How aluminum, an intracellular ROS generator promotes hepatic and neurological diseases: the metabolic tale

The cytotoxic/genotoxic role of impurities in soluble minerals: The case of natural (fibrous epsomite) versus synthetic (Epsom salt) magnesium sulphate

Epsomite and Epsom salt are very common mineral phases, and many known uses are found in agriculture, and in food and pharmaceutical industries. Natural epsomite can be fibrous and inhalable, potentially reaching the digestive tract after dissolving in mucus and saliva. Epsom salt is a common food additive (E 518) to which humans can be exposed daily, although its health effects are still debated. This study aims to (i) determine if natural epsomite (MP) and Epsom salt (SE) may be toxic to humans and (ii) identify and quantify the impurities in natural epsomite and try to ascertain their role in the toxicity of this mineral. In vitro experiments were performed on human colon epithelial cancer cells (Caco-2), enterocyte-like Caco-2-derived monolayers, human monocytic cell line THP-1, and THP-1-derived M0 macrophages. Generally, MP showed significantly higher toxicity in terms of oxidative stress, DNA damage and inflammation than SE, whose effects can be considered negligible. The higher pathogenicity of MP undoubtedly comes from the toxic elements of impurities, which are absent in pure SE. This research clarifies the role of impurities in the toxicity of natural epsomite, which may be higher than previously supposed. Moreover, considering its extensive use in the food industry, it represents a new step in assessing the safety of ingesting magnesium sulphate.

Potential protection of resveratrol-tempeh against nephrotoxic and hepatotoxic histological damage in mice induced by aluminum

Aluminum is a widely distributed metal that, while generally safe at low levels, can become toxic when accumulated in the body. Its exposure is daily through various sources, including food, water, and medications. High levels of aluminum have been shown to adversely affect the kidneys and liver, leading to significant organ damage. Resveratrol-tempeh is a safe protective agent against organ damage caused by aluminum. Here, we investigated the impact of resveratrol on liver and kidney toxicity and Al-induced levels of catalase and malondialdehyde. The mice group was the control group, Al-group, Al+REST5-group, and Al+REST10-group. Aluminum and resveratrol were administered intraperitoneally to mice for four weeks, but resveratrol was administered one hour after exposure to aluminum. Mice were killed by cervical dislocation; the liver and kidney were isolated for slide, and the level of an antioxidant enzyme of catalase and oxidant of malondialdehyde was measured. The results showed that administration of aluminum at a dose of 200 mg/kg body weight caused glomerular shrinkage and proximal tubule degeneration in the kidneys. In addition, it also caused liver tissue damage, with hepatocytes undergoing degeneration, sinusoids dilating, and decreased body weight in the mice. Administration of resveratrol-tempeh tended to decrease malondialdehyde levels and increase catalase activity, although the changes were not significant. It seems that resveratrol-tempeh can repair liver and kidney damage and restore them to normal conditions. Conclusion: Aluminum at 200 mg/kg is toxic to mice. Resveratrol-tempeh can be considered a potential candidate to protect kidney and liver damage caused by aluminum chloride toxicity.

Toxicity and inflammatory potential of mineral fibres: The contribute of released soluble metals versus cell contact direct effects

Asbestos fibres have been considered an environmental hazard for decades. However, little is known about the attempts of circulating immune cells to counteract their toxicity. We addressed the early effects of fibre-released soluble factors (i.e. heavy metals) in naïve immune cells, circulating immediately below the alveolar/endothelial cell layer. By comparison, the direct fibre effects on endotheliocytes were also studied since these cells are known to sustain inflammatory processes. The three mineral fibres analysed showed that mainly chrysotile (CHR) and erionite (ERI) were able to release toxic metals in extracellular media respect to crocidolite (CRO), during the first 24 h. Nevertheless, all three fibres were able to induce oxidative stress and genotoxic damage in indirectly challenged naïve THP-1 monocytes (separated by a membrane). Conversely, only CHR-released metal ions induced apoptosis, NF-κB activation, cytokines and CD163 gene overexpression, indicating a differentiation towards the M0 macrophage phenotype. On the other hand, all three mineral fibres in direct contact with HECV endothelial cells showed cytotoxic, genotoxic and apoptotic effects, cytokines and ICAM-I overexpression, indicating the ability of these cells to promote an inflammatory environment in the lung independently from the type of inhaled fibre. Our study highlights the different cellular responses to mineral fibres resulting from both the nature of the cells and their function, but also from the chemical-physical characteristics of the fibres. In conclusion, CHR represented the main pro-inflammatory trigger, able to recruit and activate circulating naïve monocytes, through its released metals, already in the first 24 h after inhalation.

Aluminum exposure impairs oocyte quality via subcellular structure disruption and DNA damage-related apoptosis in mice

Aluminum (Al) can lead to an exposure of creature in varieties ways for its universality, and it could disturb normal physiological metabolism, with the damage to multisystem including reproduction. Since the oocyte quality is critical for female reproduction, we inspected the toxicity of Al on mouse oocyte maturation. We constructed in vitro exposure mouse model, and we found that 5 mmol/L Al had adverse effects on oocyte maturation by impairing organelle and cytoskeleton. Aberrant spindle and misaligned chromosomes which might be considered to be caused by elevated levels of acetylation, as well as abnormal distribution of actin dynamics could hinder normal meiosis of oocytes. Organelle dysfunction indicated that Al affected proteins synthesis, transport and digestion, which would further damage oocyte maturation. In order to explore the mechanism of Al toxicity, our further investigation demonstrated that Al caused mitochondrial dysfunction and imbalance calcium homeostasis, resulting in limited energy supply. Moreover, high level of reactive oxygen species, DNA damage and apoptosis caused by oxidative stress were also the manifestation of Al toxicity on oocytes. In conclusion, our study provided the evidence that Al exposure affected oocyte quality through its effects on spindle organization, actin dynamics, organelle function and the induction of DNA damage-related apoptosis with mouse model.

Hepatocellular degeneration in mice co-exposed to in-utero aluminium and cadmium: Implication of a disordered antioxidant and energy homeostatic response in the liver

The current study comprised four groups of pregnant animals viz; Control (CTR) received 10 ml/kg of normal saline, Al:10 mg/kg of AlCl3, Cd: 1.5 mg/Kg of CdCl2 Al+Cd; 10 mg/kg of AlCl3 and 1.5 mg/Kg of CdCl2. Treatment was done from pregnancy days (PNT) 7-20. After delivery, male animals were weaned on PSD 21 and sacrificed on PSD 78. From the study significant increases on serum liver enzymes in the group exposed to Cd and that exposed to Al+Cd were observed. The study further showed altered serum and hepatic antioxidant balance for the Cd, Al and Al+Cd groups compared to control. Similarly, lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) activities in the liver were elevated in Cd and Al+Cd groups while an altered liver histological feature in treated groups were also observed. it was concluded that in utero co-exposure to Al and Cd had the ability to alter hepatic functional indices.

Rutin, Puerarin and Silymarin Regulated Aluminum-Induced Imbalance of Neurotransmitters and Metal Elements in Brain of Rats

Non-specifically binding of aluminum to various substances in the organism can result in toxicity. The accumulation of large amounts of aluminum can cause an imbalance in metal homeostasis and interfere with the synthesis and release of neurotransmitters. Flavonoids have strong metal chelating activity, which can reduce damage to the central nervous system. The purpose of this study was to investigate the protective effect of three representative flavonoids, rutin, puerarin and silymarin, on the brain toxicity induced by long-term exposure to aluminum trichloride (AlCl3). Sixty-four Wistar rats were randomly divided into eight groups (n = 8). The rats in six intervention groups were given 100 or 200 mg/kg BW/day of three different flavonoids for four weeks after a 4-week exposure to 281.40 mg/kg BW/day AlCl3·6H2O, while the rats in the AlCl3-toxicity and control groups were given the vehicle after the period of AlCl3 exposure. The results showed that rutin, puerarin, and silymarin could increase the concentrations of magnesium, iron, and zinc in the brains of the rats. Moreover, the intake of these three flavonoids regulated the homeostasis of amino acid neurotransmitters and adjusted the concentrations of monoamine neurotransmitters to normal levels. Taken together, our data suggest that rutin, puerarin, and silymarin could ameliorate AlCl3-induced brain toxicity in the rats by regulating imbalance of metal elements and neurotransmitters in the brains of rats.

Cleavage and Noncleavage Chemistry in Reactive Oxygen Species (ROS)-Responsive Materials for Smart Drug Delivery

The design and development of advanced drug delivery systems targeting reactive oxygen species (ROS) have gained significant interest in recent years for treating various diseases, including cancer, psychiatric diseases, cardiovascular diseases, neurological diseases, metabolic diseases, and chronic inflammations. Integrating specific chemical bonds capable of effectively responding to ROS and triggering drug release into the delivery system is crucial. In this Review, we discuss commonly used conjugation linkers (chemical bonds) and categorize them into two groups: cleavable linkers and noncleavable linkers. Our goal is to clarify their unique drug release mechanisms from a chemical perspective and provide practical organic synthesis approaches for their efficient production. We showcase numerous significant examples to demonstrate their synthesis routes and diverse applications. Ultimately, we strive to present a comprehensive overview of cleavage and noncleavage chemistry, offering insights into the development of smart drug delivery systems that respond to ROS.

Environmental pollutants induce NLRP3 inflammasome activation and pyroptosis: Roles and mechanisms in various diseases

Environmental pollution is changing with economic development. Most environmental pollutants are characterized by stable chemical properties, strong migration, potential toxicity, and multiple exposure routes. Harmful substances are discharged excessively, and large quantities of unknown new compounds are emerging, being transmitted and amplifying in the food chain. The increasingly severe problems of environmental pollution have forced people to re-examine the relationship between environmental pollution and health. Pyroptosis and activation of the NLRP3 inflammasome are critical in maintaining the immune balance and regulating the inflammatory process. Numerous diseases caused by environmental pollutants are closely related to NLRP3 inflammasome activation and pyroptosis. We intend to systematically explain the steps and important events that are common in life but easily overlooked by which environmental pollutants activate the NLRP3 inflammasome and pyroptosis pathways. This comprehensive review also discusses the interaction network between environmental pollutants, the NLRP3 inflammasome, pyroptosis, and diseases. Thus, research progress on the impact of decreasing oxidative stress levels to inhibit the NLRP3 inflammasome and pyroptosis, thereby repairing homeostasis and reshaping health, is systematically examined. This review aims to deepen the understanding of the impact of environmental pollutants on life and health and provide a theoretical basis and potential programs for the development of corresponding treatment strategies.

Animal models of Alzheimer's disease: An originof innovativetreatments and insight to the disease's etiology

Alzheimer's disease (AD) is a progressive neurodegenerative disorder. The main pathogenic features are the development and depositionof senile plaques and neurofibrillary tangles in brain. Recent developments in the knowledge of the pathophysiological mechanisms behind Alzheimer's disease and other cognitive disorders have suggested new approaches to treatment development. These advancements have been significantly aided by the use of animal models, which are also essential for the assessment of therapies. Various approaches as transgenic animal model, chemical models, brain injury are used. This review will presentAD pathophysiology and emphasize several Alzheimer like dementia causingchemical substances, transgenic animal model and stereotaxy in order to enhance our existing knowledge of their mechanism of AD induction, dose, and treatment duration.

Assessment of Anti-Alzheimer Pursuit of Jambolan Fruit Extract and/or Choline against AlCl3 Toxicity in Rats

Jambolan fruit extract and choline were investigated for Aluminum tri chloride (AlCl₃)-induced Alzheimer's disease in rats. Thirty-six male "Sprague Dawley" rats weighing (150 ± 10 g) were allocated into six groups; the first group was fed a baseline diet and served as a negative control. Alzheimer's disease (AD) was induced in Group 2 rats by oral administration of AlCl₃ (17 mg/kg body weight) dissolved in distilled water (served as a positive control). Rats in Group 3 were orally supplemented concomitantly with both 500 mg/kg BW of an ethanolic extract of jambolan fruit once daily for 28 days and AlCl₃ (17 mg/kg body weight). Group 4: Rivastigmine (RIVA) aqueous infusion (0.3 mg/kg BW/day) was given orally to rats as a reference drug concomitantly with oral supplementation of AlCl₃ (17 mg/kg body weight) for 28 days. Group 5 rats were orally treated with choline (1.1 g/kg) concomitantly with oral supplementation of AlCl₃ (17 mg/kg body weight). Group 6 was given 500 mg/kg of jambolan fruit ethanolic extract and 1.1 g/kg of choline orally to test for additive effects concurrently with oral supplementation of AlCl₃ (17 mg/kg bw) for 28 days. Body weight gain, feed intake, feed efficiency ratio, and relative brain, liver, kidney, and spleen weight were calculated after the trial. Brain tissue assessment was analyzed for antioxidant/oxidant markers, biochemical analysis in blood serum, a phenolic compound in Jambolan fruits extracted by high-performance liquid chromatography (HPLC), and histopathology of the brain. The results showed that Jambolan fruit extract and choline chloride improved brain functions, histopathology, and antioxidant enzyme activity compared with the positive group. In conclusion, administering jambolan fruit extract and choline can lower the toxic impacts of aluminum chloride on the brain.

Celastrol and thymoquinone alleviate aluminum chloride-induced neurotoxicity: Behavioral psychomotor performance, neurotransmitter level, oxidative-inflammatory markers, and BDNF expression in rat brain

Exposure to aluminum chloride (AlCl₃) induces progressive multiregional neurodegeneration in animal models by promoting oxidative stress and neuroinflammation. The current study was designed to assess the potential efficacy of the natural antioxidants celastrol and thymoquinone (TQ) for alleviating AlCl₃-induced psychomotor abnormalities and oxidative-inflammatory burden in male albino rats. Four treatment groups were compared: (i) a vehicle control group, (ii) a AlCL₃ group receiving daily intraperitoneal (i.p.) injection of AlCl₃ (10 mg/kg) for 6 weeks, (iii) a AlCl₃ plus TQ (10 mg/kg, i.p.) cotreatment group, and (iv) a AlCl₃ plus celastrol (1 mg/kg, i.p.) cotreatment group. Open-field, rotarod, and forced swimming tests were conducted to assess locomotor activity, motor coordination, anxiety-like behavior, and depressive-like behavior. Acetylcholine (ACh), dopamine, and serotonin levels were measured in brain homogenates. Malondialdehyde (MDA), total antioxidant capacity (TAC), and catalase activity were measured as oxidative stress markers, while tumor necrosis factor-α (TNF-α) and interlukin-6 (IL-6) expression levels were measured as inflammatory markers. Brain derived neurotrophic factor (BDNF) mRNA was measured as an index for the endogenous neuroprotective response. Daily AlCl₃ injection reduced free ambulation, impaired motor coordination, promoted anxiety- and depression-like behaviors, reduced whole-brain ACh, dopamine, and serotonin concentrations, increased MDA accumulation, reduced TAC, elevated TNF-α and IL-6, and suppressed BDNF mRNA expression. All of these effects were significantly reversed by TQ or celastrol cotreatment. Thus, TQ and celastrol may be promising treatments for AlCl₃-induced neurotoxicity as well as neurodegenerative diseases involving oxidative stress and neuroinflammation.

Ferroptosis as a mechanism of non-ferrous metal toxicity

Ferroptosis is a recently discovered form of regulated cell death, implicated in multiple pathologies. Given that the toxicity elicited by some metals is linked to alterations in iron metabolism and induction of oxidative stress and lipid peroxidation, ferroptosis might be involved in such toxicity. Although direct evidence is insufficient, certain pioneering studies have demonstrated a crosstalk between metal toxicity and ferroptosis. Specifically, the mechanisms underlying metal-induced ferroptosis include induction of ferritinophagy, increased DMT-1 and TfR cellular iron uptake, mitochondrial dysfunction and mitochondrial reactive oxygen species (mitoROS) generation, inhibition of Xc-system and glutathione peroxidase 4 (GPX4) activity, altogether resulting in oxidative stress and lipid peroxidation. In addition, there is direct evidence of the role of ferroptosis in the toxicity of arsenic, cadmium, zinc, manganese, copper, and aluminum exposure. In contrast, findings on the impact of cobalt and nickel on ferroptosis are scant and nearly lacking altogether for mercury and especially lead. Other gaps in the field include limited studies on the role of metal speciation in ferroptosis and the critical cellular targets. Although further detailed studies are required, it seems reasonable to propose even at this early stage that ferroptosis may play a significant role in metal toxicity, and its modulation may be considered as a potential therapeutic tool for the amelioration of metal toxicity.

The Acute Toxicity of Mineral Fibres: A Systematic In Vitro Study Using Different THP-1 Macrophage Phenotypes

Alveolar macrophages are the first line of defence against detrimental inhaled stimuli. To date, no comparative data have been obtained on the inflammatory response induced by different carcinogenic mineral fibres in the three main macrophage phenotypes: M0 (non-activated), M1 (pro-inflammatory) and M2 (alternatively activated). To gain new insights into the different toxicity mechanisms of carcinogenic mineral fibres, the acute effects of fibrous erionite, crocidolite and chrysotile in the three phenotypes obtained by THP-1 monocyte differentiation were investigated. The three mineral fibres apparently act by different toxicity mechanisms. Crocidolite seems to exert its toxic effects mostly as a result of its biodurability, ROS and cytokine production and DNA damage. Chrysotile, due to its low biodurability, displays toxic effects related to the release of toxic metals and the production of ROS and cytokines. Other mechanisms are involved in explaining the toxicity of biodurable fibrous erionite, which induces lower ROS and toxic metal release but exhibits a cation-exchange capacity able to alter the intracellular homeostasis of important cations. Concerning the differences among the three macrophage phenotypes, similar behaviour in the production of pro-inflammatory mediators was observed. The M2 phenotype, although known as a cell type recruited to mitigate the inflammatory state, in the case of asbestos fibres and erionite, serves to support the process by supplying pro-inflammatory mediators.

The adjuvant aluminum fate - Metabolic tale based on the basics of chemistry and biochemistry

Aluminum is inevitable component of many vaccines. The benefit of the vaccines is undeniable but effects of aluminum toxicity might be underestimated and neglected. In this review, we highlighted the mechanims of aluminum toxicity, which is still in debate. So far, all the papers that disscused the adverse aluminum effects pointed two mechanisms responsible for Al toxicity, direct Al toxicity and aluminum induced cell damage via the oxidative metabolism. According to our knowledge, which is based on basic principles of biochemistry and inorganic chemistry, we suggested that aluminum highly interferes with iron metabolism eventually resulting in iron-mediated cell damage. More importantly, in this paper, we offered easily feasible solutions, in order to avoid aluminum toxicity in the future. We suggest that as it once was, Calcium Phosphate again to be used as the adjuvant or better solution that the vaccine adjuvants should be based on zinc compounds or even better would be non-metal adjuvants, such as microcrystalline tyrosine and monosodium urate. Until an adequate adjuvant is provided, we suggest instant postponement of vaccination with vaccines which use aluminum as the adjuvant until the 12 months of age.

Combination of donepezil and gallic acid improves antioxidant status and cholinesterases activity in aluminum chloride-induced neurotoxicity in Wistar rats

The present study compared the effect of donepezil only and combination of donepezil and gallic acid on oxidative status and cholinesterase activity in the brain of Wistar rats administered AlCl₃ for 60 days. Twenty-eight rats (180 - 200 g) were arbitrarily distributed into four groups of seven animals apiece. Group 1 served as normal control and received distilled water throughout the study. Group 2 animals received only AlCl₃ throughout the study while animals in groups 3 and 4 were administered donepezil only (10 mg/kg) and combination of donepezil (10 mg/kg) and gallic acid (50 mg/kg), respectively, in addition to AlCl₃. Treatments were administered orally by gavage. At the end of the study, animals were sacrificed and activities of acetylcholinesterase, butyrylcholinesterase, superoxide dismutase (SOD) and catalase as well as levels of malondialdehyde (MDA), total thiol and nitric oxide (NO) were evaluated in the brain. Histopathological study was conducted on the hippocampus of experimental animals. Results showed that AlCl₃ significantly (p < 0.05) increased brain activities of cholinesterases and levels of MDA and NO with a concomitant decrease in total thiol level as well as activities of SOD and catalase. Donepezil only and combination of donepezil and gallic acid reversed these alterations. Also, combination of donepezil and gallic acid significantly (p < 0.05) improved antioxidant status better than donepezil only. It could be concluded that a synergy might exist between gallic acid and donepezil especially in ameliorating oxidative stress associated with AlCl₃-induced neurotoxicity.

Characterization of cadmium accumulation and phytoextraction in three species of the genus Atriplex (canescens, halimus and nummularia) in the presence or absence of salt

This study aims to establish for the first time a comparison between the resistance to cadmium (Cd) stress of three halophyte species, Atriplex canescens, Atriplex halimus and Atriplex nummularia in addition to their already known tolerance for salt and drought. Plants were exposed to CdCl₂ (20 and 50 μM) in the presence or in the absence of salt (50 mM NaCl) for one and two months. The amount of accumulated Cd was determined in the roots and leaves as well as the amount excreted on the surface of the leaves. Physiological parameters such as chlorophyll content and stress biomarkers, including malondialdehyde and enzymatic activities, were then analyzed. The results show that these plants are able to neutralize the excess of reactive oxygen species resulting from treatments by activating the antioxidant defense mechanisms in order to restore the homeostasis of cells. All three species are also able to accumulate high amounts of Cd in the leaves (several hundred mg of Cd/kg of dry leaves) and this phenomenon is amplified in the presence of salt. All together our results allow to consider the three Atriplex species as hyperaccumulators in the presence/absence of salt and as good candidates in a strategy of Cd phytoextraction in the presence of low concentrations of the pollutant. Nevertheless, both A. canescens and A. nummularia species seem to have a higher capacity to hyper-accumulate Cd when the concentration of Cd reaches higher level of contamination.

Contamination of rice crop with potentially toxic elements and associated human health risks-a review

Production of rice, a major staple food crop, should be maintained both quantitatively and qualitatively to assure global food security. In recent decades, various natural (biogeochemical weathering of rocks) and anthropogenic (increased application of agrochemicals, solid and liquid waste discharges from domestic and industrial areas, vehicular pollution, etc.) activities have deteriorated soil and water resources by contributing potentially toxic elements (PTEs) to the environment. Shortage of land resources and requirements of the ever-increasing human population has led to increasing global trend of rice cultivation in contaminated soils, causing accumulation of various PTEs such as arsenic (As), mercury (Hg), cobalt (Co), cadmium (Cd), copper (Cu), lead (Pb), and nickel (Ni) in rice crop, especially in the grains. Rice plants uptake and accumulate PTEs leading to their entry into the food chain. Consumption of rice contaminated with PTEs disturbs the human metabolism as PTEs interfere with different physiological/molecular mechanisms causing various health problems such as weak bones; skin problems; respiratory, cardiovascular, endocrine, nervous, reproductive, and hepatic disorders; and cancer. Possible non-carcinogenic and carcinogenic health risks have been determined in some studies by following the guidelines provided by various governmental or non-governmental agencies. Considering these facts, the present study was conducted to give a broader perspective on rice contamination with various potentially toxic elements, their bioconcentration in rice, associated health risks in human beings, and strategies for bioremediation of soil and water resources to eliminate PTEs.

Diverse Effect of Vitamin C and N-Acetylcysteine on Aluminum-Induced Eryptosis

PURPOSE

The role of oxidative stress in Aluminum (Al)-induced apoptotic effects has been investigated and suicidal death of erythrocytes, eryptosis, is characterized by cell shrinkage and phosphatidylserine externalization (PSE) at the surface of the erythrocyte cell membrane. Eryptosis is stimulated by an increase in cytosolic Ca2+ concentration and reactive oxygen species (ROS). This ex vivo study was conducted to evaluate the effect of well-known antioxidants including vitamin C (vit C) and N-acetylcysteine (NAC), against Al-induced hemolysis and eryptosis.

METHODS

Isolated erythrocytes from the healthy volunteers were partitioned into various groups (6 replicates/group) and treated by various concentrations of Al (3-100 µM) in the presence and absence of vit C (0.6 mM) and NAC (1 mM). After 24 hours of treatment, hemolysis was determined from hemoglobin levels in the supernatant. Flowcytometric methods were applied to measure PSE, cell shrinkage, Ca2+ content, and ROS abundance using annexin V-binding, forward scatter, Fluo3-fluorescence, and DCFDA dependent fluorescence, respectively. Reduced glutathione (GSH) was measured by the ELISA method.

RESULTS

The results showed that a 24 hours' exposure of the erythrocytes to Al (10-100 µM) significantly increased hemolysis in a dose and Ca2+dependent manner. Al also dramatically decreased forward scatter. The percentage of PSE cells, Fluo3-fluorescence, and DCFDA fluorescence were increased by Al. Furthermore, cotreatment with NAC inhibited the effect of Al on hemolysis, eryptosis, and ROS production. Vit C decreased Al-induced ROS production. However, increased Al-induced eryptosis. There were no significant changes in glutathione after the ALCL3 treatment.

CONCLUSIONS

Al-induced eryptosis and hemolysis through triggering oxidative stress, while NAC could diverse this effect. In contrast, vit C might intensify Al-induced eryptosis at particular doses through a less known mechanism.

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.

Impact of catch-up vaccination on aluminum exposure due to new laws and post social distancing

BACKGROUND

The COVID-19 pandemic has placed significant stressors on the medical community and on the general public. Part of this includes patients skipping well-child visits to reduce risk of exposure to SARS-CoV-2 virus. Published estimates of the duration of whole-body aluminum (Al) toxicity from vaccines in infants from birth to six months indicate that CDC's recommended vaccination schedule leads to unacceptably long periods of time in which infants are in aluminum toxicity (as measured by %AlumTox).

METHODS

We utilize these established clearance and accumulation models to calculate expected per-body-weight whole-body toxicity of aluminum from vaccines considering for children of all ages under CDC's Catch-Up schedule from birth to ten years, assuming social distancing for 6 months. Our updated Pediatric Dose Limit (PDL) model assumes a linear improvement in renal function from birth to two years.

RESULTS

Our results indicate that due diligence in considering alternative spacing and use of non-aluminum containing vaccines when possible will reduce whole body toxicity and may reduce risk of morbidity associated with exposure to aluminum.

CONCLUSIONS

While reduction or elimination of aluminum exposure from all sources is always a good idea, our results indicate that careful consideration of expected aluminum exposures during regular and Catch-Up vaccination is found to be especially important for infants and children below 2 years of age. We urge caution in the mass re-starting of vaccination under CDC's Catch-Up schedule for children under 12 months and offer alternative strategies to minimize per-day/week/month exposure to aluminum hydroxide following the COVID-19 period of isolation.

Investigation of water sorption and aluminum releases from high viscosity and resin modified glass ionomer

Background

High viscosity glass ionomer cement (HVGIC) and resin-modified glass ionomer cement (RMGIC) have recently been clinically preferred thanks to their numerous advantages. However, initial moisture contamination has a negative effect on the mechanical and physical properties of these cements. The aim of this study was in vitro of HVGICs and RMGICs, with and without surface protection, on water sorption, solubility and release of aluminum.

Material and Methods

In this study, as HVGICs; Equia Forte, IonoStar Plus, Riva Self Cure; as RMCIS, Ionolux and Riva Light Cure; and as control, Z250 universal composite was used. Equia coat, Voco varnish and Riva coat were chosen as surface protective. Water sorption and solubility levels of the samples were measured according to ISO 4049:2009. Al levels released from samples were determined by graphite furnace atomic absorption spectroscopy (GFAAS) for 7, 14 and 21 days. Statistical evaluation of the results was made using one-way variance analysis (ANOVA) and Tukey post-hoc test (p<0.05).

Results

RMGICs from restorative materials showed more water absorption than HVGICs, but no differences in solubility. Among the materials tested, the water absorption values of the HVGIC and RMGIC materials without surface protection were higher than those with the surface protection (p<0.001).

Conclusions

It was determined that the Al release of HVGIC and RMGIC groups with the surface protection were lower in all time periods than the groups without surface protection (p<0.001). The application of surface protection effectively reduced water sorption and Al release from HVGICs and RMGICs.

Key words:Highly viscous glass ionomer cement, resin coating, aluminum release, water sorption, solubility.

Bergamot essential oil attenuate aluminum-induced anxiety-like behavior through antioxidation, anti-inflammatory and GABA regulation in rats

A large number of studies showed that aluminum (Al) has potential neurotoxicity to human and animal bodies. Al-treated animals showed anxiety-like behavior, oxidative stress, neuroinflammation and γ-aminobutyric acid (GABA) changes. Bergamot essential oil (BEO) is a kind of well-known plant extract from the fresh fruit of bergamot. Previous studies suggested that BEO improved mood and relieved symptoms of stress-induced anxiety. This study was designed to study the effects of BEO on anxiety-like behavior, oxidative stress, neuroinflammation and GABA system in aluminum trichloride (AlCl₃) treated rats. Results showed that AlCl₃ exposure induced anxiety-like behavior in the elevated plus maze and the open field test. Moreover, AlCl₃ exposure decreased the level of GABA and the activity of glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in the hippocampus (HP) and the frontal cortex (FC). In addition, AlCl₃ exposure increased the levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the HP and the FC. To the contrary, co-administration of BEO and AlCl₃ improved the anxiety-like behavior, GABA system, oxidative stress and neuroinflammation. These results indicated that BEO can alleviate the anxiety-like behavior of AlCl₃-exposed rats through the combined action of antioxidant, anti-inflammatory and GABA regulation.

Flavonoids ameliorate aluminum chloride-induced learning and memory impairments via suppression of apoptosis and oxidative stress in rats

The study was to investigate the effects of flavonoids (rutin, puerarin, and silymarin) on learning and memory function in rats exposed to aluminum chloride (AlCl₃). Wistar rats were administered flavonoids at a dose of 100 mg/(kg·bw)/day or 200 mg/(kg·bw)/day after exposed to 281.40 mg/(kg·bw)/day AlCl₃·6H₂O. The results of Morris water maze suggested that rutin and puerarin increased the frequency of crossing the platform and swimming time spent in the target quadrant of AlCl₃-induced rats significantly. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay indicated that three flavonoids could alleviate apoptosis of hippocampal neurons induced by AlCl₃. Real time-PCR and western blot suggested that rutin, puerarin and 100 mg/(kg·bw)/day silymarin could decrease the AlCl₃-induced high expression of Bcl-2 associated X protein (Bax) mRNA and protein in hippocampus, but the expression of B cell lymphoma/leukemia-2 (Bcl-2) mRNA and protein was not significantly different among groups. Flavonoids could up regulate the low expression of autophagy related proteins (Beclin 1 (Bcl-2-interacting protein with a coiled-coil domain 1) and LC3 (microtubule-associated protein 1 light chain 3)) caused by AlCl₃ exposure. Flavonoids could also adjust the change in adenosine triphosphatase, superoxide dismutase, glutathione peroxidase and malondialdehyde induced by intake of AlCl₃. The results of inductively coupled plasma atomic emission spectroscopy (ICP-AES) suggested that flavonoids could effectively reduce the high Al level in brain and serum of AlCl₃ exposed rats. In conclusion, three flavonoids may improve learning and memory function by inhibiting excessive apoptosis and oxidative stress in AlCl₃ exposed rats.

Enhancement of polyphenolic metabolism as an adaptive response of lettuce (Lactuca sativa) roots to aluminum stress

Polyphenols, pivotal secondary metabolites, are involved in plant adaption to abiotic stresses. Here, we investigated the role and metabolism profile of polyphenols under aluminum (Al) stress in different lettuce genotypes grown in 0.5 mM CaCl2 solution with AlCl3 (pH = 4.5). The complementary use of high-resolution mass spectrometry and quantitative biochemical approaches allowed the characterization of total and unique phenols, as well as their roles in Al tolerance. By comparing the most tolerant and sensitive genotype, 8 polyphenols, including 4 phenolic acids, 2 flavonoids, 1 xanthone and 1 unknown compound, were identified in the roots of the tolerant genotype. The total phenolic and flavonoid contents significantly increased in the tolerant genotype under Al stress. Seedlings with more phenolic accumulation usually performed greater Al tolerance. Meanwhile, principal enzymes related to phenolic biosynthesis significantly increased in roots of the tolerance genotype after Al treatment, with phenylalanine ammonia lyase (PAL), cinnamate 4-hydroxylase, and 4-coumarate coenzyme A ligase increased by 16, 18 and 30%, respectively. The elevated total phenolics were significantly suppressed by AIP, a highly specific PAL inhibitor. Consequently, the antioxidant capacity was inhibited, leading to lettuce sensitivity to Al stress. These results clearly suggested the enhancement of unique polyphenolic biosynthesis as an adaptive strategy of lettuce to Al stress by protecting plants from oxidative stress.

Aluminum Exposure and Gestational Diabetes Mellitus: Associations and Potential Mediation by n-6 Polyunsaturated Fatty Acids

As the earth's third most abundant element with various industrial applications, aluminum (Al) has received increasing concerns over its potential adverse health effects. Although Al exposure has been suggested to increase the risks of type 2 diabetes, little has been done to explore Al exposure in pregnant women and potential impact on the incidence of gestational diabetes mellitus (GDM). Our present study demonstrated positive associations between Al concentrations in maternal plasma collected in the first trimester of pregnancy and GDM risks (P_trend < 0.001) based on a nested case-control study from Wuhan, China, including 305 GDM cases and 305 healthy controls. The highest tertile of plasma Al concentrations corresponded to an odds ratio of 4.03 (95% confidence interval: [2.14, 7.58]) relative to the lowest tertile, after the adjustment for established GDM risk factors and other plasma metals. We also observed significant correlations between plasma Al and several plasma polyunsaturated fatty acids (PUFA; e.g., linoleic acid 18:2 n-6) levels. In addition, mediation effects on the associations of Al exposure with GDM risks were observed for n-6 PUFAs (estimated mediation percentage: 48.3%) and total PUFAs (48.9%). Our study is not only by far the largest study of its kind to demonstrate maternal Al exposure and the association with GDM risks, but it also offers an insight into the potential mediation roles of n-6 PUFAs in an epidemiological setting. These findings contribute to a better understanding of perinatal Al exposure and GDM risks.

Aluminium toxicosis: a review of toxic actions and effects

Aluminium (Al) is frequently accessible to animal and human populations to the extent that intoxications may occur. Intake of Al is by inhalation of aerosols or particles, ingestion of food, water and medicaments, skin contact, vaccination, dialysis and infusions. Toxic actions of Al induce oxidative stress, immunologic alterations, genotoxicity, pro-inflammatory effect, peptide denaturation or transformation, enzymatic dysfunction, metabolic derangement, amyloidogenesis, membrane perturbation, iron dyshomeostasis, apoptosis, necrosis and dysplasia. The pathological conditions associated with Al toxicosis are desquamative interstitial pneumonia, pulmonary alveolar proteinosis, granulomas, granulomatosis and fibrosis, toxic myocarditis, thrombosis and ischemic stroke, granulomatous enteritis, Crohn's disease, inflammatory bowel diseases, anemia, Alzheimer's disease, dementia, sclerosis, autism, macrophagic myofasciitis, osteomalacia, oligospermia and infertility, hepatorenal disease, breast cancer and cyst, pancreatitis, pancreatic necrosis and diabetes mellitus. The review provides a broad overview of Al toxicosis as a background for sustained investigations of the toxicology of Al compounds of public health importance.

Aluminum in liver cells - the element species matters

Aluminum (Al) can be ingested from food and released from packaging and can reach key organs involved in human metabolism, including the liver via systemic distribution. Recent studies discuss the occurrence of chemically distinct Al-species and their interconversion by contact with biological fluids. These Al species can vary with regard to their intestinal uptake, systemic transport, and therefore could have species-specific effects on different organs and tissues. This work aims to assess the in vitro hepatotoxic hazard potential of three different relevant Al species: soluble AlCl₃ and two nanoparticulate Al species were applied, representing for the first time an investigation of metallic nanoparticles besides to mineral bound γ-Al₂O₃ on hepatic cell lines. To investigate the uptake and toxicological properties of the Al species, we used two different human hepatic cell lines: HepG2 and differentiated HepaRG cells. Cellular uptake was determined by different methods including light microscopy, transmission electron microscopy, side-scatter analysis, and elemental analysis. Oxidative stress, mitochondrial dysfunction, cell death mechanisms, and DNA damage were monitored as cellular parameters. While cellular uptake into hepatic cell lines occurred predominantly in the particle form, only ionic AlCl₃ caused cellular effects. Since it is known, that Al species can convert one into another, and mechanisms including 'trojan-horse'-like uptake can lead to an Al accumulation in the cells. This could result in the slow release of Al ions, for which reason further hazard cannot be excluded. Therefore, individual investigation of the different Al species is necessary to assess the toxicological potential of Al particles.

Levocarnitine Improves AlCl3-Induced Spatial Working Memory Impairment in Swiss albino Mice

Background: Aluminum, a neurotoxic substance, causes oxidative stress induced-neurodegenerative diseases. Several lines of evidence suggest that levocarnitine has an antioxidant effect and also plays an important role in beta-oxidation of fatty acids. However, the role of levocarnitine in aluminum-induced neurotoxicity has not been well documented. Here we aimed to investigate the effect of levocarnitine on aluminum chloride (AlCl₃)-induced oxidative stress and memory dysfunction.

Methods: Male Swiss albino mice (n = 30) were treated with either control (saline) or AlCl₃ or AlCl₃ plus levocarnitine or levocarnitine or astaxanthin plus AlCl₃ or astaxanthin alone. The spatial working memory was determined by radial arm maze (RAM). In addition, we measured the lipid peroxidation (MDA), glutathione (GSH), advanced oxidation of protein products (AOPP), nitric oxide (NO) and activity of superoxide dismutase (SOD) in the various brain regions including prefrontal cortex (PFC), striatum (ST), parietal cortex (PC), hippocampus (HIP) hypothalamus (HT) and cerebellum (CB). We used astaxanthin as a standard antioxidant to compare the antioxidant activity of levocarnitine.

Results: The RAM data showed that AlCl₃ treatment (50 mg/kg) for 2 weeks resulted in a significant deficit in spatial learning in mice. Moreover, aluminum exposure significantly (p < 0.05) increased the level of oxidative stress markers such as MDA, GSH, AOPP and NO in the various brain regions compared to the controls. In addition, combined administration of levocarnitine and AlCl₃ significantly (p < 0.05) lowered the MDA, AOPP, GSH and NO levels in mice.

Conclusion: Our results demonstrate that levocarnitine could serve as a potential therapeutic agent in the treatment of oxidative stress associated diseases as well as in memory impairment.

Chia seed (Salvia hispanica L.) supplementation may contribute to raising the levels of vitamin B12: An option for the vegan diet

ABSTRACT Objective The chia seed, an ancient pseudocereal, is rich in omega-3 fatty acids and polyphenols, and has been suggested to possess several health benefits. Although it has gained popularity among nutritionists, little is known about the systemic effects of chia and their interactions. Hence, hepatorenal indicators and plasma vitamin concentrations in chia-supplemented aluminum-exposed rats were investigated. Methods Wistar albino rats were either fed on a chia-rich- or standard-diet for 21 days and exposed to aluminum. Liver function tests (Alanine Aminotransferase, Aspartate Aminotransferase, Alkaline Phosphatase, Lactate Dehydrogenase), kidney function tests (Urea Nitrogen, Creatinine), and vitamin B12 and folic acid measurements were performed by using an automated analyzer. Results Aluminum exposure had no influence on renal function, as did chia supplementation. However, liver function was disturbed with the exposure to Aluminum and chia was of no use against it. Surprisingly, it was found that the animals fed on a chia-rich diet displayed higher concentrations of vitamin B12 which was not the case for folic acid. Conclusion It was deduced that a chia-rich diet has no effect on the renal function and is not able to reverse aluminum-induced hepatotoxicity; however, it may be of benefit against vitamin B12 insufficiency and thus, it may offer a novel treatment option which is particularly important in the vegan diet.

Cell toxicity mechanism and biomarker

Cell toxicity may result in organ dysfunction and cause severe health problem. Recent studies revealed many toxicants may induced the over production of Nitric oxide, reactive oxygen species and the subsequent oxidative stress, cause cell toxicity. Mitochondrion dysfunction maybe the subsequent consequence of oxidative stress and has been recognized as another contributing factor in cell toxicity. Besides, oxidative products induced by some toxicants may also produce the compounds that damage cell DNA, leading to toxicity. Especially, the significance of nanoparticle induced cell toxicity was disclosed recently and attract more concern. The mechanism mainly includes inflammation, oxidative stress and DNA damage. On the other side, some biomarkers of cell toxicity including autophagy, cytokines, miRNA has been identified. The understanding of these phenomenon may enable us to clarify the cell toxicity mechanism then contribute to cell toxicity protection, disease treatment and drug side effect prevention.

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.

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.

Reactive nitrogen species (RNS)-resistant microbes: adaptation and medical implications

Nitrosative stress results from an increase in reactive nitrogen species (RNS) within the cell. Though the RNS - nitric oxide (·NO) and peroxynitrite (ONOO-) - play pivotal physiological roles, at elevated concentrations, these moieties can be poisonous to both prokaryotic and eukaryotic cells alike due to their capacity to disrupt a variety of essential biological processes. Numerous microbes are known to adapt to nitrosative stress by elaborating intricate strategies aimed at neutralizing RNS. In this review, we will discuss both the enzymatic systems dedicated to the elimination of RNS as well as the metabolic networks that are tailored to generate RNS-detoxifying metabolites - α-keto-acids. The latter has been demonstrated to nullify RNS via non-enzymatic decarboxylation resulting in the production of a carboxylic acid, many of which are potent signaling molecules. Furthermore, as aerobic energy production is severely impeded during nitrosative stress, alternative ATP-generating modules will be explored. To that end, a holistic understanding of the molecular adaptation to nitrosative stress, reinforces the notion that neutralization of toxicants necessitates significant metabolic reconfiguration to facilitate cell survival. As the alarming rise in antimicrobial resistant pathogens continues unabated, this review will also discuss the potential for developing therapies that target the alternative ATP-generating machinery of bacteria.

The pathophysiological role of mitochondrial oxidative stress in lung diseases

Mitochondria are critically involved in reactive oxygen species (ROS)-dependent lung diseases, such as lung fibrosis, asbestos, chronic airway diseases and lung cancer. Mitochondrial DNA (mtDNA) encodes mitochondrial proteins and is more sensitive to oxidants than nuclear DNA. Damage to mtDNA causes mitochondrial dysfunction, including electron transport chain impairment and mitochondrial membrane potential loss. Furthermore, damaged mtDNA also acts as a damage-associated molecular pattern (DAMP) that drives inflammatory and immune responses. In this review, crosstalk among alveolar epithelial cells, alveolar macrophages and mitochondria is examined. ROS-related transcription factors and downstream cell signaling pathways are also discussed. We conclude that targeting oxidative stress with antioxidant agents, such as thiol molecules, polyphenols and superoxide dismutase (SOD), and promoting mitochondrial biogenesis should be considered as novel strategies for treating lung diseases that currently have no effective treatment options.

The putative role of environmental aluminium in the development of chronic neuropathology in adults and children. How strong is the evidence and what could be the mechanisms involved?

The conceptualisation of autistic spectrum disorder and Alzheimer's disease has undergone something of a paradigm shift in recent years and rather than being viewed as single illnesses with a unitary pathogenesis and pathophysiology they are increasingly considered to be heterogeneous syndromes with a complex multifactorial aetiopathogenesis, involving a highly complex and diverse combination of genetic, epigenetic and environmental factors. One such environmental factor implicated as a potential cause in both syndromes is aluminium, as an element or as part of a salt, received, for example, in oral form or as an adjuvant. Such administration has the potential to induce pathology via several routes such as provoking dysfunction and/or activation of glial cells which play an indispensable role in the regulation of central nervous system homeostasis and neurodevelopment. Other routes include the generation of oxidative stress, depletion of reduced glutathione, direct and indirect reductions in mitochondrial performance and integrity, and increasing the production of proinflammatory cytokines in both the brain and peripherally. The mechanisms whereby environmental aluminium could contribute to the development of the highly specific pattern of neuropathology seen in Alzheimer's disease are described. Also detailed are several mechanisms whereby significant quantities of aluminium introduced via immunisation could produce chronic neuropathology in genetically susceptible children. Accordingly, it is recommended that the use of aluminium salts in immunisations should be discontinued and that adults should take steps to minimise their exposure to environmental aluminium.

Feline vaccine-associated sarcomagenesis: Is there an inflammation-independent role for aluminium?

Aluminium has been found in feline vaccine-associated sarcomas. In this study, we investigated the potential for aluminium to contribute directly to tumourigenesis. Our results indicated that an aluminium hydroxide adjuvant preparation was cytotoxic and mutagenic in human-Chinese hamster ovary (CHO) hybrid cells in vitro. Moreover, CHO cells deficient in DNA double strand break (DSB), but not single-strand break (SSB), repair, were particularly sensitive to aluminium exposure compared with repair proficient cells, suggesting that aluminium is associated with DSBs. In contrast to CHO cells, primary feline skin fibroblasts were resistant to the cytotoxic effects of aluminium compounds and exposure to an aluminium chloride salt promoted cell growth and cell cycle progression at concentrations much less than those measured in particular feline rabies vaccines. These findings suggest that aluminium exposure may contribute, theoretically, to both initiation and promotion of tumours in the absence of an inflammatory response.

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.

Brain aluminium accumulation and oxidative stress in the presence of calcium silicate dental cements

Mineral trioxide aggregate (MTA) is a calcium silicate dental cement used for various applications in dentistry. This study was undertaken to test whether the presence of three commercial brands of calcium silicate dental cements in the dental extraction socket of rats would affect the brain aluminium (Al) levels and oxidative stress parameters. Right upper incisor was extracted and polyethylene tubes filled with MTA Angelus, MTA Fillapex or Theracal LC, or left empty for the control group, were inserted into the extraction socket. Rats were killed 7, 30 or 60 days after operation. Brain tissues were obtained before killing. Al levels were measured by atomic absorption spectrometry. Thiobarbituric acid reactive substances (TBARS) levels, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were determined using spectrophotometry. A transient peak was observed in brain Al level of MTA Angelus group on day 7, while MTA Fillapex and Theracal LC groups reached highest brain Al level on day 60. Brain TBARS level, CAT, SOD and GPx activities transiently increased on day 7 and then returned to almost normal levels. This in vivo study for the first time indicated that initial washout may have occurred in MTA Angelus, while element leaching after the setting is complete may have taken place for MTA Fillapex and Theracal LC. Moreover, oxidative stress was induced and antioxidant enzymes were transiently upregulated. Further studies to search for oxidative neuronal damage should be done to completely understand the possible toxic effects of calcium silicate cements on the brain.

Astaxanthin ameliorates aluminum chloride-induced spatial memory impairment and neuronal oxidative stress in mice

Aluminum chloride induces neurodegenerative disease in animal model. Evidence suggests that aluminum intake results in the activation of glial cells and generation of reactive oxygen species. By contrast, astaxanthin is an antioxidant having potential neuroprotective activity. In this study, we investigate the effect of astaxanthin on aluminum chloride-exposed behavioral brain function and neuronal oxidative stress (OS). Male Swiss albino mice (4 months old) were divided into 4 groups: (i) control (distilled water), (ii) aluminum chloride, (iii) astaxanthin+aluminum chloride, and (iv) astaxanthin. Two behavioral tests; radial arm maze and open field test were conducted, and OS markers were assayed from the brain and liver tissues following 42 days of treatment. Aluminum exposed group showed a significant reduction in spatial memory performance and anxiety-like behavior. Moreover, aluminum group exhibited a marked deterioration of oxidative markers; lipid peroxidation (MDA), nitric oxide (NO), glutathione (GSH) and advanced oxidation of protein products (AOPP) in the brain. To the contrary, co-administration of astaxanthin and aluminum has shown improved spatial memory, locomotor activity, and OS. These results indicate that astaxanthin improves aluminum-induced impaired memory performances presumably by the reduction of OS in the distinct brain regions. We suggest a future study to determine the underlying mechanism of astaxanthin in improving aluminum-exposed behavioral deficits.

The interaction of Hg2+and trivalent ions with two new fluorescein bio-inspired dual colorimetric/fluorimetric probes

Two new bio-inspired fluorescein derivatives were successfully synthesized and both the compounds showed a “turn on” fluorescence in the presence of trivalent (Al³⁺, Fe³⁺, Ga³⁺, Cr³⁺) and Hg²⁺metal ions, forming mononuclear complexes in acetonitrile.

Dysfunctional mitochondrial bioenergetics and the pathogenesis of hepatic disorders

The liver is involved in a variety of critical biological functions including the homeostasis of glucose, fatty acids, amino acids, and the synthesis of proteins that are secreted in the blood. It is also at the forefront in the detoxification of noxious metabolites that would otherwise upset the functioning of the body. As such, this vital component of the mammalian system is exposed to a notable quantity of toxicants on a regular basis. It therefore comes as no surprise that there are over a hundred disparate hepatic disorders, encompassing such afflictions as fatty liver disease, hepatitis, and liver cancer. Most if not all of liver functions are dependent on energy, an ingredient that is primarily generated by the mitochondrion, the power house of all cells. This organelle is indispensable in providing adenosine triphosphate (ATP), a key effector of most biological processes. Dysfunctional mitochondria lead to a shortage in ATP, the leakage of deleterious reactive oxygen species (ROS), and the excessive storage of fats. Here we examine how incapacitated mitochondrial bioenergetics triggers the pathogenesis of various hepatic diseases. Exposure of liver cells to detrimental environmental hazards such as oxidative stress, metal toxicity, and various xenobiotics results in the inactivation of crucial mitochondrial enzymes and decreased ATP levels. The contribution of the latter to hepatic disorders and potential therapeutic cues to remedy these conditions are elaborated.

The role of the Nrf2/Keap1 pathway in obesity and metabolic syndrome

Nuclear factor erythroid 2 related factor 2 (Nrf2) is a key regulator of antioxidant signaling that may prevent the development of metabolic syndrome and related cardiovascular diseases. However, emerging evidence shows that lack of Nrf2 could ameliorate insulin resistance, adipogenesis and adipocyte differentiation. Consistent with this, overexpression of Nrf2 gene could also cause insulin resistance under certain conditions. Furthermore, an increasing number of studies indicate that redox balance can be a critical element that contributes to the contradictory effects of Nrf2 on insulin sensitivity and resistance. Reactive oxygen species can promote normal insulin-mediated signal transduction under physiological conditions but also induce insulin resistance under certain pathological conditions. Therefore, the contradictory effects of Nrf2 on insulin signaling pathways may be related to its regulation of redox homeostasis. This review attempts to summarize the latest developments in our understanding of the mechanisms of Nrf2-mediated signaling and its role in the modulation of metabolic homeostasis.

Mitochondrial functional impairment in response to environmental toxins in the cardiorenal metabolic syndrome

Environmental toxins can promote cardiovascular, metabolic, and renal abnormalities, which characterize the cardiorenal metabolic syndrome (CRS). Heavy metals, such as mercury and arsenic, represent two of the most toxic pollutants. Exposure to these toxins is increasing due to increased industrialization throughout much of the world. Studies conducted to understand the impact of environmental toxins have shown a major impact on mitochondrial structure and function. The maladaptive stress products caused by these toxins, including aggregated proteins, damaged organelles, and intracellular pathogens, can be removed through autophagy, which is also known as mitophagy in mitochondria. Although the underlying mechanisms involved in the regulation of mitophagy in response to pollution are not well understood, accumulating evidence supports a role for maladaptive mitochondrial responses to environmental pollution in the pathogenesis of the CRS. In this review, we discuss the ongoing research, which explores the mechanisms by which these toxins promote abnormalities in mitophagy and associated mitochondrial dysfunction and the CRS.