Hepatic response to aluminum toxicity: dyslipidemia and liver diseases

Chronic aluminium chloride exposure induces redox imbalance, metabolic distress, DNA damage, and histopathologic alterations in Wistar rat liver

Aluminium, a ubiquitous environmental toxicant, is distinguished for eliciting a broad range of physiological, biochemical, and behavioural alterations in laboratory animals and humans. The present work was conducted to study the functional and structural changes induced by aluminium in rat liver. Twenty five adult male Wistar rats (150-200 g) were randomly divided into five groups; control group and four Al-treated groups viz: Al 1 (25 mg AlCl3/kg b.wt), Al 2 (35 mg AlCl3/kg b.wt), Al 3 (45 mg AlCl3/kg b.wt), and Al 4 (55 mg AlCl3/kg b.wt). Rats in the aluminium-treated groups were administered AlCl3 for 30 days through oral gavage. Aluminium significantly increased the serum levels of liver function markers (ALT, AST, and ALP), phospholipids, and cholesterol. The activities of hepatocyte membrane (ALP, GGT, and LAP) and carbohydrate metabolic (G6P, F16BP, HK, LDH, MDH, ME, and G6PDH) enzymes were significantly altered by AlCl3 administration. Prolonged Al exposure induced oxidative stress in the liver, as evident by significant hepatocellular DNA damage, increased lipid peroxidation, and decreased non-enzymatic and enzymatic antioxidants. The toxic effects observed in this study were AlCl3 dose-dependent. Histopathological examination of liver sections revealed enlargement of sinusoidal spaces, derangement of the hepatic chord, loss of discrete hepatic cell boundaries, congestion of hepatic sinusoids, and degeneration of hepatocytes in Al-intoxicated rats. In conclusion, aluminium causes severe hepatotoxicity by inhibiting the hepatocyte membrane enzymes and disrupting the liver's energy metabolism and antioxidant defence.

Hepatoprotective effect of silymarin-chitosan nanocomposite against aluminum-induced oxidative stress, inflammation, and apoptosis

Aluminum (Al) is abundant in the environment, and its toxicity is attributed to free radical formation and subsequent oxidative stress. While silymarin is a well-known antioxidant, its low water solubility and bioavailability limit its therapeutic effects. This study was designated to formulate silymarin chitosan nanoparticles (SM-CS-NPs) and evaluate its ameliorative effect against hepatotoxicity induced by aluminum chloride (AlCl3). SM-CS-NPs were prepared by ionotropic gelation method and characterized using different techniques. Rats were distributed into six groups (n=7/group), control, silymarin (SM; 15 mg/kg B.W), silymarin-chitosan nanoparticles (SM-CS-NPs; 15 mg/kg), aluminum chloride (AlCl3, 34 mg/kg), SM or SM-CS-NPs administrated orally one hour before the treatment with AlCl3 for 30 days, respectively. Results showed that supplementation of SM-CS-NPs or SM solo improved the antioxidant state and reduced oxidative stress. On the other hand, the pretreatment with SM-CS-NPs or SM followed by AlCl3 significantly restored liver functions (AST, ALT, ALP, LDH, total protein, albumin, globulin, and bilirubin) and modulated oxidative stress biomarkers (TBARS and H2O2), with improved cellular antioxidant defense (SOD, CAT, GPx, GR, GST, and GSH) and maintained normal liver histological structure compared to rats treated with AlCl3 alone. Furthermore, they alleviated the inflammation and apoptosis by downregulating the expression level of COX-2, caspase-3, and TNFα. This ameliorative effect was stronger with silymarin nanoform than in bulk-state silymarin. According to the findings, silymarin preparation in nanoform boosts its ameliorative and protective effects against AlCl3 hepatotoxicity.

Assessment of Histopathological Alterations and Oxidative Stress in the Liver and Kidney of Male Rats following Exposure to Aluminum Chloride

The study aims to investigate the residual and histopathological effects of chronic aluminum chloride (AlCl3) toxicity in the kidney and liver of male rats. After 30-, 60-, and 90-day exposure period, analyses were conducted to assess the toxicity in the kidney and liver. The results showed that the concentration of AlCl3 in the kidney and liver increased significantly in 30-, 60-, and 90-day periods. The effects of oxidative stress on the kidneys and liver were dose- and time-dependent. Levels of malondialdehyde (MDA) significantly increased when exposed to AlCl3 groups. Conversely, the activity of antioxidant parameters, including reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD), significantly decreased in the AlCl3 exposed groups, indicating compromised oxidant mechanisms. Both the kidney and liver exhibited severe tissue damage, including necrosis, fibrosis, and inflammatory cell infiltration, in rats exposed to AlCl3. Kidney sections showed hyperplasia of the epithelial cells lining the renal tubules, resembling finger-like structures. Liver sections displayed severe lobular hyperplasia and an increase in mitotic figures. Our study suggests that AlCl3 has a detrimental impact on these vital organs and emphasizes the importance of monitoring and mitigating aluminum exposure, particularly where it is present in high concentration.

Blood Concentration of Macro- and Microelements in Women Who Are Overweight/Obesity and Their Associations with Serum Biochemistry

Risk elements in blood matrices can affect human health status through associations with biomarkers at multiple levels. The aim of this study was to analyze 15 macro- and microelements in the blood serum of women with overweight (BMI of ≥25 kg/m2) and obesity (BMI of ≥30 kg/m2) and to examine possible associations with biochemical, liver enzymatic parameters, and markers of oxidative stress. Based on the power calculation, the study involved women (in the postmenopausal stage) with overweight (n = 26) and obesity (n = 22), aged between 50-65 years. Multifrequency bioelectrical impedance analysis was used to measure body composition parameters. Concentrations of elements were determined by inductively coupled plasma optical emission spectrometry, and Hg was measured using cold-vapor atomic absorption spectroscopy. Individuals with obesity, as indicated by a higher BMI, percentage of body fat, and visceral fat area, had elevated serum levels of Ca, Mg, Fe, Al, Sr, Pb, and Hg. Concentrations of Al, Cu, K, Sb, Zn, and Pb significantly affected biochemical and liver function markers in women with overweight or obesity. Elements such as Cu and Al were associated with increased total cholesterol. The correlation analysis between total antioxidant status and Cu, Al, and Ni confirmed associations in both groups. Our findings underscore the importance of addressing excess body weight and obesity in relation to risk elements. The results of the research could be beneficial in identifying potential targets for the treatment or prevention of comorbidities in people with obesity.

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

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

Comparative toxicity of coal and coal ash: Assessing biological impacts and potential mechanisms through in vitro and in vivo testing

BACKGROUND

Coal and coal ash present inorganic elements associated with negative impacts on environment and human health. The objective of this study was to compare the toxicity of coal and coal ash from a power plant, assess their inorganic components, and investigate the biological impacts and potential mechanisms through in vitro and in vivo testing.

METHODS

Particle-Induced X-ray Emission method was used to quantify inorganic elements and the toxicity was evaluated in Caenorhabditis elegans and Daphnia magna in acute and chronic procedures. The genotoxic potential was assessed using alkaline and FPG-modified Comet assay in HepG2 cells and mutagenicity was evaluated using Salmonella/microsome assay in TA97a, TA100, and TA102 strains.

RESULTS

Inorganic elements such as aluminum (Al) and chromium (Cr) were detected at higher concentrations in coal ash compared to coal. These elements were found to be associated with increased toxicity of coal ash in both Caenorhabditis elegans and Daphnia magna. Coal and coal ash did not induce gene mutations, but showed genotoxic effects in HepG2 cells, which were increased using the FPG enzyme, indicating DNA oxidative damage.

CONCLUSIONS

The combined findings from bioassays using C. elegans and D. magna support the higher toxicity of coal ash, which can be attributed to its elevated levels of inorganic elements. The genotoxicity observed in HepG2 cells confirms these results. This study highlights the need for continuous monitoring in areas affected by environmental degradation caused by coal power plants. Additionally, the analysis reveals significantly higher concentrations of various inorganic elements in coal ash compared to coal, providing insight into the specific elemental composition contributing to its increased toxicity.

Associations between the detailed milk mineral profile, milk composition, and metabolic status in Holstein cows

The causes of variation in the milk mineral profile of dairy cattle during the first phase of lactation were studied under the hypothesis that the milk mineral profile partially reflects the animals' metabolic status. Correlations between the minerals and the main milk constituents (i.e., protein, fat, and lactose percentages), and their associations with the cows' metabolic status indicators were explored. The metabolic status indicators (MET) that we used were blood energy-protein metabolites [nonesterified fatty acids, β-hydroxybutyrate (BHB), glucose, cholesterol, creatinine, and urea], and liver ultrasound measurements (predicted triacylglycerol liver content, portal vein area, portal vein diameter and liver depth). Milk and blood samples, and ultrasound measurements were taken from 295 Holstein cows belonging to 2 herds and in the first 120 d in milk (DIM). Milk mineral contents were determined by ICP-OES; these were considered the response variable and analyzed through a mixed model which included DIM, parity, milk yield, and MET as fixed effects, and the herd/date as a random effect. The MET traits were divided in tertiles. The results showed that milk protein was positively associated with body condition score (BCS) and glucose, and negatively associated with BHB blood content; milk fat was positively associated with BHB content; milk lactose was positively associated with BCS; and Ca, P, K and S were the minerals with the greatest number of associations with the cows' energy indicators, particularly BCS, predicted triacylglycerol liver content, glucose, BHB and urea. We conclude that the protein, fat, lactose, and mineral contents of milk partially reflect the metabolic adaptation of cows during lactation and within 120 DIM. Variations in the milk mineral profile were consistent with changes in the major milk constituents and the metabolic status of cows.

The protective effects of sesamol and/or the probiotic, Lactobacillus rhamnosus, against aluminum chloride-induced neurotoxicity and hepatotoxicity in rats: Modulation of Wnt/β-catenin/GSK-3β, JAK-2/STAT-3, PPAR-γ, inflammatory, and apoptotic pathways

Introduction: Aluminium (Al) is accumulated in the brain causing neurotoxicity and neurodegenerative disease like Alzheimer's disease (AD), multiple sclerosis, autism and epilepsy. Hence, attenuation of Al-induced neurotoxicity has become a "hot topic" in looking for an intervention that slow down the progression of neurodegenerative diseases. Objective: Our study aims to introduce a new strategy for hampering aluminum chloride (AlCl3)-induced neurotoxicity using a combination of sesamol with the probiotic bacteria; Lactobacillus rhamnosus (L. rhamnosus) and also to test their possible ameliorative effects on AlCl3-induced hepatotoxicity. Methods: Sprague-Dawley male rats were randomly divided into five groups (n = 10/group) which are control, AlCl3, AlCl3 + Sesamol, AlCl3 + L. rhamnosus and AlCl3 + Sesamol + L. rhamnosus. We surveilled the behavioral, biochemical, and histopathological alterations centrally in the brain and peripherally in liver. Results: This work revealed that the combined therapy of sesamol and L. rhamnosus produced marked reduction in brain amyloid-β, p-tau, GSK-3β, inflammatory and apoptotic biomarkers, along with marked elevation in brain free β-catenin and Wnt3a, compared to AlCl3-intoxicated rats. Also, the combined therapy exerted pronounced reduction in hepatic expressions of JAK-2/STAT-3, inflammatory (TNF-α, IL-6, NF-κB), fibrotic (MMP-2, TIMP-1, α-SMA) and apoptotic markers, (caspase-3), together with marked elevation in hepatic PPAR-γ expression, compared to AlCl3 -intoxicated rats. Behavioral and histopathological assessments substantiated the efficiency of this combined regimen in halting the effect of neurotoxicity. Discussion: Probiotics can be used as an add-on therapy with sesamol ameliorate AlCl3 -mediated neurotoxicity and hepatotoxicity.

Investigation of the anti-oxidative and anti-inflammatory effects of melatonin on experimental liver damage by radiation

Radiotherapy is one of the inevitable treatment approaches for several types of cancer. We aimed to show the protective and therapeutic effects of daily use of melatonin on liver tissues subjected to a single dose of 10 Gy (gamma-ray) total body radiation. Rats were divided into 6 groups, of which 10 were in each: control, sham, melatonin, radiation, radiation+melatonin, and melatonin+radiation. The rats received 10 Gy of external radiation throughout their entire bodies. The rats were given 10 mg/kg/day of melatonin intraperitoneally before or after radiation treatment, depending on the group. Histological methods, immunohistochemical analysis (Caspase-3, Sirtuin-1, α-SMA, NF_ΚB-p65), biochemical analysis by ELİSA (SOD, CAT, GSH-PX, MDA, TNF-α, TGF-β, PDGF, PGC-1α) and the Comet assay as a marker of DNA damage were applied to the liver tissues. Histopathological examinations showed structural changes in the liver tissue of the radiation group. Radiation treatment increased the immunoreactivity of Caspase-3, Sirtuin-1 and α-SMA, but these effects were relatively attenuated in the melatonin-treated groups. The melatonin+radiation group had statistically significant results close to those of the control group, in terms of Caspase-3, NF_ΚB-p65 and Sirtuin-1 immunoreactivity. In melatonin treated groups, hepatic biochemical markers, MDA, SOD, TNF-α, TGF-β levels, and DNA damage parameters were decreased. Administration of melatonin before and after radiation has beneficial effects, but using it before radiation may be more efficient. Accordingly, daily melatonin usage could mitigate ionizing radiation induced damage.

Aluminum as a Possible Cause Toward Dyslipidemia

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

Associations of metals and metals mixture with lipid profiles: A repeated-measures study of older adults in Beijing

Metals inevitably and easily enter into human bodies and can induce a series of pathophysiological changes, such as oxidative stress damage and lipid peroxidation, which then may further induce dyslipidemia. However, the effects of metals and metals mixture on the lipid profiles are still unclear, especially in older adults. A three-visits repeated measurement of 201 older adults in Beijing was conducted from November 2016 to January 2018. Linear Mixed Effects models and Bayesian kernel machine regression models were used to estimate associations of eight blood metals and metals mixture with lipid profiles, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), Castelli risk indexes I (CRI-1), Castelli risk indexes II (CRI-2), atherogenic coefficient (AC), and non-HDL cholesterol (NHC). Cesium (Cs) was positively associated with TG (β_Cs = 0.14; 95% CI: 0.02, 0.26) whereas copper (Cu) was inversely related to TG (β_Cu = -0.65; 95%CI: -1.14, -0.17) in adjusted models. Manganese (Mn) was mainly related to higher HDL-C (β_Mn = 0.14; 95% CI: 0.07, 0.21) whereas molybdenum showed opposite association. Metals mixture was marginally positive associated with HDL-C, among which Mn played a crucial role. Our findings suggest that the effects of single metal on lipid profiles may be counteracted in mixtures in the context of multiple metal exposures; however, future studies with large sample size are still needed to focus on the detrimental effects of single metals on lipid profiles as well as to identify key components.

Bromelain Modulates Liver Injury, Hematological, Molecular, and Biochemical Perturbations Induced by Aluminum via Oxidative Stress Inhibition

Aluminum (Al) is an important factor in the environment as it is used in agriculture and several industries leading to hazardous effects via oxidative stress. Bromelain is a cheap extract from the byproduct waste of Ananas comosus stem. It has been used in several biological and therapeutic applications. So, this study was undertaken to assess the hepatoprotective potential of bromelain versus oxidative stress induced by aluminum chloride in rats. Results revealed that administration of AlCl₃ reduced the body and liver weights and increased Al concentration in the blood and liver tissue. Also, AlCl₃ caused valuable changes in hematological parameters and increased TBARS and H₂O₂ concentrations in rat liver. Enzymatic (SOD, CAT, GPx, GR, and GST) and nonenzymatic (GSH) antioxidants and protein content were significantly decreased. Furthermore, alterations in liver biomarkers such as bilirubin level and enzyme activities in both serum and liver homogenate (LDH, ALP, AST, and ALT) were detected. AlCl₃ also caused inflammation as indicated by upregulation of the inflammation-related genes [interleukin 1 beta (IL-1β)], tumor necrosis factor-alpha (TNF-α), as well as matrix metalloproteinase (MMP9), and downregulation of nuclear factor erythroid 2 (Nrf2) expression. In addition, histopathological examination showed significant variations in the liver that confirms the biochemical results. Otherwise, bromelain intake alone slumped lipid peroxidation and gotten better antioxidant status significantly. Moreover, supplementation with bromelain before AlCl₃ intoxication restores enzymatic and nonenzymatic antioxidants as well as biochemical indices and tissue architecture with respect to the AlCl₃ group. In conclusion, bromelain proved its remarkable protective power to abolish AlCl₃ toxicity. So, it might represent a new strategy in the therapy of metal toxicity by its antioxidant capacity.

Amelioration of aluminum-induced hepatic and nephrotoxicity by Premna odorata extract is mediated by lowering MMP9 and TGF-β gene alterations in Wistar rat

This study aims to investigate the effect of Premna odorata (P. odorata) (Lamiaceae) on the hepatic and nephrotoxicity induced by aluminum chloride (AlCl3) in rat. Wistar male rats were equally classified into four groups: control, P. odorata extract (500 mg/kg B.W.), AlCl3 (70 mg/kg B.W.), and P. odorata extract plus AlCl3 groups. All treatments were given orally for 4 weeks. Serum transaminases and some biochemical parameters, hepatic and renal antioxidant/oxidant biomarker; tumor necrosis factor-α (TNF-α); matrix metalloproteinase (MMP9) and transforming growth factor-β (TGF-β) mRNA expression; histopathological examination of the liver, and kidneys were investigated. The obtained results revealed that AlCl3 significantly increased the activities of serum aspartate transaminase, alanine transaminase, and alkaline phosphatase as well as produced a significant increase in total cholesterol, triglyceride, urea, and creatinine concentrations, while there were no changes observed in the total protein, albumin, and globulin concentrations. Also, aluminum administration significantly decreased the reduced glutathione content and increased the catalase activity, malondialdehyde, and TNF-α concentrations in the liver and kidney tissue. Moreover, AlCl3 results in congestion, degeneration, and inflammation of the liver and kidney tissue. Co-treatment of P. odorata extract with AlCl3 alleviated its harmful effects on the previous parameters and reduced the histopathological alterations induced by AlCl3. Therefore, Premna odorata may have a potent protective effect against oxidative stress induced by Al toxicity through downregulation of MMP9 and TGF-β gene expression.

Characterization and Toxicity Analysis of Lab-Created Respirable Coal Mine Dust from the Appalachians and Rocky Mountains Regions

Coal mine workers are continuously exposed to respirable coal mine dust (RCMD) in workplaces, causing severe lung diseases. RCMD characteristics and their relations with dust toxicity need further research to understand the adverse exposure effects to RCMD. The geographic clustering of coal workers’ pneumoconiosis (CWP) suggests that RCMD in the Appalachian region may exhibit more toxicity than other geographic regions such as the Rocky Mountains. This study investigates the RCMD characteristics and toxicity based on geographic location. Dissolution experiments in simulated lung fluids (SLFs) and in vitro responses were conducted to determine the toxicity level of samples collected from five mines in the Rocky Mountains and Appalachian regions. Dust characteristics were investigated using Fourier-transform infrared spectroscopy, scanning electron microscopy, the BET method, total microwave digestion, X-ray diffraction, and X-ray photoelectron spectroscopy. Inductively coupled plasma mass spectrometry was conducted to determine the concentration of metals dissolved in the SLFs. Finer particle sizes and higher mineral and elemental contents were found in samples from the Appalachian regions. Si, Al, Fe, Cu, Sr, and Pb were found in dissolution experiments, but no trends were found indicating higher dissolutions in the Appalachian region. In vitro studies indicated a proinflammatory response in epithelial and macrophage cells, suggesting their possible participation in pneumoconiosis and lung diseases development.

Mitochondrial Dysfunction and Acute Fatty Liver of Pregnancy

The liver is one of the richest organs in mitochondria, serving as a hub for key metabolic pathways such as β-oxidation, the tricarboxylic acid (TCA) cycle, ketogenesis, respiratory activity, and adenosine triphosphate (ATP) synthesis, all of which provide metabolic energy for the entire body. Mitochondrial dysfunction has been linked to subcellular organelle dysfunction in liver diseases, particularly fatty liver disease. Acute fatty liver of pregnancy (AFLP) is a life-threatening liver disorder unique to pregnancy, which can result in serious maternal and fetal complications, including death. Pregnant mothers with this disease require early detection, prompt delivery, and supportive maternal care. AFLP was considered a mysterious illness and though its pathogenesis has not been fully elucidated, molecular research over the past two decades has linked AFLP to mitochondrial dysfunction and defects in fetal fatty-acid oxidation (FAO). Due to deficient placental and fetal FAO, harmful 3-hydroxy fatty acid metabolites accumulate in the maternal circulation, causing oxidative stress and microvesicular fatty infiltration of the liver, resulting in AFLP. In this review, we provide an overview of AFLP and mitochondrial FAO followed by discussion of how altered mitochondrial function plays an important role in the pathogenesis of AFLP.

Aluminum Poisoning with Emphasis on Its Mechanism and Treatment of Intoxication

Aluminum poisoning has been reported in some parts of the world. It is one of the global health problems that affect many organs. Aluminum is widely used daily by humans and industries. Residues of aluminum compounds can be found in drinking water, food, air, medicine, deodorants, cosmetics, packaging, many appliances and equipment, buildings, transportation industries, and aerospace engineering. Exposure to high levels of aluminum compounds leads to aluminum poisoning. Aluminum poisoning has complex and multidimensional effects, such as disruption or inhibition of enzymes activities, changing protein synthesis, nucleic acid function, and cell membrane permeability, preventing DNA repair, altering the stability of DNA organization, inhibition of the protein phosphatase 2A (PP2A) activity, increasing reactive oxygen species (ROS) production, inducing oxidative stress, decreasing activity of antioxidant enzymes, altering cellular iron homeostasis, and changing NF-kB, p53, and JNK pathway leading to apoptosis. Aluminum poisoning can affect blood content, musculoskeletal system, kidney, liver, and respiratory and nervous system, and the extent of poisoning can be diagnosed by assaying aluminum compounds in blood, urine, hair, nails, and sweat. Chelator agents such as deferoxamine (DFO) are used in the case of aluminum poisoning. Besides, combination therapies are recommended.

Effect of Resveratrol, L-Carnitine, and Aromatic Amino Acid Supplements on the Trace Element Content in the Organs of Mice with Dietary-Induced Obesity

Given environmental contamination with toxic metals, diets that promote the elimination of these metals from the body of individuals, including those suffering from obesity, are urgently needed. The aim of this study was to determine the effects of supplementation with resveratrol (Res), L-carnitine (L-Car), tyrosine (Tyr), and tryptophan (Trp) on the content of trace elements in the organs of mice. DBA/2J mice and DBCB tetrahybrid mice received diets high in carbohydrate and fat supplemented with Res, L-Car, Tyr, or Trp for 65 days. In the liver, kidneys, and brain, the contents of 18 elements, including Al, As, Cu, Fe, Mn, Pb, Se, and Zn, were determined by inductively coupled plasma mass spectrometry. Res, L-Car, Tyr, and Trp had minimal or no effect on the essential elements (Fe, Mg, Cu, Zn, Se) in all organs studied. The Mn content notably increased in the organs of mice consuming L-Car and Trp. Mn accumulation was stimulated by Res in organs exclusively in DBCB mice and by Tyr exclusively in livers and brains of DBA/2J mice. Al levels were significantly reduced by L-Car and Trp in all organs of the mice, by Res in only DBCB mice, and by Tyr in only kidneys and livers of DBA/2J mice. In addition, L-Car and Trp decreased Pb accumulation in most organs of mice. Res and Tyr also inhibited Pb accumulation in some cases. Thus, the studied supplements affected the metabolism of trace elements, which may contribute to dietary treatments for obese individuals.

Counterions determine uptake and effects of aluminum in human intestinal and liver cells

Aluminum (Al) is highly abundant in the biosphere and can occur in different physico-chemical states. It is present in human food and undergoes transitions between dissolved and particulate species during the passage of the gastrointestinal tract. Moreover, in a complex matrix such as food different inorganic and organic counterions can affect the chemical behavior of Al following oral uptake. In this work, the effects of different counterions, namely chloride, citrate, sulfate, lactate and acetylacetonate, on Al uptake and toxicity in the human intestine are studied. The respective Al salts showed different dissolution behavior in biological media and formed nanoscaled particles correlating in reverse with the amount of their dissolved fraction. The passage through the intestinal barrier was studied using a Caco-2 Transwell® system, showing counterion-dependent variance in cellular uptake and transport. In addition, Al toxicity was investigated using Al species (Al³⁺, metallic Al⁰ and oxidic γAl₂O₃ nanoparticles) and counterions individually or in mixtures on Caco-2 and HepG2 cells. The strongest toxicity was observed using a combination of Al species, depending on solubility, and the lipophilic counterion acetylacetonate. Notably, only the combination of both led to toxicity, while both substances individually did not show toxic effects. A toxification of previously non-toxic Al-species by the presence of acetylacetonate is shown here for the first time. The dependency on the concentration of free Al ions was demonstrated using sodium hydrogen phosphate, which was able to counteract the toxic effects by complexing free Al ions. These findings, using Al salts as an example for a common food contaminant, underline the importance of a consideration of the chemical properties of human nutrition, especially dissolution and hydrophobicity, which can significantly influence the cellular uptake and effects of xenobiotic substances.

Associations of plasma metal concentrations with incident dyslipidemia: Prospective findings from the Dongfeng-Tongji cohort

Metal exposures are ubiquitous around the world, while it is lack of prospective studies to evaluate the associations of exposure to multiple metal/metalloids with incident dyslipidemia. A total of 2947 participants without dyslipidemia at baseline were included in the analyses. We utilized inductively coupled plasma mass spectrometry to measure the baseline plasma metal concentrations. Unconditional logistic regression models were applied to estimate the relations between plasma metals and risk of incident dyslipidemia, and principal component analysis was performed to extract principal components of metals. During 5.01 ± 0.31 years of follow-up, 521 subjects were diagnosed with incident dyslipidemia. After multivariable adjustment, the odds ratios (ORs) of dyslipidemia comparing the highest quartiles to the lowest were 1.58 (95% CI: 1.20, 2.08; P_trend = 0.001) for aluminum, 1.34 (95% CI: 1.03, 1.75; P_trend = 0.03) for arsenic, 1.44 (1.09, 1.91; P_trend = 0.03) for strontium, and 1.47 (95% CI: 1.09, 2.00; P_trend = 0.005) for vanadium. The four metals also showed significant associations with the subtypes of dyslipidemia, including low HDL-C and high LDL-C. The first principal component, which mainly represented aluminum, arsenic, barium, lead, vanadium, and zinc, was associated with increased risk of incident dyslipidemia, and the adjusted OR was 1.40 (95% CI: 1.07, 1.84; P_trend = 0.02) comparing extreme quartiles. The study indicated that elevated plasma aluminum, arsenic, strontium, and vanadium concentrations were associated with a higher incidence of dyslipidemia. These findings highlight the importance of controlling metal exposures for dyslipidemia prevention.

Ginsenoside Rg3 Alleviates Aluminum Chloride-Induced Bone Impairment in Rats by Activating the TGF-β1/Smad Signaling Pathway

Aluminum (Al)-induced bone formation and metabolism disorder through inhibition of the TGF-β1/Smad signaling pathway is one of the important mechanisms of bone impairment. Ginsenoside Rg3 (Rg3), a specific biological effector molecule, can provide protection to bones. Previously, we demonstrated that Rg3 can reverse aluminum chloride (AlCl₃)-induced oxidative stress and metabolic disorder of bones; however, whether the TGF-β1/Smad signaling pathway is involved in it remains unclear. First, we found that Rg3 attenuated Al-induced bone impairment in vivo and in vitro by relieving structural damage to the femur, increasing MC3T3-E1 cell activity, differentiation, mineralization, inhibition of cell apoptosis, and upregulating the extracellular matrix (ECM) synthesis and the expression of TGF-β1/Smad signaling pathway key factors. Subsequently, in the signal pathway intervention experiment, the protective effect of Rg3 on bone impairment induced by Al was weakened; these results indicate that activating the TGF-β1/Smad signaling pathway is one of the mechanisms of Rg3-attenuated Al-induced bone impairment.

Association of multiple metals with lipid markers against different exposure profiles: A population-based cross-sectional study in China

We sought to evaluate whether essential and toxic metals are cross-sectionally related to blood lipid levels using data among adults from Shimen (n = 564) and Huayuan (n = 637), two counties with different exposure profiles in Hunan province of China. Traditional and grouped weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were performed to assess association between exposure to a mixture of 22 metals measured in urine or plasma, and lipid markers. Most of the exposure levels of metals were significantly higher in Shimen area than those in Huayuan area (all P-values < 0.001). Traditional WQS regression analyses revealed that the WQS index were both significantly associated with lipid markers in two areas, except for the HDL-C. Grouped WQS revealed that essential metals group showed significantly positive associations with lipid markers except for HDL-C in Huayuan area, while toxic metals group showed significantly negative associations except for HDL-C and LDL-C in Huayuan area. There were no significant joint effects, but potential non-linear relationships between metals mixture and TC or LDL-C levels were observed in BKMR analyses. Although consistent significantly associations of zinc and titanium with TG levels were found in both areas, the metals closely related to other lipid markers were varied by sites. Additionally, the BKMR analyses revealed an inverse U shaped association of iron with LDL-C levels and interaction effects of zinc and cadmium on LDL-C in Huayuan area. The relationship between metal exposure and blood lipid were not identical against different exposure profiles.

Aluminium adjuvants in vaccines - A way to modulate the immune response

Aluminium salts have been used as adjuvants in vaccines for almost a century, but still no clear understanding of the mechanisms behind the immune stimulating properties of aluminium based adjuvants is recognized. Aluminium adjuvants consist of aggregates and upon administration of a vaccine, the aggregates will be recognized and phagocytosed by sentinel cells such as macrophages or dendritic cells. The adjuvant aggregates will persist intracellularly, maintaining a saturated intracellular concentration of aluminium ions over an extended time. Macrophages and dendritic cells are pivotal cells of the innate immune system, linking the innate and adaptive immune systems, and become inflammatory and antigen-presenting upon activation, thus mediating the initiation of the adaptive immune system. Both types of cell are highly adaptable, and this review will discuss and highlight how the occurrence of intracellular aluminium ions over an extended time may induce the polarization of macrophages into inflammatory and antigen presenting M1 macrophages by affecting the: endosomal pH; formation of reactive oxygen species (ROS); stability of the phagosomal membrane; release of damage associated molecular patterns (DAMPs); and metabolism (metabolic re-programming). This review emphasizes that a persistent intracellular presence of aluminium ions over an extended time has the potential to affect the functionality of sentinel cells of the innate immune system, inducing polarization and activation. The immune stimulating properties of aluminium adjuvants is presumably mediated by several discrete events, however, a persistent intracellular presence of aluminium ions appears to be a key factor regarding the immune stimulating properties of aluminium based adjuvants.

Role of mitochondria in liver metabolic health and diseases

The liver is a major organ that coordinates the metabolic flexibility of the whole body, which is characterized by the ability to adapt dynamically in response to fluctuations in energy needs and supplies. In this context, hepatocyte mitochondria are key partners in fine-tuning metabolic flexibility. Here we review the metabolic and signalling pathways carried by mitochondria in the liver, the major pathways that regulate mitochondrial function and how they function in health and metabolic disorders associated to obesity, i.e. insulin resistance, non-alcoholic steatosis and steatohepatitis and hepatocellular carcinoma. Finally, strategies targeting mitochondria to counteract liver disorders are discussed.

Differential susceptibility of PC12 and BRL cells and the regulatory role of HIF-1α signaling pathway in response to acute methylmercury exposure under normoxia

Hypoxia-inducible factor 1 (HIF-1) is a critical nuclear transcription factor for adaptation to hypoxia; its regulatable subunit, HIF-1α, is a cytoprotective regulatory factor. We examined the effects of methylmercury (MeHg) in rat adrenal pheochromocytoma (PC12) cells and the rat hepatocyte cell line BRL. MeHg treatment led to time- and concentration-dependent toxicity in both lines with statistically significant cytotoxic effects at 5 μM and 10 μM in PC12 and BRL, respectively, at 0.5 h. HIF-1α protein levels were significantly decreased at 2.5 (PC12) and 5 (BRL) μM MeHg. Furthermore, MeHg reduced the protein levels of HIF-1α and its target genes (glucose transporter-1, vascular endothelial growth factor-A and erythropoietin). Overexpression of HIF-1α significantly attenuated MeHg-induced toxicity in both cell types. Notably, cobalt chloride, a pharmacological inducer of HIF-1α, significantly attenuated MeHg-induced toxicity in BRL but not PC12. In both cell lines, an inhibitor of prolyl hydroxylase, 3, 4-dihydroxybenzoic acid, and the proteasome inhibitor carbobenzoxy-L-leucyl-L-leucyl-L-leucinal(MG132), antagonized MeHg toxicity, while 2-methoxyestradiol, a HIF-1α inhibitor, significantly increased it. These data establish that: (a) neuron-like PC12 cells are more sensitive to MeHg than non-neuronal BRL cells; (b) HIF-1α plays a similar role in MeHg-induced toxicity in both cell lines; and (c) upregulation of HIF-1α offers general cytoprotection against MeHg toxicity in PC12 and BRL cell lines.

Metals and low dose IR: Molecular effects of combined exposures using HepG2 cells as a biological model

Uranium mining sites produce residues rich in metals and radionuclides, that may contaminate all environmental matrices, exposing human and non-human biota to low doses of ionizing radiation (LDIR) and to the chemical toxicity of several metals. To date, experimental and radio-epidemiological studies do not provide conclusive evidence of LDIR induced cancer. However, co-exposures (LDIR plus other contaminants), may increase the risks. To determine the potential for genotoxic effects in human cells induced by the exposure to LDIR plus metals, HEPG2 cells were exposed to different concentrations of a uranium mine effluent for 96 h. DNA damage was evaluated using the comet assay and changes in the expression of tumor suppressor and oncogenes were determined using qPCR. Results show that effluent concentrations higher than 5%, induce significant DNA damage. Also, a significant under-expression of ATM and TP53 genes and a significant overexpression of GADD45a gene was observed. Results show that the exposure to complex mixtures cannot be disregarded, as effects were detected at very low doses. This study highlights the need for further studies to clarify the risks of exposure to LDIR along with other stressors, to fully review the IR exposure risk limits established for human and non-human biota.

Biochemical pathways to α-ketoglutarate, a multi-faceted metabolite

α-Ketoglutarate (AKG) also known as 2-oxoglutarate is an essential metabolite in virtually all organisms as it participates in a variety of biological processes including anti-oxidative defence, energy production, signalling modules, and genetic modification. This keto-acid also possesses immense commercial value as it is utilized as a nutritional supplement, a therapeutic agent, and a precursor to a variety of value-added products such as ethylene and heterocyclic compounds. Hence, the generation of KG in a sustainable and environmentally-neutral manner is a major ongoing research endeavour. In this mini-review, the enzymatic systems and the metabolic networks mediating the synthesis of AKG will be described. The importance of such enzymes as isocitrate dehydrogenase (ICDH), glutamate dehydrogenase (GDH), succinate semialdehyde dehydrogenase (SSADH) and transaminases that directly contribute to the formation of KG will be emphasized. The efficacy of microbial systems in providing an effective platform to generate this moiety and the molecular strategies involving genetic manipulation, abiotic stress and nutrient supplementation that result in the optimal production of AKG will be evaluated. Microbial systems and their components acting via the metabolic networks and the resident enzymes are well poised to provide effective biotechnological tools that can supply renewable AKG globally.

Geraniol attenuates oxidative stress, bioaccumulation, serological and histopathological changes during aluminum chloride-hepatopancreatic toxicity in male Wistar rats

Aluminum chloride (AlCl₃) has different industrial applications including manufacturing paint and water treatment. The present study was designed to evaluate the alleviating effect of geraniol against AlCl₃-induced hepatopancreatic toxicity. To this end, forty male Wistar rats were divided into control (0.9% NaCl, IP), geraniol (100 mg/kg orally), AlCl₃ (70 mg/kg, IP), and AlCl₃ (70 mg/kg, IP) plus geraniol (100 mg/kg orally) groups and then were treated daily for 28 days. Based on the results, serum cholesterol, triglyceride, as well as liver and pancreas enzymes increased significantly (P < 0.05) while the level of insulin significantly decreased in AlCl₃-treated rats compared to the control group (P < 0.05). The presence of geraniol relieved the toxic effects of AlCl₃ as well. On the other hand, the level of malondialdehyde (MDA) increased in the AlCl₃-treated group while the activities of glutathione peroxidase and the total antioxidant activity demonstrated a reduction. However, the MDA level decreased while the antioxidant enzymes increased in co-treated with geraniol group. Histopathological examination revealed that simultaneous treatment with geraniol in AlCl₃ intoxicated rats ameliorate the liver lesions such as necrosis, inflammatory cell infiltration, vacuolar degeneration, along with hyperemia and the cell density of the Langerhans islands. Finally, the results indicated that geraniol attenuated the side effect of AlCl₃-induced hepatopancreatic toxicity.

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.

Enhanced osteogenic differentiation of human mesenchymal stromal cells as response to periodical microstructured Ti6Al4V surfaces

Titanium-based alloys, for example, Ti6Al4V, are frequently employed for load-bearing orthopedic and dental implants. Growth of new bone tissue and therefore osseointegration can be promoted by the implant's microtopography, which can lead to improved long-term stability of the implant. This study investigates the effect that an organized, periodical microstructure produced by an electron beam (EB) technique has on the viability, morphology, and osteogenic differentiation capacity of human mesenchymal stromal cells (hMSC) in vitro. The technique generates topographical features of 20 μm in height with varying distances of 80-240 μm. Applied alterations of the surface roughness and local alloy composition do not impair hMSC viability (>94%) or proliferation. A favorable growth of hMSC onto the structure peaks and well-defined focal adhesions of the analyzed cells to the electron beam microstructured surfaces is verified. The morphological adaptation of hMSC to the underlying topography is detected using a three-dimensional (3D) visualization. In addition to the morphological changes, an increase in the expression of osteogenic markers such as osteocalcin (up to 17-fold) and osteoprotegerin (up to sixfold) is observed. Taken together, these results imply that the proposed periodical microstucturing method could potentially accelerate and enhance osseointegration of titanium-based bone implants.

A water-soluble molecular probe with aggregation-induced emission for discriminative detection of Al3+ and Pb2+ and imaging in seedling root of Arabidopsis

Luminogens with aggregation-induced emission (AIE) have been used to develop a new type of molecular probes based on analyte-triggered aggregation, but it still remains a challenge to design water-soluble AIE-active probe for specific detection of metal ions. Herein, we designed and synthesized a water-soluble molecular probe with AIE property for discriminative detection of aluminum ion and lead ion. Four carboxylic acid groups were incorporated into a tetraphenylethylene unit to enhance the coordination affinity and increase water-solubility in aqueous solution. The designed probe can be selectively lighted up by aluminum ion and lead ion via coordination-triggered AIE process. Discrimination of aluminum ion and lead ions based on the probe can be achieved in quantitative manner with the assistance of suitable masking reagents. This probe was further used to image aluminum ions in living cells of seedling roots of Arabidopsis, and the results showed that this probe is capable of imaging aluminum ions in living cells avoiding the interference of lead ions, and is suited for long-term imaging due to its excellent photostability. This work expands the application scope of AIE-active probes in discriminative detection of metal ions, and provides a design direction for water-soluble AIE probes to avoid the false signals from self-precipitation under physiological conditions.

Aluminium levels in hair and urine are associated with overweight and obesity in a non-occupationally exposed population

BACKGROUND

Data on the association between aluminium (Al) exposure and obesity and/or metabolic syndrome are insufficient. The objective of the present study was to investigate the association between hair and urine Al levels and obesity.

METHODS

A total of 206 lean and 205 obese non-occupationally exposed subjects (30-50 y.o.) were enrolled in the study. Hair and urine Al levels were assessed with ICP-MS. Laboratory quality control was performed using the certified reference materials of human hair, plasma, and urine.

RESULTS

Hair and urinary Al levels in obese subjects were significantly higher by 31% and 46% compared to the control levels, respectively. The presence of hypertension (41% cases), atherosclerosis (8%), type 2 diabetes mellitus (10%), and non-alcoholic fatty liver disease (NAFLD) (53%) in obese patients were not associated with Al levels in the studied subjects. An overall multiple regression model established urinary Al levels (β = 0.395; p < 0.001), hypertension (β = 0.331; p < 0.001) and NAFLD (β = 0.257; p = 0.003) were significantly and directly associated with BMI. Hair Al levels were found to be border-line significantly related to BMI after adjustment for several confounders (β = -0.205; p = 0.054).

CONCLUSIONS

Aluminium body burden is associated with increased body weight, although the causal relationship between Al exposure and obesity is not clear. Both clinical and experimental studies are required to further investigate the impact of Al exposure on metabolic parameters in obesity and especially direct effects of Al in adipose tissue.

Role of Curtobacterium herbarum strain CAH5 on aluminum bioaccumulation and enhancement of Lactuca sativa growth under aluminum and drought stresses

Aluminum (Al) bioaccumulation by a novel Al and drought tolerant Curtobacterium herbarum strain CAH5 isolated from rhizosphere soil of Beta vulgaris grown in acidic Andisols were examined. The rhizobacterial strain also presented important plant growth promoting traits even with Al and drought stresses under in-vitro conditions in broth. In experiments with a 2-6 mM as initial Al concentrations, the percentages of Al removal by bacteria were 89-93% and 78-91% within 72 h incubation under the normal and drought conditions, respectively. Cytogenotoxicity assay revealed that the toxicity of Al was reduced after bioaccumulation process. In the greenhouse study, formulated bio-inoculant CAH5 significantly improves the Lactuca sativa growth under Al and drought stress by reducing oxidative stress, lipid peroxidation and Al accumulation in plant parts. Our results highlighted that strain CAH5 could be used as a promising bioresource for restoration of agricultural soil with presence of phytotoxic Al improving crop production even under drought conditions.

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.

Human health risk associated with the management of phosphorus in freshwaters using lanthanum and aluminium

The use of geo-engineering materials to manage phosphorus in lakes has increased in recent years with aluminium and lanthanum based materials being most commonly applied. Hence the potential impact of the use of these compounds on human health is receiving growing interest. This review seeks to understand, evaluate and compare potential unintended consequences on human health and ecotoxicological risks associated with the use of lanthanum- and aluminium-based materials to modify chemical and ecological conditions in water bodies. In addition to their therapeutic use for the reduction of intestinal phosphate absorption in patients with impaired renal function, the phosphate binding capacity of aluminium and lanthanum also led to the development of materials used for water treatment. Although lanthanum and aluminium share physicochemical similarities and have many common applications, their uptake and kinetics within the human body and living organisms importantly differ from each other which is reflected in a different toxicity profile. Whilst a causal role in the development of neurological pathologies, skeletal lesions, hematopoietic disorders and respiratory effects has unequivocally been demonstrated with increased exposure to aluminium, studies until now have failed to find such a clear association after exposure to lanthanum although caution is warranted. Our review indicates that lanthanum and aluminium have a distinctly different profile with respect to their potential effects on human health. Regular monitoring of both aluminium and lanthanum concentrations in lanthanum-/aluminium-treated water by the responsible authorities is recommended to avoid acute accidental or chronic low level accumulation.

NMR-based lipidomics of fish from a metal(loid) contaminated wetland show differences consistent with effects on cellular membranes and energy storage

Metals and metalloids are priority contaminants due to their non-degradable and bioaccumulative nature, and their ability to regulate and perturb diverse physiological processes in various species. Metal(loid)s are known to cause oxidative stress through production of reactive oxygen species (ROS), thus related endpoints like lipid peroxidation (LPO) have received considerable attention as biomarkers of exposure. However, the implications of metal(loid) toxicity including LPO on actual lipid profiles of species inhabiting contaminated systems are poorly understood. Here we applied Nuclear Magnetic Resonance (NMR) spectroscopy for untargeted lipidomics of mosquitofish (Gambusia holbrooki) collected from reference and metal(loid)-contaminated wetlands. We measured a range of trace elements in water and fish using inductively coupled plasma - mass spectrometry (ICP-MS), and interpreted site differences in the lipid profiles of mosquitofish in the context of known physiological responses to sub-lethal metal(loid) exposure. Results indicate deregulation of cellular membrane lipids (i.e., glycerophospholipids, cholesterol and sphingolipids) and increased energy storage molecules (i.e., triacylglycerols and fatty acids) in fish from the contaminated wetland. These responses are consistent with the recognised induction of oxidative stress pathways in organisms exposed to metal(loid)s and could also be symptomatic of mitochondrial dysfunction and endocrine disruption. It is difficult to attribute metal(loid)s as the sole factor causing differences between wetlands, and a more controlled experimental approach is therefore warranted to further explore mechanistic pathways. Nevertheless, our study highlights the benefits of untargeted ¹H NMR-based lipidomics as a relatively fast and simple approach for field-scale assessment and monitoring of organisms inhabiting metal(loid) contaminated environments.

Mixtures of Aluminum and Indium Induce More than Additive Phenotypic and Toxicogenomic Responses in Daphnia magna

Aquatic systems are contaminated by many metals but their effects as mixtures on organisms are not well understood. Here, we assessed effects of aluminum with fairly well-known modes of actions and indium, an understudied emerging contaminant from electronics, followed by studying equi-effective mixtures thereof. We report acute and adverse phenotypic effects in Daphnia magna adults and global transcriptomic effects employing RNA sequencing in neonates. The mixture induced more than additive activity in mortality and in physiological effects, including growth and reproduction. Similarly, transcriptomic effects were more than additive, as indicated by a markedly higher number of 463 differentially expressed transcripts in the mixture and by distinct classes of genes assigned to several biological functions, including metabolic processes, suggesting depleted energy reserves, which may be responsible for the observed impaired reproduction and growth. A gene set enrichment analysis (GSEA) of a priori known response pathways for aluminum confirmed activation of distinct molecular pathways by indium. Our study is highlighting more than additive effects at the transcriptional and physiological level and is providing a state-of-the art approach to mixture analysis, which is important for risk assessment of these metals and metal mixtures.

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.

Cyclin B1/CDK1-regulated mitochondrial bioenergetics in cell cycle progression and tumor resistance

A mammalian cell houses two genomes located separately in the nucleus and mitochondria. During evolution, communications and adaptations between these two genomes occur extensively to achieve and sustain homeostasis for cellular functions and regeneration. Mitochondria provide the major cellular energy and contribute to gene regulation in the nucleus, whereas more than 98% of mitochondrial proteins are encoded by the nuclear genome. Such two-way signaling traffic presents an orchestrated dynamic between energy metabolism and consumption in cells. Recent reports have elucidated the way how mitochondrial bioenergetics synchronizes with the energy consumption for cell cycle progression mediated by cyclin B1/CDK1 as the communicator. This review is to recapitulate cyclin B1/CDK1 mediated mitochondrial activities in cell cycle progression and stress response as well as its potential link to reprogram energy metabolism in tumor adaptive resistance. Cyclin B1/CDK1-mediated mitochondrial bioenergetics is applied as an example to show how mitochondria could timely sense the cellular fuel demand and then coordinate ATP output. Such nucleus-mitochondria oscillation may play key roles in the flexible bioenergetics required for tumor cell survival and compromising the efficacy of anti-cancer therapy. Further deciphering the cyclin B1/CDK1-controlled mitochondrial metabolism may invent effect targets to treat resistant cancers.

Hair Trace Elements in Overweight and Obese Adults in Association with Metabolic Parameters

The objective of the present study was to investigate the level of toxic and essential trace elements in hair of adult overweight and obese persons as well as its association with metabolic parameters. Hair trace element levels were assessed using inductively coupled plasma mass-spectrometry in 112 overweight and obese patients and 106 lean controls. Serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), glucose, uric acid (UA) levels, and cholinesterase (CE) and gamma-glutamyltransferase (GGT) activity were also assessed. Excessive body weight significantly affected hair trace element levels. In particular, hair Co (33%), Cu (13%), I (30%), Mg (2-fold), Mn (25%), Zn (17%), and Ni (21%) levels were lower, whereas Al (14%) and As levels were higher in comparison to those in the control group. Correlation analysis demonstrated the most significant correlations for hair Mg with body weight, BMI, systolic and diastolic blood pressure, and UA, and for hair Al with body weight, BMI, TC, glucose, TG, CE, GGT, and UA. Multiple regression analysis demonstrated that trace elements were not associated with TC and LDL-C levels neither in crude nor in adjusted models. In turn, crude and adjusted models accounted for 25 and 43% of serum TG variance. The most significant associations were observed for hair Al, Fe, Si, and V in adjusted model. The obtained data demonstrate that obesity-related metabolic disorders may be at least partially mediated by altered trace element and mineral levels.

Aluminum Exposure from Parenteral Nutrition: Early Bile Canaliculus Changes of the Hepatocyte

Background: Neonates on long-term parenteral nutrition (PN) may develop parenteral nutrition-associated liver disease (PNALD). Aluminum (Al) is a known contaminant of infant PN, and we hypothesize that it substantially contributes to PNALD. In this study, we aim to assess the impact of Al on hepatocytes in a piglet model. Methods: We conducted a randomized control trial using a Yucatan piglet PN model. Piglets, aged 3–6 days, were placed into two groups. The high Al group (n = 8) received PN with 63 µg/kg/day of Al, while the low Al group (n = 7) received PN with 24 µg/kg/day of Al. Serum samples for total bile acids (TBA) were collected over two weeks, and liver tissue was obtained at the end of the experiment. Bile canaliculus morphometry were studied by transmission electron microscopy (TEM) and ImageJ software analysis. Results: The canalicular space was smaller and the microvilli were shorter in the high Al group than in the low Al group. There was no difference in the TBA between the groups. Conclusions: Al causes structural changes in the hepatocytes despite unaltered serum bile acids. High Al in PN is associated with short microvilli, which could decrease the functional excretion area of the hepatocytes and impair bile flow.

Mitigation of Acute Aluminum Toxicity by Sodium Selenite and N-Acetylcysteine in Adult Male Rats

The objective of this study is to investigate the toxic effects of aluminum and the potential alleviation of selenite and N-acetylcysteine (NAC) on this toxicity. Acute aluminum toxicity was induced by intraperitoneal (i.p.) injection of AlCl₃ (30 mg Al³⁺/kg) for four consecutive days. Al³⁺ damaged the synthetic capability and regeneration power of liver cells and induced inflammation. It also damaged the kidney and disturbed the lipid profile enhancing the total cholesterol level and LDL-cholesterol level increasing the risks of atherosclerosis. Al³⁺ reduced the cellular antioxidant milieu typified by the decrease in reduced glutathione, vitamin E, and four antioxidant enzymes and induced lipid peroxidation (LPO). Selenite at 1 mg Se/kg and NAC at 150 mg/kg injected either simultaneously with or after Al³⁺ mitigated most of these damaging effects probably by the virtue of scavenging the free radicals, binding aluminum and stimulating its excretion and reducing its bioavailability, bolstering the endogenous antioxidant defense systems, stabilizing the cell membrane, and preventing LPO. The beneficial effects of selenite and NAC against aluminum toxicity were also confirmed by the light and electron histopathology study. There were no significant differences between the two regimens used (protection and therapeutic) in the current study probably due to the short time of exposure, and the abrogation of Al³⁺ toxicity offered by selenite was better than that provided by NAC on the histopathology level.