Modulatory role of simvastatin against aluminium chloride-induced behavioural and biochemical changes in rats

The Role of Histone H2B Acetylation Modification in Aluminum-Induced Cognitive Dysfunction

Aluminum (Al) is a low toxic trace element that can accumulate in the nervous system and induce cognitive disorders characterized by reduced learning and memory ability. Neuroepigenetic effects are structural changes in cellular function by the brain in response to environmental stimuli by altering the expression of specific genes and repressing normal cellular transcription, leading to abnormalities in a variety of biological processes within the nervous system and affecting neurobehavioral responses. One of the most important mechanisms of epigenetic control on chromatin shape is histone modification. In the present study, we established an offspring rat model of Al intoxication to investigate the changes in spatial learning and memory retention abilities and the relationship with histone H2B acetylation modification in rats exposed to different doses of Al over a long period of time. The results demonstrated that long-term AlCl3 staining resulted in decreased CBP gene and protein expression, increased HDAC3 gene and protein levels, as well as decreased histone H2B and acH2BK20 protein expression levels in the hippocampus of rats. In conclusion, long-term exposure to Al may vary the expression of histone H2B and acH2BK20 through the regulation of enzymes that specifically regulate histone acetylation, hence hastening the deterioration of the nervous system that impairs cognitive function.

Exploring the molecular mechanisms of MSC-derived exosomes in Alzheimer's disease: Autophagy, insulin and the PI3K/Akt/mTOR signaling pathway

Alzheimer's disease (AD) is a devastating neurological condition characterized by cognitive decline, motor coordination impairment, and amyloid plaque accumulation. The underlying molecular mechanisms involve oxidative stress, inflammation, and neuronal degeneration. This study aimed to investigate the therapeutic effects of mesenchymal stem cell-derived exosomes (MSC-exos) on AD and explore the molecular pathways involved, including the PI3K/Akt/mTOR axis, autophagy, and neuroinflammation. To assess the potential of MSC-exos for the treatment of AD, rats were treated with AlCl3 (17 mg/kg/once/day) for 8 weeks, followed by the administration of an autophagy activator (rapamycin), or MSC-exos with or without an autophagy inhibitor (3-methyladenin; 3-MA+ chloroquine) for 4 weeks. Memory impairment was tested, and brain tissues were collected for gene expression analyses, western blotting, histological studies, immunohistochemistry, and transmission electron microscopy. Remarkably, the administration of MSC-exos improved memory performance in AD rats and reduced the accumulation of amyloid-beta (Aβ) plaques and tau phosphorylation. Furthermore, MSC-exos promoted neurogenesis, enhanced synaptic function, and mitigated astrogliosis in AD brain tissues. These beneficial effects were associated with the modulation of autophagy and the PI3K/Akt/mTOR signalling pathway, as well as the inhibition of neuroinflammation. Additionally, MSC-exos were found to regulate specific microRNAs, including miRNA-21, miRNA-155, miRNA-17-5p, and miRNA-126-3p, further supporting their therapeutic potential. Histopathological and bioinformatic analyses confirmed these findings. This study provides compelling evidence that MSC-exos hold promise as a potential therapeutic approach for AD. By modulating the PI3K/Akt/mTOR axis, autophagy, and neuroinflammation, MSC-exos have the potential to improve memory, reduce Aβ accumulation, enhance neurogenesis, and mitigate astrogliosis. These findings shed light on the therapeutic potential of MSC-exos and highlight their role in combating AD.

Protective effect of resveratrol and tannic acid combination on aluminium chloride induced neurotoxicity in rats

OBJECTIVE

Alzheimer's disease is a progressive neurodegenerative disease and one of the most common causes of dementia. Despite recent advancements, there exists an unmet need for a suitable therapeutic option. This study aimed to evaluate the protective effects of the combination of resveratrol (20 mg/kg/day p.o.) and tannic acid (50 mg/kg/day p.o.) to reduce aluminium trichloride-induced Alzheimer's disease in rats.

METHODS

Wistar rats weighing 150-200g were administered with aluminium chloride (100 mg/kg/day p.o.) for 90 days to induce neurodegeneration and Alzheimer's disease. Neurobehavioral changes were assessed using novel object recognition test, elevated plus maze test, and Morris water maze test. Histopathological studies were performed using H&E stain and Congo Red stains to check amyloid deposits. Further oxidative stress was measured in brain tissue.

RESULTS

Aluminium trichloride treated negative control group showed cognitive impairment in the Morris water maze test, novel object recognition test, and elevated plus maze test. Further, the negative control group showed significant oxidative stress, increase amyloid deposits, and severe histological changes. Treatment with the combination of resveratrol and tannic acid showed significant attenuation in cognitive impairment. The oxidative stress markers and amyloid plaque levels were significantly attenuated with the treatment.

CONCLUSION

The present study indicates the beneficial effects of resveratrol-tannic acid combination in AlCl3 induced neurotoxicity in rats.

Trace Elements in Alzheimer's Disease and Dementia: The Current State of Knowledge

Changes in trace element concentrations are being wildly considered when it comes to neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. This study aims to present the role that trace elements play in the central nervous system. Moreover, we reviewed the mechanisms involved in their neurotoxicity. Low zinc concentrations, as well as high levels of copper, manganese, and iron, activate the signalling pathways of the inflammatory, oxidative and nitrosative stress response. Neurodegeneration occurs due to the association between metals and proteins, which is then followed by aggregate formation, mitochondrial disorder, and, ultimately, cell death. In Alzheimer's disease, low Zn levels suppress the neurotoxicity induced by β-amyloid through the selective precipitation of aggregation intermediates. High concentrations of copper, iron and manganese cause the aggregation of intracellular α-synuclein, which results in synaptic dysfunction and axonal transport disruption. Parkinson's disease is caused by the accumulation of Fe in the midbrain dopaminergic nucleus, and the pathogenesis of multiple sclerosis derives from Zn deficiency, leading to an imbalance between T cell functions. Aluminium disturbs the homeostasis of other metals through a rise in the production of oxygen reactive forms, which then leads to cellular death. Selenium, in association with iron, plays a distinct role in the process of ferroptosis. Outlining the influence that metals have on oxidoreduction processes is crucial to recognising the pathophysiology of neurodegenerative diseases and may provide possible new methods for both their avoidance and therapy.

A review of the epidemiological and laboratory evidence of the role of aluminum exposure in pathogenesis of cardiovascular diseases

The objective of the present study was to review the epidemiological and laboratory evidence on the role of aluminum (Al) exposure in the pathogenesis of cardiovascular diseases. Epidemiological data demonstrated an increased incidence of cardiovascular diseases (CVD), including hypertension and atherosclerosis in occupationally exposed subjects and hemodialysis patients. In addition, Al body burden was found to be elevated in patients with coronary heart disease, hypertension, and dyslipidemia. Laboratory studies demonstrated that Al exposure induced significant ultrastructural damage in the heart, resulting in electrocardiogram alterations in association with cardiomyocyte necrosis and apoptosis, inflammation, oxidative stress, inflammation, and mitochondrial dysfunction. In agreement with the epidemiological findings, laboratory data demonstrated dyslipidemia upon Al exposure, resulting from impaired hepatic lipid catabolism, as well as promotion of low-density lipoprotein oxidation. Al was also shown to inhibit paraoxonase 1 activity and to induce endothelial dysfunction and adhesion molecule expression, further promoting atherogenesis. The role of Al in hypertension was shown to be mediated by up-regulation of NADPH-oxidase, inhibition of nitric oxide bioavailability, and stimulation of renin-angiotensin-aldosterone system. It has been also demonstrated that Al exposure targets cerebral vasculature, which may be considered a link between Al exposure and cerebrovascular diseases. Findings from other tissues lend support that ferroptosis, pyroptosis, endoplasmic reticulum stress, and modulation of gut microbiome and metabolome are involved in the development of CVD upon Al exposure. A better understanding of the role of the cardiovascular system as a target for Al toxicity will be useful for risk assessment and the development of treatment and prevention strategies.

Biochemical characterization of chamomile essential oil: Antioxidant, antibacterial, anticancer and neuroprotective activity and potential treatment for Alzheimer's disease

Alzheimer's disease (AD) causes dementia among older adults, increasing the global burden of dementia. Therefore, this study investigates the potential neuroprotective, antioxidant, and anticancer effects of chamomile essential oil (CCO) in Alzheimer's disease. CCO's main volatile compounds (VOCs) were α-bisabolol, camazulene, and bisabolol oxide A, representing 81 % of all VOCs. CCO scavenged 93 % of DPPH free radicals and inhibited the pathogenic bacteria, i.e., Staphylococcus aureus and Salmonella typhi, besides reducing 89 % of brain cancer cell lines (U87). Eighty albino rats were randomized into four groups: standard control, Alzheimer's disease group caused by AlCl3, and treated groups. The results indicated that the mean value of tumor necrosis factor α (TNF-α), amyloid precursor protein (APP), amyloid beta (Aβ), caspase-3, & B-cell lymphoma 2 (Bcl-2) was significantly elevated due to the harmful effect of AlCl3; however, CCO downregulated these values, and this effect was attributed to the considerable volatile compounds and phenolic compounds content. Additionally, CCO rats showed a significant increment in noradrenergic (NE), dopaminergic (DO), and serotoninergic systems with relative increases of 50, 50, and 14 % compared to diseased rats. The brain histology of CCO-treated rats showed a significant reduction in neuronal degeneration and improved brain changes, and its histology was close to that of the control brain. The results indicated that CCO offers a new strategy that could be used as an antioxidant and neuroprotective agent for AD due to its considerable contents of antioxidants and anti-inflammatory compounds.

Simvastatin attenuates aluminium chloride-induced neurobehavioral impairments through activation of TGF-β1/ SMAD2 and GSK3β/β-catenin signalling pathways

Alzheimer's disease (AD) is a neurodegenerative disease characterised by the presence of β-amyloid plaques and acetylcholine depletion leading to neurobehavioral defects. AD was contributed also with downregulation of TGF-β1/SMAD2 and GSK3β/β-catenin pathways. Simvastatin (SMV) improved memory function experimentally and clinically. Hence, this study aimed to investigate the mechanistic role of SMV against aluminium chloride (AlCl3) induced neurobehavioral impairments. AD was induced by AlCl3 (50 mg/kg) for 6 weeks. Mice received Simvastatin (10 or 20 mg/kg) or Donepezil (3 mg/kg) for 6 weeks after that the histopathological, immunohistochemical and biochemical test were examined. Treatment with SMV improved the memory deterioration induced by AlCl3 with significant recovery of the histopathological changes. This was concomitant with the decrease of AChE and Aβ (1-42). SMV provides its neuroprotective effect through upregulating the protein expression of β-catenin, TGF-β1 and downregulating the expression of GSK3β, TLR4 and p-SMAD2.

Aluminum as a Possible Cause Toward Dyslipidemia

Aluminum, the third most abundant metal present in the earth's crust, is present almost in all daily commodities we use, and exposure to it is unavoidable. The interference of aluminum with various biochemical reactions in the body leads to detrimental health effects, out of which aluminum-induced neurodegeneration is widely studied. However, the effect of aluminum in causing dyslipidemia cannot be neglected. Dyslipidemia is a global health problem, which commences to the cosmic of non-communicable diseases. The interference of aluminum with various iron-dependent enzymatic activities in the tri-carboxylic acid cycle and electron transport chain results in decreased production of mitochondrial adenosine tri-phosphate. This ultimately contributes to oxidative stress and iron-mediated lipid peroxidation. This mitochondrial dysfunction along with modulation of α-ketoglutarate and L-carnitine perturbs lipid metabolism, leading to the atypical accumulation of lipids and dyslipidemia. Respiratory chain disruption because of the accumulation of reduced nicotinamide adenine di-nucleotide as a consequence of oxidative stress and the stimulatory effect of aluminum exposure on glycolysis causes many health issues including fat accumulation, obesity, and other hepatic disorders. One major factor contributing to dyslipidemia and enhanced pro-inflammatory responses is estrogen. Aluminum, being a metalloestrogen, modulates estrogen receptors, and in this world of industrialization and urbanization, we could corner down to metals, particularly aluminum, in the development of dyslipidemia. As per PRISMA guidelines, we did a literature search in four medical databases to give a holistic view of the possible link between aluminum exposure and various biochemical events leading to dyslipidemia.

Therapeutic and Preventive Effects of Piperine and its Combination with Curcumin as a Bioenhancer Against Aluminum-Induced Damage in the Astrocyte Cells

Recently, studies conducted with astrocyte cells have drawn attention to neurodegeneration pathologies caused by aluminum exposure. In particular, investigating the potential of herbal therapeutic agents to prevent this effect of aluminum has gained importance. The purpose of this study was to investigate the therapeutic and preventive effects of piperine, curcumin, and the combination of these compounds on reactive primary astrocyte cells. In order to examine the preventive effect, certain concentrations of compounds were applied to the cells before the aluminum application, and to be able to determine the therapeutic effect, the compounds were examined after the aluminum application. The efficacy of the compounds was analyzed in terms of cell viability, apoptosis, necrosis, and cytokine release. In conclusion, the results of the study showed that the use of different concentrations of piperine, curcumin, and their combination had significantly higher % cell viability on aluminum-induced damage in astrocyte cells compared to the damaged control group. In addition, a decrease in the number of apoptotic and necrotic cells was observed in the same groups, which indicated that piperine increased curcumin activity. The decrease in the amount of IL-6 and TGF-β cytokines also supported that piperine increased the effectiveness of curcumin. Considering all these results, it can be said that in terms of aluminum damage in astrocyte cells, the bioavailability-enhancing property of piperine on curcumin was shown for the first time in the literature. In line with these results, it is inevitable to carry out further studies.

In Vitro and In Vivo Neuroprotective Effects of Sarcosine

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by behavioral and psychological symptoms in addition to cognitive impairment and loss of memory. The exact pathogenesis and genetic background of AD are unclear and there remains no effective treatment option. Sarcosine, an n-methyl derivative of glycine, showed a promising therapeutic strategy for some cognitive disorders. To our knowledge, the impacts of sarcosine supplementation against AD have not yet been elucidated. Therefore, we aimed to determine the neuroprotective potential of sarcosine in in vitro and in vivo AD model. In vitro studies have demonstrated that sarcosine increased the percentage of viable cells against aluminum induced neurotoxicity. In AlCl₃-induced rat model of AD, the level of antioxidant capacity was significantly decreased and expression levels of APP, BACE1, TNF-α, APH1A, and PSENEN genes were elevated compared to the control group. Additionally, histopathological examinations of the hippocampus of AlCl₃-induced rat brains showed the presence of neurofibrillary tangles (NFTs). However, the administration of sarcosine produced marked improvement and protection of AD-associated pathologies induced by AlCl₃ in experimental rats. Therefore, this investigation may contribute to design novel therapeutic strategies using sarcosine for the management of AD pathologies.

Assessment of the neuroprotective potential of d-cycloserine and l-serine in aluminum chloride-induced experimental models of Alzheimer’s disease: In vivo and in vitro studies

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by the accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles in the brain accompanied by synaptic dysfunction and neurodegeneration. No effective treatment has been found to slow the progression of the disease. Therapeutic studies using experimental animal models have therefore become very important. Therefore, this study aimed to investigate the possible neuroprotective effect of D-cycloserine and L-serine against aluminum chloride (AlCl₃)-induced AD in rats. Administration of AlCl₃ for 28 days caused oxidative stress and neurodegeneration compared to the control group. In addition, we found that aluminum decreases α-secretase activity while increasing β-secretase and γ-secretase activities by molecular genetic analysis. D-cycloserine and L-serine application resulted in an improvement in neurodegeneration and oxidative damage caused by aluminum toxicity. It is believed that the results of this study will contribute to the synthesis of new compounds with improved potential against AlCl₃-induced neurodegeneration, cognitive impairment, and drug development research.

The neuroprotective effect of Xylopia parviflora against aluminum chloride-induced neurotoxicity in rats

Neurodegenerative disease such as Alzheimer's disease, are progressive disorders which has been linked to oxidative imbalance and associated perturbations characterised by loss of memory, cognition and cholinergic deficit. To date, cholinesterase inhibition and neuroprotection are the two major strategies in drug development. Xylopia parviflora (Annonacea family) is a spice consumed in Cameroon and has been used in traditional medicine to treat various pains. In this study, X. parviflora was evaluated on behavioural studies, ion homeostasis, cholinesterase inhibitory and antioxidant activities. Rats were exposed to aluminium chloride (75 mg/kg) during 60 days, and were treated with the extract of X. parviflora (150 and 300 mg/kg BW) and two drugs references (Donepezil and Curcumin). Behavioural parameters were assessed using the Morris-Maze test and the Open Field, followed by biochemical investigations, namely, cholinesterase enzyme activity (AChE and BChE), oxidative stress (NO, MDA, GSH level, SOD and Catalase activities) and ion homeostasis (Mg²⁺ and Ca²⁺ levels). AlCl₃ administration shows a decrease in learning and memory improvement during behavioural studies, significant alteration of the central cholinergic system characterised by an increase in AChE and BChE activities to 2.72 ± 0.002 mol/min/g and 5.74 ± 0.12 mol/min/g respectively, disturbance of ion homeostasis with an increase in Ca²⁺ level (25.68 ± 3.78 μmol/mg protein) and a decrease in Mg²⁺ level (15.97 ± 2.05 μmol/mg protein) and an increase in oxidative stress compared to the positive control group. Treatment with the different doses of X. parviflora increased memory and improved locomotion, improved cholinesterase activities, ion homeostasis and stabilized brain oxidative stress levels. The study suggests that X. parviflora could potentially be used for the management of some biochemical alterations associated with Alzheimer's disease. It could even be a good alternative to chemical drugs for neurotoxicity and memory enhancement.

Intranasal Oxytocin Attenuates Cognitive Impairment, β-Amyloid Burden and Tau Deposition in Female Rats with Alzheimer's Disease: Interplay of ERK1/2/GSK3β/Caspase-3

Oxytocin is a neuropeptide hormone that plays an important role in social bonding and behavior. Recent studies indicate that oxytocin could be involved in the regulation of neurological disorders. However, its role in modulating cognition in Alzheimer’s disease (AD) has never been explored. Hence, the present study aims to investigate the potential of chronic intranasal oxytocin in halting memory impairment & AD pathology in aluminum chloride-induced AD in female rats. Morris water maze was used to assess cognitive dysfunction in two-time points throughout the treatment period. In addition, neuroprotective effects of oxytocin were examined by assessing hippocampal acetylcholinesterase activity, β-amyloid 1–42 protein, and Tau levels. In addition, ERK1/2, GSK3β, and caspase-3 levels were assessed as chief neurobiochemical mediators in AD. Hippocampi histopathological changes were also evaluated. These findings were compared to the standard drug galantamine alone and combined with oxytocin. Results showed that oxytocin restored cognitive functions and improved animals’ behavior in the Morris test. This was accompanied by a significant decline in acetylcholinesterase activity, 1–42 β-amyloid and Tau proteins levels. Hippocampal ERK1/2 and GSK3β were also reduced, exceeding galantamine effects, thus attenuating AD pathological hallmarks formation. Determination of caspase-3 revealed low cytoplasmic positivity, indicating the ceasing of neuronal death. Histopathological examination confirmed these findings, showing restored hippocampal cells structure. Combined galantamine and oxytocin treatment showed even better biochemical and histopathological profiles. It can be thus concluded that oxytocin possesses promising neuroprotective potential in AD mediated via restoring cognition and suppressing β-amyloid, Tau accumulation, and neuronal death.

Antioxidant and Anticholinesterase Properties of the Aqueous Extract of Balanites aegyptiaca L. Delile Fruit Pulp on Monosodium Glutamate-Induced Excitotoxicity in Swiss Mice

Balanites aegyptiaca L. Delile (B. aegyptiaca) is used in traditional medicine for the treatment of memory impairment. This work aims to evaluate the antioxidant and anticholinesterase potential of BA fruit pulp extract on excitotoxicity induced by monosodium glutamate (MSG). MSG was administered 30 minutes after treatment with B. aegyptiaca aqueous fruit pulp extract (50, 125, 250, and 500 mg/kg) and vitamin C (100 mg/kg) for 30 days. The negative control group received only MSG, while the control group was given distilled water daily. Behavioral tests parameters (using the novel object recognition, Y-maze, and Barnes maze tests), oxidative stress biomarkers (malondialdehyde, superoxide dismutase, and catalase), nitric oxide, and acetylcholinesterase activity and hippocampal architecture were evaluated. Results obtained revealed that different doses of B. aegyptiaca significantly reversed the deleterious effect of MSG on memory. This was displayed by a significant ( $p<0.05$ ) increment in the percentage of spontaneous alternation in the Y-maze test and a significant ( $p<0.001$ ) increase in discrimination index in novel object recognition observed with 500 mg/kg extract dose. Moreover, the extract (250 and 500 mg/kg doses) significantly ( $p<0.001$ ) increased direct search strategy and significantly decreased ( $p<0.01$ ) the time taken to find the target hole in the Barnes maze. A modulation of hyperactivity was observed after administration of all extract doses compared to the negative control group in the open arena. Furthermore, the highest dose of the extract caused a significant ( $p<0.001$ ) improvement in antioxidant enzymes activity, associated with a significant ( $p<0.001$ ) decrement in nitric oxide and malondialdehyde concentrations and a significant ( $p<0.01$ ) decrease in acetylcholinesterase activity. Treatment with the extract also restored normal hippocampal cell architecture. B. aegyptiaca fruit pulp extract could thus confer neuroprotection through its antioxidant and anticholinesterase potential.

Modelling amyotrophic lateral sclerosis in rodents

The efficient study of human disease requires the proper tools, one of the most crucial of which is an accurate animal model that faithfully recapitulates the human condition. The study of amyotrophic lateral sclerosis (ALS) is no exception. Although the majority of ALS cases are considered sporadic, most animal models of this disease rely on genetic mutations identified in familial cases. Over the past decade, the number of genes associated with ALS has risen dramatically and, with each new genetic variant, there is a drive to develop associated animal models. Rodent models are of particular importance as they allow for the study of ALS in the context of a living mammal with a comparable CNS. Such models not only help to verify the pathogenicity of novel mutations but also provide critical insight into disease mechanisms and are crucial for the testing of new therapeutics. In this Review, we aim to summarize the full spectrum of ALS rodent models developed to date.

Naproxen as a potential candidate for promoting rivastigmine anti-Alzheimer activity against aluminum chloride-prompted Alzheimer's-like disease in rats; neurogenesis and apoptosis modulation as a possible underlying mechanism

BACKGROUND AND AIM

Alzheimer's disease (AD) is one of the leading causes of dependence and disability among the elderly worldwide. The traditional anti-Alzheimer medication, rivastigmine, one of the cholinesterase inhibitors (ChEIs), fails to achieve a definitive cure. We tested the hypothesis that naproxen administration to the rivastigmine-treated aluminum chloride (AlCl3) Alzheimer's rat model could provide an additive neuroprotective effect compared to rivastigmine alone.

MATERIALS AND METHODS

The studied groups were control (Cont), AlCl₃ treated (Al), rivastigmine treated (RIVA), naproxen treated (Napro), and combined rivastigmine and naproxen treated (RIVA + Napro). Rats' memory, spatial learning, and cognitive behavior were assessed followed by evaluation of hippocampal acetylcholinesterase (AChE) activity. Hippocampal and cerebellar histopathology were thoroughly examined. Activated caspase-3 and the neuroepithelial stem cells marker; nestin expressions were immunohistochemically assayed.

RESULTS

AD rats displayed significantly impaired memory and cognitive function, augmented hippocampal AChE activity; massive neurodegeneration associated with enhanced astrogliosis, apoptosis, and impaired neurogenesis. Except for the enhancement of neurogenesis and suppression of apoptosis, the combination therapy had no additional neuroprotective benefit over rivastigmine-only therapy.

CONCLUSION

Naproxen's efficacy was established by its ability to function at the cellular level, improved neurogenesis, and decreased, apoptosis without having an additional mitigating impact on cognitive impairment in rivastigmine-treated AD rats.

Assessment of bone marrow-derived mesenchymal stem cells capacity for odontogenic differentiation and dentin regeneration in methimazole-treated albino rats (Light microscopic Study)

BACKGROUND

Methimazole is an antithyroid drug. It has side effects on many tissues. Bone marrow-derived mesenchymal stem cells (BM-MSCs) are promising in the field of tissue regeneration.

OBJECTIVE

To investigate the capacity of BM-MSCs on odontogenic differentiation and dentin regeneration at different time intervals in methimazole treated rats.

METHODS

Twenty-eight male albino rats were classified as: Group I: got distilled water. Group II: obtained therapeutic dosage of methimazole as pro-drug "Neo-Mercazole®". Group III: received methimazole then solitary injection of BM-MSCs at day 21. Group IV: obtained methimazole and single injection of BM-MSCs at the beginning of the experiment. Light microscope was used to examine specimens. Recently formed collagen and β-catenin-immunoreactivity area% were appraised histomorphometrically and statistically.

RESULTS

Histological examination of odontoblasts and dentin illustrated normal structure in Group I and nearly normal features in Group IV. Group II demonstrated discontinuation of odontoblastic layer and areas of different stainability in dentin. Group III showed an evidently wide layer of odontoblast-like cells and distinct dentinal tubules. Masson's trichrome results of dentin in Groups I &IV showed apparently equal areas of new and old collagen. Group II illustrated old collagen mainly. Group III explored new collagen only. β-catenin-immunoreactivity was strong in Groups I & IV, mild in Group II and moderate in Group III. Statistical results revealed that the highest mean of newly formed collagen area% was in Group III, followed by Group I, Group IV then Group II respectively. Regarding β-catenin-immunoreactivity area%, the highest mean was recorded in Group I, subsequently Group IV, next Group III then Group II.

CONCLUSIONS

Methimazole has destructive consequences. BM-MSCs have a time-based increased capacity for odontogenic differentiation and regeneration of dentin.

Spermine protects aluminium chloride and iron-induced neurotoxicity in rat model of Alzheimer's disease via attenuation of tau phosphorylation, Amyloid-β (1-42) and NF-κB pathway

Alzheimer's disease (AD) is the most prevalent type of dementia, characterized by a gradual decline in cognitive and memory functions of the aged peoples. Long-term exposure to heavy metals (aluminium and iron) cause neurotoxicity by amyloid plaques accumulation, tau phosphorylation, increased oxidative stress, neuroinflammation, and cholinergic neurons degeneration, contributes to the development of AD-like symptoms. The present research work is designed to investigate the neuroprotective effect of spermine in aluminium chloride (AlCl₃), and iron (Fe) induced AD-like symptoms in rats. Rats were administered of AlCl₃ (100 mg/kg p.o.) alone and in combination with iron (120 μg/g, p.o.) for 28 days. Spermine (5 and 10 mg/kg) through intraperitoneal (i.p.) route was given for 14 days. The recognition and spatial memory impairment were tasted using Morris water maze (MWM), actophotometer, and Novel Object Recognition test (NORT). All the rats were sacrificed on day 29, brains were isolated, and tissue homogenate was used for neuroinflammatory, biochemical, neurotransmitters, metals concentration, and nuclear factor-kappa B (NF-κB) analysis. In the present study, AlCl₃ and iron administration elevated oxidative stress, cytokines release, dysbalanced neurotransmitters concentration, and biochemical changes. Rats treated with spermine dose-dependently improved the recognition and spatial memory, attenuated proinflammatory cytokine release, and restored neurotransmitters concentration and antioxidant enzymes. Spermine also mitigated the increased beta-amyloid (Aβ42), with downregulation of tau phosphorylation. Furthermore, spermine augmented the hippocampal levels of B cell leukaemia/lymphoma-2 (Bcl-2), diminished nuclear factor-kappa B (NF-κB) and caspase-3 (casp-3) expression. Moreover, spermine exhibited the neuroprotective effect through anti-inflammatory, antioxidant, neurotransmitters restoration, anti-apoptotic Aβ42 concentration.

Computational and Experimental Assessments of Magnolol as a Neuroprotective Agent and Utilization of UiO-66(Zr) as Its Drug Delivery System

The phenolic natural product magnolol exhibits neuroprotective properties through β-amyloid toxicity in PC-12 cells and ameliorative effects against cognitive deficits in a TgCRND8 transgenic mice model. Its bioavailability and blood-brain barrier crossing ability have been significantly improved using the metal-organic framework (MOF) UiO-66(Zr) as a drug delivery system (DDS). To investigate the neuroprotective effects of the Zr-based DDS, magnolol and magnolol-loaded-UiO-66(Zr) (Mag@UiO-66(Zr)) were evaluated for inhibitory activity against β-secretase and AlCl₃-induced neurotoxicity. Due to the moderate inhibition observed for magnolol in vitro, in silico binding studies were explored against β-secretase along with 11 enzymes known to affect Alzheimer's disease (AD). Favorable binding energies against CDK2, CKD5, MARK, and phosphodiesterase 3B (PDE3B) and dynamically stable complexes were noted through molecular docking and molecular dynamic simulation experiments, respectively. The magnolol-loaded DDS UiO-66(Zr) also showed enhanced neuroprotective activity against two pathological indices, namely, neutrophil infiltration and apoptotic neurons, in addition to damage reversal compared to magnolol. Thus, MOFs are promising drug delivery platforms for poorly bioavailable drugs.

Analysing Curcuma caesia fractions and essential oil for neuroprotective potential against anxiety, depression, and amnesia

Scientific pieces of evidence support the pharmacological activity of Curcuma caesia for its antidepressant, analgesic, anticonvulsant and antioxidant effect. Here, we evaluate the bioactivity of essential oil and the various polarity-based solvent partitioned fractions obtained from Curcuma caesia for anti-amnesia, anxiolytic and antidepressant activities using Elevated plus maze and Morris water maze models. The cold maceration technique using methanol was adopted for extraction from dried powdered rhizomes and essential oil was extracted by hydrodistillation method. Partitioning of the methanolic extract based on solvent polarity by hexane, ethyl acetate, and methanol was continued, followed by column chromatography of the ethyl acetate fraction. Suspensions were prepared for fractions (dissolved in distilled water) and essential oil (dissolved in tween 20) at 200 mg/kg and 400 mg/kg after acute toxicity study and were orally administered to Wistar albino female rats after the orientation of hypoxia by sodium nitrite (50 mg/kg) and amnesia by scopolamine (1 mg/kg). Behavioural observations, biochemical and histopathological examinations were carried out for all the treated groups. Diazepam (12 mg/kg) and galantamine (3 mg/kg) were used as standard drugs for this study against hypoxia and amnesia. Data acquired from behavioural, biochemical (acetylcholinesterase, myeloperoxidase, superoxide dismutase, reduced glutathione, catalase) and histopathological studies have illustrated that fraction II acquires highly significant memory-enhancing, anxiolytic and antidepressant effects. Rest fractions (I and III) and essential oil showed moderate efficacy. In prospects, identification of active molecules from the most active fraction (fraction II) and further studies on a molecular basis would substantiate its specific mechanism of neuroprotective action.

Ameliorative effects of astaxanthin on brain tissues of alzheimer's disease-like model: cross talk between neuronal-specific microRNA-124 and related pathways

Alzheimer's disease (AD) is a chronic, progressive, multifactorial, and the most common neurodegenerative disease which causes dementia and mental deterioration in the elderly. The available treatments for AD are not disease-modifying drugs and only provide symptomatic relief. Astaxanthin (ATX), a second-generation antioxidant, is a dark red carotenoid and exhibits the highest antioxidant capacity, anti-inflammatory, neuroprotective, and antiapoptotic effects. In this study, we investigated the therapeutic effect of different doses of ATX on the cerebral cortex and hippocampus of AD-like rats. The AD-like model was induced in rats using hydrated aluminum chloride (AlCl₃.6H₂O) solution that was given orally at a dose of 75 mg/kg daily for 6 weeks. Morris water maze (MWM) behavioral test was performed to confirm the cognitive dysfunction then AD-like rats were orally treated with different doses of ATX (5, 10, and 15 mg/kg) dissolved in dimethyl sulfoxide (DMSO) for six weeks. The results indicated that ATX significantly and dose-dependently improved the performance of AD-like rats treated with ATX during MWM and suppress the accumulation of amyloid β_1-42 and malondialdehyde. Also, significantly inhibit acetylcholinesterase and monoamine oxidase activities and the expression of β-site amyloid precursor protein cleaving enzyme 1 (BACE 1). ATX also significantly elevated the content of acetylcholine, serotonin, and nuclear factor erythroid-2-related factor 2 (Nrf2) and miRNA-124 expression. The effect of ATX treatment was confirmed by histopathological observations using H&E stain and morphometric tissue analysis. From this study, we concluded that ATX may be a promising therapeutic agent for AD through targeting different pathogenic pathways.

The protective effect of Indian Catechu methanolic extract against aluminum chloride-induced neurotoxicity, A rodent model of Alzheimer's disease

Alzheimer's disease (AD) is the commonest neurodegenerative disorder with a wide array of manifestations, courses, and contributing causes. Despite being clinically characterized a long time ago; no treatment has been developed that could improve the pathology or slow down the disease manifestation- so far. Indian Catechu methanolic extract (ICME) has proved to have multiple beneficial effects that support its use in several disorders- especially those with complex etiology. In the present study, we evaluated the neuroprotective effect of ICME in a rat model of AD using Aluminum Chloride (AlCl3). The results showed that ICME could have a positive impact on the course of AD through its anticholinesterase effect and significant antioxidant effect which was reflected on the animals both on behavioral tests as well as hallmark pathological findings.

Anticholinesterase activity and antioxidant properties of Heinsia crinita and Pterocarpus soyauxii in Drosophila melanogaster model

Background

Plant alkaloids have become important sources of nutraceuticals owing to their pharmacological importance especially in the management of neurodegenerative diseases such as Alzheimer’s disease. In assessing the therapeutic potentials of plant phytochemicals, the fruit fly (Drosophila melanogaster) has emerged as a very veritable tool and has been largely accepted as an alternative model in biomedical research.

Objectives

In this study, alkaloid extracts from bush apple (Heinsia crinita (Afzel.) G. Taylor and padauk (Pterocarpus soyauxii Taub.) leaves were assessed on D. melanogaster exposed to aluminum toxicity.

Materials and methods

Alkaloid extracts were prepared by solvent extraction method. Thereafter, the extracts were evaluated for their in vitro antioxidant properties, Fe²⁺-chelating abilities and inhibitory effects on drosophila acetylcholinesterase (AChE) activity. The samples were also characterized for their constituent alkaloids via HPLC. Thereafter, effective safe dose of the extracts were determined in D. melanogaster (Harwich strain). Subsequently, flies assaulted with AlCl₃ were co-treated with the extracts (8.3 and 16.6 μg/g) for seven days, during which their survival rate was monitored. This was followed by assaying for the activities of AChE, antioxidant enzymes [superoxide dismutase (SOD), catalase and glutathione-S-transferase (GST)]. Also, the flies were assayed for levels of thiobarbituric acid reaction substance (TBARS) and reactive oxygen species (ROS).

Results

The results revealed that both extracts showed in vitro antioxidant properties with Padauk showing significantly higher antioxidant properties in vitro. However, there was no significant difference in their in vitro AChE inhibition. In vivo, Al-induced toxicity reduced survival rate, elevated AChE, SOD and GST activities, as well as TBARS and ROS levels which were ameliorated by the extracts. It was also revealed that piperine was predominant in PA, while 1-cyclohexen-1-yl-pyrrolidine was predominant in BA.

Conclusion

Our data suggest that the protective abilities of these extracts against Al-induced toxicity can be primarily associated with their anticholinesterase and metal chelating abilities. Thus, these vegetables can be potential sources of nutraceuticals against aluminum toxicity and associated diseases.

Schiff base-functionalized silatrane-based receptor as a potential chemo-sensor for the detection of Al3+ ions

Excess Al³⁺ ions are considered toxic to living organisms.

Effect of epigallocatechin gallate on aluminum chloride-induced changes in behavior, biochemical parameters, and spermatogenesis of Sprague-Dawley rats

Background

Epigallocatechin gallate (EGCG) acts as an antioxidant by preventing oxidative stress. The effect of EGCG on aluminum-induced testicular injury is not clear. Hence, the present study is planned to investigate the effect of EGCG on aluminum chloride (AlCl3)-induced changes in behavior, biochemical parameters, and spermatogenesis in male Sprague-Dawley rats. The rats were divided into six groups with six animals each. All the animals were administered with respective assigned treatment once daily for 28 days. The animals in groups I to VI were administered with drug vehicle, AlCl3, vitamin C, EGCG, vitamin C, and EGCG, respectively. The animals in groups V and VI were additionally challenged with AlCl3 (10 mg/kg) immediately after vitamin C and EGCG administration, respectively. Changes in behavior were measured on day 1, 14 and 28. At the end of the study, the blood sample was collected from all the animals, and the serum was separated and used for biochemical analysis. Later, the rats were subjected to bilateral orchiectomy; sperm was collected from the cauda epididymis for microscopic examination. Then, the animals were sacrificed, and the organs such as the brain, lungs, heart, liver, kidney, spleen, and testis were collected for organ weight analysis.

Results

The animal administered with AlCl3 showed a reduction in locomotor activity, grip strength, and escape latency time whereas vitamin C prevented the effect of AlCl3. But, EGCG did not show any significant changes in AlCl3-induced behavioral and biochemical changes. At the end of the study, vitamin C prevented AlCl3-induced behavioral and biochemical changes. The group of animals administered with AlCl3 showed a reduction in the number of spermatozoa whereas AlCl3 + vitamin C and AlCl3 + EGCG did not show any significant changes in the number of spermatozoa when compared to the control group.

Conclusion

EGCG prevented AlCl3-induced reduction in epididymal sperm count of male rats and did not show any significant effect on AlCl3-induced changes in behavior and biochemical parameters, whereas vitamin C had an ameliorative effect on AlCl3-induced changes in behavior, biochemical parameter, and spermatogenesis.

Graphical abstract

Aluminum chloride-induced amyloid β accumulation and endoplasmic reticulum stress in rat brain are averted by melatonin

Accumulation of aluminium (Al) in the brain is known to be a toxic insult that result in neurodegenerative diseases and melatonin is known to have neuroprotective role. The present study was designed to investigate the neuroprotective effects of melatonin for aluminium chloride (AlCl₃)-induced neurotoxicity in rats. Twelve-week old male Wistar rats were orally received 175 mg/kg AlCl₃ with or without 5 mg/kg melatonin intraperitoneal pretreatment. Group 3 intraperitoneally recieved 5 mg/kg melatonin and group 4 rats were orally treated with saline solution for 8 weeks. A series of behavioral tests, biochemical analysis and expression of AD-associated proteins in the brain were determined after 7 weeks of all treatments. Our results indicated that AlCl₃ treatment tends to induce memory and cognitive impairment. However, melatonin treatment attenuated amyloid beta (Aβ) (1-42) level by decreasing β-secretase, augmented low-density lipoprotein receptor-related protein 1, and neprilysin protein expression. Moreover, AlCl₃ -induced endoplasmic reticulum (ER) stress and oxidative stress was attenuated by melatonin supplementation. In conclusion, these findings demonstrate a protective role of melatonin against Aβ peptide accumulation, ER stress and oxidative stress in the AlCl₃ -treated AD model. Hence, the melatonin supplement might be an alternative way to alleviate the development of AD.

The Protective Effects of Melatonin on Aluminum-Induced Hepatotoxicity and Nephrotoxicity in Rats

Aluminum (Al) is a ubiquitous element with known toxicity for both humans and animals. Herein, we aimed to investigate the potential role of melatonin (MEL) in hepatotoxicity and nephrotoxicity following aluminum chloride (AlCl₃) treatment in rats. Adult male rats were treated with AlCl₃ (34 mg/kg bwt) for eight weeks. Exposure to AlCl₃ enhanced the serum activities of the liver transaminases (alanine aminotransferase and aspartate aminotransferase) and increased the level of bilirubin, in addition to the serum kidney function markers urea and creatinine. AlCl₃ intoxication boosted oxidative stress, as evidenced by increases in the levels of lipid peroxidation (LPO) and nitric oxide (NO) along with simultaneous decreases in the levels of glutathione (GSH), various antioxidant enzymes, and Nrf2 mRNA expression. MEL (5 mg/kg bwt) treatment repressed LPO and NO levels, whereas it augmented GSH content. The activities of the antioxidant enzymes GPx, SOD, CAT, and GR were also restored concomitantly when MEL was administered before AlCl₃. MEL also suppressed the apoptotic effect of AlCl₃ by enhancing Bcl-2 protein expression in the liver and kidney and decreasing the expression levels of proinflammatory cytokines. Histopathological findings in the liver and kidney tissues confirmed the beneficial effect of MEL against AlCl₃ toxicity. These findings indicate that MEL prevents AlCl₃ toxicity by enhancing the antioxidant defense system.

Modulatory effect of simvastatin on redox status, caspase-3 expression, p-protein kinase B (p-Akt), and brain-derived neurotrophic factor (BDNF) in an ethanol-induced neurodegeneration model

Neurodegenerative diseases are a common cause of morbidity and mortality worldwide, with oxidative stress, inflammation, and protein aggregation representing the main underlying mechanisms that ultimately lead to cell death. Ethanol has shown strong neurodegenerative consequences in experimental animal brains. Statins are a class of lipid-lowering drugs with many pleotropic effects. Therefore, the aim of the present study was to explore the modulatory effect of simvastatin (10 mg·kg^-1·day^-1) before and after the development of neurodegeneration (for 55 and 25 days, respectively) on redox state, caspase-3 expression, p-protein kinase B (p-Akt), and brain-derived neurotrophic factor (BDNF) in ethanol-induced (15% ethanol solution for 55 days) neurodegeneration. Seventy female Albino Swiss mice were included and randomly divided into five groups: C, control group; E, ethanol group; ES, group treated with simvastatin from the first day of ethanol intake; E + S, group treated with simvastatin after neurodegeneration development; and S, simvastatin group. Administration of simvastatin from the first day improved the biochemical changes, suppressed apoptosis, and induced autophagy and neurogenesis; however, its administration after the development of neurodegeneration resulted in partial improvement. The histopathological findings confirmed the biochemical changes. In conclusion, simvastatin has a neuroprotective effect against the development of ethanol-induced neurodegeneration and its progression.

Histological, Histochemical and Immunohistochemical Evaluation of the Role of Bone Marrow-Derived Mesenchymal Stem Cells on the Structure of Periodontal Tissues in Carbimazole-Treated Albino Rats

OBJECTIVE

To elucidate the role of bone marrow-mesenchymal stem cells (BM-MSCs) on the structure of periodontal tissues in carbimazole (antithyroid drug) treated rats at different durations.

DESIGN

28 albino rats were divided into: Group I: received distilled water. Group II: received therapeutic dose of carbimazole. Group III: received carbimazole then single injection of BM-MSCs by the end of 3^rd week. Group IV: received carbimazole and single injection of BM-MSCs at the beginning of the experiment. Specimens were examined by light microscope. New collagen and β-catenin-immunoreactivity area% were assessed histomorphometrically, and statistically using ANOVA test.

RESULTS

Histological examination revealed normal periodontal tissues structure in Groups I & IV. Group II showed disorganized periodontal ligament fibers and different stainability of cementum and alveolar bone. Group III illustrated dense periodontal ligament fibers, normal stainability of cementum and most of alveolar bone. Masson's trichrome results of Groups I & IV illustrated large areas of new collagen in periodontal ligament, old collagen in cementum and intermingled old and new collagen in alveolar bone. Group II showed old collagen. Group III revealed only new collagen. β-catenin-immunoreactivity was strong in Groups I & IV, negative in Group II and moderate in Group III. Statistically, Group III showed highest mean of new collagen area% followed by Groups I, IV and II respectively. Highest mean of β-catenin-immunoreactivity area% was for Group I followed by Groups IV, III and II respectively.

CONCLUSIONS

Carbimazole has damaging effects and BM-MSCs are capable to mend these destructive outcomes in time dependent manner.

Cassia tora extract alleviates Aβ1-42 aggregation processes in vitro and protects against aluminium-induced neurodegeneration in rats

OBJECTIVES

To examine the ability of Cassia tora extract to produce, in vitro and in vivo, beneficial effects with respect to events occurring during Alzheimer's disease.

METHODS

Previously characterised methanol extract of C. tora was tested for its ability to lessen Aβ₄₂ aggregation processes in vitro and to alleviate aluminium-induced impairments in vivo in rats.

KEY FINDINGS

Cassia tora extract prevents the aggregation of monomeric, oligomeric and fibrillary Aβ_1-42 in vitro. Moreover, the daily ingestion of 100 and 400 milligrams of the extract per kilogram of body weight for 60 days ameliorates the neurobehavioral and cognitive abilities of aluminium-treated rats in vivo. Importantly, treatments with the extract trigger a significant recovery of antioxidant enzymes function, a diminution of lipid peroxidation and acetylcholinesterase activity, a decrease of pro-inflammatory cytokines expression and an increase of brain-derived neurotrophic factor levels in both the hippocampus and the frontal cortex. Finally, we evidence that the extract is able to ameliorate the aluminium-dependent loss of neuronal integrity in the CA1 and CA3 regions of the hippocampus.

CONCLUSIONS

Altogether, our results reveal that methanol extract of C. tora is able to prevent typical AD-related events and therefore stands as a promising mild and natural anti-AD multitarget compound.

The Protective Effect of DiDang Tang Against AlCl3-Induced Oxidative Stress and Apoptosis in PC12 Cells Through the Activation of SIRT1-Mediated Akt/Nrf2/HO-1 Pathway

Aluminum (Al) is considered a pathological factor for various neurological and neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). The neurotoxicity of aluminum can cause oxidative brain damage, trigger apoptosis, and ultimately cause irreversible damage to neurons. DiDang Tang (DDT), a classic formula within traditional Chinese medicine for promoting blood circulation and removing blood stasis and collaterals, is widely used for the treatment of stroke and AD. In this study, models of oxidative stress and apoptosis were established using AlCl₃, and the effects of DDT were evaluated. We found that DDT treatment for 48 h significantly increased cell viability and reduced the release of lactate dehydrogenase (LDH) in AlCl₃-induced PC12 cells. Moreover, DDT attenuated AlCl₃-induced oxidative stress damage by increasing antioxidant activities and apoptosis through mitochondrial apoptotic pathways. Additionally, DDT treatment significantly activated the Sirtuin 1 (SIRT1) -mediated Akt/nuclear factor E2 related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathways to limit AlCl₃-mediated neurotoxicity. Our data indicated that DDT potently inhibited AlCl₃-induced oxidative-stress damage and apoptosis in neural cells by activating the SIRT1-mediated Akt/Nrf2/HO-1 pathway, which provides further support for the beneficial effects of DDT on Al-induced neurotoxicity.

The prospective role of mesenchymal stem cells exosomes on circumvallate taste buds in induced Alzheimer's disease of ovariectomized albino rats: (Light and transmission electron microscopic study)

OBJECTIVE

To elucidate the effect of Alzheimer's disease on the structure of circumvallate papilla taste buds and the possible role of exosomes on the taste buds in Alzheimer's disease.

DESIGN

Forty two ovariectomized female adult albino rats were utilized and divided into: Group I: received vehicle. Group II: received aluminum chloride to induce Alzheimer's disease. Group III: after the induction of Alzheimer's disease, each rat received single dose of exosomes then left for 4 weeks. The circumvallate papillae were prepared for examination by light and transmission electron microscope.

STATISTICAL ANALYSIS

histomorphometric data were statistically analyzed.

RESULTS

Histological examination of circumvallate papilla in Group I showed normal histological features. Group II revealed distorted features. Group III illustrated nearly normal histological features of circumvallate. Silver impregnation results showed apparently great number of heavily impregnated glossopharyngeal nerve fibers in both Groups I & III but markedly decreased in Group II. Synaptophysin-immunoreactivity was strong in Group I, mild in Group II and moderate in Group III. The ultra-structural examination of taste bud cells revealed normal features in Group I, distorted features in Group II and almost normal features in Group III. Statistically highest mean of Synaptophysin-immunoreactivity area% was for Group I, followed by Group III, and the least value was for Group II.

CONCLUSIONS

Alzheimer's disease has degenerative effects. Bone marrow mesenchymal stem cell (BM-MSC)-derived exosomes have the ability to improve the destructive changes induced by Alzheimer's disease.

Experimental and Computational Studies to Characterize and Evaluate the Therapeutic Effect of Albizia lebbeck (L.) Seeds in Alzheimer's Disease

Background and Objectives: Alzheimer's disease (AD) is a neurodegenerative disorder that deteriorates daily life due to loss of memory and cognitive impairment. It is believed that oxidative stress and cholinergic deficit are the leading causes of AD. Disease-modifying therapies for the treatment of AD are a challenging task for this century. The search for natural and synthetic agents has attracted the attention of researchers. The objective of this study was a scientific approach to search for most suitable remedy for AD by exploiting the potential of Albizia lebbeck (L.) seeds. Materials and Methods: Hydromethanolic extract of Albizia lebbeck seeds (ALE) was prepared by maceration. The plant was characterized by physico-chemical, phyto-chemical, and high-performance liquid chromatography (HPLC). Thirty-six Wistar albino rats were used in this study and divided into six groups (n = 6). Group I: normal control; Group II: disease control (AlCl3; 100 mg/Kg); Group III: standard control (galantamine; 0.5mg/Kg); Groups IV-VI were treated ALE at 100, 200 and 300 mg/Kg dose levels, respectively. All the treatments were given orally for 21 consecutive days. Y-maze, T-maze, Morris water maze, hole board, and open field behavioral tests were performed to analyze the cognitive impairment. Biochemical, histological, and computational studies were performed to support the results of behavioral tests. Results: HPLC analysis indicated the presence of quercetin, gallic acid, m-coumaric acid, and sinapic acid. ALE significantly improved the memory and cognitive impairments. Endogenous antioxidant stress biomarker levels and histopathological outcomes supported the therapeutic potential of A. lebbeck in AD. Cholinergic deficits were also ameliorated by ALE co-administration, possibly by the inhibition of hyperactive acetylcholinesterase (AChE). Docking studies supported the potential of ALE against AD. Conclusions: The data suggested that ALE has neuroprotective potential that can be exploited for beneficial effects to treat AD.

Ameliorative effects of autophagy inducer, simvastatin on alcohol-induced liver disease in a rat model

Alcoholic liver disease (ALD) encompasses a variety of liver injuries with various underlying mechanisms but still no effective treatment. So we aimed to monitor the influence of simvastatin on alcohol-induced liver injury and elucidate the underlying mechanisms of its cytoprotective effect. Thirty male albino rats were randomly divided into five equal groups. Group 1 (control): received a standard diet; group 2: received simvastatin (10 mg kg^-1  day ^-1 ) once a day orally for 8 weeks; group 3: received 20% ethanol (7.9 g kg ^-1  day ^-1 ) daily orally for 8 weeks; group 4: received 20% ethanol along with same simvastatin dose daily for 8 weeks; group 5: received 20% ethanol orally for 8 weeks then received the same simvastatin dose for the next 8 weeks. Serum alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were measured. Liver tissue malondialdehyde, reduced glutathione levels, and superoxide dismutase activity were estimated. B-cell lymphoma 2 and C/EBP homologous protein levels were evaluated by enzyme linked immunosorbent assay (ELISA). Light chain 3-II and peroxisome proliferation-activated receptor gamma messenger RNA expression was assessed by real-time polymerase chain reaction. Immunohistochemical staining was performed using anti-rat tumor necrosis factor-alpha antibody. Our results revealed that simvastatin treatment was able to ameliorate alcohol-induced liver damage; the improved biochemical data were confirmed by histopathological evaluation. Simvastatin being an autophagy inducer was able to prevent and reverse alcohol-induced liver changes via induction of autophagy, attenuation of oxidative stress, inflammation, and endoplasmic reticulum stress-induced apoptosis. Therefore, our findings suggest that treatment with simvastatin may be a useful approach in the management strategy of ALD.

Neuromodulatory potential of phenylpropanoids; para-methoxycinnamic acid and ethyl-p-methoxycinnamate on aluminum-induced memory deficit in rats

Para-methoxycinnamic acid (PMCA) and Ethyl-p-methoxycinnamate (EPMC) are reported to possess neuroprotective effect in reversing an acute memory deficit. However, there is a dearth of evidence for their therapeutic effect in chronic memory deficit. Thus, there is a scope to study these derivatives against the chronic model of cognitive dysfunction. The present study was aimed to determine the cognitive enhancing activity of PMCA and EPMC in aluminum-induced chronic dementia. Cognitive enhancing property of PMCA and EPMC was assessed using Morris water maze by analyzing spatial memory parameters such as escape latency, D-quadrant latency, and island entries. To find a possible mechanism, the effect of test compounds on altered acetylcholinesterase (AChE) activity and oxidative stress was determined in the hippocampus and frontal cortex of rats. Docking interaction of these derivatives with acetylcholinesterase enzyme and glutamate receptors was also studied. Treatment with PMCA and EPMC showed a significant improvement in spatial memory markers and altered hippocampal AChE activity in rats with cognitive dysfunction. The implication of hippocampal and cortical oxidative stress in memory impairment was confirmed with decreased catalase/increased thiobarbituric acid reactive substances (TBARS) in rats. PMCA and EPMC reversed the oxidative stress in the brain by negatively affecting TBARS levels. Against depleted catalase levels, PMCA was more effective than EPMC in raising the depleted catalase levels. In silico analysis revealed poor affinity of EPMC and PMCA with AChE enzyme and glutamate receptor. To conclude, PMCA and EPMC exerted cognitive enhancing property independent of direct AChE and glutamate receptor inhibition.

Selenium-Rich Yeast Protects Against Aluminum-Induced Renal Inflammation and Ionic Disturbances

The aim of this study was to evaluate the protective effects of SeY (selenium-rich yeast) against Al (aluminum)-induced inflammation and ionic imbalances. Male Kunming mice were treated with Al (10 mg/kg) and/or SeY (0.1 mg/kg) by oral gavage for 28 days. The degree of inflammation was assessed by mRNA expression of inflammatory biomarkers. Ionic disorders were assessed by determining the Na⁺, K⁺, and Ca²⁺ content, as well as the alteration in ATP-modifying enzymes (ATPases), including Na⁺K⁺-ATPase, Ca²⁺-ATPase, Mg²⁺-ATPase, Ca²⁺Mg²⁺-ATPase, and the mRNA levels of ATPase's subunits in kidney. It was observed here that SeY exhibited a significant protective effect on the kidney against the Al-induced upregulation of pro-inflammatory and downregulation of anti-inflammatory cytokines. Furthermore, a significant effect of Al on the Na⁺, K⁺, Ca²⁺, and Mg²⁺ levels in kidney was observed, and Al was observed to decrease the activities of Na⁺K⁺-ATPase, Mg²⁺-ATPase, and Ca²⁺Mg²⁺-ATPase. The mRNA expression of the Na⁺K⁺-ATPase subunits and Ca²⁺-ATPase subunits was regulated significantly by Al. Notably, SeY modulated the Al-induced alterations of ion concentrations, ATPase activity, and mRNA expression of their subunits. These results suggest that SeY prevents renal toxicity caused by Al via regulation of inflammatory responses, ATPase activities, and transcription of their subunits.

Neuroprotective role of hyperforin on aluminum maltolate-induced oxidative damage and apoptosis in PC12 cells and SH-SY5Y cells

Many reports demonstrated that aluminum maltolate (Almal) has potential toxicity to human and animal. Our study has demonstrated that Almal can induce oxidative damage and apoptosis in PC12 cells and SH-SY5Y Cells, two in vitro models of neuronal cells. Hyperforin (HF) is a well-known antioxidant, anti-inflammatory, anti-amyloid and anti-depressant compound extracted from Hypericum perforatum extract. Here, we investigated the neuroprotective effect of HF against Almal-induced neurotoxicity in cultured PC12 cells and SH-SY5Y cells, mainly caused by oxidative stress. In the present study, HF significantly inhibited the formation of reactive oxygen species (ROS), decreased the level of lipid peroxide and enhanced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) compared with Almal group in PC12 cells and SH-SY5Y cells. Additionally, HF suppressed the reduction of the mitochondrial membrane potential (MMP), cytochrome c (Cyt-c) release, activation of caspase-3, and the down-regulation of Bcl-2 expression and up-regulation of Bax expression induced by Almal in PC12 cells and SH-SY5Y cells. In summary, HF protects PC12 cells and SH-SY5Y cells from damage induced by Almal through reducing oxidative stress and preventing of mitochondrial-mediated apoptosis.

Protective effect of Centella asiatica against D-galactose and aluminium chloride induced rats: Behavioral and ultrastructural approaches

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder and the commonest cause of dementia among the aged people. _D-galactose (D-gal) is a senescence agent, while aluminium is a known neurotoxin linked to pathogenesis of AD. The combined administration of rats with d-gal and aluminium chloride (AlCl₃) is considered to be an easy and a cheap method to obtain an animal model of AD. The plant Centella asiatica (CA) is reported to exert neuroprotective effects both in vitro and in vivo. Therefore, this study explored the protective effects of CA on cognition and brain ultrastructure in d-gal and AlCl₃ induced rats.

MATERIALS AND METHODS

Rats were exposed to d-gal 60 mg/kg/b.wt/day + AlCl₃ 200 mg/kg/b.wt/day and CA (200, 400 and 800 mg/kg/b.wt/day) and 1 mg/kg/b.wt/day of donepezil for 70 days. Different cognitive paradigms viz. T maze spontaneous alternation, modified elevated plus maze and novel object recognition test, were used to evaluate full lesions of the hippocampus, spatial learning and memory and non-spatial learning and memory respectively. Nissl's staining was used to determine the survival of hippocampus CA1 pyramidal cells, while transmission electron microscopy was used to check the ultrastructural changes.

RESULTS

The results revealed that d-gal and AlCl₃ could significantly impair behavior and cognitive functions, besides causing damage to the hippocampal CA1 pyramidal neurons in rats. In addition, it also caused ultrastructural morphological alterations in rat hippocampus. Conversely, co-administration o;f CA, irrespective of the dosage used, alleviated the cognitive impairments and pathological changes in the rats comparable to donepezil.

CONCLUSION

In conclusion the results suggest that CA could protect cognitive impairments and morphological alterations caused by d-gal and AlCl₃ toxicity in rats. Biochemical and molecular studies are ongoing to elucidate the probable pharmacodynamics of CA.

EGCG Nanoparticles Attenuate Aluminum Chloride Induced Neurobehavioral Deficits, Beta Amyloid and Tau Pathology in a Rat Model of Alzheimer's Disease

Rational: Alzheimer's disease (AD) is a neurodegenerative pathology characterized by the presence of neuritic plaques and neurofibrillary tangles. Aluminum has been reported to play an important role in the etiology and pathogenesis of this disease. Hence, the present study aimed to evaluate the neuroprotective role of epigallocatechin-gallate (EGCG) loaded nanoparticles (nanoEGCG) against aluminum chloride (AlCl3) induced neurobehavioral and pathological changes in AD induced rats. Method: 100 mg/kg body weight AlCl3 was administered orally for 60 days, which was followed by 10 mg/kg body weight free EGCG and nanoEGCG treatment for 30 days. Morris water maze, open field and novel object recognition tests were employed for neurobehavioral assessment of the rats. This was followed by histopathological assessment of the cortex and the hippocampus in the rat brain. For further validation biochemical, immunohistochemistry and western blot assays were carried out. Result: Aluminum exposure reduced the exploratory and locomotor activities in open field and significantly reduced the memory and learning curve of rats in Morris water maze and novel object recognition tests. These neurobehavioral impairments were significantly attenuated in nanoEGCG treated rats. Histopathological assessment of the cortex and hippocampus of AlCl3 induced rat brains showed the presence of both neuritic plaques and neurofibrillary tangles. In nanoEGCG treated rats this pathology was absent. Significant increase in biochemical, immunohistochemical and protein levels was noted in AlCl3 induced rats. While these levels were greatly reduced in nanoEGCG treated rats. Conclusion: In conclusion, this study strengthens the hypothesis that EGCG nanoparticles can reverse memory loss, neuritic plaque and neurofibrillary tangles formation.

Combined Donepezil and Ethanolic Extract of Propolis Improved Memory Better Than Donepezil and Propolis Monotherapy in Wild Type Drosophila melanogaster

BACKGROUND

Donepezil is the most common drug used in the treatment of disorders associated with memory loss, especially that in Alzheimer's disease. Healthy individuals however have continued to use it as a memory enhancer. This study was aimed at evaluating the combined therapy of donepezil and propolis on cognition in Drosophila melanogaster. Method. Drosophila melanogaster flies were divided into five groups and fed with the different treatment doses of ethanolic extract of propolis and donepezil as follows: normal food, propolis 250 mg/mL, propolis 50 mg/mL, donepezil 0.001M, and donepezil 0.001M/propolis 50 mg/mL added to their food. The flies were fed from larval stage for 30 days. The memory and learning tests were conducted after every 10 days to assess improvement with time.

RESULTS

The results obtained showed that the combination of propolis with donepezil caused a remarkable improvement in both the short- and long-term memory. In addition, there was a dose dependent improvement with the administration of propolis.

CONCLUSION

Propolis extract obtained from different parts of Uganda expressed cognitive improvement when coadministered with donepezil in wild type Drosophila melanogaster.

Evaluation of neuroprotective effects of wedelolactone and gallic acid on aluminium-induced neurodegeneration: Relevance to sporadic amyotrophic lateral sclerosis

Al exposure causes an alteration in the several ions in the body and causes toxicity. Such as apoptosis, oxidative stress, disruption in neuronal transport, mitochondrial damage, excitotoxicity, generation of inflammatory mediators, and microglial activation. These multiple mechanisms lead to the several neurodegenerative diseases, including sporadic amyotrophic lateral sclerosis (sALS). The study aims to unravel the mechanisms behind the neuroprotective effects of wedelolactone (WL) and gallic acid (GA) against aluminium-induced neurodegeneration and thereby to unlock a platform to find a cure for sALS. We studied the neuroprotective effects of WL (100 & 200 mg/kg) and GA (100 & 200 mg/kg) using aluminium chloride (AlCl₃)-induced neurodegeneration model. The study was conducted using male Wistar rats. We assessed the effects of WL and GA on motor learning ability, motor coordination, locomotor activity, cytokine production, BDNF, glutathione peroxidase (GPx), m-calpain, caspase-3 inhibition and L-glutamate level. The study suggests that the treatment with WL and GA could protect the motor neurons from the toxicity that caused by Al via improving the antioxidant status, BDNF, and by preventing glutamate excitotoxicity. Also, WL and GA are found to be effective in inhibiting caspase-3 activation and downregulating inflammatory cytokines. WL and GA also found effective in improving the motor learning abilities and motor coordination in rats. The protective effects of the WL and GA were further confirmed from histopathological results. WL and GA prevent the neurofibrillary tangle formation and neuronal damage. The study concluded that the WL and GA were dose-dependently effective in managing the AlCl₃-induced neurodegeneration.

Effect of insulin on spatial memory in aluminum chloride-induced dementia in rats

Latest reports suggest the involvement of insulin in modulating memory. A few published in-vitro studies favor the antidementia effect of insulin. Thus, the present study aimed to evaluate the prophylactic role of insulin and its combination with glucose and its possible mechanism(s) in an aluminum chloride (AlCl3)-induced cognitive dysfunction model in rodents, with a special focus on memory centers namely, the hippocampus and the frontal cortex. Male Wistar rats were exposed to AlCl3 (175 mg/kg orally) for 60 days. Insulin (0.5 IU/kg), Insulin (0.5 IU/kg) in combination with glucose (200 mg/kg), and rivastigmine (1 mg/kg) were administered intraperitoneally 45 min before the administration of AlCl3 for 60 days. Spatial memory was assessed using the Morris water-maze test. After 60 days of treatment, animals were killed, and the hippocampus and frontal cortex were collected and analyzed for acetylcholinesterase activity and antioxidant enzyme level. Blood glucose levels were also analyzed. Treatment with the standard drug, rivastigmine (1 mg/kg), produced a significant reduction in escape latency and increased the time spent in the target quadrant compared with the AlCl3-treated group. Insulin and its combination with glucose could not inhibit the behavioral impairments in aluminum-exposed rats. Treatment with insulin alone and its combination with glucose reversed the increased glucose levels. Insulin alone and its combination with glucose could not inhibit aluminum-induced oxidative stress and impaired cholinergic transmission in the hippocampus and frontal cortex regions. The study suggests the inability of prophylactic insulin administration against cognitive dysfunction induced by environmental toxin (AlCl3) in the hippocampus and the frontal cortex.