In vivo and in vitro effects of aluminum on the activity of mouse brain acetylcholinesterase

Silica Nanoparticles from Melon Seed Husk Abrogated Binary Metal(loid) Mediated Cerebellar Dysfunction by Attenuation of Oxido-inflammatory Response and Upregulation of Neurotrophic Factors in Male Albino Rats

Silica nanoparticles (SiNPs) have been touted for their role in the management of non-communicable diseases. Their neuroprotective benefits against heavy metal-induced neurotoxicity remain largely unexplored. This is a comparative evaluation of the oxido-inflammatory and neurotrophic effects of Ni, Al, and Ni/Al mixture on the cerebellum of male albino rats with or without treatment with SiNPs generated from melon seed husk. The study complied with the ARRIVE guidelines for reporting in vivo experiments. A total of 91, 7-9 week-old weight-matched male Sprague rats (to avoid sex bias) were randomly divided into 13 different dosing groups where Group 1 served as the control. Other groups received 0.2 mg/kg Ni, 1 mg/kg Al, and 0.2 mg/kg Ni + 1 mg/kg Al mixture with or without different doses of SiNP for 90 days. Rotarod performance was carried out. Oxidative stress markers, Ni, Al, Ca, Fe, Mg, neurotrophic factors, amyloid beta (Aβ-42), cyclooxygenase-2 (COX-2), and acetylcholinesterase (AChE) were determined in the cerebellum. SiNPs from melon seed husk caused a significant decrease in Aβ-42 level and activities of AChE and COX-2 and a significant increase in brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) mediated by Ni, Al, and Ni/Al mixture exposure in rats. Neurotoxicity of the Ni/Al mixture is via heightened neuronal lipoperoxidative damage, decreased Mg, and increased Fe, and co-administration of SiNPs from melon seed husk with the Ni/Al mixture attenuated some of these biochemical changes in the cerebellum.

Metal Toxicity and Dementia Including Frontotemporal Dementia: Current State of Knowledge

Frontotemporal dementia (FTD) includes a number of neurodegenerative diseases, often with early onset (before 65 years old), characterized by progressive, irreversible deficits in behavioral, linguistic, and executive functions, which are often difficult to diagnose due to their similar phenotypic characteristics to other dementias and psychiatric disorders. The genetic contribution is of utmost importance, although environmental risk factors also play a role in its pathophysiology. In fact, some metals are known to produce free radicals, which, accumulating in the brain over time, can induce oxidative stress, inflammation, and protein misfolding, all of these being key features of FTD and similar conditions. Therefore, the present review aims to summarize the current evidence about the environmental contribution to FTD-mainly dealing with toxic metal exposure-since the identification of such potential environmental risk factors can lead to its early diagnosis and the promotion of policies and interventions. This would allow us, by reducing exposure to these pollutants, to potentially affect society at large in a positive manner, decreasing the burden of FTD and similar conditions on affected individuals and society overall. Future perspectives, including the application of Artificial Intelligence principles to the field, with related evidence found so far, are also introduced.

Succinimide Derivatives as Acetylcholinesterase Inhibitors-In Silico and In Vitro Studies

We studied the effect of succinimide derivatives on acetylcholinesterase activity due to the interest in compounds that influence this enzyme's activity, which could help treat memory issues more effectively. The following parameters were established for this purpose based on kinetic investigations of the enzyme in the presence of succinimide derivatives: the half-maximal inhibitory concentration, the maximum rate, the inhibition constant, and the Michaelis-Menten constant. Furthermore, computational analyses were performed to determine the energy required for succinimide derivatives to dock with the enzyme's active site. The outcomes acquired in this manner demonstrated that all compounds inhibited acetylcholinesterase in a competitive manner. The values of the docking energy parameters corroborated the kinetic parameter values, which indicated discernible, albeit slight, variations in the inhibitory intensity among the various derivatives.

New bithiophene derivative attenuated Alzheimer's disease induced by aluminum in a rat model via antioxidant activity and restoration of neuronal and synaptic transmission

BACKGROUND

One of the hypotheses that leads to an increased incidence of Alzheimer's disease (AD) is the accumulation of aluminum in the brain's frontal cortex. The present study aimed to evaluate the therapeutic role of a novel bithiophene derivative at two doses against AlCl3-induced AD in a rat model.

METHODOLOGY

Adult male rats were divided into six groups, 18 rats each. Group 1: naïve animals, group 2: animals received a daily oral administration of bithiophene dissolved in DMSO (1 mg/kg) for 30 days every other day, groups 3-6: animals received a daily oral administration of AlCl3 (100 mg/kg/day) for 45 consecutive days. Groups 4 and 5 received an oral administration of low or high dose of the bithiophene (0.5 or 1 mg/kg, respectively). Group 6; Animals were treated with a daily oral dose of memantine (20 mg/kg) for 30 consecutive days.

MAIN FINDINGS

Al disturbed the antioxidant milieu, elevated the lipid peroxidation, and depleted the antioxidants. It also disturbed the synaptic neurotransmission by elevating the activities of acetylcholine esterase and monoamine oxidase resulting in the depletion of dopamine and serotonin and accumulation of glutamate and norepinephrine. Al also deteriorated the expression of genes involved in apoptosis and the production of amyloid-β plaques as well as phosphorylation of tau. The new bithiophene at the low dose reversed most of the previous deleterious effects of aluminum in the cerebral cortex and was in many instances superior to the reference drug; memantine.

CONCLUSION

Taking together, the bithiophene modulated the AD etiology through antioxidant activity, prevention of neuronal and synaptic loss, and probably mitigating the formation of amyloid-β plaques and phosphorylation of tau.

REM Sleep Loss-Induced Elevated Noradrenaline Plays a Significant Role in Neurodegeneration: Synthesis of Findings to Propose a Possible Mechanism of Action from Molecule to Patho-Physiological Changes

Wear and tear are natural processes for all living and non-living bodies. All living cells and organisms are metabolically active to generate energy for their routine needs, including for survival. In the process, the cells are exposed to oxidative load, metabolic waste, and bye-products. In an organ, the living non-neuronal cells divide and replenish the lost or damaged cells; however, as neuronal cells normally do not divide, they need special feature(s) for their protection, survival, and sustenance for normal functioning of the brain. The neurons grow and branch as axons and dendrites, which contribute to the formation of synapses with near and far neurons, the basic scaffold for complex brain functions. It is necessary that one or more basic and instinct physiological process(es) (functions) is likely to contribute to the protection of the neurons and maintenance of the synapses. It is known that rapid eye movement sleep (REMS), an autonomic instinct behavior, maintains brain functioning including learning and memory and its loss causes dysfunctions. In this review we correlate the role of REMS and its loss in synaptogenesis, memory consolidation, and neuronal degeneration. Further, as a mechanism of action, we will show that REMS maintains noradrenaline (NA) at a low level, which protects neurons from oxidative damage and maintains neuronal growth and synaptogenesis. However, upon REMS loss, the level of NA increases, which withdraws protection and causes apoptosis and loss of synapses and neurons. We propose that the latter possibly causes REMS loss associated neurodegenerative diseases and associated symptoms.

Environmental impacts of industrial activities on floral coverage with special emphasis on detoxification enzyme activities in Cataglyphis savignyi as pollution biomarker

The present study investigates the environmental impact of industrial activities on floral coverage within the major industrial district of Borg El-Arab City, Egypt. Additionally, it aims to evaluate the detoxification enzymatic activity of Cataglyphis savignyi as a pollution biomarker. To achieve this objective, seasonal soil samples were collected from the studied sites to determine soil properties and heavy metal concentrations. Furthermore, a seasonal specimen of C. savignyi was collected to study the enzymatic activity of acetylcholinesterase (AChE) and glutathione-S-transferase (GST). Heavy metal contamination pollution indices were calculated, and fourteen plant species were identified at the investigated sites for four successive seasons from 2020 to 2021. The soil physicochemical parameters significantly varied in the industrial sites compared to the control site. The accumulation of heavy metal contamination in soil for investigated sites followed the order Ni > As > Pb > Hg. Calculated Cdeg and PLI for industrial 3 revealed a very high degree of contamination, attributed to increased industrial activity from the chemical and silicate factories that characterize this region. The current results highlight the inhibition of GST levels in C. savignyi at the industrial site compared to the control site. In contrast, AChE increases, which might be due to heavy metals enhancing acetylcholine activity at synapses. Consequently, the antioxidant enzymatic activities are useful as biomarkers for assessing and monitoring environmental contamination. In conclusion, this study underscores insects as potent biomarkers for heavy metal contamination, marking a significant advancement in environmental monitoring. These bioindicators offer crucial insights into the impacts of climate change and industrial pollution. The research reveals distinct plant diversity variations and higher heavy metal content in industrial sites, indicating pronounced contamination. Additionally, the study highlights altered enzyme activities in insects, emphasizing their utility as biomarkers for assessing environmental contamination. This work represents a substantial leap forward in comprehending the complex dynamics between contamination and ecological balance.

Effects of simultaneous versus post exposure epigallocatechin-3-gallate treatment on aluminum induced neurotoxicity in rat hippocampus: A multi-approach study

Chronic aluminium(Al) exposure can affect the antioxidant and glutaminergic systems through N-methyl-D-aspartate receptors (NMDAR). This study was aimed to investigate the neurotoxic effect of Al through different mechanisms in rat hippocampus and to evaluate the protective role of epigallocatechin gallate (EGCG), a well-known antioxidant, with simultaneous administration of Al,as well as post-treatment after Al exposure.For this purpose, aluminum chloride(AlCl₃) was administered simultaneously with two different EGCG doses for 8 weeks as the first part of the study.In the second part of the study, after 4 weeks of AlCl₃ pre-administration, two different EGCG doses were also administered during four additional weeks as post-treatment.Al administration led to oxidative stress and increased acetylcholinesterase levels.NMDAR subunit mRNA expressions were down-regulated by Al, which was apparent in NMDAR1/2B subunits.Simultaneous EGCG treatment has shown a better neuroprotective effect in terms of these mechanisms and represents novel approach for the prevention of neurodegenerative diseases likely to be induced by Al.

Aluminum alters excitability by inhibiting calcium, sodium, and potassium currents in bovine chromaffin cells

Aluminum (Al³⁺ ) has long been related to neurotoxicity and neurological diseases. This study aims to describe the specific actions of this metal on cellular excitability and neurotransmitter release in primary culture of bovine chromaffin cells. Using voltage-clamp and current-clamp recordings with the whole-cell configuration of the patch clamp technique, online measurement of catecholamine release, and measurements of [Ca²⁺ ]_c with Fluo-4-AM, we have observed that Al³⁺ reduced intracellular calcium concentrations around 25% and decreased catecholamine secretion in a dose-dependent manner, with an IC₅₀ of 89.1 μM. Al³⁺ blocked calcium currents in a time- and concentration-dependent manner with an IC₅₀ of 560 μM. This blockade was irreversible since it did not recover after washout. Moreover, Al³⁺ produced a bigger blockade on N-, P-, and Q-type calcium channels subtypes (69.5%) than on L-type channels subtypes (50.5%). Sodium currents were also inhibited by Al³⁺ in a time- and concentration-dependent manner, 24.3% blockade at the closest concentration to the IC₅₀ (399 μM). This inhibition was reversible. Voltage-dependent potassium currents were low affected by Al³⁺ . Nonetheless, calcium/voltage-dependent potassium currents were inhibited in a concentration-dependent manner, with an IC₅₀ of 447 μM. This inhibition was related to the depression of calcium influx through voltage-dependent calcium channels subtypes coupled to BK channels. In summary, the blockade of these ionic conductance altered cellular excitability that reduced the action potentials firing and so, the neurotransmitter release and the synaptic transmission. These findings prove that aluminum has neurotoxic properties because it alters neuronal excitability by inhibiting the sodium currents responsible for the generation and propagation of impulse nerve, the potassium current responsible for the termination of action potentials, and the calcium current responsible for the neurotransmitters release.

Hizikia fusiforme functional oil (HFFO) prevents neuroinflammation and memory deficits evoked by lipopolysaccharide/aluminum trichloride in zebrafish

Background

Oxidative stress, cholinergic deficiency, and neuroinflammation are hallmarks of most neurodegenerative disorders (NDs). Lipids play an important role in brain development and proper functioning. Marine-derived lipids have shown good memory-improving potentials, especially those from fish and microalgae. The cultivated macroalga Hizikia fusiforme is healthy food and shows benefits to memory, but the study is rare on the brain healthy value of its oil. Previously, we had reported that the Hizikia fusiforme functional oil (HFFO) contains arachidonic acid, 11,14,17-eicosatrienoic acid, phytol, and other molecules displaying in vitro acetylcholinesterase inhibitory and nitroxide scavenging activity; however, the in vivo effect remains unclear. In this study, we further investigated its potential effects against lipopolysaccharides (LPS)- or aluminum trichloride (AlCl3)-induced memory deficiency in zebrafish and its drug-related properties in silica.

Methods

We established memory deficit models in zebrafish by intraperitoneal (i.p.) injection of lipopolysaccharides (LPS) (75 ng) or aluminum trichloride (AlCl3) (21 μg), and assessed their behaviors in the T-maze test. The interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), acetylcholine (ACh), and malondialdehyde (MDA) levels were measured 24 h after the LPS/AlCl3 injection as markers of inflammation, cholinergic activity, and oxidative stress. Furthermore, the interaction of two main components, 11,14,17-eicosatrienoic acid and phytol, was investigated by molecular docking, with the important anti-inflammatory targets nuclear factor kappa B (NF-κB) and cyclooxygenase 2 (COX-2). Specifically, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) and drug-likeness properties of HFFO were studied by ADMETlab.

Results

The results showed that HFFO reduced cognitive deficits in zebrafish T-maze induced by LPS/AlCl3. While the LPS/AlCl3 treatment increased MDA content, lowered ACh levels in the zebrafish brain, and elevated levels of central and peripheral proinflammatory cytokines, these effects were reversed by 100 mg/kg HFFO except for MDA. Moreover, 11,14,17-eicosatrienoic acid and phytol showed a good affinity with NF-κB, COX-2, and HFFO exhibited acceptable drug-likeness and ADMET profiles in general.

Conclusion

Collectively, this study's findings suggest HFFO as a potent neuroprotectant, potentially valuable for the prevention of memory impairment caused by cholinergic deficiency and neuroinflammation.

Functionalized MOF as a Sensitive Spectroscopic Probe for Hg2+, Co2+, and Al3+ Ions Detection in Aqueous Media

A modified metal-organic framework (MOF) named Al-MIL-53-N=SA-Br was synthesized via a Schiff-base reaction between the MOFs (Al-MIL-53-NH2) and 5-bromo salicylaldehyde. The robust functionalized Al-MIL-53-N=SA-Br was used as a novel spectrophotometric sensor for detecting Hg2+, Co2+, and Al3+ ions. In a wide range of concentrations, the absorption spectral intensity of Al-MIL-53-N=SA-Br increased linearly upon increasing the concentration of Hg2+, Co2+, and Al3+ ions. The limit of detection (LOD) of the proposed Al-MIL-53-N=SA-Br sensor reached 1.52 ppm of Hg2+ ion (7.56 × 10-9 M). Therefore, this study introduces a novel ratiometric Hg2+, Co2+, and Al3+ ions chemosensor. Simple treatment using thiourea or ethylenediaminetetraacetic acid can remove the metal ions from the used sensor and use it many times with a high efficiency. In addition, the Al-MIL-53-N=SA-Br sensor has a high adsorption capacity for these metal ions. The design of the robust Al-MIL-53-N=SA-Br sensor provided high stability, reproducibility, selectivity, high sensitivity, and a facile sensing design. Furthermore, the good absorption spectral stability of Al-MIL-53-N=SA-Br in aqueous media, the broad linear in sensing, and the low LOD of the Hg2+, Co2+, and Al3+ ions show its high potential in determining these ions in real water.

Role of Environmental Toxicants on Neurodegenerative Disorders

Neurodegeneration leads to the loss of structural and functioning components of neurons over time. Various studies have related neurodegeneration to a number of degenerative disorders. Neurological repercussions of neurodegeneration can have severe impacts on the physical and mental health of patients. In the recent past, various neurodegenerative ailments such as Alzheimer’s and Parkinson’s illnesses have received global consideration owing to their global occurrence. Environmental attributes have been regarded as the main contributors to neural dysfunction-related disorders. The majority of neurological diseases are mainly related to prenatal and postnatal exposure to industrially produced environmental toxins. Some neurotoxic metals, like lead (Pb), aluminium (Al), Mercury (Hg), manganese (Mn), cadmium (Cd), and arsenic (As), and also pesticides and metal-based nanoparticles, have been implicated in Parkinson’s and Alzheimer’s disease. The contaminants are known for their ability to produce senile or amyloid plaques and neurofibrillary tangles (NFTs), which are the key features of these neurological dysfunctions. Besides, solvent exposure is also a significant contributor to neurological diseases. This study recapitulates the role of environmental neurotoxins on neurodegeneration with special emphasis on major neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease.

Pharmacological evaluation of bromelain in mouse model of Alzheimer's disease

The current study elucidates pharmacological evaluation of bromelain as a bioactive compound obtain from pineapple stem belongs to family Bromeliaceae in AlCl3 and D - galactose induced mice. In mice, co-administration of AlCl3 at dose 5 mg/kg b.w., via the oral route, and D - galactose at dose 60 mg/kg b.w., via intraperitoneal route for 90 days resulted in cognitive impairment, spatial learning, and memory deficits, as well as neurotoxicity. However, 30 consecutive days, treatments via an intraperitoneal route with bromelain low dose (Brm L) at dose 10 mg/kg b.w., bromelain high dose (Brm H) at dose 20 mg/kg b.w., donepezil (Dnpz) at dose 2 mg/kg b.w., and Brm L + Dnpz at doses 10, 2 mg/kg b.w. were considerably reversed the effect of AlCl3 and D - galactose induced AD mice. Consequences of behavioral parameters (Morris water maze, elevated plus maze and locomotor), biochemical estimation (MDA, GSH, SOD, CAT, Nitrite and AChE), and ELISA tests (mouse BACE, Aβ1 - 42, TNF-α, IL-6, and BDNF) confirmed significant (p < 0.05) neuroprotective effect of treatments in AlCl3 and D - galactose induced mice. Additionally, hematoxylin and eosin staining of the cerebral cortex and the hippocampus exposed eosinophilic lesions and hyperchromatic nuclei in AD mice, but these neurodegenerative effects were eliminated by Brm L, Brm H, Dnpz, and Brm L + Dnpz treatments. Thus, bromelain alone and in combination with donepezil prevent AlCl3 and D - galactose induced spatial learning and memory deficits, as well as cognitive impairment, by increasing cholinergic activity and synaptic plasticity, as well as reducing oxidative damage, neuroinflammation, Aβ 1-42 aggregations, and histopathological damage, according to our findings. The present study consequences indicate that bromelain alone and in combination with donepezil appears to have neuroprotective properties. Henceforward, this may be a promising treatment option for Alzheimer's disease.

Honey bee (Apis mellifera ligustica) acetylcholinesterase enzyme activity and aversive conditioning following aluminum trichloride exposure

Background

Aluminum is the third most prevalent element in the earth’s crust. In most conditions, it is tightly bound to form inaccessible compounds, however in low soil pH, the ionized form of aluminum can be taken up by plant roots and distributed throughout the plant tissue. Following this uptake, nectar and pollen concentrations in low soil pH regions can reach nearly 300 mg/kg. Inhibition of acetylcholinesterase (AChE) has been demonstrated following aluminum exposure in mammal and aquatic invertebrate species. In honey bees, behaviors consistent with AChE inhibition have been previously recorded; however, the physiological mechanism has not been tested, nor has aversive conditioning.

Results

This article presents results of ingested aqueous aluminum chloride exposure on AChE as well as acute exposure effects on aversive conditioning in an Apis mellifera ligustica hive. Contrary to previous findings, AChE activity significantly increased as compared to controls following exposure to 300 mg/L Al3+. In aversive conditioning studies, using an automated shuttlebox, there were time and dose-dependent effects on learning and reduced movement following 75 and 300 mg/L exposures.

Conclusions

These findings, in comparison to previous studies, suggest that aluminum toxicity in honey bees may depend on exposure period, subspecies, and study metrics. Further studies are encouraged at the moderate-high exposure concentrations as there may be multiple variables that affect toxicity which should be teased apart further.

Nanocurcumin, Promising Potential Protective Agent Against Histopathological Damage in the Cerebral Cortex of Mice Induced by Aluminum Chloride

&lt;b&gt;Background and Objective:&lt;/b&gt; Aluminum (Al) is widely used in many aspects of daily life, such as food packaging, cooking utensil components, food additives, cosmetics and water distillation. This study aimed to evaluate the protective role of nanocurcumin on the cerebral cortex of one and two-month-old mice exposed to 200 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; b.wt., aluminium. &lt;b&gt;Materials and Methods:&lt;/b&gt; The Swiss Webster mice were used in this study. The control group only received sterile distilled water, the Al group was administered 200 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; b.wt., of AlCl&lt;sub&gt;3&lt;/sub&gt; solution and the Al+Na Cur group was administered 200 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; b.wt., AlCl&lt;sub&gt;3&lt;/sub&gt;+200 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; nanocurcumin by intraperitoneal injection. The nanocurcumin was administered one hour after AlCl&lt;sub&gt;3 &lt;/sub&gt;exposure and then on days 0, 3, 6, 9, 12, 15, 18, 21, 24, 27 and 30. All the mice were anaesthetized and their brains were collected and fixed in a neutral formalin buffer solution for histological analysis. The paraffin method was used in this study. &lt;b&gt;Results:&lt;/b&gt; The death of granular neuron cells and karyolysis cells and the vacuolation of the pyramid cell layer of the cerebral cortex could be prevented by the intraperitoneal administration of nanocurcumin. The effect of nanocurcumin administration on the Al group at two months of age was more effective than on the Al group at one month of age. &lt;b&gt;Conclusion:&lt;/b&gt; Nanocurcumin can be a promising candidate protective agent against cerebral cortex changes after aluminium administration.

In Vitro and In Silico Kinetic Studies of Patented 1,7-diEthyl and 1,7-diMethyl Aminoalkanol Derivatives as New Inhibitors of Acetylcholinesterase

Two aminoalkanol derivatives of 1,7-diEthyl-8,9-diphenyl-4azatricyclo (5.2.1.02.6) dec-8-ene-3,5,10-trione and two derivatives of 1,7-diMethyl-8,9-diphenyl-4-azatricyclo (5.2.1.02.6) dec-8-ene-3,5,10-trione were evaluated in vitro for their inhibition efficacy of acetylcholinesterase. The Km, Vmax, slope angles of Lineweaver-Burk plots, Ki and IC50 values showed that all four aminoalkanol derivatives are competitive inhibitors of acetylcholinesterase whose inhibitory potency depends, to a varying extent, on the nature of the four different substituents present in the main compound structure. Studies have shown that the most potent acetylcholinesterase inhibitors are derivatives containing isopropylamine and/or methyl substituents in their structure. In contrast, dimethylamine and/or ethyl substituents seem to have a weaker, albeit visible, effect on the inhibitory potency of acetylcholinesterase. Additionally, docking studies suggest that studied compounds binds with the peripheral anionic site and not enter into the catalytic pocket due to the presence of the sterically extended substituent.

JM-20 treatment prevents neuronal damage and memory impairment induced by aluminum chloride in rats

The number of people with dementia worldwide is estimated at 50 million by 2018 and continues to rise mainly due to increasing aging and population growth. Clinical impact of current interventions remains modest and all efforts aimed at the identification of new therapeutic approaches are therefore critical. Previously, we showed that JM-20, a dihydropyridine-benzodiazepine hybrid molecule, protected memory processes against scopolamine-induced cholinergic dysfunction. In order to gain further insight into the therapeutic potential of JM-20 on cognitive decline and Alzheimer's disease (AD) pathology, here we evaluated its neuroprotective effects after chronic aluminum chloride (AlCl3) administration to rats and assessed possible alterations in several types of episodic memory and associated pathological mechanisms. Oral administration of aluminum to rodents recapitulates several neuropathological alterations and cognitive impairment, being considered a convenient tool for testing the efficacy of new therapies for dementia. We used behavioral tasks to test spatial, emotional- associative and novel object recognition memory, as well as molecular, enzymatic and histological assays to evaluate selected biochemical parameters. Our study revealed that JM-20 prevented memory decline alongside the inhibition of AlCl3 -induced oxidative stress, increased AChE activity, TNF-α and pro-apoptotic proteins (like Bax, caspase-3, and 8) levels. JM-20 also protected against neuronal damage in the hippocampus and prefrontal cortex. Our findings expanded our understanding of the ability of JM-20 to preserve memory in rats under neurotoxic conditions and confirm its potential capacity to counteract cognitive impairment and etiological factors of AD by breaking the progression of key steps associated with neurodegeneration.

Effects of aluminum chloride and coenzyme Q10 on the molecular structure of lipids and the morphology of the brain hippocampus cells

Aluminum chloride (AlCl3) is a neurotoxic substance, while coenzyme Q10 (CoQ10) is considered a lipid antioxidant. Herein, their effects on the molecular structure of lipids and the morphology of the hippocampus brain tissue were investigated. Three groups of Wistar albino male rats were used in this study. For four weeks, one group was kept as a control group; the second group was given AlCl3; the third group was given AlCl3/CoQ10. Fourier transform infrared (FTIR) and histopathological examinations were utilized to estimate alterations in the molecular structure of the lipids and the cell morphology, respectively. The FTIR spectra revealed considerable decreases in the CH contents and alterations in the molecular ratios of olefinic[double bond, length as m-dash]CH/νas(CH3), νas(CH2)/νas(CH3), and νas(CH2)/[νas(CH2) + νs(CH2)] in the group given AlCl3. However, no significant changes were detected in those rats given AlCl3/CoQ10. Histopathology images uncovered shrinking and dark centers in the pyramidal cells of brain tissue hippocampal cells. The diameters of the pyramidal cells were estimated to be 4.81 ± 0.55 μm, 4.04 ± 0.71 μm, and 4.63 ± 0.71 μm for the control, AlCl3, and AlCl3/CoQ10 groups, respectively. The study showed that the AlCl3 could cause a shrinking of around 16% in the hippocampus pyramidal cells; besides, CoQ10 is a powerful therapeutic antioxidant to help restore the hippocampal neurons to a regular state.

Pomegranate juice reverses AlCl3-Induced neurotoxicity and improves learning and memory in female mice

BACKGROUND

Aluminum is a neurotoxic element that can accumulate in the brain and cause neurodegenerative disorders. In addition, the antioxidants found in pomegranate juice (PJ) are much more than those existing in other fruits. It was proven to provide protection against neurodegenerative diseases.

OBJECTIVES

This experiment aimed to clarify the amelioration efficiency of PJ against aluminum chloride-induced neurobehavioral and biochemical disorders in female mice.

METHODS

The female mice were given oral administrations for 35 days as follows. The control group received tap water, the PJ groups received 20% and 40% pomegranate juice, the aluminum chloride (AlCl₃) group was treated with 400 mg/kg AlCl₃, and the last two groups received AlCl₃ + 20% PJ and AlCl₃ + 40% PJ, respectively. The neurobehavioral features were assessed by shuttle box, T-maze, and Morris water maze devices. Furthermore, the neurotransmitters and oxidative indicators in the brains of the female mice were determined at the end of experiment.

RESULTS

Significant effects of AlCl₃ were observed on female mice in the body weight, during the behavioral tasks (shuttle box, T-maze, and Morris water maze), and in neurotransmitters and oxidative stress parameters. Pomegranate juice, especially at low concentrations, induced remarkable improvements in body weight, spatial memory and learning during T-maze, Morris water maze and shuttle box tasks, as well as in neurotransmitters and oxidative biomarkers in the AlCl₃-treated female mice.

CONCLUSION

PJ reversed AlCl₃-induced neurotoxicity and improved learning and memory in female mice. However, PJ contains a group of antioxidants that may be considered double-edged swords in the cellular redox status especially at high doses.

Exposure to aluminium causes behavioural alterations and oxidative stress in the brain of adult zebrafish

Aluminium (Al) water pollution is an increasing environmental problem. Accordingly, this study aimed to find out more about its toxic effects on aquatic organisms. Adult zebrafish were exposed to 11 mg/L of Al and the behavioural responses and its correlation with brain oxidative stress, antioxidant-defences, changes in metabolism and neurotransmission were assessed at 10, 15 and 20 days of exposure. The behavioural and locomotory responses, suggest an increase in the anxiety state, especially observed in animals exposed to Al for 15 days. The reactive oxygen species increased in a time-dependent trend, while the oxidative damage varied over exposure time. The activity of antioxidant enzymes, as superoxide dismutase, glutathione peroxidase and glutathione S-transferases, and the metallothioneins levels increased after short-term exposures and tended to decrease or stabilize at longer times. The results contribute to understand the toxic mechanisms activated by Al highlighting correlations like behavioural disorders and oxidative state.

Neuroprotective effects of ononin against the aluminium chloride-induced Alzheimer's disease in rats

Alzheimer’s disease (AD) is a chronic neurodegenerative disease categorized by the deficiency in the cognition and memory. Approximately 50 million peoples has the AD, which is categorized by the deficiency in the cognition, memory and other kinds of cognitive dissention. The present exploration was designed to unveil the ameliorative properties of ononin against the aluminium chloride (AlCl3)-provoked AD in animals via the suppression of oxidative stress and neuroinflammation. AD was provoked to the Sprague Dawley rats through administering orally with 0.5 ml/100 g b.wt. of AlCl3 25 days and then supplemented with the 30 mg/kg of ononin orally for 25th day to 36th day. The behavioural changes were examined using open field and Morris Water Maze test. The acetylcholine esterase (AChE) activity was studied by standard method. The status of Aβ1-42, MDA, SOD, total antioxidant capacity (TAC) were quantified using respective assay kits. The interleukin(IL)-1β and TNF-α, BDNF, PPAR-γ, p38MAPK, and NF-κB/p65 status was quantified using respective assay kits. Brain histology was studied using microscope. The ononin treatment effectively modulated the AlCl3-triggered behavioural alterations in the AD animals. Ononin appreciably suppressed the AChE, Aβ1-42, and MDA and improved the SOD and TAC in the brain tissues of AD animals. The status of IL-1β, TNF-α, p38MAPK, and NF-κB were suppressed and the BDNF and PPAR-γ contents were elevated in the brain tissues of AD animals. The outcomes brain histology analysis proved the attenuate role of ononin. Our findings recommended that the ononin treatment could ameliorate the cognitive impairment, suppress the neuroinflammation and oxidative stress in the AD animals.

Acute aluminum phosphide poisoning: The menace of phosphine exposure

Aluminum phosphide (AlP) is a popular fumigant used widely for the safe storage of food grain. Although A1P is free from toxic residues, it releases phosphine which acts on mitochondrial components of almost all types of pests. Unfortunately A1P is also a common suicidal agent in developing countries with no known antidote. In addition, accidental exposure to phosphine may also occur. AlP poisoning affects cardiac and vascular tissue directly and can result in multiorgan system failure leading to death in severe cases. There is no specific biomarker for diagnosing AlP poisoning and management depends on a high level of clinical suspicion. Although acetylcholinesterase has been suggested as a surrogate biomarker of AlP exposure, there are opposing views. In this review, we analyzed the relevant published material with emphasis on the need to recognize and explore the use of plasma mitochondrial enzyme activity as a potential biomarker for AlP exposure.

Evaluation of Cerebellar Function and Integrity of Adult Rats After Long-Term Exposure to Aluminum at Equivalent Urban Region Consumption Concentrations

High amounts of aluminum (Al) are found in soil and water. It is highly bioavailable, which makes it an important agent of environmental imbalance. Moreover, Al is considered a neurotoxic agent that is associated with several neurodegenerative diseases. Thus, this study investigated the effects of long-term Al chloride (AlCl₃) exposure on motor behavior, oxidative biochemistry, and cerebellar tissue parameters. For this, adult Wistar rats were divided into three groups: Al-D1 (8.3 mg kg^-1 day^-1), Al-D2 (5.2 mg kg^-1 day^-1), and control (distilled water); all groups were orally exposed for 60 days by intragastric gavage. After the exposure period, animals performed the open field, elevated plus maze, rotarod, and beam walking tests. Then, the blood and cerebellum were collected to evaluate Al levels and biochemical and morphological analyses, respectively. Our results demonstrate that animals exposed to Al doses presented a higher Al level in the blood. In the spontaneous locomotor activity, Al exposure groups had traveled a lower total distance when compared with the control group. There was no statistically significant difference (p > 0.05) between exposed and control groups when anxiogenic profile, forced locomotion, fine motor coordination/balance, pro-oxidative parameter, and density Purkinje cells were compared. Thus, aluminum exposure in equivalent doses to human consumption in urban regions did not promote significant changes in the cerebellum or motor parameters.

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.

Aluminum induced oxidative stress, astrogliosis and cell death in rat astrocytes, is prevented by curcumin

Aluminum (Al) is recognized potent neurotoxic metal, which causes oxidative stress leading to intracellular accumulation of reactive oxygen species (ROS) and neuronal cell death in various neurodegenerative diseases. Among several medicinal plants with beneficial effects on health, curcumin acts as a multi-functional drug with antioxidant activity. Thus, the purpose of the present study was to evaluate the protective effect of curcumin against aluminum induced-oxidative stress and astrocytes death, in vitro ad in vivo. Incubation of cultured rat astrocytes with two concentrations of Al (37 μM and 150 μM) for 1 h provoked a dose-dependent reduction of the number of living cells as evaluated by Fluorescein diacetate and lactate dehydrogenase assay. Al-treated cells exhibited a reduction of both superoxide dismutase (SOD) and catalase activities. Pretreatment of astrocytes with curcumin (81 μM) prevented Al-induced cell death. Regarding in vivo study, rats were exposed acutely during three consecutive days to three different doses of Al (25 mg/kg, 50 mg/kg and 100 mg/kg, i.p injection), together with curcumin treatment (30 mg/kg). For the chronic model, animals were exposed to Al (3 g/l) in drinking water from intrauterine age to 4 months ages, plus curcumin treatment (175 mg/kg). Data showed that both acute and chronic Al intoxication induced an obvious astrogliosis within motor cortex and hippocampus, while, such effects were restored by curcumin. We showed herein that Al was highly toxic, induced astrocytes death. Then, curcumin protected astrocytes against Al-toxicity. The cytoprotective potential of curcumin is initiated by stimulation of endogenous antioxidant system.

Critical Review of the Alzheimer's Disease Non-Transgenic Models: Can They Contribute to Disease Treatment?

Alzheimer's disease (AD) is a growing neurodegenerative disease without effective treatments or therapies. Despite the use of different approaches and an extensive variety of genetic amyloid based models, therapeutic strategies remain elusive. AD is characterized by three main pathological hallmarks that include amyloid-β plaques, neurofibrillary tangles, and neuroinflammatory processes; however, many other pathological mechanisms have been described in the literature. Nonetheless, the study of the disease and the screening of potential therapies is heavily weighted toward the study of amyloid-β transgenic models. Non-transgenic models may aid in the study of complex pathological states and provide a suitable complementary alternative to evaluating therapeutic biomedical and intervention strategies. In this review, we evaluate the literature on non-transgenic alternatives, focusing on the use of these models for testing therapeutic strategies, and assess their contribution to understanding AD. This review aims to underscore the need for a shift in preclinical research on intervention strategies for AD from amyloid-based to alternative, complementary non-amyloid approaches.

Protective role of functional food in cognitive deficit in young and senile rats

Cognitive decline and neurodegenerative diseases pose a significant burden on healthcare resources both in developed and developing countries which is a major socio-economic and healthcare concern. Alzheimer's disease is the most common form of progressive neurodegenerative dementia of the aged brain. Aluminum is a constituent of antacids, deodorants, kitchenware and food additives which allows easy access into the body posing risk to development of senile dementia of Alzheimer's type. Virgin coconut oil was declared as a potential cognitive strengthener. Assessment of cognitive and memory-enhancing effects of virgin coconut oil in senile and young rats to gain vital insights into its effective use in the prevention of neurodegeneration in dementia/Alzheimer's disease-like manifestations and alleviate cognitive dysfunction and learning impairment with neuronal damage imparted by daily oral intake of aluminum. Alzheimer's disease-like symptoms and memory impairment were experimentally induced using oral anhydrous aluminum chloride given daily for five successive weeks in young and old age albino rats. Treatment groups received virgin coconut oil to assess protection during the experimental period. Behavioral test, Morris water maze was conducted before/after induction/treatment. At the end of the experimental period, cholinergic, dopaminergic, noradrenergic and serotonergic neurotransmission as well as brain-derived neurotrophic factor were being investigated, in addition to immunochemical and histopathological examination of targeted brain regions. Virgin coconut oil significantly improved cholinergic activity and monoaminergic neurotransmission. Moreover, immunochemical and histopathological examination revealed marked protection with virgin coconut oil against aluminum-induced Alzheimer's disease-like pathology and cognitive deficit.

Fish Oil and Primrose Oil Suppress the Progression of Alzheimer's Like Disease Induced by Aluminum in Rats

The role of fish oil, primrose oil and their mixture in ameliorating the changes in Alzheimer's like model was evaluated in rats. Primrose oil and primrose/fish oil mixture fatty acids composition was assessed by gas chromatography. The rat experiment consisted of 5 groups; the first fed on balanced diet as control normal (CN); the other four groups treated with intraperitoneal aluminum lactate and consumed dyslipidemic diet; one group served as control Alzheimer's like disease (CA) while the other three groups (test groups) received daily oral dose from primrose oil, fish oil and primrose/fish oil mixture separately for 5 weeks. Results showed primrose oil and primrose/ fish oil mixture to contain gamma linolenic acid as 9.15 and 4.3% of total fatty acids, respectively. Eicosapentaenoic and docosahexaenoic were present as 10.9 and 6.5 %, respectively in the oil mixture. Dyslipidemia and increased erythrocyte sedimentation rate (ESR), plasma butyrylcholinesterase (BChE), brain malondialdehyde (MDA) and NO with decrease in plasma magnesium, brain catalase, reduced glutathione, body weight gain and brain weight were demonstrated in CA compared to CN. Brain histopathology and immuno-histochemistry showed neuronal degeneration and neurofibrillary tangles with elevated myeloperoxidase and nuclear factor-kappa B in CA compared to CN. The tested oils demonstrated neuro-protection reflected in the variable significant improvement of biochemical parameters, immuno-histochemistry and brain histopathology. Primrose/fish oil mixture was superior in reducing ESR, brain MDA, plasma activity of BChE and brain histopathological changes along with elevating plasma magnesium. Primrose/fish oil mixture and fish oil were more promising in improving plasma high density lipoprotein cholesterol (HDL-C) than primrose. Fish oil was the most efficient in improving plasma total cholesterol (T-C), low density lipoprotein cholesterol and T-C /HDL-C. Primrose/fish oil mixture and primrose oil were superior in elevating brain catalase compared to fish oil. Other parameters were equally improved by the different oil treatments. Primrose oil, fish oil and their mixture reduced the progression of Alzheimer's disease in rats with superiority to primrose/fish oil mixture.

Curcumin prevents the midbrain dopaminergic innervations and locomotor performance deficiencies resulting from chronic aluminum exposure in rat

Aluminum (Al) among the abundant metals on the earth crust, is able to cross the biological barriers via the gastrointestinal and lung tissues. Once in the body, this heavy metal accumulates in different organs, especially the central nervous system. Though its influence is evidently shown in the substantia nigra of Parkinson's disease patients and other brain areas in other neurodegenerative diseases, few studies have demonstrated that Al could trigger profound changes in neurotransmission systems including the dopaminergic (DAergic) system. A variety of medicinal plants may be prescribed in such contamination, including some culinary spices such as Curcumin (Cur). Several studies have proven Cur to exhibit a wide variety of biological and pharmacological activities, especially its antioxidant potential. Using the immunohistochemistry, of tyrosine hydroxylase (TH), in the midbrain substantia nigra pars compact (SNc) and the ventral tegmental area (VTA) and the open field test, we examined the DAergic system together with the locomotor behavior respectively in rats exposed chronically to Al (0,3%) in drinking water during 4 months since the intra-uterine age, as well as the neuroprotective effect of the concomitant administration of Cur I (30 mg/kg B.W) of chronic Al exposed rats. Our results have shown a significant decrease of TH immureactivity in both SNc and VTA associated to a loss of the number of crossed boxes, leading to a difficient locomotor performance in the Al group while Cur I prevents such TH immunoreactivity impairment and maintains a higher locomotor activity in the Al-CurI group. Our findings lead to suppose a powerful and obvious neuroprotective potential of CurI against Al-induced neurotoxicity of the DAergic system involved in the control of the locomotor behavior.

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.

Protective effects of low-intensity pulsed ultrasound on aluminum overload-induced cerebral damage through epigenetic regulation of brain-derived neurotrophic factor expression

In consideration of its noninvasive administration and endogenous stimulation property, the enhancement of brain-derived neurotrophic factor (BDNF) via low-intensity pulsed ultrasound (LIPUS) could be a novel strategy for aluminum (Al) overload-induced cerebral damage. LIPUS was pre-treated 7 days before concomitantly given with aluminum chloride (AlCl₃) daily for a period of 42 days. Morris water maze and elevated plus maze were performed to analyze spatial learning and memory. Western Blot and immunoprecipitation were used to detect BDNF and histone acetylation of histone H3 lysine 9 (H3K9) and histone H4 lysine 12 (H4K12) in the hippocampus. Assay of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-Px) indicated the extent of oxidative damages. Aluminium exposure in rats can cause attenuated spatial learning and memory, followed by up-regulated histone deacetylase 6 (HDAC6) expression, down-regulated H3K9 and H4K12 acetylation at the PIII and PIV promoter of BDNF, all of which will eventually inhibit BDNF expression. LIPUS can recover reduced cognitive function by restoring histone acetylation and BDNF expression, accompanied with increased SOD, GSH, and GSH-Px activity. LIPUS treatment might alleviate aluminium exposure-induced cognitive decline by acetylation regulation of BDNF expression and reducing oxidative stress in the hippocampus.

Effect of treated wastewater irrigation in East Central region of Tunisia (Monastir governorate) on the biochemical and transcriptomic response of earthworms Eisenia andrei

Treated wastewater (TWW) reuse for irrigation has become an excellent way to palliate water scarcity in Mediterranean arid regions. However, the toxicological effects of these effluents on the soil's organisms, especially earthworms, have not been well studied as yet. In this paper, earthworms Eisenia andrei were exposed for 7 days and 14 days to five agricultural soils irrigated with TWW for different periods: 1 year, 8 years, and 20 years. In addition, they were also exposed to soil from one reference site sampled from the Ouardenin perimeter in the Monastir Governorate in Tunisia. The effect on earthworms was assessed at the biochemical level by evaluating for catalase (CAT), glutathione-S-transferase (GST), malondialdehyde accumulation (MDA) and acetylcholinesterase inhibition (AChE). On the other hand, genotoxicity and transcriptomic responses were evaluated using micronuclei test (MNT) and gene expression level of CAT and GST. Moreover, metals uptake by earthworms was analyzed. Results showed that CAT and GST activity in the earthworm increased significantly when they were exposed to soils irrigated with TWW for 1, 8 and 20 years. Furthermore, MDA concentration also increased significantly with the increase in exposure period. However, AChE activity decreased and MNi frequency increased in earthworms after 7 and 14 days of exposure to soils irrigated with TWW for more than a year. The gene expression level of CAT and GST showed a significant variability, thus data are discussed in relation to the studied biomarkers (CAT and GST). These data provide new insights into the effect of toxicity of TWW on the soil's macro fauna, which is strongly affected by the trace elements and other organic compounds accumulated in soils after 20 years of TWW irrigation.

Enhanced luminescence for detection of small molecules based on doped lanthanide compounds with a dinuclear double-stranded helicate structure

A family of isostructural lanthanide compounds was explored and enhanced luminescence accomplished by doping. A novel and multifunctional fluorescence probe was developed, which was able to detect CH₃COOH, Al³⁺ and Cr₂O₇²⁻.

Acute aluminum chloride toxicity revisited: Study on DNA damage and histopathological, biochemical and neurochemical alterations in rat brain

AIMS

Due to rapid increase in industrialization in the last few years, use of aluminum (Al) and its alloys have been increased in different industrial fields. Ample evidence supports the neurotoxic effects of chronic aluminum chloride (AlCl₃) administration in rats but acute Al toxicity has been less described so the present study was aimed to investigate the neurotoxic effects of acute AlCl₃.

MAIN METHODS

To investigate such effects 12 male albino Wistar rats were randomly divided into control and test rats. AlCl₃ at a dose of 150 mg/kg was intraperitoneally injected to test rats for 7 days. Rats were subjected to behavioral assessments 24 h after last dose and after behavioral assessment rats were sacrificed to collect brain samples for further neurochemical, biochemical and histopathological examinations.

KEY FINDINGS

In the present study acute administration of AlCl₃ resulted in noticeable behavioral deficits. Cognitive deficits and neuropsychiatric disturbances were evident in AlCl₃ injected rats. Test rats also exhibited marked antioxidant enzymes, cholinergic, serotonergic and dopaminergic dysfunctions and DNA fragmentation. Histopathological alterations were observed in hippocampus and cortex of rats injected with AlCl₃.

SIGNIFICANCE

The observed effects may be due to pro-oxidant nature of Al and its participation in free radical mediated cellular injury. Al by promoting oxidative stress, impairing antioxidant defense system and altering brain neurochemistry may act as a potent neurotoxic agent as evident from observed histopathological alterations in brain of test rats. This investigation may further confirm and shed some more light on deleterious effects of acute Al intoxication on brain.

Neuroprotective Effect of Caryocar brasiliense Camb. Leaves Is Associated with Anticholinesterase and Antioxidant Properties

Pequi (Caryocar brasiliense) is an endemic species from Brazilian Cerrado, and their fruits are widely used in regional cuisine. In this work, a crude hydroalcoholic extract (CHE) of C. brasiliense leaves and its resulting fractions in hexane (HF), chloroform (CF), ethyl acetate (EAF), and butanol (BF) were investigated for their antioxidant properties and anticholinesterase activities. The antioxidant properties were evaluated by free radical scavenging and electroanalytical assays, which were further correlated with the total phenolic content and LC-MS results. The acetylcholinesterase and butyrylcholinesterase inhibitory activities were examined using Ellman's colorimetric method. The LC-MS analysis of EAF revealed the presence of gallic acid and quercetin. CHE and its fractions, EAF and BF, showed anticholinesterase and antioxidant activities, suggesting the association of both effects with the phenolic content. In addition, behavioral tests performed with CHE (10, 100, and 300 mg/kg) showed that it prevented mice memory impairment which resulted from aluminium intake. Moreover, CHE inhibited brain lipid peroxidation and acetyl and butyryl-cholinesterase activities and the extract's neuroprotective effect was reflected at the microscopic level. Therefore, the leaves of pequi are a potential source of phenolic antioxidants and can be potentially used in treatments of memory dysfunctions, such as those associated with neurodegenerative disorders.

Vitis vinifera acts as anti-Alzheimer's agent by modulating biochemical parameters implicated in cognition and memory

Background

Aluminum a known neuro and cholinotoxin has been implicated in the pathogenesis of Alzheimer’s disease. Its exposure is associated with impairment of the memory and cognition.

Objective

The present study was undertaken to evaluate the anti-Alzheimer’s activity of Vitis vinifera in aluminum induced Alzheimer’s disease.

Materials and methods

In this study, we investigated the behavioral and biochemical effects of aluminum in Sprague-Dawley rats. Animals were exposed to aluminum chloride (100 mg/kg/day) orally for a period of 8 weeks. Vitis was given in doses of 250 mg/kg and 500 mg/kg for 16 weeks and the possible effects of Vitis vinifera on the expression of Tau and amyloid precursor protein were evaluated by PCR analysis and the possible activities of lipid peroxidation, inflammation and anti-cholinesterase activity were evaluated.

Results

Aluminum intoxication was associated with significant impairment in learning and memory in Morris water maze test. A significant improvement was observed with Vitis vinifera in a dose dependent manner.

Conclusion

The findings of the present study revealed the significant neuroprotective actions of Vitis vinifera by modifying the biochemical parameters and inhibited the mRNA expression of Amyloid Precursor Protein and Tau, which are the key pathological hallmarks of Alzheimer’s disease, which was further confirmed by histopathological observations.

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.

Synergistic Effect of Quercetin and α-Lipoic Acid on Aluminium Chloride Induced Neurotoxicity in Rats

Objectives

The present study was carried out to study the protective effects of quercetin and α-lipoic acid alone and in combination against aluminum chloride induced neurotoxicity in rats.

Materials and Methods

The study consisted of eight groups, namely, Group 1: control rats, Group 2: rats receiving aluminium chloride 7 mg/kg body weight intraperitoneal route (i.p) for two weeks, Group 3: rats receiving quercetin 50 mg/kg body weight i.p. for two weeks, Group 4: rats receiving quercetin 50 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks, Group 5: rats receiving α-lipoic acid 20 mg/kg body weight i.p. for two weeks, Group 6: rats receiving lipoic acid 20 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks, Group 7: rats receiving α-lipoic acid 20 mg/kg body weight and quercetin 50 mg/kg body weight i.p. for two weeks, and Group 8: rats receiving α-lipoic acid 20 mg/kg body weight and quercetin 50 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks. The animals were killed after 24 hours of the last dose by cervical dislocation.

Results

Aluminium chloride treatment of rats resulted in significant increases in lipid peroxidation, protein carbonyl levels, and acetylcholine esterase activity in the brain. This was accompanied with significant decreases in reduced glutathione, activities of the glutathione reductase, and superoxide dismutase. Pretreatment of AlCl₃ exposed rats to either quercetin or α-lipoic acid also restored altered lipid peroxidation and superoxide dismutase to near normal levels. Quercetin or α-lipoic acid pretreatment of AlCl₃ exposed rats improved the protein carbonyl and reduced glutathione, glutathione reductase, and acetylcholine esterase activities in rat brains towards normal levels. Combined pretreatment of AlCl3 exposed rats with quercetin and α-lipoic acid resulted in a tendency towards normalization of most of the parameters.

Conclusions

Quercetin and α-lipoic acid complemented each other in protecting the rat brain against oxidative stress induced by aluminium chloride.

A novel covalent post-synthetically modified MOF hybrid as a sensitive and selective fluorescent probe for Al3+ detection in aqueous media

A modified MOF named UiO-66-NH₂-SA was synthesized based on the covalent post synthetic attachment of the MOFs (UiO-66-NH₂) and salicylaldehyde via a Schiff-base reaction. The as-prepared functionalized UiO-66-NH₂-SA not only maintains its structural integrity during the PSM process, but also shows excellent luminescence and good fluorescence stability in water. It was further utilized as a novel fluorescent probe for detecting of Al³⁺. The fluorescence intensity of UiO-66-NH₂-SA increased linearly upon increasing the concentration of Al³⁺ in the range of 0-500 μM with a detection limit of 6.98 μM. The possible mechanism is discussed. This study presents a new ratiometric and colorimetric Al³⁺ fluorescent sensor. The good fluorescence stability of UiO-66-NH₂-SA in aqueous media, the low detection limit and the broad linear in sensing Al³⁺ indicate its high potential in practical applications.

Aluminium oxide nanoparticles compromise spatial learning and memory performance in rats

Recently, the biosafety and potential influences of nanoparticles on central nervous system have received more attention. In the present study, we assessed the effect of aluminium oxide nanoparticles (Al2O3-NPs) on spatial cognition. Male Wistar rats were intravenously administered Al2O3-NP suspension (20 mg/kg body weight/day) for four consecutive days, after which they were assessed. The results indicated that Al2O3-NPs impaired spatial learning and memory ability. An increment in malondialdehyde levels with a concomitant decrease in superoxide dismutase activity confirmed the induction of oxidative stress in the hippocampus. Additionally, our findings showed that exposure to Al2O3-NPs resulted in decreased acetylcholinesterase activity in the hippocampus. Furthermore, Al2O3-NPs enhanced aluminium (Al) accumulation and disrupted mineral element homoeostasis in the hippocampus. However, they did not change the morphology of the hippocampus. Our results show a connection among oxidative stress, disruption of mineral element homoeostasis, and Al accumulation in the hippocampus, which leads to spatial memory deficit in rats treated with Al2O3-NPs.

Protective effects of kinetin against aluminum chloride and D-galactose induced cognitive impairment and oxidative damage in mouse

Increasing evidence indicates that aluminum exposure and oxidative stress play crucial roles in the initiation and development of Alzheimer's disease (AD). Aluminum chloride (AlCl₃) and d-galactose (d-gal) combined treatment of mice is considered as an easy and cheap way to obtain an animal model of AD. Kinetin is a plant cytokinin, which is also reported to exert neuro-protective effects in vivo and in vitro. Thus, in this study, neuro-protective effects of kinetin were investigated in an AD model of mice induced by AlCl₃ and d-gal. The Morris water maze (MWM) test was performed to directly evaluate neuro-protective effects of kinetin on the memory and spatial learning abilities, while the histopathological changes were examined by hematoxylin and eosin (H & E) staining method. To further investigate mechanisms involved, Al content in cortex and hippocampus was determined. In addition, related detection kits were used to determine acetylcholine (ACh) content and activity of acetylcholinesterase (AChE). Activities of anti-oxidative enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and the content of heme oxygenase-1 (HO-1) were also measured. Besides, the content of oxidative damage bio-markers including 8-iso-prostaglandin F (8-iso-PGF), advanced glycation end products (AGEs) and 8-hydroxy-2-deoxyguanosine (8-OHdG) were determined by ELISA kits. Finally, the distribution of beta-amyloid protein 1-42 (Aβ_1-42) was detected by immunohistochemistry (IHC), while the expression levels of amyloidogenic proteins including β-amyloid precursor protein (APP), β-secretase, γ-secretase and Aβ_1-42 were detected by western blotting (WB) method. Results showed that kinetin improved performance in MWM test, attenuated histopathological changes, reduced Al level in cortex and hippocampus, increased ACh content and decreased AChE activity. In addition, kinetin elevated activities of anti-oxidative enzymes and reduced the levels of oxidative damage biomarkers in AD model of mice. Furthermore, kinetin also increased the content of HO-1, and inhibited the distribution of Aβ_1-42 and the expressions of amyloidogenic proteins (APP, β-secretase, γ-secretase and Aβ_1-42) in brain tissue of AD mice. Our results indicate that kinetin has neuro-protective effects on the AD model of mice induced by AlCl₃ and d-gal, suggesting that kinetin may be a candidate drug for treatment of AD.

Aluminum-Induced Cholinergic Deficits in Different Brain Parts and Its Implications on Sociability and Cognitive Functions in Mouse

Aluminum is associated with etiology of many neurodegenerative diseases specially Alzheimer's disease. Chronic exposure to aluminum via drinking water results in aluminum deposition in the brain that leads to cognitive deficits. The study aimed to determine the effects of aluminum on cholinergic biomarkers, i.e., acetylcholine level, free choline level, and choline acetyltransferase gene expression, and how cholinergic deficit affects novel object recognition and sociability in mice. Mice were treated with AlCl₃ (250 mg/kg). Acetylcholine level, free choline level, and choline acetyltransferase gene expression were determined in cortex, hippocampus, and amygdala. The mice were subjected to behavior tests (novel object recognition and social novelty preference) to assess memory deficits. The acetylcholine level in cortex and hippocampus was significantly reduced in aluminum-treated animals, as compared to cortex and hippocampus of control animals. Acetylcholine level in amygdala of aluminum-treated animals remained unchanged. Free choline level in all the three brain parts was found unaltered in aluminum-treated mice. The novel object recognition memory was severely impaired in aluminum-treated mice, as compared to the control group. Similarly, animals treated with aluminum showed reduced sociability compared to the control mice group. Our study demonstrates that aluminum exposure via drinking water causes reduced acetylcholine synthesis in spite of normal free choline availability. This deficit is caused by reduced recycling of acetylcholine due to lower choline acetyltransferase level. This cholinergic hypofunction leads to cognitive and memory deficits. Moreover, hippocampus is the most affected brain part after aluminum intoxication.

Determination of Aluminum in Edible Jellyfish Using Chrome Azurol S with Spot Test on Filter Paper

Aluminum (Al) has been well known as an environmental factor that may affect several enzymes and other biomolecules related to Alzheimer's disease. The increasing use of Al in the preparation and storage of food currently represents the main form of Al exposure for the general public. The present study was aimed to develop a household procedure for the rapid test determination of Al in edible jellyfish. The method was developed based on the reaction of Chrome Azurol S with Al in acidic medium, forming a colored compound on the surface of filter paper. Experimental design methodologies were used to optimize the measurement conditions. The proposed method was applied successfully to the analysis of Al in edible jellyfish products in clinical laboratory and household settings.

Aluminium sulfate exposure: A set of effects on hydrolases from brain, muscle and digestive tract of juvenile Nile tilapia (Oreochromis niloticus)

Aluminium is a major pollutant due to its constant disposal in aquatic environments through anthropogenic activities. The physiological effects of this metal in fish are still scarce in the literature. This study investigated the in vivo and in vitro effects of aluminium sulfate on the activity of enzymes from Nile tilapia (Oreochromis niloticus): brain acetylcholinesterase (AChE), muscle cholinesterases (AChE-like and BChE-like activities), pepsin, trypsin, chymotrypsin and amylase. Fish were in vivo exposed during 14days when the following experimental groups were assayed: control group (CG), exposure to Al₂(SO₄)₃ at 1μg·mL^-1 (G1) and 3μg·mL^-1 (G3) (concentrations compatible with the use of aluminium sulfate as coagulant in water treatment). In vitro exposure was performed using animals of CG treatment. Both in vivo and in vitro exposure increased cholinesterase activity in relation to controls. The highest cholinesterase activity was observed for muscle BChE-like enzyme in G3. In contrast, the digestive enzymes showed decreased activity in both in vivo and in vitro exposures. The highest inhibitory effect was observed for pepsin activity. The inhibition of serine proteases was also quantitatively analyzed in zymograms using pixel optical densitometry as area under the peaks (AUP) and integrated density (ID). These results suggest that the inhibition of digestive enzymes in combination with activation of cholinesterases in O. niloticus is a set of biochemical effects that evidence the presence of aluminium in the aquatic environment. Moreover, these enzymatic alterations may support further studies on physiological changes in this species with implications for its neurological and digestive metabolisms.

Aluminum chloride induces neuroinflammation, loss of neuronal dendritic spine and cognition impairment in developing rat

Aluminum (Al) is present in the daily life of humans, and the incidence of Al contamination increased in recent years. Long-term excessive Al intake induces neuroinflammation and cognition impairment. Neuroinflammation alter density of dendritic spine, which, in turn, influence cognition function. However, it is unknown whether increased neuroinflammation is associated with altered density of dendritic spine in Al-treated rats. In the present study, AlCl3 was orally administrated to rat at 50, 150 and 450 mg/kg for 90d. We examined the effects of AlCl3 on the cognition function, density of dendritic spine in hippocampus of CA1 and DG region and the mRNA levels of IL-1β, IL-6, TNF-α, MHC II, CX3CL1 and BNDF in developing rat. These results showed exposure to AlCl3 lead to increased mRNA levels of IL-1β, IL-6, TNF-α and MCH II, decreased mRNA levels of CX3CL1 and BDNF, decreased density of dendritic spine and impaired learning and memory in developing rat. Our results suggest AlCl3 can induce neuroinflammation that may result in loss of spine, and thereby leads to learning and memory deficits.

Understanding Aspects of Aluminum Exposure in Alzheimer's Disease Development

Aluminum is a ubiquitously abundant nonessential element. Aluminum has been associated with neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis, and dialysis encephalopathy. Many continue to regard aluminum as controversial although increasing evidence supports the implications of aluminum in the pathogenesis of AD. Aluminum causes the accumulation of tau protein and Aβ protein in the brain of experimental animals. Aluminum induces neuronal apoptosis in vivo and in vitro, either by endoplasmic stress from the unfolded protein response, by mitochondrial dysfunction, or a combination of them. Some, people who are exposed chronically to aluminum, either from through water and/or food, have not shown any AD pathology, apparently because their gastrointestinal barrier is more effective. This article is written keeping in mind mechanisms of action of aluminum neurotoxicity with respect to AD.

Response of biochemical biomarkers in the aquatic crustacean Daphnia magna exposed to silver nanoparticles

The proliferation of silver nanoparticle (AgNP) production and use owing to their antimicrobial properties justifies the need to examine the resulting environmental impacts. The discharge of biocidal nanoparticles to water bodies may pose a threat to aquatic species. This study evaluated the effects of citrate-coated AgNPs on the standardized test organism Daphnia magna Straus clone MBP996 by means of biochemical biomarker response. AgNP toxicity was compared against the toxic effect of Ag(+). The toxicity endpoints were calculated based upon measured Ag concentrations in exposure media. For AgNPs, the NOAEC and LOAEC values at 48 h were 5 and 7 μg Ag/L, respectively, while these values were 0.5 and 1 μg Ag/L, respectively, for Ag(+). The EC50 at 48 h was computed to be 12.4 ± 0.6 and 2.6 ± 0.1 μg Ag/L for AgNPs and Ag(+), respectively, with 95 % confidence intervals of 12.1-12.8 and 2.3-2.8 μg Ag/L, respectively. These results indicate significant less toxicity of AgNP compared to free Ag(+) ions. Five biomarkers were evaluated in Daphnia magna neonates after acute exposure to Ag(+) or AgNPs, including glutathione (GSH) level, reactive oxygen species (ROS) content, and catalase (CAT), acetylcholinesterase (AChE), and superoxide dismutase (SOD) activity. AgNPs induced toxicity and oxidative stress responses in D. magna neonates at tenfold higher concentrations than Ag. Biochemical methods revealed a clear increase in AChE activity, decreased ROS level, increased GSH level and CAT activity, but no significant changes in SOD activity. As Ag(+) may dissolve from AgNPs, these two types of Ag could act synergistically and produce a greater toxic response. The observed remarkably high toxicity of AgNPs (in the parts-per-billion range) to crustaceans indicates that these organisms are a vulnerable link in the aquatic food chain with regard to contamination by nanosilver. Graphical Abstract ᅟ.