluminum-intoxicated rats treated daily with aluminum trichloride (AlCl3) (100 mg/kg, orally) for 30 d and aluminum-intoxicated animals protected by receiving daily ashwagandha extract (200 mg/kg, orally) one hour before AlCl3 administration for 30 d. Levels of lipid peroxidation, nitric oxide, reduced glutathione and tumor necrosis factor-α were measured in the cortex, hippocampus and striatum. In addition, the activities of Na+, K+, ATPase and acetylcholinesterase were determined in the three studied brain regions. Results: Aluminum increased the levels of lipid peroxidation and nitric oxide in the cortex, hippocampus and striatum and decreased the reduced glutathione level in the hippocampus and striatum. In rats protected with ashwagandha extract, non significant changes were observed in lipid peroxidation, nitric oxide and reduced glutathione. In addition, ashwagandha extracts prevented the increased activity of acetylcholinesterase and Na+, K+, ATPase induced by AlCl3 in the cortex, hippocampus and striatum. The present findings also showed that the significant increase in tumor necrosis factor-α induced by AlCl3 in the cortex and hippocampus was prevented by ashwagandha extract. Conclusions: The present results suggest that ashwagandha extract possesses antioxidant and anti-inflammatory effects against aluminum neurotoxicity. In addition, ashwagandha extract could prevent the decline in cholinergic activity by maintaining normal acetylcholinesterase activity. The later effect could recommend the use of ashwagandha as a memory enhancer

Dose-dependent biological toxicity of green synthesized silver nanoparticles in rat’s brain

Abstract Metal nanoparticles, in general, and silver nanoparticles (AgNPs), in particular, have been the focus of numerous studies over the last two decades. Recently, the green synthesis of metal nanoparticles has been favored over chemical synthesis due to its low toxicity and easy preparation. The present study aims to investigate the dose-dependent toxicity of green synthesized AgNPs on rats’ brains. Thirty-four Wistar male rats were divided into four groups. The first, second, and third groups were administered for 14 days with three different doses (0.5, 5, and 10 mg/kg) of AgNPs, respectively. The fourth group, which served as a control group, was given normal saline for the same period. The toxicity of the green synthesized AgNPs on the cortical and hippocampal levels of the oxidative stress markers (MDA, NO, and GSH) as well as the activity of acetylcholinesterase (AchE) and the monoamine neurotransmitters (DA, NE, and 5H-T) were investigated. AgNPs showed minimal oxidative stress in the cortex and hippocampus for the administered doses. However, AgNPs showed an inhibitory effect on AchE activity in a dose-dependent manner and a decrease in the 5H-T and NE levels. The green synthesized AgNPs showed an ultrastructural change in the cellular membranes of the neurons. The green synthesis of AgNPs has reduced their cytotoxic oxidative effects due to their capping with biologically compatible and boosting molecules such as flavonoids. However, another neurotoxicity was observed in a dose-dependent manner

Assessment of the antidepressant effect of caffeine using rat model of depression induced by reserpine

Abstract Objective The present objective is to evaluate the antidepressant activity of caffeine. Material and methods Three groups of rats were used; control, reserpine-induced rat model of depression, and rat model of depression treated daily with caffeine. At the end of the experiment, the motor activity of rats was measured using open field test. On the next day, the animals of the three groups were sacrificed to measure levels of serotonin, norepinephrine, and dopamine in the cortex and hippocampus by spectrofluorometer. In addition, the levels of lipid peroxidation (MDA), nitric oxide (NO), and reduced glutathione (GSH) together with the activities of acetylcholinesterase (AchE) and Na+, K+, ATPase were measured in the two studied brain regions by spectrophotometer. Results In the rat model of depression, the animals showed a significant decrease in motor activity. This was associated with significant decreases in serotonin, norepinephrine, and dopamine in the cortex and hippocampus. However, significant increases in the activities of AchE and Na+, K+, ATPase, and the levels of MDA and NO were recorded in both areas of rat model of depression while GSH showed a significant decrease in the hippocampus. Caffeine failed to restore the decrease in motor activity. Caffeine treatment ameliorated the changes in cortical and hippocampal norepinephrine and dopamine and hippocampal serotonin. In addition, it restored MDA and GSH levels. However, it failed to prevent the increased AchE and Na+, K+, ATPase activities, and NO levels. Conclusions The present findings indicate that caffeine has a partial antidepressant effect mediated by its antioxidant activity and enhancement of monoamine levels

A Neurochemical and Electrophysiological Study on the Combined Effects of Caffeine and Nicotine in the Cortex of Rats

Introduction: Caffeine and nicotine are the most widely consumed psychostimulants worldwide. Although the effects of each drug alone on the central nervous system have been studied extensively, the literature on the neurochemical and electrophysiological effects of their combined treatments is scarce. The present study investigated the cortical electrophysiological and neurochemical alterations induced by acute administration of caffeine and nicotine in rats.  Methods: The rats received caffeine and nicotine at a 1-hour interval between the two treatments.  Results: Caffeine and nicotine administration resulted in a significant decrease in the concentrations of cortical amino acid neurotransmitters, namely glutamate, aspartate, glycine, and taurine, while γ-aminobutyric acid (GABA) significantly increased. Increased cortical lipid peroxidation and reduced glutathione and nitric oxide levels and acetylcholinesterase and Na⁺/K⁺-ATPase activities were also observed. The Electroencephalogram (EEG) showed an increase in delta frequency power band, whereas theta, beta-1, and beta-2 decreased after caffeine and nicotine treatment.  Conclusion: These findings suggest that caffeine and nicotine adversely exacerbate their stimulant effects manifested by the EEG changes mediated by increasing cholinergic transmission and disturbing the balance between the excitatory and inhibitory amino acids leading to oxidative stress

Evaluation of the neuroprotective effect of taurine and green tea extract against oxidative stress induced by pilocarpine during status epilepticus

Status epilepticus (SE) has functional and structural consequences resulting in brain damage. The present study aims to investigate the role of taurine and green tea extract in the neuroprotection against oxidative stress and changes in acetylcholinesterase (AChE) and Na+,K+-ATPase activities during SE induced by pilocarpine in the hippocampus of adult male rats. Animals received an oral administration of either taurine (100 mg/kg) or green tea extract containing 100 mg/kg epigallocatechin gallate for 3 days before the induction of SE with pilocarpine (380 mg/kg, i.p.) and were sacrificed 1 h after pilocarpine injection. Data indicated that a state of oxidative stress has evolved during SE as evident from the significant increase in lipid peroxidation level and significant decrease in reduced glutathione (GSH) level. Significant decreases in AChE and Na+,K+-ATPase activities were also recorded. Pretreatment of rats with taurine exaggerated the increase in lipid peroxidation and failed to prevent the decrease in Na+,K+-ATPase activity resulting from pilocarpine. However, taurine pretreatment prevented the reduced activity of hippocampal AChE induced by pilocarpine during SE. Pretreatment of rats with green tea extract prevented the increase in lipid peroxidation occurring during SE. However, it failed to inhibit the decrease in Na+,K+-ATPase activity. In conclusion, taurine pretreatment failed to reduce the oxidative stress induced during SE. In contrast, pretreatment of rats with green tea extract ameliorated the oxidative stress induced by pilocarpine and this may assist in reducing the insults of hyperexcitability and excitotoxicity that occur during SE and thereby reduce neuronal damage

Bone Marrow-Derived Mesenchymal Stem Cells and γ-Secretase Inhibitor Treatments Suppress Amyloid-β25–35-Induced Cognitive Impairment in Rat Dams and Cortical Degeneration in Offspring

Alzheimer’s disease (AD) is the most frequent cause of age-related neurodegeneration and ensuing cognitive impairment. Progressive deposition of extracellular amyloid beta (Aβ) aggregates (plaques) and intracellular hyperphosphorylated Tau protein (p-Tau) are the core pathological markers of AD but may precede clinical symptoms by many years, presenting a therapeutic window of opportunity. Females are more frequently afflicted by AD than males, necessitating evaluation of novel treatments for the female population. The current study examined the protective efficacies of intravenous bone marrow-derived mesenchymal stem cells (BM-MSCs) and oral gamma-secretase inhibitor-953 (GSI-953) during pregnancy on cognitive impairment in rat dams and neurodegeneration in offspring induced by intracerebroventricular injection of Aβ25–35 prior to pregnancy. The Aβ25–35 (AD) group exhibited significant (P<0.001) impairments in the Y-maze and novel object recognition test performance prior to conception. Histological analysis of the offspring cortex revealed substantial dendritic shrinkage and activation of microglial cells, while neurochemical analysis demonstrated significant increases in the proinflammatory cytokine interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). In contrast, BM-MSC or GSI-953 treatment of dams following Aβ25–35 injection significantly (P<0.001) reduced the number and size of activated microglial cells, markedly increased dendrite length, and reversed proinflammatory cytokine elevations in offspring. Moreover, BM-MSC or GSI-953 treatment reversed the Aβ25–35-induced amyloid precursor protein and p-Tau elevations in the offspring brain; these changes were accompanied by upregulation of the brain-derived neurotrophic factor and downregulation of glycogen synthase kinase-3β in the serum and brain. Treatment with BM-MSCs or GSI-953 also reversed Aβ25–35-induced elevations in different gene expressions in the neonatal cortex. Finally, treatment of dams with BM-MSCs or GSI-953 prevented the Aβ25–35-induced disruption of newborn brain development. Thus, BM-MSC and GSI-953 treatments have broad-spectrum effects against Aβ25–35-induced brain pathology, including the suppression of neural inflammation, restoration of developmental plasticity, and promotion of neurotrophic signaling