Evaluation of the Therapeutic Effect of Curcumin-Conjugated Zinc Oxide Nanoparticles on Reserpine-Induced Depression in Wistar Rats

Depression, a devastating brain illness, necessitates the exploration of novel antidepressant treatments. We evaluated the antidepressant effects of free curcumin, zinc oxide nanoparticles (ZnO NPs), and curcumin-conjugated zinc oxide nanoparticles (Zn(cur)O NPs). The nanoformulations were extensively characterized using advanced techniques. An acute toxicity study ensured the safety of Zn(cur)O NPs. Rats were assigned to one of five groups: control, reserpine-induced depression model, treatment with ZnO NPs, free curcumin, or Zn(cur)O NPs. Behavioral assessments (forced swimming test [FST] and open-field test [OFT]) and neurochemical analyses were conducted. Zn(cur)O NPs exhibited superior efficacy in ameliorating reserpine-induced behavioral and neurochemical effects compared to free curcumin and ZnO NPs. The reserpine-induced model displayed reduced motor activity, swimming time, and increased immobility time in the FST and OFT. Treatment with Zn(cur)O NPs 45 mg/kg significantly improved motor activity and reduced immobility time. Furthermore, Zn(cur)O NPs decreased malondialdehyde (MDA) levels while increasing reduced glutathione (GSH) and catalase (CAT) levels. Additionally, concentrations of serotonin (5-HT) and norepinephrine (NE) increased. In conclusion, curcumin-conjugated zinc oxide nanoparticles demonstrate potent antidepressant effects, alleviating depressive-like behavior in rats. These findings support Zn(cur)O NPs as a promising therapeutic strategy for depression management, warranting further investigation and clinical validation.

Cerebrolysin potentiates the antidepressant effect of lithium in a rat model of depression

RATIONALE

Depression is the most prevalent psychiatric disorder worldwide. Although numerous antidepressant treatments are available, there is a serious clinical concern due to their severe side effects and the fact that some depressed patients are resistant to them. Lithium is the drug of choice for bipolar depression and has been used as adjunct therapy with other groups of antidepressants.

OBJECTIVES

The present study aims to investigate the effect of lithium augmentation with cerebrolysin on the neurochemical, behavioral and histopathological alterations induced in the reserpine model of depression.

METHODS

The animals were divided into control and reserpine-induced model of depression. The model animals were further divided into rat model of depression, rat model treated with lithium, rat model treated with cerebrolysin and rat model treated with a combination of lithium and cerebrolysin.

RESULTS

Treatment with lithium, cerebrolysin, or their combination alleviated most of the changes in behavior, oxidative stress parameters, acetylcholinesterase and monoamines in the cortex and hippocampus of the reserpine-induced model of depression. It also improved the alterations in brain-derived neurotrophic factor (BDNF) and histopathology induced by reserpine.

CONCLUSIONS

The augmentation of lithium with cerebrolysin showed a clear beneficial effect in the present model of depression suggesting the use of cerebrolysin as an adjuvant in antidepressant treatment.

Effect of caffeine-chitosan nanoparticles and α-lipoic acid on the cardiovascular changes induced in rat model of obesity

The current research aims to study the therapeutic efficacy of alpha-lipoic acid (α-LA) and caffeine-loaded chitosan nanoparticles (Caf-CNs) against cardiovascular complications induced by obesity. Rats were divided randomly into: control, high fat diet (HFD) induced obesity rat model, obese rats treated with α-LA and/or Caf-CNs. Triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) as well as activities of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) significantly increased in the serum of obese rats. In addition, plasma atherogenic index, atherogenic coefficient and Castelli's risk indices I and II showed a significant increase. Additionally, levels of malondialdehyde (MDA) and nitric oxide (NO) and activity of monoamine oxidase (MAO) were significantly elevated in heart tissues of obese rats. However, cardiac Na+/K+-ATPase and acetylcholinesterase (AchE) activities and reduced glutathione (GSH), serotonin (5-HT), norepinephrine (NE) and dopamine (DA) as well as serum high-density lipoprotein cholesterol (HDL-C) were significantly reduced in obese rats. Treatment with α-LA and/or Caf-CNs ameliorated almost all the biochemical and histopathological alterations caused by obesity. In conclusion, the present data revealed that α-LA and/or Caf-CNs may be an effective therapeutic approach against cardiac complications caused by obesity through their antilipemic, anti-atherogenic, antioxidant, and anti-inflammatory activities.

Transcranial photobiomodulation ameliorates midbrain and striatum neurochemical impairments and behavioral deficits in reserpine-induced parkinsonism in rats

Photobiomodulation (PBM) of deep brain structures through transcranial infrared irradiation might be an effective treatment for Parkinson's disease (PD). However, the mechanisms underlying this intervention should be elucidated to optimize the therapeutic outcome and maximize therapeutic efficacy. The present study aimed at investigating the oxidative stress-related parameters of malondialdehyde (MDA), nitric oxide (NO), and reduced glutathione (GSH) and the enzymatic activities of sodium-potassium-ATPase (Na+, K+-ATPase), Acetylcholinesterase (AChE), and monoamine oxidase (MAO) and monoamine levels (dopamine (DA), norepinephrine (NE) and serotonin (5-HT) in the midbrain and striatum of reserpine-induced PD in an animal model treated with PBM. Furthermore, the locomotor behavior of the animals has been determined by the open field test. Animals were divided into three groups; the control group, the PD-induced model group, and the PD-induced model treated with the PBM group. Non-invasive treatment of animals for 14 days with 100 mW, 830 nm laser has demonstrated successful attainment in the recovery of oxidative stress, and enzymatic activities impairments induced by reserpine (0.2 mg/kg) in both midbrain and striatum of adult male Wistar rats. PBM also improved the decrease in DA, NE, and 5-HT in the investigated brain regions. On a behavioral level, animals showed improvement in their locomotion activity. These findings have shed more light on some mechanisms underlying the treatment potential of PBM and displayed the safety, easiness, and efficacy of PBM treatment as an alternative to pharmacological treatment for PD.

Effect of alpha-lipoic acid and caffeine-loaded chitosan nanoparticles on obesity and its complications in liver and kidney in rats

The present work investigated the effect of α-lipoic acid (ALA) and caffeine-loaded chitosan nanoparticles (CAF-CS NPs) on obesity and its hepatic and renal complications in rats. Rats were divided into control, rat model of obesity induced by high fat diet (HFD), and obese rats treated with ALA and/or CAF-CS NPs. At the end of the experiment, the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) and the levels of urea, creatinine, interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were determined in the sera of animals. In addition, malondialdehyde (MDA), nitric oxide (NO), and reduced glutathione (GSH) were measured in hepatic and renal tissues. Renal Na+, K+-ATPase was assessed. The histopathological changes were examined in the hepatic and renal tissues. Obese rats showed a significant increase in AST, ALT, ALP, urea, and creatinine. This was associated with a significant increase in IL-1β, TNF-α, MDA, and NO. A significant decrease in hepatic and renal GSH and renal Na+, K+-ATPase activity was recorded in obese rats. Obese rats also showed histopathological alterations in hepatic and renal tissues. Treatment with ALA and/or CAF-CS NPs reduced the weight of obese rats and ameliorated almost all the hepatic and renal biochemical and histopathological changes induced in obese rats. In conclusion, the present findings indicate that ALA and/or CAF-CS NPs offered an effective therapy against obesity induced by HFD and its hepatic and renal complications. The therapeutic effect of ALA and CAF-CS NPs could be mediated through their antioxidant and anti-inflammatory properties.

Mesenchymal Stem Cells and Begacestat Mitigate Amyloid-β 25-35-Induced Cognitive Decline in Rat Dams and Hippocampal Deteriorations in Offspring

Alzheimer's disease (AD) is the most common cause of age-related neurodegeneration and cognitive decline. AD more commonly occurs in females than in males, so it is necessary to consider new treatments specifically targeting this population. The present study investigated the protective effects of Begacestat (γ-secretase inhibitor-953, GSI-953) and bone marrow-derived mesenchymal stem cells (BM-MSCs) during pregnancy on cognitive impairment in rat dams and neurodegeneration in offspring caused by the intracerebroventricular injection of Aβ 25-35 before pregnancy. The performances of dams injected with amyloid-β 25-35 (Aβ 25-35) during behavioral tests were significantly impaired. The offspring of Aβ 25-35-injected dams treated with BM-MSCs or GSI-953 showed a dramatically reduced number and size of activated microglial cells, enhancement in the processes length, and a decrease in the proinflammatory cytokine levels. Additionally, BM-MSC or GSI-953 therapy reduced Aβ 25-35-induced increases in tau phosphorylation and amyloid precursor protein levels in the neonates' hippocampus and elevated the lower levels of glycogen synthase kinase-3 and brain-derived neurotrophic factor; moreover, reversed Aβ 25-35-induced alterations in gene expression in the neonatal hippocampus. Finally, the treatments with BM-MSC or GSI-953 are globally beneficial against Aβ 25-35-induced brain alterations, particularly by suppressing neural inflammation, inhibiting microglial cell activation, restoring developmental plasticity, and increasing neurotrophic signaling.

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.

Evaluation of the therapeutic potential of cerebrolysin and/or lithium in the male Wistar rat model of Parkinson's disease induced by reserpine

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease worldwide and represents a challenge for clinicians. The present study aims to investigate the effects of cerebrolysin and/or lithium on the behavioral, neurochemical and histopathological alterations induced by reserpine as a model of PD. The rats were divided into control and reserpine-induced PD model groups. The model animals were further divided into four subgroups: rat PD model, rat PD model treated with cerebrolysin, rat PD model treated with lithium and rat PD model treated with a combination of cerebrolysin and lithium. Treatment with cerebrolysin and/or lithium ameliorated most of the alterations in oxidative stress parameters, acetylcholinesterase and monoamines in the striatum and midbrain of reserpine-induced PD model. It also ameliorated the changes in nuclear factor-kappa and improved the histopathological picture induced by reserpine. It could be suggested that cerebrolysin and/or lithium showed promising therapeutic potential against the variations induced in the reserpine model of PD. However, the ameliorating effects of lithium on the neurochemical, histopathological and behavioral alterations induced by reserpine were more prominent than those of cerebrolysin alone or combined with lithium. It can be concluded that the antioxidant and anti-inflammatory effects of both drugs played a significant role in their therapeutic potency.

The Behavioral and Neurochemical Changes Induced by Boldenone and/or Tramadol in Adult Male Rats

Boldenone and tramadol are abused among large sectors of adolescents. Therefore, the behavioral changes concerned with memory and cognitive functions and neurochemical variations were investigated in the cortex of rats treated with boldenone and/or tramadol. Rats were divided into control and rats treated with boldenone, tramadol, or both drugs. At the end of the treatment period, the memory and cognitive functions were evaluated by the Y-maze test (YMT) and elevated plus maze test (EPMT) and the motor activity was determined by the open field test (OFT). The cortex was dissected to carry out the neurochemical analyses. Rats treated with boldenone and/or tramadol showed impaired memory and cognitive functions and reduced motor activity. A significant increase in lipid peroxidation (MDA), nitric oxide (NO), and a significant decrease in reduced glutathione (GSH) were observed in the cortex of rats treated with boldenone and/or tramadol. The levels of acetylcholinesterase (AChE) and monoamine oxidase (MAO) decreased significantly. Western blot data showed a significant decrease in Bcl2 and a significant increase in caspase-3 and inducible nitric oxide synthase (iNOS) in rats treated with boldenone and/or tramadol. These changes were associated with neuronal death as indicated from the histopathological examination.

The present findings indicate that boldenone and/or tramadol induced impairment in memory and cognitive functions. These changes could be mediated by the increase in oxidative stress, neuroinflammation, reduced AChE level, and reduced number of survived neurons in the cortex as indicated from the decreased Bcl2 level and the histological examination.

Evaluation of the therapeutic effect of mesoporous silica nanoparticles loaded with Gallic acid on reserpine-induced depression in Wistar rats

Background

The current study evaluates the free gallic acid (GA) and GA-loaded mesoporous silica nanoparticles (MSNs) antidepressant efficacy in a rat model of depression caused by reserpine.

Methods

By using a scanning electron microscope (SEM), dynamic light scattering (DLS), and zeta potential, MSNs and GA-loaded MSNs were characterized. The efficiency of encapsulation and the release of GA-loaded MSNs were also investigated. The effect of GA, either in its free form or loaded on (MSNs) on oxidative stress biomarkers and monoamine neurotransmitters levels (serotonin (5-HT), norepinephrine (NEP), and dopamine (DA)), were evaluated in these areas (cortex, hippocampus, striatum, and hypothalamus) of control, a depression model of rat, a depression model of rat treated with either free GA, MSNs or GA loaded MSNs. The forced swimming test (FST) also the open field test (OFT) were carried out to evaluate the behavioral changes in all groups.

Results

Reserpine caused a decrease in the time spent in motor and swimming activity besides increasing the time of immobility, as demonstrated by OFT and FST. Significantly reductions in 5-HT, NEP, and DA were obtained in the cortex, hippocampus, hypothalamus, and striatum of reserpine-treated rats. Free GA was more effective in increasing the serotonin level in the cortex, hippocampus, and hypothalamus, while GA-loaded MSNs were more effective in increasing it in the striatum. GA-loaded MSNs also increased the level of NEP in the four studied brain areas. Free GA increased dopamine levels in the cortex and striatum, whereas GA-loaded MSNs increased DA levels in the hippocampus and hypothalamus compared with the depressed untreated group.

Conclusions

MSNs can be used as a drug delivery system to target GA selectively to specific brain areas.

Effect of curcumin nanoparticles on streptozotocin-induced male Wistar rat model of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease that afflicts millions of people all over the world. Intracerebroventricular (ICV) injection of a sub-diabetogenic dose of streptozotocin (STZ) was established as an experimental animal model of AD. The present study was conducted to evaluate the efficacy of curcumin nanoparticles (CNs) against the behavioral, neurochemical and histopathological alterations induced by ICV-STZ. The animals were divided into: control animals, the animal model of AD that received a single bilateral ICV microinjection of STZ, and the animals protected by a daily oral administration of CNs for 6 days before the ICV-STZ injection. The animals of all groups were subjected to surgical operation on the 7th day of administration. Then the administration of distilled water or CNs was continued for 8 days. The ICV-STZ microinjection produced cognitive impairment as evident from the behavioral Morris water maze (MWM) test and induced oxidative stress in the cortex and hippocampus as indicated by the significant increases in lipid peroxidation and nitric oxide (NO) levels and the significant decrease in reduced glutathione (GSH) levels. It also produced a significant increase in acetylcholinesterase (AChE) and tumor necrosis-alpha (TNF-ɑ) and a significant decrease in Na+,K + -ATPase. In addition, a significant increase in amino acid neurotransmitters occurred in the hippocampus, whereas a significant decrease was obtained in the cortex of STZ-induced AD rats. CNs ameliorated the behavioral, immunohistochemical and most of the neurochemical alterations induced by STZ in the hippocampus and cortex. It may be concluded that CNs might be considered as a promising therapeutic agent for the treatment of AD.

The Neuroprotective Effect of α-Lipoic Acid and/or Metformin against the Behavioral and Neurochemical Changes Induced by Hypothyroidism in Rat

OBJECTIVE

The present study evaluates the neuroprotective effect of α-lipoic acid (ALA) and/or metformin (MET) on the behavioral and neurochemical changes induced by hypothyroidism.

METHODS

Rats were divided into control, rat model of hypothyroidism induced by propylthiouracil, and rat model of hypothyroidism treated with ALA, MET, or their combination.

RESULTS

Behaviorally, hypothyroid rats revealed impaired memory and reduced motor activity as indicated from the novel object recognition test and open-field test, respectively. Hypothyroidism induced a significant increase in lipid peroxidation (malondialdehyde [MDA]) and a significant decrease in reduced glutathione (GSH) and nitric oxide (NO) in the cortex and hippocampus. These were associated with a significant increase in tumor necrosis factor-α (TNF-α) and a significant decrease in brain-derived neurotrophic factor (BDNF). Hypothyroidism decreased significantly the levels of serotonin (5-HT), norepinephrine (NE), and dopamine (DA) and reduced the activities of acetylcholinesterase (AchE) and Na+, K+-ATPase in the cortex and hippocampus. Treatment of hypothyroid rats with ALA and/or MET showed an improvement in memory function and motor activity. Moreover, ALA and/or MET prevented the increase in MDA and TNF-α, and the decline in GSH, NO, BDNF, 5-HT, NE, and DA. It also restored AchE and Na+, K+-ATPase activities in the studied brain regions.

CONCLUSION

ALA and/or MET has a potential neuroprotective effect against the adverse behavioral and neurochemical changes induced by hypothyroidism in rats.

Antidepressant and antioxidant effects of transcranial irradiation with 830-nm low-power laser in an animal model of depression

The present study aimed at investigating the antidepressant and antioxidant actions of near-infrared (NIR) laser at a wavelength of 830 nm and power of 100 mW which applied transcranially on an animal model of depression induced by repeated doses of reserpine (0.2 mg/kg). Thirty male Wistar adult rats were divided into three groups: rat model of depression; rat model of depression irradiated with laser for 14 days after induction of depression; and the control group that was given the drug vehicle and sham-exposed to the laser. Forced swimming test (FST) was used to verify the induction of animal model of depression and to screen the effect of antidepressant effect of low-level laser at the end of the experiment. Monoamine level, oxidative stress markers, and activities of acetylcholinesterase (AchE) and monoamine oxidase (MAO) were determined in the cortex and hippocampus of the rat brain. Reserpine resulted in depletion of monoamines and elevation in the oxidative stress markers and change in the enzymatic activities measured in both brain areas. Laser irradiation has an inhibitory action on the monoamine oxidase (MAO) in the cortex and hippocampus leading to elevation of the monoamine levels and attenuation of the oxidative stress in the studied areas. FST has emphasized the antidepressant effect of the utilized laser irradiation parameters on the behavioral level. The present findings provide evidence for the antidepressant and antioxidant actions of NIR low-power laser in the rat model of depression. Accordingly, low-laser irradiation may be presented as a potential candidate modality for depression treatment.

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.

Antidepressant effects of curcumin-coated iron oxide nanoparticles in a rat model of depression

The antidepressant effect of curcumin-coated iron oxide nanoparticles (Cur-IONPs) was investigated in the current study using depression rat model induced by reserpine. IONPs were synthesized by curcumin as a reducing agent producing Cur-IONPs. Rats were divided into control, depression rat model, and depressed rats treated with Cur-IONPs. After treatment rat behavior was evaluated using forced swimming test (FST). Serotonin (5-HT), norepinephrine (NE), dopamine (DA), monoamine oxidase (MAO), acetylcholinesterase (AchE), Na⁺, K⁺, ATPase, lipid peroxidation (MDA), reduced glutathione (GSH), glutathione-s-transferase (GST) and nitric oxide (NO) were measured in the cortex and hippocampus. In depressed rats, FST showed increased immobilization time and reduced swimming time. This was associated with a significant decrease in 5-HT, NE, DA and GSH and a significant increase in MDA and NO levels and GST, MAO, AchE and Na⁺, K⁺, ATPase activities in the cortex and hippocampus. Treatment with Cur-NONPs for two weeks increased the swimming time reduced the immobility time, and elevated 5-HT, NE and DA levels. Cur-IONPs attenuated the oxidative stress induced by reserpine and restored the MAO, AchE and Na⁺, K⁺, ATPase. The present green method used curcumin in the IONPs synthesis and has several merits; obtaining nanoform of iron oxide, increasing the bioavailability of curcumin and reducing the oxidative stress induced by iron. The present antidepressant effect of Cur-IONPs could be attributed to the ability of Cur-IONPs to restore monoamine neurotransmitter levels by increasing their synthesis and reducing their metabolism. In addition, the antioxidant activity of curcumin prevented oxidative stress in the depressed rats.

The Effect of Curcumin Nanoparticles on Cisplatin-Induced Cardiotoxicity in Male Wistar Albino Rats

The cardiotoxicity of chemotherapeutic drugs as cisplatin has become a major issue in recent years. The present study investigates the efficacy of curcumin nanoparticles against the cardiotoxic effects of cisplatin by assessment of oxidative stress parameters, Na+,K+-ATPase, acetylcholinesterase (AchE) and tumor necrosis factor-alpha (TNF-α) in cardiac tissue in addition to serum lactate dehydrogenase (LDH). Rats were divided into three groups: control rats that received saline for 14 days; cisplatin-treated rats that received a single intraperitoneal (i.p.) injection of cisplatin (12 mg/kg) followed by a daily oral administration of saline (0.9%) for 14 days and rats treated with a single i.p. injection of cisplatin (12 mg/kg) followed by a daily oral administration of curcumin nanoparticles (50 mg/kg) for 14 days. Cisplatin resulted in a significant increase in lipid peroxidation, nitric oxide (NO), and TNF-α and a significant decrease in reduced glutathione (GSH) levels and Na+, K+- ATPase activity. Moreover, significant increases in cardiac AchE and serum lactate dehydrogenase activities were recorded. Treatment of cisplatin-injected animals with curcumin nanoparticles ameliorated all the alterations induced by cisplatin in the heart of rats. This suggests that curcumin nanoparticles can be used as an important therapeutic adjuvant in chemotherapeutic and other toxicities mediated by oxidative stress and inflammation.

Electrophysiological and neurochemical evaluation of the adverse effects of REM sleep deprivation and epileptic seizures on rat's brain

AIM

The current study aims to investigate the impact of paradoxical (REM) sleep deprivation and/or epileptic seizures on rat's cortical brain tissues.

MAIN METHODS

Animals were divided into four groups; control, epileptic, REM sleep deprived and epileptic subjected to REM sleep deprivation. Electrocorticogram (ECoG) signals were recorded and quantitatively analyzed for each group. Concentrations of amino acid neurotransmitters; proinflammatory cytokines; and oxidative stress parameters; and acetylcholinesterase activity were determined in the cortex of the animals in different groups.

KEY FINDINGS

Results showed significant variations in the spectral distribution of ECoG waves in the epilepsy model, 24- and 48-hours of REM sleep deprivation and their combined effects indicating a state of cortical hyperexcitability. Significant increases in NO and taurine and significant decrement in glutamine, GABA and glycine were determined. In REM sleep deprived rats significant elevation in glutamate, aspartate, glycine and taurine and a significant lowering in GABA were obtained. This was accompanied by significant reduction in AchE and IL-β. In the cortical tissue of epileptic rats deprived from REM sleep significant increases in lipid peroxidation, TNF-α, IL-1β, IL-6 and aspartate and a significant reduction in AchE were observed.

SIGNIFICANCE

The present data indicate that REM sleep deprivation induces an increase in lipid peroxidation and storming in proinflammatory cytokines in the cortex of rat model of epilepsy during SRS. These changes are associated with a decreased seizure threshold as inferred from the increase in alpha and Beta waves and a decrease in Delta waves of ECoG.

Neurochemical effects of sleep deprivation in the hippocampus of the pilocarpine-induced rat model of epilepsy

OBJECTIVES

The present study aims to investigate the pathological mechanisms mediating the effect of paradoxical sleep deprivation (PSD) for 48 hr on the spontaneous recurrent seizures (SRS) stage of the pilocarpine rat model of temporal lobe epilepsy.

MATERIALS AND METHODS

This was carried out through assessment of amino acid neurotransmitter levels, the main oxidative stress parameters, and the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in the hippocampus. The experimental animals were divided into 4 groups: control, epileptic, PSD, and epileptic+PSD groups.

RESULTS

Data indicated that PSD in epileptic rats induced a significant decrease in GSH levels. TNF-α increased significantly in the PSD group and decreased significantly in both epileptic rats and epileptic rats deprived of paradoxical sleep. PSD induced a significant increase in glutamine, glutamate, and aspartate and a significant decrease in GABA. In epileptic rats and epileptic rats deprived of PS, a significant increase in aspartate and a significant decrease in GABA and taurine were recorded.

CONCLUSION

The present data suggest that exposure to PSD for 48 hr did not worsen the alterations produced in the present epileptic model. However, epileptic, PSD, epileptic + PSD groups showed a state of hyperexcitability and oxidative stress. PSD may increase the susceptibility of animals to the development of epilepsy.

Effect of frankincense oil on the neurochemical changes induced in rat model of status epilepticus

Background

The current objective is to evaluate the effect of frankincense oil on the convulsions and the associated neurochemical alterations produced in pilocarpine-induced status epilepticus rat model.

Methods

Rats were divided randomly into: control, status epilepticus rat model and rat model of status epilepticus pretreated with frankincense oil daily for 5 days before pilocarpine treatment. On the fifth day, after pilocarpine injection, rats were observed to evaluate the severity of seizures for 2 h. The oxidative stress parameters malondialdehyde, reduced glutathione and nitric oxide, the proinflammatory cytokines interleukin-6 and interleukin-1β and acetylcholinesterase were determined in the cortex, hippocampus and striatum. Dopamine, norepinephrine and serotonin were measured in the cortex and striatum.

Results

The status epilepticus model exhibited repetitive seizures in the form of generalized tonic- clonic convulsions after 30 min. of pilocarpine injection. This was associated with a significant increase in the levels of malondialdehyde and nitric oxide and a significant decrease in reduced glutathione in the three regions. A significant increase was also observed in interleukin-1β, interleukin-6 and acetylcholinesterase. In the cortex and striatum, a significant decrease was recorded in monoamine levels. Pretreatment of rat model of status epilepticus with frankincense oil decreased the severity of seizures that appeared in the form of tremors and facial automatisms and prevented the increase in malondialdehyde, nitric oxide, interleukin-1β, interleukin-6 and acetylcholinesterase and the decrease in reduced glutathione induced by pilocarpine in the studied brain regions. Frankincense oil failed to restore the decreased level of cortical serotonin and dopamine. In the striatum, frankincense oil improved the levels of serotonin and norepinephrine but failed to restore the decreased dopamine levels.

Conclusion

It is clear from the present results that frankincense oil reduced the severity of seizures induced by pilocarpine. This could be mediated by its potent antioxidant and anti-inflammatory effects.

Thymoquinone-encapsulated chitosan nanoparticles coated with polysorbate 80 as a novel treatment agent in a reserpine-induced depression animal model

Depression is a mental illness with a high prevalence in humans reaching 21% of the worldwide population.The present study aims to evaluate the antidepressant effect of different formulations of Thymoquinone; free Thymoquinone (TQ), Thymoquinone-loaded Chitosan nanoparticles (TQ-TPP-Cs NPs) and Thymoquinone-loaded Chitosan nanoparticles coated with polysorbate 80 (TQ-TPP-Cs NPs-PSb80) that have been prepared to avoid the low bioavailability of TQ. Rats were randomly separated into control rats, depression control induced by reserpine, rat model treated with TQ, rat model treated with TQ-TPP-Cs NPs and rat model treated with TQ-TPP-Cs NPs-PSb80. The results indicate that TQ-TPP-Cs NPs loaded with polysorbate 80 was more efficient in ameliorating the behavioral and neurochemical changes induced by reserpine than TQ and TQ-TPP-Cs NPs. Formulationswere characterized for size, morphology, encapsulation efficiency and in vitro drug release before their use in treatment. Reserpine induced a reduction in motor activity and swimming time and increased immobility time as indicated from the open field test (OFT) and forced swimming test (FST). In addition, a significant decrease in the monoamine neurotransmitters serotonin (5-HT), norepinephrine (NE) and dopamine (DA) was recorded in the cortex, hippocampus and striatum of reserpine-treated rats. The present data suggest that the antidepressant efficacy of TQ could be enhanced by engaging TQ with chitosan nanoparticles as a drug carrier and the formulations were modified by coating with polysorbate 80.

Neuroprotective effect of PPAR alpha and gamma agonists in a mouse model of amyloidogenesis through modulation of the Wnt/beta catenin pathway via targeting alpha- and beta-secretases

The present study was conducted to evaluate the efficacy of fenofibrate and pioglitazone in a mouse model of amyloidogenesis induced by amyloidβ (βA) peptide. Mice were injected intracerebroventricularly with βA1-40 (400 pmol/mouse) once, followed by treatment with fenofibrate (300 mg/kg), pioglitazone (30 mg/kg),or both. After 21 days of daily treatment, memory impairment and cognitive function were evaluated by Morris water maze (MWM), Y-maze and object recognition tests. On the 22nd day, mice were sacrificed, and their hippocampi were dissected to determine the levels of α- and β-secretase, peroxisome proliferator-activated receptor (PPARα and β), Wnt and β-catenin. Significant memory impairment and cognitive dysfunction were observed in the mouse model group. This finding was associated with a significant increase in α- and β-secretase levels and a significant decrease in Wnt, β-catenin, and PPARα and β levels. Neuronal damage was also evident after histopathological examination. Treatment with fenofibrate, pioglitazone and their combination resulted in a significant improvement in the behavioural and neurochemical changes induced by βA injection. The present findings indicate that the combined administration of fenofibrate and pioglitazone was more effective than monotherapy in ameliorating the behavioural, neurochemical and histopathological changes in amyloidogenesis model mice and provide a promising therapeutic approach in the management of Alzheimer's disease complicated by diabetes and hypercholesterolemia.

Neuroprotective Effect of Ashwagandha Extract against the Neurochemical Changes Induced in Rat Model of Hypothyroidism

The current aim is to evaluate the effect of ashwagandha root extract (AE) on the neurochemical changes induced in the cortex and hippocampus as a consequence of thyroid dysfunction induced by propylthiouracil (PTU). Male Wistar rats were divided into; control, AE treated rats, rat model of hypothyroidism and rat model of hypothyroidism treated with either AE or L-thyroxine (T4) for 1 month. Rat model of hypothyroidism showed a significant decrease in serum levels of tri-iodothyronine (T3) and T4 and a significant increase in cortical and hippocampal lipid peroxidation (MDA), nitric oxide (NO), superoxide dismutase (SOD) and catalase (CAT). However, reduced glutathione (GSH) decreased significantly. This was associated with a significant increase in hippocampal tumor necrosis factor-α (TNF-α) and cortical dopamine levels. Both L-thyroxine and AE restored T3 and T4 levels. In the hippocampus L-Thyroxine prevented the increase in MDA and restored GSH but failed to restore the increased NO and TNF-α. In the cortex L-thyroxine didn't change the increased MDA and NO and the decreased GSH induced by PTU. L-thyroxine increased cortical and hippocampal SOD and CAT. AE prevented the increased hippocampal MDA, NO and TNF-α and the decreased GSH level induced by PTU. In the cortex AE failed to restore MDA and NO but prevented the decrease in GSH. The increase in cortical dopamine level induced by PTU was ameliorated by L-thyroxine and improved by AE. The present data indicate that AE could prevent thyroid dysfunction and reduce its complications on the nervous system including oxidative stress and neuroinflammation.

Protective effect of curcumin nanoparticles against cardiotoxicity induced by doxorubicin in rat

The present study designed to investigate the protective effect of curcumin nanoparticles (CUR-NPs) on the cardiotoxicity induced by doxorubicin. Rats were divided into four groups; control, rats treated daily with CUR-NPs (50 mg/kg) for 14 days, rats treated with an acute dose of doxorubicin (20 mg/kg) and rats treated daily with CUR-NPs for 14 days injected with doxorubicin on the 10th day. After electrocardiogram (ECG) recording from rats at different groups, rat decapitation was carried out and the heart of each rat was excised out to measure the oxidative stress parameters; lipid peroxidation (MDA), nitric oxide (NO) and reduced glutathione (GSH) and the activities of Na,K,ATPase and acetylcholinesterase (AchE). In addition, the levels of dopamine (DA), norepinephrine (NE) and serotonin (5-HT) were determined in the cardiac tissues. Lactate dehydrogenase (LDH) activity was measured in the serum. The ECG recordings indicated that daily pretreatment with CUR- NPs has prevented the tachycardia (i.e. increase in heart rate) and ameliorated the changes in ST wave and QRS complex induced by doxorubicin. In addition, CUR-NPs prevented doxorubicin induced significant increase in MDA, NO, DA, AchE and LDH and doxorubicin induced significant decrease in GSH, NE, 5-HT and Na,K,ATPase. According to the present findings, it could be concluded that CUR-NPs have a protective effect against cardiotoxicity induced by doxorubicin. This may shed more light on the importance of CUR-NPs pretreatment before the application of doxorubicin therapy.

The chronic effect of pulsed 1800 MHz electromagnetic radiation on amino acid neurotransmitters in three different areas of juvenile and young adult rat brain

The extensive use of mobile phones worldwide has raised increasing concerns about the effects of electromagnetic radiation (EMR) on the brain due to the proximity of the mobile phone to the head and the appearance of several adverse neurological effects after mobile phone use. It has been hypothesized that the EMR-induced neurological effects may be mediated by amino acid neurotransmitters. Thus, the present study investigated the effect of EMR (frequency 1800 MHz, specific absorption rate 0.843 W/kg, power density 0.02 mW/cm2, modulated at 217 Hz) on the concentrations of amino acid neurotransmitters (glutamic acid, aspartic acid, gamma aminobutyric acid, glycine, taurine, and the amide glutamine) in the hippocampus, striatum, and hypothalamus of juvenile and young adult rats. The juvenile and young adult animals were each divided into two groups: control rats and rats exposed to EMR 1 h daily for 1, 2, and 4 months. A subgroup of rats were exposed daily to EMR for 4 months and then left without exposure for 1 month to study the recovery from EMR exposure. Amino acid neurotransmitters were measured in the hippocampus, striatum, and hypothalamus using high-performance liquid chromatography. Exposure to EMR induced significant changes in amino acid neurotransmitters in the studied brain areas of juvenile and young adult rats, being more prominent in juvenile animals. It could be concluded that the alterations in amino acid neurotransmitters induced by EMR exposure of juvenile and young adult rats may underlie many of the neurological effects reported after EMR exposure including cognitive and memory impairment and sleep disorders. Some of these effects may persist for some time after stopping exposure.

Cannabis sativa Increases Seizure Severity and Brain Lipid Peroxidation in Pentylenetetrazole-Induced Kindling in Rats

The effect of Cannabis sativa extract on chemical kindling induced in rats by the repeated intraperitoneal (ip) injections of pentylenetetrazole (PTZ) was studied. Rats were treated with PTZ (35 mg/kg) once every 48 hours for 12 times alone or with ip Cannabis sativa (20 mg/kg expressed as Δ9-THC content) 30 min prior to PTZ injection. Seizures were recorded for 20 minutes. Control rats received ip saline. Cannabis treatment caused significant elevation of mean seizure score as compared to PTZ only group after the 5th, 6th and 7th PTZ repeated injections during seizure development. In particular, cannabis caused significant elevation in the frequency of myoclonic jerks, rearing (stage 3), turn over onto one side position and back position (stage 4), and generalized tonic-clonic seizures (stage 5) compared with the PTZ only group. PTZ caused significant elevations in brain lipid peroxidation (malondialdehyde), and nitric oxide along with deceased reduced glutathione level. In addition, brain acetylcholinesterase (AChE) activity significantly decreased compared to control value after PTZ treatment. Cannabis given to PTZ treated rats caused significant increase in brain malondialdehyde and AChE activity compared to PTZ only group. Reduced glutathione level was restored by cannabis. Histopathological studies indicated the presence of spongiform changes, degenerated and necrotic neurons, inflammatory cells, and gliosis in cerebral cortex and degeneration of some Purkinje cells in the cerebellum in both PTZ- and cannabis-PTZ-treated groups. It is concluded that in an epilepsy model induced by repeated PTZ administration, cannabis increased lipid peroxidation and mean seizure score.

Neuroprotective effect of curcumin nanoparticles against rat model of status epilepticus induced by pilocarpine

Background

The present study aims to investigate the neuroprotective effect of curcumin nanoparticles (Cur-NP) on the rat model of status epilepticus (SE) induced by pilocarpine.

Methods

In the present study, animals were divided into three groups: control animals, rat model of SE induced by a single dose of pilocarpine (380 mg/kg) injected intraperitoneally, and rat model of SE that received a daily intraperitoneal injection of Cur-NP (50 mg/kg) for four consecutive days prior to pilocarpine administration.

Results

The present results revealed a state of oxidative stress in the cortex and hippocampus of rat model of SE as compared to control. This was evident from the significant increase in lipid peroxidation and the significant decrease in reduced glutathione and nitric oxide. In addition, a significant increase in the levels of tumor necrosis factor-alpha (TNF-α) and caspase-3 was detected in the two studied brain regions of rat model of SE. The activities of acetylcholinesterase (AchE) and Na+/K+-ATPase decreased significantly in the cortex and hippocampus of rat model of SE. Protection with Cur-NP prevented oxidative stress and improved the elevated level of caspase-3 in the hippocampus and cortex and the hippocampal TNF-α to nonsignificant changes. Although Cur-NP prevented the decrease in AchE activity in the two studied brain regions, it failed to return Na+/K+-ATPase activity to its normal value.

Conclusions

It is clear from the present findings that Cur-NP could prevent the oxidative stress and neuroinflammation and cell death that were induced during SE. This in turn may help in ameliorating the subsequent cascades of events that follow SE and its development into epileptogenesis.

Protection by Neostigmine and Atropine Against Brain and Liver Injury Induced by Acute Malathion Exposure

We examined the effect of treatment with neostigmine alone or with atropine on brain oxidative stress and on brain and liver tissue damage following acute malathion toxicity. Rats were intraperitoneally treated with malathion 150 mg/kg along with neostigmine (200 or 400 μg/kg) or neostigmine (200 μg/kg) + atropine (1 mg/kg) and euthanized 4 h later. Results indicated that compared with the saline group, malathion resulted in (i) higher brain malondialdehyde (MDA) and nitric oxide (46.4% and 86.2%); (ii) decreased brain reduced glutathione (GSH) (67.6%); (iii) decreased brain paraoxonase-1 (PON1), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities (31.2%, 21.6% and 60%); (iv) decreased brain glucose (-38.1%); (v) neuronal degeneration in cortex and hippocampus and markedly increased glial fibrillary acidic protein (GFAP) immunostaining in the hippocampus; (v) hydropic and fatty degeneration in liver. Rats treated with malathion along with neostigmine or neostigmine + atropine showed no change in brain MDA but decreased nitric oxide (-34.2%-48%). GSH increased after neostigmine 200 μg/kg or neostigmine + atropine (35.8% and 41%). PON1 activity increased (42%-35.2%) and glucose concentrations increased (91.5%-81.5%) by 400 μg/kg neostigmine or neostigmine + atropine. Brain AChE activity remained unchanged but BChE activity showed 18.3% increment after 400 μg/kg neostigmine. Rats treated with 400 μg/kg neostigmine or neostigmine + atropine had normal neuronal appearance in cortex and hippocampus and weak GFAP expression in hippocampus. Liver damage was prevented by neostigmine + atropine. These results suggest that treatment with neostigmine + atropine afforded protection against the deleterious effects of acute malathion on the brain and liver.

Nitric oxide synthase inhibitors protect against brain and liver damage caused by acute malathion intoxication

OBJECTIVE

To investigate the effect of N^G-nitro-l-arginine methyl ester (l-NAME), a non-selective nitric oxide synthase (NOS) inhibitor, and 7-nitroindazole (7-NI), a selective neuronal NOS inhibitor, on oxidative stress and tissue damage in brain and liver and on DNA damage of peripheral blood lymphocytes in malathion intoxicated rats.

METHODS

Malathion (150 mg/kg) was given intraperitoneally (i.p.) along with l-NAME or 7-NI (10 or 20 mg/kg, i.p.) and rats were euthanized 4 h later. The lipid peroxidation product malondialdehyde (MDA), nitric oxide (nitrite), reduced glutathione (GSH) concentrations and paraoxonase-1 (PON-1) activity were measured in both brain and liver. Moreover, the activities of glutathione peroxidase (GPx) acetylcholinesterase (AChE), and butyrylcholinesterase (BChE), total antioxidant capacity (TAC), glucose concentrations were determined in brain. Liver enzyme determination, Comet assay, histopathological examination of brain and liver sections and inducible nitric oxide synthase (iNOS) immunohistochemistry were also performed.

RESULTS

(i) Rats treated with only malathion exhibited increased nitric oxide and lipid peroxidation (malondialdehyde) accompanied with a decrease in GSH content, and PON-1 activity in brain and liver. Glutathione peroxidase activity, TAC, glucose concentrations, AChE and BChE activities were decreased in brain. There were also raised liver aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and increased DNA damage of peripheral blood lymphocytes (Comet assay). Malathion caused marked histopathological changes and increased the expression of iNOS in brain and liver tissues. (ii) In brain of malathion-intoxicated rats, l-NAME or 7-NI resulted in decreased nitrite and MDA contents while increasing TAC and PON1 activity. Reduced GSH and GPx activity showed an increase by l-NAME. AChE activity increased by 20 mg/kg l-NAME and 10 mg/kg 7-NI. AChE activity decreased by the higher dose of 7-NI while either dose of 7-NI resulted in decreased BChE activity. (iii) In liver of malathion-intoxicated rats, decreased MDA content was observed after l-NAME or 7-NI. Nitrite level was unchanged by l-NAME but increased after 7-NI which also resulted in decreased GSH concentration and PON1 activity. Either inhibitor resulted in decreased liver ALT activity. (iv) DNA damage of peripheral blood lymphocytes was markedly inhibited by l-NAME or 7-NI treatment. (v) iNOS expression in brain and liver decreased by l-NAME or 7-NI. (vi) More marked improvement of the histopathological alterations induced by malathion in brain and liver was observed after 7-NI compared with l-NAME.

CONCLUSIONS

In malathion intoxicated rats, the neuronal NOS inhibitor 7-NI and to much less extent l-NAME were able to protect the brain and liver tissue integrity along with improvement in oxidative stress parameters. The decrease in DNA damage of peripheral blood lymphocytes by NOS inhibitors also suggests the involvement of nitric oxide in this process.

Neuroprotective and Therapeutic Effect of Caffeine on the Rat Model of Parkinson's Disease Induced by Rotenone

The present study aimed to investigate the protective and therapeutic effects of caffeine on rotenone-induced rat model of Parkinson's disease (PD). Rats were divided into control, PD model induced by rotenone (1.5 mg/kg intraperitoneally (i.p.) for 45 days), protected group injected with caffeine (30 mg/kg, i.p.) and rotenone for 45 days (during the development of PD model), and treated group injected with caffeine (30 mg/kg, i.p.) for 45 days after induction of PD model. The data revealed a state of oxidative and nitrosative stress in the midbrain and the striatum of animal model of PD as indicated from the increased lipid peroxidation and nitric oxide levels and the decreased reduced glutathione level and activities of glutathione-S-transferase and superoxide dismutase. Rotenone induced a decrease in acetylcholinesterase and Na⁺/K⁺-ATPase activities and an increase in tumor necrosis factor-α level in the midbrain and the striatum. Protection and treatment with caffeine ameliorated the oxidative stress and the changes in acetylcholinesterase and Na⁺/K⁺-ATPase activities induced by rotenone in the midbrain and the striatum. This was associated with improvement in the histopathological changes induced in the two areas of PD model. Caffeine protection and treatment restored the depletion of midbrain and striatal dopamine induced by rotenone and prevented decline in motor activities (assessed by open field test) and muscular strength (assessed by traction and hanging tests) and improved norepinephrine level in the two areas. The present study showed that caffeine offered a significant neuroprotection and treatment against neurochemical, histopathological, and behavioral changes in a rotenone-induced rat model of PD.

Acetylcholinesterase, butyrylcholinesterase and paraoxonase 1 activities in rats treated with cannabis, tramadol or both

OBJECTIVE

To investigate the effect of Cannabis sativa resin and/or tramadol, two commonly drugs of abuse on acetylcholinesterase and butyrylcholinesterase activities as a possible cholinergic biomarkers of neurotoxicity induced by these agents.

METHODS

Rats were treated with cannabis resin (5, 10 or 20 mg/kg) (equivalent to the active constituent Δ⁹-tetrahydrocannabinol), tramadol (5, 10 and 20 mg/kg) or tramadol (10 mg/kg) combined with cannabis resin (5, 10 and 20 mg/kg) subcutaneously daily for 6 weeks. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities were measured in brain and serum. We also measured the activity of paraoxonase-1 (PON1) in serum of rats treated with these agents.

RESULTS

(i) AChE activity in brain increased after 10-20 mg/kg cannabis resin (by 16.3-36.5%). AChE activity in brain did not change after treatment with 5-20 mg/kg tramadol. The administration of both cannabis resin (5, 10 or 20 mg/kg) and tramadol (10 mg/kg) resulted in decreased brain AChE activity by 14.1%, 12.9% and 13.6%, respectively; (ii) BChE activity in serum was markedly and dose-dependently inhibited by cannabis resin (by 60.9-76.9%). BChE activity also decreased by 17.6-36.5% by 10-20 mg/kg tramadol and by 57.2-63.9% by the cannabis resin/tramadol combined treatment; (iii) Cannabis resin at doses of 20 mg/kg increased serum PON1 activity by 25.7%. In contrast, tramadol given at 5, 10 and 20 mg/kg resulted in a dose-dependent decrease in serum PON1 activity by 19%, 36.7%, and 46.1%, respectively. Meanwhile, treatment with cannabis resin plus tramadol resulted in 40.2%, 35.8%, 30.7% inhibition of PON1 activity compared to the saline group.

CONCLUSIONS

These data suggest that cannabis resin exerts different effects on AChE and BChE activities which could contribute to the memory problems and the decline in cognitive function in chronic users.

Neurochemical impact of bisphenol A in the hippocampus and cortex of adult male albino rats

Bisphenol A (BPA), an endocrine-disrupting chemical, is widely used in the manufacture of polycarbonated plastics and epoxy resins and line metal beverage cans. Growing evidence suggests that BPA acts directly on neuronal functions as it is lipophilic and could accumulate in the brain. The present study aims to investigate the effect of two doses of BPA (10 mg/kg for 6 and 10 weeks and 25 mg/kg for 6 weeks) on excitatory (glutamate and aspartate) and inhibitory (γ-aminobutyric acid, glycine, and taurine) amino acid neurotransmitter levels in the cortex and hippocampus. This study extends to investigate the effect of BPA on acetylcholinesterase (AchE) activity and some oxidative stress parameters in the two regions. In the cortex, a significant increase in the excitatory and a significant decrease in the inhibitory amino acids occurred after BPA (10 mg/kg for 10 weeks and 25 mg/kg for 6 weeks). This was accompanied by a significant increase in lipid peroxidation, nitric oxide, and reduced glutathione after 6 weeks of BPA (25 mg/kg). In the hippocampus, a significant increase in the excitatory and inhibitory amino acid neurotransmitters occurred after 6 weeks of BPA. Hippocampal lipid peroxidation increased significantly after BPA exposure and hippocampal reduced glutathione increased significantly after 6 weeks of BPA exposure (10 mg/kg). BPA induced a significant increase in cortical and hippocampal AchE activity. The present neurochemical changes in the cortex and hippocampus suggest that BPA induced a state of excitotoxicity and oxidative stress. This may raise concerns about the exposure of humans to BPA due to its wide applications in industry.

The effect of bisphenol A on some oxidative stress parameters and acetylcholinesterase activity in the heart of male albino rats

Bisphenol A (BPA) is an endocrine disrupting chemical used on a wide range in industry. Several studies reported that BPA may cause cardiovascular disorders in humans and animals. The present study aims to investigate the effect of BPA on the heart of adult male rats. The rats received a daily oral administration of BPA (25 mg/kg for 6 weeks and 10 mg/kg for 6 and 10 weeks). It was found that BPA at the two studied doses induced a significant increase in malondialdehyde, and a significant decrease in catalase after 6 weeks. Moreover, a significant decrease in reduced glutathione and acetylcholinesterase (AchE) activity was observed after treatment with the two doses of BPA throughout the studied time intervals. The two doses (25 and 10 mg/kg) resulted in a significant decrease in nitric oxide (NO) levels after 6 and 10 weeks, respectively. A significant increase in body weight gain occurred in all animals after BPA treatment. These results suggest that BPA has cardiotoxic effects which are mediated by the oxidative stress resulting from the overproduction of free radicals, the deficiency of NO and the inhibition of AchE leading to cholinergic activation. The obesity promoting effect of BPA may also participate in the observed cardiovascular disturbances.

The effect of pulsed electromagnetic radiation from mobile phone on the levels of monoamine neurotransmitters in four different areas of rat brain

BACKGROUND

The use of mobile phones is rapidly increasing all over the world. Few studies deal with the effect of electromagnetic radiation (EMR) on monoamine neurotransmitters in the different brain areas of adult rat.

AIM

The aim of the present study was to investigate the effect of EMR on the concentrations of dopamine (DA), norepinephrine (NE) and serotonin (5-HT) in the hippocampus, hypothalamus, midbrain and medulla oblongata of adult rats.

MATERIALS AND METHODS

Adult rats were exposed daily to EMR (frequency 1800 MHz, specific absorption rate 0.843 W/kg, power density 0.02 mW/cm2, modulated at 217 Hz) and sacrificed after 1, 2 and 4 months of daily EMR exposure as well as after stopping EMR for 1 month (after 4 months of daily EMR exposure). Monoamines were determined by high performance liquid chromatography coupled with fluorescence detection (HPLC-FD) using their native properties.

RESULTS

The exposure to EMR resulted in significant changes in DA, NE and 5-HT in the four selected areas of adult rat brain.

CONCLUSIONS

The exposure of adult rats to EMR may cause disturbances in monoamine neurotransmitters and this may underlie many of the adverse effects reported after EMR including memory, learning, and stress.

One-pot three-component synthesis of novel heterocyclic steroids as a central antioxidant and anti-inflammatory agents

Oxidative stress and inflammation have been implicated in several neurodegenerative and developmental brain disorders. The present work was devoted to the design and synthesis of novel steroid derivatives bearing promising heterocyclic moiety that would act to reduce neuro-inflammation and oxidative stress in brain. The novel heterocyclic steroids were synthesized and their chemical structures were confirmed by studying their analytical and spectral data. The tested compounds were assayed in the model of neuro-inflammation produced in rats by cerebral lipopolysaccharide injection. The intracerebral administration of bacterial endotoxin resulted in cerebral inflammatory state evidenced by increased malondialdehyde (MDA), decreased reduced glutathione (GSH) level, increased nitric oxide as well as increased acetylcholinesterase (AChE) activity in the brain. Compounds 6, 10, 8b and 13a markedly increased reduced glutathione. Malondialadehyde and nitric oxide levels were reduced to normal values after treatment with all tested compounds. AChE activity was normalized by compound 8b and reduced to below normal values by compounds 10 and 14a. These results are exciting in that these agents might be useful candidates in treatment of cerebral inflammation.

Evaluation of the antiepileptic effect of curcumin and Nigella sativa oil in the pilocarpine model of epilepsy in comparison with valproate

The present study aimed to investigate the effect of curcumin and Nigella sativa oil (NSO) on amino acid neurotransmitter alterations and the histological changes induced by pilocarpine in the hippocampus and cortex of rats. Epilepsy was induced by i.p. injection of pilocarpine, and the animals were left for 22 days to establish spontaneous recurrent seizures. They were then treated with curcumin, NSO or valproate for 21 days. Pilocarpine induced a significant increase in hippocampal aspartate and a significant decrease in glycine and taurine levels. In the cortex, a significant increase in aspartate, glutamate, GABA, glycine, and taurine levels was obtained after pilocarpine injection. Treatment of pilocarpinized rats with curcumin and valproate ameliorated most of the changes in amino acid concentrations and reduced the histopathological abnormalities induced by pilocarpine. N. sativa oil failed to improve the pilocarpine-induced abnormalities. This may explain the antiepileptic effect of curcumin and suggest its use as an anticonvulsant.

Nicotine restores monoamine neurotransmitter changes in the cortex and hippocampus of reserpinized rats as a model of depression

BACKGROUND AND OBJECTIVES

A number of studies have shown that nicotine has an antidepressant-like effect. The prevalence of smoking is much higher in people suffering from depression. In addition, the administration of nicotine from transdermal nicotine patch can exert antidepressant activity in nonsmokers and the continuous infusion of nicotine to rats attenuates learned helplessness, a putative behavioral model of depression. The aim of the present study is to elucidate the neurochemical effect of nicotine on monoamine levels in the cerebral cortex and hippocampus of reserpinized rats as a model of depression.

MATERIALS AND METHODS

In the present study, rats were divided into control animals treated with saline and reserpinized group which received a daily i.p injection of reserpine for 15 days to establish the animal model of depression. Starting from the 16th day, the reserpinized rats were divided into reserpinized rats, and reserpinized rats treated daily with nicotine (0.4 mg/kg) for 15 and 30 days. After decapitation, the cerebral cortex and hippocampus of each rat were dissected out. The levels of monoamine neurotransmitters (serotonin, norepinephrine and dopamine) were measured in each area using a spectrofluorimeter.

RESULTS

The daily i.p injection of reserpine induced a significant decrease in monoamine levels in the cortex and hippocampus. Nicotine administration restored the changes in monoamine neurotransmitters induced by reserpine in both areas after 30 days.

DISCUSSION

The data of the present study suggest that the antidepressant-like effect of nicotine could be mediated by the effect of nicotine on monoamine neurotransmitters in the cortex and hippocampus of rat brain.

Effect of oxidative stress induced by paradoxical sleep deprivation on the activities of Na+, K+-ATPase and acetylcholinesterase in the cortex and hippocampus of rat

Several studies revealed the importance of paradoxical sleep as a homeostatic mechanism by which the brain can control oxidative stress. The aim of the present study is to investigate the effect of 72 h of paradoxical sleep deprivation on the oxidative stress markers and its insults on the activities of Na(+), K(+)-ATPase and acetylcholinesterase in the cortex and hippocampus of albino rat. Animals were subjected to paradoxical sleep deprivation for 72 h. At the end of the experiment, the rats were sacrificed, and catalase activity, levels of reduced glutathione, lipid peroxidation, and nitric oxide were assayed together with the activities of Na(+), K(+)-ATPase and acetylcholinesterase in the cortex and hippocampus. The present study revealed a significant increase in lipid peroxidation accompanied by a significant decrease in reduced glutathione in the cortex and hippocampus. Na(+), K(+)-ATPase decreased significantly in both areas. However, acetylcholinesterase showed a significant increase in the investigated brain regions. The present data showed that 72 h of paradoxical sleep deprivation induced oxidative stress in the cortex and hippocampus. It could be suggested that the inhibition of Na(+), K(+)-ATPase and the increased acetylcholinesterase activity may underlie memory impairment, increased brain excitability, and anxiety induced by paradoxical sleep deprivation.