AlCl3-induced Neurotoxicity Research Articles

Neuroprotective Potential of Spirulina Platensis Against Aluminium Chloride-Induced Neural Degeneration

Free radicals are involved in neurodegenerative disorders such as ischemia and aging. Treatments with Spirulina have been shown to reduce neurodegenerative changes in animals. The present study has been designed to examine the potential neuroprotective effects of Spirulina platensis (Sp.) against AlCl3-induced neurotoxicity in different regions of brain (cerebral cortex, hippocampus and hind brain) of rats. AlCl3 caused significant increase in thiobarbituric acid-reactive substances, tumor necrosis factor-a and aluminium concentration, while decrease glutathione, total antioxidant capacity, antioxidant enzymes (SOD, CAT, GST and GPx), total thiol content, monoamine oxidase, Na+-K+ ATPase and total ATPase. These results were confifirmed by histopathological and fluorescence examination of different regions of brain. Cerebral cortex and hippocampus of AlCl3 showed loss of normal structure, neuronal degeneration and increase in the number of neurodegenerative features, more illuminated aggregates, higher fluorescence emission intensity in the presence of amyloid protein fifibrils. While, the presence of Spirulina with AlCl3 in the combination group exhibited more normal neurons with few pyknotic nuclei and residual fine vacuolations and reduction in the number of illuminate aggregates. Collectively, Spirulina platensis supplementation could overcome AlCl3-induced neurodegenerative disorder by abolishing oxidative tissue injuries.

Asiatic Acid Attenuated Aluminum Chloride-Induced Tau Pathology, Oxidative Stress and Apoptosis Via AKT/GSK-3β Signaling Pathway in Wistar Rats.

Asiatic acid (AA), a triterpenoid present in Centella asiatica, possesses the ability to cross blood brain barrier and received considerable attention for its neuroprotective role. We have reported the benefit of AA against aluminum chloride (AlCl3)-induced amyloid pathology, enhanced acetylcholine esterase (AChE) activity, and inflammation in Alzheimer's disease (AD) like model rats. Based on that, to find the exact mechanism of action of AA, the present study was designed to evaluate the oxidative stress, tau pathology, apoptosis, and Akt/GSK3β signaling pathway on AlCl3-induced neurotoxicity in Wistar rats. AD-like pathology was induced by oral administration of AlCl3 (100mg/kg b.w.) for 6weeks, which demonstrated a significant reduction in spatial memory performance, anxiety, and motor dysfunction and diminished the expression of cyclin-dependent kinase 5 (CDK 5-enzyme implicated in the phosphorylation of tau proteins), pTau, oxidative stress, and apoptosis, whereas oral ingestion of AA (75mg/kg b.w.) for 7weeks attenuated the above-said indices, which could be by activating Akt/GSK3β pathway. Current results suggested that AA could be able to modulate various pathological features of AD and could hold promise in AD treatment.

Glycyrrhizic acid and silymarin alleviate the neurotoxic effects of aluminum in rats challenged with fructose-induced insulin resistance: possible role of toll-like receptor 4 pathway

Aluminum is implicated in the etiology of different neurodegenerative diseases, diabetes and cancer. The current study was conducted to evaluate the protective effects of glycyrrhizic acid (GAM) and silymarin (SLY) on AlCl3-induced neurotoxicity in insulin resistant rats. Insulin resistance (IR) was induced by fructose (10%) in drinking water for 18 weeks. Rats received AlCl3 (34 mg/kg/day) with or without fructose, GAM (40 mg/kg/day), or SLY (100 mg/kg/day). The administration of GAM or SLY suppressed AlCl3-induced memory deficit, oxidative stress, and neuroinflammation in brain tissue of IR rats. Both agents inhibited AlCl3-induced activation of TLR4 signaling pathway including the downstream activation of NF-κB. The results show that IR can partly exacerbate AlCl3-induced neurotoxicity, particularly memory deficit and neuroinflammation. In addition, GAM and SLY showed promising neuroprotective effect against AlCl3-induced brain damage in IR rats. The neuroprotection induced by these natural products might be mediated through their antioxidant and anti-inflammatory effects. The latter effect seems to be mediated via inhibition of TLR4 signaling pathway providing new insights on the mechanisms implicated in AlCl3-induced neurotoxicity and the neuroprotection afforded by GAM and SLY.

Effect of Methanolic Extract of Platycerium angolence on Aluminium Chloride-induced Neurotoxicity in Rats

The aim of this study is to determine the ameliorative effects of methanolic extract of Platycerium angolence (MEPA)on aluminium chloride (AlCl3)-induced neurotoxicity in rats. Rats were randomly separated into five groups containing four rats each. Group 1 serves as the control group and received normal saline, group 2 rats were administered with 100 mg/kg body weight of AlCl3 orally for 28 days to induce neuronal damage, while groups 3 and 4 rats received 250 mg/kg and 500 mg/kg of MEPA for 7days after induction of neuronal damage by AlCl3 for 28 days. Group 5 rats were administered donepezil drug (0.2 mg/kg) which served as reference drug. Behavioural study such as elevated plus maze, Y-maze and open field tests were investigated on the rats. Biochemical assays such as lipid peroxidation, acetylcholinesterase activities, and metal concentration in the whole brain homogenates were estimated using standard procedures. Results revealed a significant (p<0.05) increase in the memory index (MI), lipid peroxidation of animals in the AlCl3 group when compared with the control and the MEPA treated groups. The significant (p<0.05) decrease on lipid peroxidation MEPA was dose dependent. The acetylcholinesterase activities observed in the brain of 250 mg/kg (0.49 μmol acetylcholine/hr/mg protein) group and 500 mg/kg of extract (0.66 μmol acetylcholine/hr/mg protein) has comparative effect with the group treated with the standard drug donepezil when compared with AlCl3 induced group (1.31 μmol acetylcholine/hr/mg protein). This study revealed that both doses of 250 and 500 mg/kg of MEPA has ameliorative potential against AlCl3-induced neurotoxicity in rats but 500 mg/kg of the extract shows better protection.

Evaluation of antioxidant and anti-inflammatory efficacy of caffeine in rat model of neurotoxicity

Objective: The present study aims to investigate the neuroprotective effect of caffeine against aluminum chloride (AlCl3)-induced neurotoxicity in rats.Methods: Twenty-one male albino rats were divided into 3 groups: control, AlCl3-intoxicated group that received daily oral administration of AlCl3 (100 mg/kg for 30 days) and protected group injected daily with caffeine (20 mg/kg intraperitoneally) one hour before oral administration of AlCl3 for 30 days. Levels of lipid peroxidation, reduced glutathione, and nitric oxide and the activities of acetylcholinesterase (AchE) and Na+/K+-ATPase were measured spectrophotometrically. Tumor necrosis factor-α (TNF-α) was evaluated by ELISA kit.Results: The data revealed evidence of oxidative and nitrosative stress in the cerebral cortex, hippocampus, and striatum of AlCl3-intoxicated rats. This was indicated from the increased levels of lipid peroxidation and nitric oxide together with the decreased level of reduced glutathione. Moreover, the daily AlCl3 administration increased AchE and Na+/K+-ATPase activities and the level of TNF-α in the selected brain regions. Protection with caffeine ameliorated the oxidative stress induced by AlCl3 in the cerebral cortex, hippocampus, and striatum. In addition, caffeine restored the elevated level of TNF-α in the hippocampus and striatum. This was accompanied by an improvement in the activities of AchE and Na+/K+-ATPase in the studied brain regions.Discussion and conclusions: The present findings clearly indicate that caffeine provides a significant neuroprotection against AlCl3-induced neurotoxicity mediated by its antioxidant, anti-inflammatory, and anticholinesterase properties.

Anti-hyperuricemic and neuroprotective effects of Populus nigra L. (Saliacaceae) flower buds used in Algerian folk medicine

Context: Populus nigra L., is a species of cottonwood poplar that belongs to the Salicaceae family, is cultivated in multiple areas in Algeria, with an Algerian name of Safsaf. Aims: To evaluate the Populus nigra flower buds extract for its effects on brain modifications against aluminum-induced neurotoxicity in mice. The hypouricemic action of the extract was also evaluated. Methods: To evaluate the effect of extract on AlCl3-induced neurotoxicity on mice a battery of tests was performed to assess a spectrum of learning and memory functions. The hypouricemic action of the extract was studied by the measure of uric acid levels and liver xanthine oxidoreductase activity in normal and hyperuricemic mice. Results: Co-administration of P. nigra extract (200 mg/kg) and AlCl3 (100 mg/kg/day) combined with D-galactose (200 mg/kg/day) during four weeks was found to antagonize the harmful effects of AlCl3 by restoring all the test parameters. Moreover, extract restored the pyramidal cells to near normal in cerebral cortex of mice. Extract, when administered three times orally to the normal and oxonate-induced hyperuricemic mice, was able to elicit significantly hypouricemic effect comparable to that of allopurinol. Conclusions: P. nigra flower buds extract can be considered as food enabling to antagonize AlCl3 toxicity and to control serum uric acid levels.

Phenolic alkaloid oleracein E attenuates oxidative stress and neurotoxicity in AlCl3-treated mice

AimsChelation therapy and antioxidant supplements have been demonstrated to be useful in ameliorating aluminum (Al) induced neurotoxicity. Oleracein E (OE) is a phenolic antioxidant alkaloid which possesses a rare tetrahydroisoquinoline/pyrrolidone tricyclic skeleton and a catechol moiety. The aim of this study was to investigate whether OE can chelate with Al and alleviate AlCl3-induced oxidative stress and neurotoxicity. Main methodsKunming mice were administered AlCl3 (40mg/kg/d, i.p., 28days), with co-administration of OE (3mg/kg/d, 15mg/kg/d, i.g.) and the positive control piracetam (PA, 400mg/kg/d, i.g.). The Al contents in the brain and plasma were determined using ICP-MS. Al chelating ability of OE was assayed using UV spectroscopy. MDA, GSH, SOD or CAT, in the brain or plasma were determined. HE staining was used to examine hippocampal morphology alterations. IHC staining was employed to measure the expression of apoptotic-related proteins Bax, Bcl-2 and Caspase-3. Key findingsAlCl3 remarkably increased the brain and plasma Al contents, increased lipid peroxidation and induced hippocampal neuronal damage. OE chelated with Al to form a stable complex. An increase in brain Al content by OE (15mg/kg) likely occurred through chelating with Al, which reduced the toxicity of free Al ion in the brain. OE significantly decreased MDA by regulating some antioxidant biomarkers. Furthermore, OE significantly ameliorated the protein expression changes in some apoptotic indices induced by AlCl3. SignificanceThe phenolic alkaloid OE, as an antioxidant, Al chelator and apoptosis inhibitor, alleviates oxidative stress and neurotoxicity induced by AlCl3.

Protective Effect of Pluchea lanceolata against Aluminum Chloride-induced Neurotoxicity in Swiss Albino Mice.

Background:Aluminum chloride (AlCl3) is a known potent environmental neurotoxin causing progressive neurodegenerative changes in the brain. The herb Pluchea lanceolata is commonly known as “Rasana” and used as a nerve tonic in neuroinflammatory conditions in Indian system of medicine.Objective:To evaluate the neuroprotective activity of hydroalcoholic extract of P. lanceolata in chronic AlCl3-induced neurotoxicity in Swiss albino mice.Materials and Methods:Albino mice were categorized into four different groups; Group 1served as vehicle control, Group 2 mice were administered with AlCl3, 40 mg/kg body weight by intraperitoneal route for 45 consecutive days. Groups 3 and 4 mice were administered with AlCl3, 40 mg/kg body weight intraperitoneal for 45 consecutive days along with hydroalcoholic extract of P. lanceolata at 200 and 400 mg/kg body weight.Results:Chronic administration of AlCl3 resulted in behavioral deficits, triggered lipid peroxidation, increased acetylcholinesterase (AChE) activity, and histological alterations. Co-administration of hydroalcoholic extract of P. lanceolata attenuated many of the AlCl3-induced alterations such as behavioral, lipid peroxidation, AChE, and histological changes of brain tissue.Conclusion:The results of the present study have demonstrated the protective role of hydroalcoholic extract of P. lanceolata against AlCl3-induced neurotoxicity in Swiss albino mice. The neuroprotective efficacy of P. lanceolata can help reduce the symptoms caused by toxic protein aggregates in several degenerative diseases.SUMMARY The hydro alcoholic extract of Pluchea lanceolata showed neuroprotective activity in albino mice against AlCl3 toxicityThe benefits of Pluchea lanceolata against AlCl3 toxicity includes reduced lipid peroxidation and acetylcholine esterase activity with improved behavioral functionsThe hydro alcoholic extract of Pluchea lanceolata rendered protection against AlCl3 in forebrain, midbrain, cerebellum and hippocampusTherefore Pluchea lanceolata holds pharmacological potentials for treating diseases associated with neuronal toxicity. Abbreviations used: HAPL: Hydro alcoholic extract of Pluchea lanceolata; CAT: Catalase; GSH-Px: Glutathione peroxidase; SOD: Superoxide dismutase; TBARS: Thio-barbituric acid reactive substances; MDA: Malondialdehyde; AChE: Acetylcholine esterase; AOT: Acute oral toxicity; CNS: Central nervous system; H2O2: Hydrogen peroxide; ML: molecular layer; GL: granular layer; MC: microcytic changes; BV: blood vessels; DG: dentate gyrus; PC: pyramidal cells; LD: Lethal dose; ANOVA: Analysis of variance; SEM: Standard error of mean; PCL: Pyramidal cell layer; OCL: Outer granular layer; BV: blood vessels; PM: Pia mater.

Memory-enhancing effect of aspirin is mediated through opioid system modulation in an AlCl3-induced neurotoxicity mouse model.

Neurodegenerative disorders such as Alzheimers disease (AD) are multifaceted and there are currently a limited number of therapeutic strategies available to treat them. Aspirin is known to act on multiple therapeutic targets and is a successful anti-inflammatory agent in various tissues. The present study aimed to ascertain the performance of aspirin when employed as a therapeutic agent to treat neurodegeneration on novel targets, including opioid system genes, in an AlCl3-induced neurotoxicity mouse model. The effects of two doses of aspirin (5 and 20 mg/kg aspirin for 12 days) were investigated in an AlCl3-induced neurotoxicity mouse model (150 mg/kg AlCl3 for 12 days). Neurological improvements were assessed through different behavioral tests and the effects of aspirin on opioid system gene expression levels were assessed by reverse transcription-polymerase chain reaction. Both doses resulted in improvements in cognitive behavior. A 5 mg/kg dose of aspirin was revealed to be effective for spatial memory improvement (7.14±0.84 sec), whilst a 20 mg/kg dose was superior for improving extinction learning (7.63±4.04%). Aspirin (5 mg/kg) also significantly improved contextual memory (48.05±10.6%) when compared with the AlCl3-treated group (1.49±0.62%; P<0.001). Aspirin was also observed to significantly decrease δ-opioid receptor expression in the cortex (1.09±0.08 and 1.27±0.08, respectively) at both doses (5 and 20 mg/kg) when compared with the AlCl3-treated group (3.69±1.43; P<0.05). Furthermore, aspirin at 5 mg/kg significantly reduced expression of prodynorphin in the cortex (0.57±0.20) when compared with the AlCl3-treated group (1.95±0.84; P<0.05). Notably, the effect of aspirin was significant in the cortex but not in the hippocampus. In summary, aspirin was effective in ameliorating the AD-like symptoms via the modulation of opioid systems. However, additional studies are required to determine the long term effects of aspirin on such conditions.

Alpha-lipoic acid-mediated activation of muscarinic receptors improves hippocampus- and amygdala-dependent memory

Aluminum (Al) is a neurotoxic agent which readily crosses the blood-brain-barrier (BBB) and accumulates in the brain leading to neurodegenerative disorders, characterised by cognitive impairment. Alpha-lipoic acid (ALA) is an antioxidant and has a potential to improve cognitive functions. This study aimed to evaluate the neuroprotective effect of ALA in AlCl3-induced neurotoxicity mouse model. Effect of ALA (25mg/kg/day) was evaluated in the AlCl3-induced neurotoxicity (AlCl3 150 mg/kg/day) mouse model on learning and memory using behaviour tests and on the expression of muscarinic receptor genes (using RT-PCR), in hippocampus and amygdala. Following ALA treatment, the expression of muscarinic receptor genes M1, M2 and choline acetyltransferase (ChaT) were significantly improved (p<0.05) relative to AlCl3-treated group. ALA enhanced fear memory (p<0.01) and social novelty preference (p<0.001) comparative to the AlCl3-treated group. Fear extinction memory was remarkably restored (p<0.001) in ALA-treated group demonstrated by reduced freezing response as compared to the AlCl3-treated group which showed higher freezing. In-silico analysis showed that racemic mixture of ALA has higher binding affinity for M1 and M2 compared to acetylcholine. These novel findings highlight the potential role of ALA in cognitive functions and cholinergic system enhancement thus presenting it an enviable therapeutic candidate for the treatment of neurodegenerative disorders.

Ibuprofen targets neuronal pentraxins expresion and improves cognitive function in mouse model of AlCl3-induced neurotoxicity.

Aluminum is known to exert neurotoxic effects associated with various neurodegenerative disorders, including Alzheimer's disease (AD). Ibuprofen is a well-known non-steroidal anti-inflammatory drug, which has demonstrated potential efficacy in the treatment of numerous inflammatory and neurodegenerative disorders, including AD. The present study aimed to investigate the protective effects of ibuprofen on cognitive function, and the expression levels of neuronal pentraxins (NPs) and interleukin (IL)-1β in an aluminum chloride (AlCl3)-induced mouse model of neurotoxicity. The effects of ibuprofen (100 mg/kg/day for 12 days) on learning and memory were evaluated in the AlCl3-induced neurotoxic mice using a Morris water maze and open field tests. In addition, ibuprofen was assessed for its effects on the expression levels of NPs and IL-1β in the hippocampus, cortex and amygdala of the brain. Treatment of the AlCl3-treated mice with ibuprofen decreased anxiety levels (6.90±0.34 min) compared with the AlCl3-treated group (1.80±0.29 min), as indicated by the time spent in the central area in an open field test. Furthermore, the expression levels of NP1 (1.32±0.47) and IL-1β (0.99±0.21) were significantly decreased in the hippocampus of mice following ibuprofen treatment, as compared with the AlCl3-treated mice (8.62±1.54 and 7.47±0.53, respectively). In the present study, ibuprofen was able to target novel structures in order to attenuate the inflammation associated with an AlCl3-induced mouse model of neurotoxicity; thus suggesting that ibuprofen may be considered a potential therapeutic option for the treatment of neurodegenerative diseases, including AD.

Mangiferin ameliorates aluminium chloride-induced cognitive dysfunction via alleviation of hippocampal oxido-nitrosative stress, proinflammatory cytokines and acetylcholinesterase level

Mangiferin is a phytochemical primarily present in the stem, leaves and bark of Mangifera indica. It offers neuroprotection mainly through inhibition of oxidative stress, and decreasing proinflammatory cytokines level in the brain. Aluminium has been reported to cause oxidative stress-associated damage in the brain. In the present investigation, protective effect of mangiferin against aluminium chloride (AlCl3)-induced neurotoxicity and cognitive impairment was studied in male Swiss albino mice. AlCl3 (100mg/kg) was administered once daily through oral gavage for 42 days. Mangiferin (20 and 40mg/kg, p.o.) was given to mice for last 21 days of the study. We found cognitive dysfunction in AlCl3-treated group, which was assessed by Morris water maze test, and novel object recognition test. AlCl3-treated group showed elevated level of oxidative stress markers, proinflammatory cytokines level and lowered hippocampal brain-derived neurotrophic factor (BDNF) content. Mangiferin (40mg/kg) prevented the cognitive deficits, hippocampal BDNF depletion, and biochemical anomalies induced by AlCl3-treatment. In conclusion, our data demonstrated that mangiferin offers neuroprotection in AlCl3-induced neurotoxicity and it may be a potential therapeutic approach in the treatment of oxido-nitrosative stress and inflammation-associated neurotoxicity.

Apurinic/apyrimidinic endonuclease 1 is a key modulator of aluminum-induced neuroinflammation

BackgroundChronic administration of Aluminum is proposed as an environmental factor that may affect several enzymes and other biomolecules related to neurotoxicity and Alzheimer's disease (AD). APE1 a multifunctional protein, functions in DNA repair and plays a key role in cell survival versus cell death upon stimulation with cytotoxic agent, making it an attractive emerging therapeutic target. The promising protective effect of resveratrol (resv), which is known to exert potent anti-inflammatory effects on neurotoxicity induced by aluminum chloride (AlCl3), may be derived from its own antioxidant properties. In the present work we investigated the modulation of APE1 expression during AlCl3-induced neuroinflammation (25 mg/Kg body weight by oral gavages) in experimental rats. We tested the hypothesis that a reactive oxygen species (ROS)-scavenger, resveratrol at 0.5 mg/kg bodyweight, which is known to exert potent anti-inflammatory effects, would attenuate central inflammation and modulate APE1 expression in AlCl3-fed rats. Neuroinflammation-induced genes including β-secretase (BACE), amyloid-β precursor protein (APP), presenilin 2 (PSEN-2) and sirt-2 were determined by RT-PCR. APE1 is determined at mRNA and protein levels and confirmed by immunohistochemistry. The expression of pro-inflammatory cytokines (TNF-α, IL6) and iNOS by the rat brain extract were measured by RT-PCR.ResultOur results indicate that resveratrol may attenuate AlCl3-induced direct neuroinflammation in rats, and its mechanisms are, at least partly, due to maintaining high APE1 level. Resveratrol co-administration with aluminum chloride exerted more protective effect than pre-administration or treatment of induced rats. A significant elevation of APE1 at both mRNA and protein levels was observed in addition to a marked reduction in β-secretase and amyloid-β. We found that AlCl3 stimulated the expression of TNF-α, IL-6, and iNOS in rat brain in which NF-κB was involved. Resveratrol inhibited AlCl3-induced expression and release of TNF-α, IL-6, and iNOS in rat brain.ConclusionsThese findings establish a role for APE1 as a master regulator of AlCl3 dependent inflammatory responses in rat brain. In addition, there was an ameliorative change with resveratrol against AlCl3-induced neurotoxicity. These results suggest that rat brain cells produce pro-inflammatory cytokines in response to AlCl3 in a similar pattern, and further suggest that resveratrol exerts anti-inflammatory effects in rat brain, at least partly, by inhibiting different pro-inflammatory cytokines and key signaling molecules. It might be a potential agent for treatment of neuroinflammation-related diseases, such as AD.