Aluminum content of human semen: Implications for semen quality

Trajectory model to analyze the effect of multi-metal exposures on sperm parameters and sex hormones of the MARHCS cohort in China

BACKGROUND

At present, several cross-sectional studies have found that exposure to metal/metalloid elements is closely associated with male reproduction. However, the long-term effects of metal exposure on male reproduction have not been explored.

METHODS

In 2013, 796 volunteers were recruited, followed by first and second follow-ups in 2014 and 2015. Urine, semen, and blood samples were collected at each stage to examine urinary metal/metalloid levels, sperm parameters, and sex hormones. Initially, the latent class trajectory model (LCTM) was utilized to analyze the trajectories of urinary metals. Subsequently, the effects of urinary metal trajectories on semen parameters and sex hormones were examined using the linear mixed model. Finally, the impact of urinary metal trajectories on the classification of semen quality (normal or abnormal) was evaluated using the generalized linear mixed model.

RESULTS

Among the 18 metals/metalloids studied, trajectories were formed by 6 of them (Li, Al, Fe, Zn, As, Rb). Further analysis using the linear mixed model and the generalized linear mixed model revealed that Li was negatively correlated with semen volume, and sperm motility (P < 0.05). The maximum-decreasing trajectory group had a detrimental effect on semen quality (OR = 1.75, 95%CI: 1.22, 2.53) compared to the minimum-stable trajectory group. Al showed negative associations with sperm concentration, total sperm count, and normal morphology (P < 0.05). Rb was positively associated with progressive motility (P < 0.05). The high-stable trajectory group exhibited a protective effect on semen quality (OR = 0.66, 95%CI: 0.49, 0.90) compared to the low-stable trajectory group. Additionally, Fe was observed to have a negative relationship with follicle-stimulating hormone (FSH) (P < 0.05), and Rb exhibited a negative correlation with progesterone (P) (P < 0.05).

CONCLUSION

Our three-year cohort study provides new evidence that Li and Al have a negative impact on semen quality, whereas Rb is associated with beneficial effects. Additionally, Rb and Fe are endocrine disruptors of sex hormones.

Associations between seminal plasma metals/metalloids and semen quality: A cross-sectional study

Exposure to metals/metalloids is reported to potentially influence semen quality. While most studies have focused on single metal impacts, the link between exposure to multiple metals and semen quality has remained less explored. The study aimed to investigate the effects of both individual and mixed metal/metalloid exposure on semen quality. A total of 330 men were recruited from three reproductive centers in eastern China. Seminal plasma levels of 25 metals/metalloids and sperm parameters were determined. We used the Generalized Linear Model (GLM) and Restricted Cubic Spline (RCS) to assess the relationships between single metals/metalloids and semen quality. The weighted quantile sum (WQS) models were then applied to evaluate the combined effect of all these metals/metalloids. We observed positive associations of exposure to lithium (Li), zinc (Zn), and magnesium (Mg) with an increased risk of below reference values for progressive motility and total motility using a logistic regression model (P < 0.05). Additionally, our results also revealed a significant inverse relationship between aluminum (Al) and both sperm concentration and count, while cobalt (Co) demonstrated a positive association with sperm concentration (P < 0.05). Notably, the WQS model indicated a significant positive association between exposure to metal/metalloid mixtures and the risk of abnormal progressive motility (OR: 1.57; 95%CI: 1.10, 2.24) and abnormal total motility (OR: 1.53; 95%CI: 1.06, 2.19), with this association primarily driven by Li, Mg, and Zn. In summary, our findings indicate that exposure to metal/metalloid mixtures might have an adverse effect on semen quality.

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.

Mechanism and impact of heavy metal-aluminum (Al) toxicity on male reproduction: Therapeutic approaches with some phytochemicals

Heavy metals are ubiquitous environmental toxicants that have been known to have a serious effect on human and animal health. Aluminum (Al) is a widely distributed metal in nature. Al exposure has a detrimental impact on human fertility. This review focused on Al-induced male reproductive toxicity and the potential therapeutic approaches with some phytochemicals. Data from the literature showed that Al exposure is accompanied by a drastic decline in blood levels of FSH, LH, and testosterone, reduced sperm count, and affected sperm quality. Al exposure at high levels can cause oxidative stress by increasing ROS and RNS production, mediated mainly by downregulating Nrf2 signaling. Moreover, several investigations demonstrated that Al exposure evoked inflammation, evidenced by increased TNF-α and IL-6 levels. Additionally, substantial evidence concluded the key role of apoptosis in Al-induced testicular toxicity mediated by upregulating caspase-3 and downregulating Bcl2 protein. The damaging effects of Al on mitochondrial bioenergetics are thought to be due to the excessive generation of free radicals. This review helps to clarify the main mechanism involved in Al-associated testicular intoxication and the treatment strategy to attenuate the notable harmful effects on the male reproductive system. It will encourage clinical efforts to target the pathway involved in Al-associated testicular intoxication.

Transcriptome-based analysis of the toxic effects of aluminum chloride exposure on spermatocytes

Aluminum chloride (AlCl3) exposure is pervasive in our daily lives. Numerous studies have demonstrated that exposure to AlCl3 can lead to male reproductive toxicity. However, the precise mechanism of action remains unclear. The objective of this study is to investigate the mechanism of aluminum-induced toxicity by analyzing the alterations in the global transcriptome gene profile of mouse spermatocytes (GC-2spd cells) exposed to AlCl3. GC-2spd cells were exposed to concentrations of 0, 1, 2, and 4 mM AlCl3, and high-throughput mRNA-seq was performed to investigate the changes in the transcriptome after exposure to 4 mM AlCl3. Our findings indicate that exposure to AlCl3 led to an increase in oxidative stress, disrupted glutathione metabolism, reduced cell viability, and altered gene expression in mouse spermatocytes. Gene enrichment analysis revealed that the differentially expressed genes (DEGs) were associated with various biological functions such as mitochondrial inner membrane, response to oxidative stress. Furthermore, these DEGs were found to be enriched in pathways including proteasome, glutathione metabolism, oxidative phosphorylation, and Hif-1 signaling pathway. Real-time PCR and western blot were employed to validate the expression alterations of pivotal genes, and the outcomes exhibited concordance with the mRNA-seq findings. This study provides a theoretical basis for revealing the potential mechanism of male reproductive toxicity caused by aluminum exposure.

Impacts of heavy metal exposure on the prostate of murine models: Mechanisms of toxicity

Heavy metals are elements found into the environment mainly due to anthropogenic activities. Naturally occurring and higher released doses cause disorders in the prostate, which depends on appropriate hormonal regulation, and exposure to heavy metals may impair prostate homeostasis. The current work highlighted the main mechanisms of toxicity of different environmental heavy metal contaminants, such as aluminum, arsenic, cadmium, chromium, lead, mercury, and nickel, and their impacts found in the prostate morphophysiology of murine models. The repercussions triggered by heavy metals on the prostate include hormonal imbalance and oxidative damage, leading to morphological alterations, which can vary according to the chemical properties of each element, exposure time and concentration, and age. The information of altered biological pathways and its impacts on the prostate of exposed murines are related to human outcomes being useful in the real context of human exposure.

Influence of Seminal Metals on Assisted Reproduction Outcome

Increased levels of metal ions in human seminal fluid have a significant correlation with male fertility. Few publications explain the effect of metals in semen and their influence on assisted reproductive treatments. Semen parameters and the levels of twenty-two metals were measured in the seminal fluid of 102 men attended in a Reproductive Unit. Metals were determined by optical emission spectrophotometry. A statistical relationship was found between spermiogram and iron, which was lower than expected in pathological spermiograms (p = 0.032); zinc (p = 0.066), calcium (p = 0.047), and magnesium (p = 0.048) mean levels were higher in normozoospermics. More days of sexual abstinence correlates with higher seminal zinc (p = 0.001) and magnesium levels (p = 0.002). Lower vanadium values were found to be associated with higher fertilization rates (p = 0.039). Higher values of lead (p = 0.052) and vanadium (p = 0.032) were obtained in patients who did not reach 100% embryo cleavage rate. Aluminium (p = 0.042) and sodium (p = 0.002) were found in lower amounts associated with better blastocyst rates. The implantation rate shows an inverse association with women's age and iron and calcium content, compared to magnesium and sodium which presented a significant direct association with this percentage. A significant direct relationship was found between the positive evolution of pregnancy and the values of zinc (p = 0.004), calcium (p = 0.013), potassium (p = 0.002), and magnesium (p = 0.009). The study confirms that zinc, iron, calcium, sodium, aluminium, magnesium, vanadium, and lead have positive-negative effects on reproduction and support the analysis of metals in semen as a new line of study on male fertility with implications for reproductive outcomes.

Dietary Egg White Hydrolysate Prevents Male Reproductive Dysfunction after Long-Term Exposure to Aluminum in Rats

Aluminum (Al) is a non-essential metal omnipresent in human life and is considered an environmental toxicant. Al increases reactive oxygen production and triggers immune responses, contributing to chronic systemic inflammation development. Here, we have tested whether an egg white hydrolysate (EWH) with potential bioactive properties can protect against changes in reproductive function in rats exposed to long-term Al dietary levels at high and low doses. Male Wistar rats received orally: low aluminum level group-AlCl₃ at 8.3 mg/kg b.w. for 60 days with or without EWH (1 g/kg/day); high aluminum level group-AlCl₃ at 100 mg/kg b.w. for 42 days with or without EWH (1 g/kg/day). The co-administration of EWH prevented the increased Al deposition surrounding the germinative cells, reducing inflammation and oxidative stress in the reproductive organs. Furthermore, the daily supplementation with EWH maintained sperm production and sperm quality similar to those found in control animals, even after Al exposure at a high dietary contamination level. Altogether, our results suggest that EWH could be used as a protective agent against impairment in the reproductive system produced after long-term exposure to Al at low or high human dietary levels.

The protective effect of esculetin against aluminium chloride-induced reproductive toxicity in rats

One of the prominent health problems caused by Aluminium was the decrease in male fertility rates. In the study, the protective effect of Esculetin (ESC) against the reproductive toxicity induced by Aluminium chloride (AlCl3 ) was investigated. For this purpose, AlCl3 was administrated to Wistar Albino rats at a dose of 34 mg/kg and ESC was administrated at a dose of 50 mg/kg for 70 days. It was determined that AlCl3 treatment reduced sperm motility and concentration, increased dead/live rate and abnormal sperm rate. It decreased serum testosterone level, and co-treatment of ESC significantly regulated these values. In the AlCl3 -treated group, MDA level increased and GSH level, GPx and CAT activities decreased compared with those of the control group. However, co-treatment of ESC showed an amelioratory effect on the values except for CAT activity. It was observed that the expression level of NRF-2 increased in the ESC and AlCl3  + ESC groups, and NF-κB increased in the AlCl3 group with the control group. It was determined that Caspase-3 expression decreased, and Bcl-2 expression increased in AlCl3  + ESC group compared to AlCl3 group. It was also determined that AlCl3 -induced tissue injury was significantly prevented by ESC co-treatment.

Paternal exposure to aluminum, acidity, and temperature affect fatty acid seminal profile, embryonic and larval development of Astyanax altiparanae

We investigated the effects of water acidity, temperature, and aluminum (Al) on the fatty acid (FA) seminal profile, reproductive parameters (fertilization and hatching) and embryonic development of Astyanax altiparanae. We treated males with different experimental treatments, corresponding to the combination of water temperature (20 °C; 25 °C), pH (neutral - 7.0; acidic - 5.5), and the absence or presence of Al (0.5 mg L^-1). After 96 h, we analyzed the FA profile of semen and performed artificial fertilization in activating medium with neutral pH or activating medium in the same experimental conditions of the males (neutral pH, acidic pH, and Al) to evaluate fertilization and hatching rates and to monitor embryonic development. Polyunsaturated FA percentage decreased in semen of fish from the neutral group, while monounsaturated FA increased in all groups maintained at 20 °C compared to 25 °C. Aluminum exposure decreased the percentage of C20:4n6 and increased the percentage of C22:5n3 at 20 °C. Males exposed to acidic pH and Al showed lower fertilization and hatching rates, as well as increased mortality of embryos and larvae. Moreover, Al favoured a higher percentage of abnormal larvae. Fertilization in Al activating medium harmed the embryos and larvae since fertilization and hatching rates decreased. Finally, temperature influenced fertilization time, hatching rate, and the morphology of embryos and larvae. Males exposed to Al had lower fertilizing capacity, which negatively affected the embryonic development of the species. Furthermore, Al activating medium reduced the number of fertilized oocytes, hatched embryos, and normal larvae. All events were temperature dependent.

Aluminum reproductive toxicity: a summary and interpretation of scientific reports

Publications addressing aluminum (Al)-induced reproductive toxicity were reviewed. Key details were compiled in summary tables. Approximate systemic Al exposure, a measure of bioavailability, was calculated for each exposure, based on the Al percentage in the dosed Al species, Al bioavailability, and absorption time course reports for the exposure route. This was limited to laboratory animal studies because no controlled-exposure human studies were found. Intended Al exposure was compared to unintended dietary Al exposure. The considerable and variable Al content of laboratory animal diets creates uncertainty about reproductive function in the absence of Al. Aluminum-induced reproductive toxicity in female mice and rats was evident after exposure to ≥25-fold the amount of Al consumed in the diet. Generally, the additional daily Al systemic exposure of studies that reported statistically significant results was greater than 100-fold above the typical human daily Al dietary consumption equivalent. Male reproductive endpoints were significantly affected after exposure to lower levels of Al than females. Increased Al intake increased fetus, placenta, and testes Al concentrations, to a greater extent in the placenta than fetus, and, in some cases, more in the testes than placenta. An adverse outcome pathway (AOP) was constructed for males based on the results of the reviewed studies. The proposed AOP includes oxidative stress as the molecular initiating event and increased malondialdehyde, DNA and spermatozoal damage, and decreased blood testosterone and sperm count as subsequent key events. Recommendations for the design of future studies of reproductive outcomes following exposure to Al are provided.

Aluminum, at an environmental concentration, associated with acidic pH and high water temperature, causes impairment of sperm quality in the freshwater teleost Astyanax altiparanae (Teleostei: Characidae)

Given the toxicity of metals, including aluminum (Al), and the effects of water temperature on ectotherms, we investigated the individual or association effect of these variables (Al + acidic pH + temperature changes) on sperm quality of Astyanax altiparanae. Mature males were divided into nine experimental groups based on the combination of each of three water temperatures (20, 25, and 30 °C) with neutral and acidic pH values (7.0 and 5.5, respectively) with or without 0.5 mg L^-1 Al. The fish were subjected to subacute, semi-static exposure and at 24 and 96 h were evaluated for seminal parameters: (1) pH; (2) osmolality; (3) sperm concentration; (4) sperm morphology; (5) sperm kinetics; and (6) sperm ultrastructure. At 30 °C, Al caused a reduction in osmolality (24 and 96 h) and sperm concentration (24 h). When analysing sperm kinetics (30 s post-activation), Al caused a reduction in total motility at all temperatures (24 h), and when this exposure time was longer (96 h), both acidic pH and Al addition to the water caused sperm motility reduction. By analysing curvilinear velocity (VCL) 30 s after sperm activation (24 and 96 h), the acidic pH caused a reduction in sperm movement at 20 and 30 °C, but at 25 °C Al triggered this reduction. Finally, Al in the water caused ultrastructural changes in the sperm head, midpiece, and flagella regardless of water temperature. Also, it was found that the combination of Al at 30 °C caused a reduction in sperm head area while at 20 °C, Al triggered a reduction in the midpiece area. Therefore, acidity influenced some A. altiparanae sperm parameters but Al in the water accentuated these effects on seminal quality, especially seminal osmolality and sperm concentration, kinetics, and ultrastructure. This toxicity was also influenced by changes in water temperature.

Protective effects of vitamin E on aluminium sulphate-induced testicular damage

Male infertility can be caused by environmental factors, genetic defects, physiological and endocrine deficiencies and testicular pathologies. Aluminium (Al) can cause male infertility through a number of mechanisms. The aim of our study was thus to determine whether vitamin E (VitE) has protective effects on Al-induced testicular damage, which was determined according to sperm counts and morphology and using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Thirty-four male Wistar rats (250-300 g) were randomly assigned to control (no procedures performed; n = 6) or 0.2 mL intraperitoneal injection group (n = 7 each; three times per week for 4 weeks): sham (distilled water), 10 mg/kg Al, 500 mg/kg VitE and 10 mg/kg Al plus 500 mg/kg VitE (Al + VitE). Sperm samples were evaluated for andrological parameters. The testes were examined by haematoxylin/eosin. The epithelial thickness and areas were calculated and Johnsen scores were determined for the germinal epithelium; the apoptotic indices were determined from TUNEL staining. For Al, the bonds between the germinal epithelial cells were broken in some tubules, and there were unidentified cells in the lumen of some tubules. For control, sham and VitE, normal morphology of the germinal epithelium was generally preserved. With Al + VitE, the full germinal epithelium cell series was maintained, with only mature sperm in the lumen. TUNEL-positive cells were significantly higher with Al compared to control and sham (p < 0.05). For Al + VitE, the number of apoptotic cells was reduced compared to Al alone and was therefore similar to control, sham and VitE (p > 0.05). Our findings show that Al caused testicular damage. VitE reduced the number of apoptotic cells during the damage caused by Al.

In Utero Exposure to Aluminium and Other Neurotoxic Elements in Urban Coastal South African Women at Delivery: An Emerging Concern

Aluminium (Al) is a non-essential neurotoxicant and there is limited information regarding exposure to Al in utero. This study sought to evaluate the in utero exposure to Al in urban South African women, its effects on birth outcomes and possible synergistic effects between Al, essential and neurotoxic elements such as lead (Pb), mercury (Hg) and arsenic (As), as well as a a potential sex-dependent response to these elements in neonates. This study has found elevated levels of Al in urban women at delivery. The Spearman’s rank correlation coefficients (p-value) of the association between maternal serum Al and birth outcomes (gestational age and parity), and between maternal serum Al and Cu, Zn and Se, were statistically significant. However, in the general and the stratified models, no association was found between any of the birth outcomes and maternal serum Al. The association between maternal serum Al and neurotoxic elements at delivery showed a significant positive correlation for Pb only (rho = 0.361; p < 0.001) which was found to be sex-dependent in neonates (males, rho = 0.285; p < 0.004 and females, rho = 0.444, p < 0.001). Our preliminary findings indicate that in utero exposure to Al is an emerging concern requiring further research and directives from public health authorities.

Aluminum and Neurofibrillary Tangle Co-Localization in Familial Alzheimer's Disease and Related Neurological Disorders

BACKGROUND

Protein misfolding disorders are frequently implicated in neurodegenerative conditions. Familial Alzheimer's disease (fAD) is an early-onset and aggressive form of Alzheimer's disease (AD), driven through autosomal dominant mutations in genes encoding the amyloid precursor protein and presenilins 1 and 2. The incidence of epilepsy is higher in AD patients with shared neuropathological hallmarks in both disease states, including the formation of neurofibrillary tangles. Similarly, in Parkinson's disease, dementia onset is known to follow neurofibrillary tangle deposition.

OBJECTIVE

Human exposure to aluminum has been linked to the etiology of neurodegenerative conditions and recent studies have demonstrated a high level of co-localization between amyloid-β and aluminum in fAD. In contrast, in a donor exposed to high levels of aluminum later developing late-onset epilepsy, aluminum and neurofibrillary tangles were found to deposit independently. Herein, we sought to identify aluminum and neurofibrillary tangles in fAD, Parkinson's disease, and epilepsy donors.

METHODS

Aluminum-specific fluorescence microscopy was used to identify aluminum in neurofibrillary tangles in human brain tissue.

RESULTS

We observed aluminum and neurofibrillary-like tangles in identical cells in all respective disease states. Co-deposition varied across brain regions, with aluminum and neurofibrillary tangles depositing in different cellular locations of the same cell.

CONCLUSION

Neurofibrillary tangle deposition closely follows cognitive-decline, and in epilepsy, tau phosphorylation associates with increased mossy fiber sprouting and seizure onset. Therefore, the presence of aluminum in these cells may exacerbate the accumulation and misfolding of amyloidogenic proteins including hyperphosphorylated tau in fAD, epilepsy, and Parkinson's disease.

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.

Unequivocal imaging of aluminium in human cells and tissues by an improved method using morin

Aluminium is biologically reactive and its ability to potentiate the immune response has driven its inclusion in both veterinary and human vaccines. Consequently, the need for unequivocal visualisation of aluminium in vivo has created a focused research effort to establish fluorescent molecular probes for this purpose. The most commonly used direct fluorescent labels for the detection of aluminium are morin (2',3,4',5,7-pentahydroxyflavone) and lumogallion [4-chloro-3-(2,4-dihydroxyphenylazo)-2-hydroxybenzene-1-sulphonic acid]. While the former has gained popularity in the detection of aluminium in plants and predominantly within root tips, the latter boasts greater sensitivity and selectivity for the detection of aluminium in human cells and tissues. Herein, we have developed a simplified morin staining protocol using the autofluorescence quenching agent, Sudan Black B. This modified protocol improves tissue morphology and increases analytical sensitivity, which allows intracellular aluminium to be detected in monocytes and when co-localised with senile plaques in human brain tissue of donors diagnosed with familial Alzheimer's disease. Overall, our results demonstrate a simple approach to minimise false positives in the use of morin to unequivocally detect aluminium in vivo.

Increased Aluminum Content in Certain Brain Structures is Correlated with Higher Silicon Concentration in Alcoholic Use Disorder

INTRODUCTION

Alcohol overuse may be related to increased aluminum (Al) exposure, the brain accumulation of which contributes to dementia. However, some reports indicate that silicon (Si) may have a protective role over Al-induced toxicity. Still, no study has ever explored the brain content of Al and Si in alcoholic use disorder (AUD).

MATERIALS AND METHODS

To fill this gap, the present study employed inductively coupled plasma optical emission spectrometry to investigate levels of Al and Si in 10 brain regions and in the liver of AUD patients (n = 31) and control (n = 32) post-mortem.

RESULTS

Al content was detected only in AUD patients at mean ± SD total brain content of 1.59 ± 1.19 mg/kg, with the highest levels in the thalamus (4.05 ± 12.7 mg/kg, FTH), inferior longitudinal fasciculus (3.48 ± 9.67 mg/kg, ILF), insula (2.41 ± 4.10 mg/kg) and superior longitudinal fasciculus (1.08 ± 2.30 mg/kg). Si content displayed no difference between AUD and control, except for FTH. Positive inter-region correlations between the content of both elements were identified in the cingulate cortex, hippocampus, and ILF.

CONCLUSIONS

The findings of this study suggest that AUD patients may potentially be prone to Al-induced neurodegeneration in their brain-although this hypothesis requires further exploration.

Water temperature and acid pH influence the cytotoxic and genotoxic effects of aluminum in the freshwater teleost Astyanax altiparanae (Teleostei: Characidae)

The toxicity of metals, including aluminum (Al), can be potentiated by temperature and acid pH, a concern in view of the current global warming scenario. The aim of this study was to evaluate the bioconcentration of Al in the testes and semen of Astyanax altiparanae and the potential of this metal, at different environmental temperatures and acid pH, to cause cytotoxicity and genotocixity in erythrocytes and spermatozoa. A. altiparanae males were divided into nine experimental groups: at each of three different water temperatures (20, 25 and 30 °C), the fish were exposed to a neutral pH, an acid pH and acidic water containing Al (0.5 mg.L^-1). The fish were subjected to subacute, semi-static exposure and sampled at 24 and 96 h. After each exposure period the comet assay (blood and semen) and micronucleus test (blood) were performed. Bioconcentration of Al was evaluated in the testes and semen. Exposure time and temperature influenced the Al bioconcentration pattern in the testes. Al concentration in the semen was higher in fish exposed at 20 and 25 °C (24 h). The DNA fragmentation score for the semen and blood was higher in fish exposed to Al at 20 (24 h) and 30 °C (96 h). The frequency of nuclear abnormalities in erythrocytes was higher in the group exposed to Al at 30 °C (96 h). It was concluded that Al bioconcentrates in the testes and semen of A. altiparanae at different temperatures and is potentially cytotoxic and genotoxic to erythrocytes and spermatozoa in this species.

Variability and exposure classification of urinary levels of non-essential metals aluminum, antimony, barium, thallium, tungsten and uranium in healthy adult men

Arsenic, cadmium and lead are well-known toxic metals, and there are substantial studies on variability of these metals in urine to optimize design of exposure assessment. For urinary levels of other nonessential metals such as aluminum (Al), antimony (Sb), barium (Ba), thallium (Tl), tungsten (W) and uranium (U), however, their within-individual and between-individual variability are unclear. Therefore, we collected 529 samples from 11 healthy adult men on 8 days during a 3-month period. We measured urinary metals and creatinine (Cr) levels, assessed the reproducibility using intraclass correlation coefficients (ICCs), and performed sensitivity and specificity analyses to assess how well 1, 2 or 3 specimens could classify exposure. Al, Sb, Ba, W and U levels measured from spot samples varied greatly over days and months (Cr-adjusted ICCs = 0.01-0.14). Serial measures of Tl levels measured from spot samples had fair-to-good reproducibility over 5 consecutive days (Cr-adjusted ICC = 0.40), but worsened when the specimens were collected months apart (Cr-adjusted ICC = 0.16). To identify men who were highly exposed (top 33%) based on their 3-month averages, tests of single spot samples and tests of first-morning voids had high specificities (0.73-0.85) but relatively low sensitivities (0.27-0.60). Collection of repeated urine specimens from each individual improved the classification.

Egg White Hydrolysate as a functional food ingredient to prevent cognitive dysfunction in rats following long-term exposure to aluminum

Aluminum (Al), which is omnipresent in human life, is a potent neurotoxin. Here, we have tested the potential for Egg White Hydrolysate (EWH) to protect against changes in cognitive function in rats exposed to both high and low levels of Al. Indeed, EWH has been previously shown to improve the negative effects induced by chronic exposure to heavy metals. Male Wistar rats received orally: Group 1) Low aluminum level (AlCl3 at a dose of 8.3 mg/kg b.w. during 60 days) with or without EWH treatment (1 g/kg/day); Group 2) High aluminum level (AlCl3 at a dose of 100 mg/kg b.w. during 42 days) with or without EWH treatment (1 g/kg/day). After 60 or 42 days of exposure, rats exposed to Al and EWH did not show memory or cognitive dysfunction as was observed in Al-treated animals. Indeed, co-treatment with EWH prevented catalepsy, hippocampal oxidative stress, cholinergic dysfunction and increased number of activated microglia and COX-2-positive cells induced by Al exposure. Altogether, since hippocampal inflammation and oxidative damage were partially prevented by EWH, our results suggest that it could be used as a protective agent against the detrimental effects of long term exposure to Al.

Effect of Aluminum Exposure on Glucose Metabolism and Its Mechanism in Rats

The effects of aluminum (Al) exposure on glucose metabolism and its mechanism were investigated. A total of 30 healthy Wistar male rats were randomly divided into two groups: control (GC) and experimental (GE). The GC group received intraperitoneal normal saline. The GE was established by intraperitoneal injected AlCl₃ solution at 10 mg/kg for 30 days. Fasting blood glucose (FBG) and serum levels of insulin (FINS) were measured. The insulin resistance index (HOMA-IR) and pancreatic β cell function index (HOMA-β) were calculated and analyzed with homeostasis model assessment (HOMA). Pancreatic tissue was taken for pathological examination. Glucose transporter 4 (GLUT4) expression in skeletal muscle was detected by quantitative PCR and Western blot. Levels of FBG and HOMA-IR in GE were higher than those in GC at day 10 and 20 (P < 0.05). FINS in GE were higher than those in GC at day 10 and 20, and lower than those in GC at day 30 (P < 0.05). HOMA-β in GE was lower than that of GC at every time point (P < 0.05). Pathology showed that pancreatic damage changed more profoundly with prolongation of time in GE. Expression levels of GLUT4 mRNA and protein in rat skeletal muscle in GE were significantly lower than those in GC (P < 0.05). The results suggested that Al exposure affected glucose metabolism through pancreatic damage and reduction of GLUT4 expression.

Unraveling the enigma: elucidating the relationship between the physicochemical properties of aluminium-based adjuvants and their immunological mechanisms of action

Aluminium salts are by far the most commonly used adjuvants in vaccines. There are only two aluminium salts which are used in clinically-approved vaccines, Alhydrogel® and AdjuPhos®, while the novel aluminium adjuvant used in Gardasil® is a sulphated version of the latter. We have investigated the physicochemical properties of these two aluminium adjuvants and specifically in milieus approximating to both vaccine vehicles and the composition of injection sites. Additionally we have used a monocytic cell line to establish the relationship between their physicochemical properties and their internalisation and cytotoxicity. We emphasise that aluminium adjuvants used in clinically approved vaccines are chemically and biologically dissimilar with concomitantly potentially distinct roles in vaccine-related adverse events.

Prenatal Exposure to Aluminum and Status of Selected Essential Trace Elements in Rural South African Women at Delivery

This study sought to evaluate the in utero exposure to aluminum and status of selected trace elements in South African women at delivery since aluminum is known to be toxic in all developmental stages even at low concentrations. Serum aluminum was negatively correlated with aluminum in urine, both uncorrected and corrected for creatinine, which suggests the retention of aluminum in body stores. Serum copper and zinc levels were found to be high in this study population. Serum copper levels were negatively correlated with aluminum in serum (β = -0.095; p = 0.05). There was a marginal negative correlation between aluminum levels in serum and manganese levels in whole blood (β = -0.087; p = 0.08). Copper levels in maternal serum were negatively correlated with birth weight and the length of neonates. There were a number of positive correlations between maternal characteristics and birth outcomes. Mothers who consumed root vegetables frequently appeared to be protected from aluminum retention and increased body burden since their serum aluminum levels were found to be significantly lower. The findings of the current study can be used as a baseline for further research on aluminum exposure and its associated interactions and outcomes in vulnerable populations.

The Metal Neurotoxins: An Important Role in Current Human Neural Epidemics?

Many published studies have illustrated that several of the present day neurological epidemics (autism, attention deficit disorder, Alzheimer's) cannot be correlated to any single neurotoxicant. However, the present scientific examination of the numerous global blood monitoring databases for adults that include the concentrations of the neurotoxic elements, aluminum (Al), arsenic (As), lead (Pb), manganese (Mn), mercury (Hg), and selenium (Se) clearly indicate that, when considered in combination, for some, the human body may become easily over-burdened. This can be explained by changes in modern lifestyles. Similar data, solely for pregnant women, have been examined confirming this. All these elements are seen to be present in the human body and at not insignificant magnitudes. Currently suggested minimum risk levels (MRL) for humans are discussed and listed together with averages of the reported distributions, together with their spread and maximum values. One observation is that many distributions for pregnant women are not too dissimilar from those of general populations. Women obviously have their individual baseline of neurotoxin values before pregnancy and any efforts to modify this to any significant degree is not yet clearly apparent. For any element, distribution shapes are reasonably similar showing broad distributions with extended tails with numerous outlier values. There are a certain fraction of people that lie well above the MRL values and may be at risk, especially if genetically susceptible. Additionally, synergistic effects between neurotoxins and with other trace metals are now also being reported. It appears prudent for women of child-bearing age to establish their baseline values well before pregnancy. Those at risk then can be better identified. Adequate instrumental testing now is commercially available for this. In addition, directives are necessary for vaccination programs to use only non-neurotoxic adjuvants, especially for young children and all women of child-bearing ages. Additionally, clearer directives concerning fish consumption must now be reappraised.

Aluminum exposure for 60days at an equivalent human dietary level promotes peripheral dysfunction in rats

Aluminum (Al) is a neurotoxic associated with a number of chronic human diseases. We investigated the effects of Al exposure at doses similar to human dietary levels and at a high level exposure to Al on the peripheral nervous system. Wistar male rats were divided into two major groups and received orally: 1) First group - Low level - rats were subdivided and treated for 60days: a) Control - received ultrapure water; b) AlCl₃ - received Al at 8.3mg/kg body weight (bw) for 60days; and 2) Second group - High level - rats were subdivided and treated for 42days: C) Control - received ultrapure water through oral gavage; d) AlCl₃ - received Al at 100mg/kg bw for 42days. Von Frey hair test, plantar test, the presence of catalepsy and the spontaneous motor activity were investigated. Reactive oxygen species, lipid peroxidation and total antioxidant capacity, immunohistochemistry to investigate the nerve inflammation and, the specific presence of Al in the sciatic nerve fibers were investigated. Al exposure at a representative human dietary level promotes the development of mechanical allodynia, catalepsy, increased inflammation in the sciatic nerve, systemic oxidative stress and, is able to be retained in the sciatic nerve. The effects of low-dose Al were similar to those found in rats exposed to Al at a dose much higher (100mg/kg). Our findings suggest that Al may be considered toxic for the peripheral nervous system, thus inducing peripheral dysfunction.

Aluminum exposure at human dietary levels promotes vascular dysfunction and increases blood pressure in rats: A concerted action of NAD(P)H oxidase and COX-2

Aluminum (Al) is a non-essential metal and a significant environmental contaminant and is associated with a number of human diseases including cardiovascular disease. We investigated the effects of Al exposure at doses similar to human dietary levels on the cardiovascular system over a 60day period. Wistar male rats were divided into two major groups and received orally: 1) Low aluminum level - rats were subdivided and treated for 60days as follows: a) Untreated - ultrapure water; b) AlCl₃ at a dose of 8.3mg/kg bw for 60days, representing human Al exposure by diet; and 2) High aluminum level - rats were subdivided and treated for 42days as follows: C) Untreated - ultrapure water; d) AlCl₃ at 100mg/kg bw for 42days, representing a high level of human exposure to Al. Effects on systolic blood pressure (SBP) and vascular function of aortic and mesenteric resistance arteries (MRA) were studied. Endothelium and smooth muscle integrity were evaluated by concentration-response curves to acetylcholine (ACh) and sodium nitroprusside. Vasoconstrictor responses to phenylephrine (Phe) in the presence and absence of endothelium and in the presence of the NOS inhibitor L-NAME, the potassium channels blocker TEA, the NAD(P)H oxidase inhibitor apocynin, superoxide dismutase (SOD), the non-selective COX inhibitor indomethacin and the selective COX-2 inhibitor NS 398 were analyzed. Vascular reactive oxygen species (ROS), lipid peroxidation and total antioxidant capacity, were measured. The mRNA expressions of eNOS, NAD(P)H oxidase 1 and 2, SOD1, COX-2 and thromboxane A2 receptor (TXA-2 R) were also investigated. Al exposure at human dietary levels impaired the cardiovascular system and these effects were almost the same as Al exposure at much higher levels. Al increased SBP, decreased ACh-induced relaxation, increased response to Phe, decreased endothelial modulation of vasoconstrictor responses, the bioavailability of nitric oxide (NO), the involvement of potassium channels on vascular responses, as well as increased ROS production from NAD(P)H oxidase and contractile prostanoids mainly from COX-2 in both aorta and mesenteric arteries. Al exposure increased vascular ROS production and lipid peroxidation as well as altered the antioxidant status in aorta and MRA. Al decreased vascular eNOS and SOD1 mRNA levels and increased the NAD(P)H oxidase 1, COX-2 and TXA-2 R mRNA levels. Our results point to an excess of ROS mainly from NAD(P)H oxidase after Al exposure and the increased vascular prostanoids from COX-2 acting in concert to decrease NO bioavailability, thus inducing vascular dysfunction and increasing blood pressure. Therefore, 60-day chronic exposure to Al, which reflects common human dietary Al intake, appears to pose a risk for the cardiovascular system.

Aluminum exposure for 60days at human dietary levels impairs spermatogenesis and sperm quality in rats

Concerns about environmental aluminum (Al) and reproductive health have been raised. We investigated the effects of Al exposure at a human relevant dietary level and a high level exposure to Al. Experiment 1 (Lower level) rats were treated orally for 60 days: a) controls - ultrapure water; b) aluminum at 1.5mg/kg bw/day and c) aluminum at 8.3mg/kg bw/day. Experiment 2 (High level) rats were treated for 42 days: a) controls - ultrapure water; b) aluminum at 100mg/kg bw/day. Al decreased sperm count, daily sperm production, sperm motility, normal morphological sperm, impaired testis histology; increased oxidative stress in reproductive organs and inflammation in testis. Our study shows the specific presence of Al in the germinative cells and, that low concentrations of Al in testes (3.35μg/g) are sufficient to impair spermatogenesis and sperm quality. Our findings provide a better understanding of the reproductive health risk of Al.

Mapping Fifteen Trace Elements in Human Seminal Plasma and Sperm DNA

Studies suggest a relationship between semen quality and the concentration of trace elements in serum or seminal plasma. However, trace elements may be linked to DNA and capable of altering the gene expression patterns. Thus, trace element interactions with DNA may contribute to the mechanisms for a trans-generational reproductive effect. We developed an analytical method to determine the amount of trace elements bound to the sperm DNA, and to estimate their affinity for the sperm DNA by the ratio: R = Log [metal concentration in the sperm DNA/metal concentration in seminal plasma]. We then analyzed the concentrations of 15 trace elements (Al, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Ti, V, Zn, As, Sb, and Se) in the seminal plasma and the sperm DNA in 64 normal and 30 abnormal semen specimens with Inductively Coupled Plasma/Mass Spectrometry (ICP-MS). This study showed all trace elements were detected in the seminal plasma and only metals were detected in the sperm DNA. There was no correlation between the metals' concentrations in the seminal plasma and the sperm DNA. Al had the highest affinity for DNA followed by Pb and Cd. This strong affinity is consistent with the known mutagenic effects of these metals. The lowest affinity was observed for Zn and Ti. We observed a significant increase of Al linked to the sperm DNA of patients with oligozoospermia and teratozoospermia. Al's reproductive toxicity might be due to Al linked to DNA, by altering spermatogenesis and expression patterns of genes involved in the function of reproduction.

Insight into the cellular fate and toxicity of aluminium adjuvants used in clinically approved human vaccinations

Aluminium adjuvants remain the most widely used and effective adjuvants in vaccination and immunotherapy. Herein, the particle size distribution (PSD) of aluminium oxyhydroxide and aluminium hydroxyphosphate adjuvants was elucidated in attempt to correlate these properties with the biological responses observed post vaccination. Heightened solubility and potentially the generation of Al³⁺ in the lysosomal environment were positively correlated with an increase in cell mortality in vitro, potentially generating a greater inflammatory response at the site of simulated injection. The cellular uptake of aluminium based adjuvants (ABAs) used in clinically approved vaccinations are compared to a commonly used experimental ABA, in an in vitro THP-1 cell model. Using lumogallion as a direct-fluorescent molecular probe for aluminium, complemented with transmission electron microscopy provides further insight into the morphology of internalised particulates, driven by the physicochemical variations of the ABAs investigated. We demonstrate that not all aluminium adjuvants are equal neither in terms of their physical properties nor their biological reactivity and potential toxicities both at the injection site and beyond. High loading of aluminium oxyhydroxide in the cytoplasm of THP-1 cells without immediate cytotoxicity might predispose this form of aluminium adjuvant to its subsequent transport throughout the body including access to the brain.

Human and Environmental Dangers Posed by Ongoing Global Tropospheric Aerosolized Particulates for Weather Modification

BACKGROUND

U.S. military perception of nuclear warfare led to countless unethical nuclear experiments performed on unsuspecting individuals without their informed consent. As evidenced here, subsequent perception of weather warfare has led to exposing millions of unsuspecting individuals to toxic coal fly ash with no public disclosure, no informed consent, and no health warnings.

METHODS

Three methods were used: (1) comparison of eight elements analyzed in rainwater samples, thought to have leached from aerosolized coal fly ash, with corresponding coal fly ash laboratory leachate; (2) comparison of 14 elements analyzed in air filter dust with corresponding elements in coal fly ash; and (3) comparison of 23 elements analyzed in fibrous mesh found after snow melted with corresponding elements in coal fly ash.

RESULTS

The rainwater element ratios show that the aerial particulate matter has essentially the same water-leach characteristics as coal fly ash. The air filter dust element ratios occur in the same range of compositions as coal fly ash, as do element ratios in fibrous mesh found on grass after snow melted. The fibrous mesh provides an inferred direct connection with the aerosolizing jet aircraft via coal fly ash association with the jet combustion environment.

CONCLUSION

Strong evidence for the correctness of the hypothesis: coal fly ash is likely the aerosolized particulate emplaced in the troposphere for geoengineering, weather modification, and/or climate alteration purposes. The documented public health associations for ≤2.5 μm particulate pollution are also applicable to aerosolized coal fly ash. The ability of coal fly ash to release aluminum in a chemically mobile form upon exposure to water or body moisture has potentially grave human and environmental consequences over a broad spectrum, including implications for neurological diseases and biota debilitation. The ability of coal fly ash to release heavy metals and radioactive elements upon exposure to body moisture has potentially grave human health implications including cancer, cardiovascular disease, diabetes, respiratory diseases, reduced male fertility, and stroke. The fibrous mesh data admit the possibility of environmentally disastrous formation of methylmercury and ozone-depleting chlorinated-fluorinated hydrocarbons in jet exhaust. Geophysical implications include atmospheric warming and rainfall retardation.

Evidence of Coal-Fly-Ash Toxic Chemical Geoengineering in the Troposphere: Consequences for Public Health

The widespread, intentional and increasingly frequent chemical emplacement in the troposphere has gone unidentified and unremarked in the scientific literature for years. The author presents evidence that toxic coal combustion fly ash is the most likely aerosolized particulate sprayed by tanker-jets for geoengineering, weather-modification and climate-modification purposes and describes some of the multifold consequences on public health. Two methods are employed: (1) Comparison of 8 elements analyzed in rainwater, leached from aerosolized particulates, with corresponding elements leached into water from coal fly ash in published laboratory experiments, and (2) Comparison of 14 elements analyzed in dust collected outdoors on a high-efficiency particulate air (HEPA) filter with corresponding elements analyzed in un-leached coal fly ash material. The results show: (1) the assemblage of elements in rainwater and in the corresponding experimental leachate are essentially identical. At a 99% confidence interval, they have identical means (T-test) and identical variances (F-test); and (2) the assemblage of elements in the HEPA dust and in the corresponding average un-leached coal fly ash are likewise essentially identical. The consequences on public health are profound, including exposure to a variety of toxic heavy metals, radioactive elements, and neurologically-implicated chemically mobile aluminum released by body moisture in situ after inhalation or through transdermal induction.