Molecular mechanisms of aluminum neurotoxicity: Update on adverse effects and therapeutic strategies

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

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

Epigenetic Mechanisms of Aluminum-Induced Neurotoxicity and Alzheimer's Disease: A Focus on Non-Coding RNAs

Aluminum (Al) is known to induce neurotoxic effects, potentially contributing to Alzheimer's disease (AD) pathogenesis. Recent studies suggest that epigenetic modification may contribute to Al neurotoxicity, although the mechanisms are still debatable. Therefore, the objective of the present study was to summarize existing data on the involvement of epigenetic mechanisms in Al-induced neurotoxicity, especially AD-type pathology. Existing data demonstrate that Al exposure induces disruption in DNA methylation, histone modifications, and non-coding RNA expression in brains. Alterations in DNA methylation following Al exposure were shown to be mediated by changes in expression and activity of DNA methyltransferases (DNMTs) and ten-eleven translocation proteins (TETs). Al exposure was shown to reduce histone acetylation by up-regulating expression of histone deacetylases (HDACs) and impair histone methylation, ultimately contributing to down-regulation of brain-derived neurotrophic factor (BDNF) expression and activation of nuclear factor κB (NF-κB) signaling. Neurotoxic effects of Al exposure were also associated with aberrant expression of non-coding RNAs, especially microRNAs (miR). Al-induced patterns of miR expression were involved in development of AD-type pathology by increasing amyloid β (Aβ) production through up-regulation of Aβ precursor protein (APP) and β secretase (BACE1) expression (down-regulation of miR-29a/b, miR-101, miR-124, and Let-7c expression), increasing in neuroinflammation through NF-κB signaling (up-regulation of miR-9, miR-125b, miR-128, and 146a), as well as modulating other signaling pathways. Furthermore, reduced global DNA methylation, altered histone modification, and aberrant miRNA expression were associated with cognitive decline in Al-exposed subjects. However, further studies are required to evaluate the contribution of epigenetic mechanisms to Al-induced neurotoxicity and/or AD development.

Effect of hesperidin in the prevention of aluminum chloride-induced testicular dysfunction in rats

Hesperidin is a citrus bioflavonoid and has numerous pharmacological actions. Hesperidin's effect on testicular dysfunction has not been well researched. Hence, the present study is aims to investigate the effect of hesperidin on aluminium chloride (AlCl3)-induced testicular dysfunction in rats. Both vitamin C (200 mg/kg) and hesperidin (50, 100, and 200 mg/kg) were administered orally for 21 days. At the end of the study, the blood samples were obtained from all animals for investigation of biochemical and hematological parameters. Then, bilateral orchiectomy was carried out to remove testicles from the animals, and sperm was collected and examined under a microscope. Finally, organs such as the liver, kidney, and testicles were also collected and utilized for histopathological analysis. Part of the liver sample was used for determination of antioxidant enzymes such as reduced glutathione (GSH) and catalase (CAT) levels. The rats administered with AlCl3 showed elevated levels of biochemical and hematological parameters and a reduction in levels of sperm count, sperm motility, and oxidative stress parameters, whereas the rats administered with vitamin C/hesperidin (200 and 400 mg/kg) were able to ameliorate AlCl3-induced testicular dysfunction by attenuating AlCl3-induced changes in biochemical and hematological parameters, sperm motility, sperm count, and oxidative stress. Both vitamin C and hesperidin had significant ameliorative effects against AlCl3-induced testicular dysfunction.

Nephroprotective effects of silymarin and its fabricated nanoparticles against aluminum-induced oxidative stress, hyperlipidemia, and genotoxicity

BACKGROUND

Aluminum (Al) is a ubiquitous element with proven nephrotoxicity. Silymarin (SM) is a mixture of polyphenolic components extracted from Silybum marianum and exhibited protective influences. However, SM bioactivity can be enhanced by its incorporation in chitosan (CS) through the use of nanotechnology. This work proposed to assess the protective influence of SM and its loaded chitosan nanoparticles (SM-CS-NPs) on aluminum chloride (AlCl3)-induced nephrotoxicity.

METHODS

Six groups were created randomly from 42 male Wistar rats and each one contains 7 rats (n = 7). Group I, acted as a control and received water. Group II received SM (15 mg/kg/day) and group III administered with SM-CS-NPs (15 mg/kg/day). Group IV received AlCl3 (34 mg/kg) and groups V and VI were treated with SM and SM-CS-NPs with AlCl3 respectively for 30 days.

RESULTS

AlCl3 administration significantly elevated TBARS, H2O2, and kidney function levels besides LDH activity. Whereas GSH, CAT, SOD, GPx, GST, and GR values were all substantially reduced along with protein content, and ALP activity. Additionally, significant alterations in lipid profile, hematological parameters, and renal architecture were observed. Moreover, TNF-α, TGF-β, and MMP9 gene expression were upregulated in kidney tissues. The administration of SM or its nanoparticles followed by AlCl3 intoxication attenuated renal dysfunction replenished the antioxidant system, and downregulated TNF-α, TGF-β, and MMP9 gene expression in renal tissues compared to the AlCl3 group.

CONCLUSION

SM-CS-NPs have more pronounced appreciated protective effects than SM and have the proficiency to balance oxidant/antioxidant systems in addition to their anti-inflammatory effect against AlCl3 toxicity.

Retinal toxicity of heavy metals and its involvement in retinal pathology

The objective of the present review is to discuss epidemiological evidence demonstrating the association between toxic metal (Cd, Pb, Hg, As, Sn, Ti, Tl) exposure and retinal pathology, along with the potential underlying molecular mechanisms. Epidemiological studies demonstrate that Cd, and to a lesser extent Pb exposure, are associated with age-related macular degeneration (AMD), while the existing evidence on the levels of these metals in patients with diabetic retinopathy is scarce. Epidemiological data on the association between other toxic metals and metalloids including mercury (Hg) and arsenic (As), are limited. Clinical reports and laboratory in vivo studies have shown structural alterations in different layers of retina following metal exposure. Examination of retina samples demonstrate that toxic metals can accumulate in the retina, and the rate of accumulation appears to increase with age. Experimental studies in vivo and in vitro studies in APRE-19 and D407 cells demonstrate that toxic metal exposure may cause retinal damage through oxidative stress, apoptosis, DNA damage, mitochondrial dysfunction, endoplasmic reticulum stress, impaired retinogenesis, and retinal inflammation. However, further epidemiological as well as laboratory studies are required for understanding the underlying molecular mechanisms and identifying of the potential therapeutic targets and estimation of the dose-response effects.

Central Causation of Autism/ASDs via Excessive [Ca2+]i Impacting Six Mechanisms Controlling Synaptogenesis during the Perinatal Period: The Role of Electromagnetic Fields and Chemicals and the NO/ONOO(-) Cycle, as Well as Specific Mutations

The roles of perinatal development, intracellular calcium [Ca2+]i, and synaptogenesis disruption are not novel in the autism/ASD literature. The focus on six mechanisms controlling synaptogenesis, each regulated by [Ca2+]i, and each aberrant in ASDs is novel. The model presented here predicts that autism epidemic causation involves central roles of both electromagnetic fields (EMFs) and chemicals. EMFs act via voltage-gated calcium channel (VGCC) activation and [Ca2+]i elevation. A total of 15 autism-implicated chemical classes each act to produce [Ca2+]i elevation, 12 acting via NMDA receptor activation, and three acting via other mechanisms. The chronic nature of ASDs is explained via NO/ONOO(-) vicious cycle elevation and MeCP2 epigenetic dysfunction. Genetic causation often also involves [Ca2+]i elevation or other impacts on synaptogenesis. The literature examining each of these steps is systematically examined and found to be consistent with predictions. Approaches that may be sed for ASD prevention or treatment are discussed in connection with this special issue: The current situation and prospects for children with ASDs. Such approaches include EMF, chemical avoidance, and using nutrients and other agents to raise the levels of Nrf2. An enriched environment, vitamin D, magnesium, and omega-3s in fish oil may also be helpful.

The potential anti-Alzheimer's activity of Oxalis corniculata Linn. Methanolic extract in experimental rats: Role of APOE4/LRP1, TLR4/NF-κβ/NLRP3, Wnt 3/β-catenin/GSK-3β, autophagy and apoptotic cues

ETHNOPHARMACOLOGICAL RELEVANCE

Oxalis corniculata (O. corniculata) is a member of Oxalidaceae family, widely distributed in Asia, Europe, America, and Africa, used extensively as food and its traditional folkloric uses include management of epilepsy, gastric disorders, and neurodegenerative diseases, together with its use in enhancing health. Numerous pharmacological benefits of O. corniculata are linked to its anti-inflammatory and antioxidant abilities. One of the most prevalent neurodegenerative disorders is Alzheimer's disease (AD) in which neuroinflammation and oxidative stress are its main pathogenic processes.

AIM OF THE STUDY

Our research aimed to study the neuroprotective effect of the methanolic extract of Oxalis corniculata Linn. (O. corniculata ME), compared to selenium (Se) against AlCl3-induced AD.

MATERIALS AND METHODS

Forty male albino rats were allocated into four groups (Gps). Gp I a control group, the rest of the animals received AlCl3 (Gp II-Gp IV). Rats in Gp III and IV were treated with Se and O. corniculata ME, respectively.

RESULTS

The chemical profile of O. corniculata ME was studied using ultraperformance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry, allowing the tentative identification of sixty-six compounds, including organic acids, phenolics and others, cinnamic acid and its derivatives, fatty acids, and flavonoids. AlCl3 showed deterioration in short-term memory and brain histological pictures. Our findings showed that O. corniculata ME and selenium helped to combat oxidative stress produced by accumulation of AlCl3 in the brain and in prophylaxis against AD. Thus, Selenium (Se) and O. corniculata ME restored antioxidant defense, via enhancing Nrf2/HO-1 hub, hampered neuroinflammation, via TLR4/NF-κβ/NLRP3, along with dampening apoptosis, Aβ generation, tau hyperphosphorylation, BACE1, ApoE4 and LRP1 levels. Treatments also promoted autophagy and modulated Wnt 3/β-catenin/GSK3β cue.

CONCLUSIONS

It was noted that O. corniculata ME showed a notable ameliorative effect compared to Se on Nrf2/HO-1, TLR4/NF-κβ/NLRP3, APOE4/LRP1, Wnt 3/β-catenin/GSK-3β and PERK axes.

Modulation of gut microbiota with probiotics as a strategy to counteract endogenous and exogenous neurotoxicity

The existing data demonstrate that probiotic supplementation affords protective effects against neurotoxicity of exogenous (e.g., metals, ethanol, propionic acid, aflatoxin B1, organic pollutants) and endogenous (e.g., LPS, glucose, Aβ, phospho-tau, α-synuclein) agents. Although the protective mechanisms of probiotic treatments differ between various neurotoxic agents, several key mechanisms at both the intestinal and brain levels seem inherent to all of them. Specifically, probiotic-induced improvement in gut microbiota diversity and taxonomic characteristics results in modulation of gut-derived metabolite production with increased secretion of SFCA. Moreover, modulation of gut microbiota results in inhibition of intestinal absorption of neurotoxic agents and their deposition in brain. Probiotics also maintain gut wall integrity and inhibit intestinal inflammation, thus reducing systemic levels of LPS. Centrally, probiotics ameliorate neurotoxin-induced neuroinflammation by decreasing LPS-induced TLR4/MyD88/NF-κB signaling and prevention of microglia activation. Neuroprotective mechanisms of probiotics also include inhibition of apoptosis and oxidative stress, at least partially by up-regulation of SIRT1 signaling. Moreover, probiotics reduce inhibitory effect of neurotoxic agents on BDNF expression, on neurogenesis, and on synaptic function. They can also reverse altered neurotransmitter metabolism and exert an antiamyloidogenic effect. The latter may be due to up-regulation of ADAM10 activity and down-regulation of presenilin 1 expression. Therefore, in view of the multiple mechanisms invoked for the neuroprotective effect of probiotics, as well as their high tolerance and safety, the use of probiotics should be considered as a therapeutic strategy for ameliorating adverse brain effects of various endogenous and exogenous agents.

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.

Evaluation of Lentilactobacillus parafarraginis A6-2 strain for aluminum removal and anti-inflammatory effects: implications for alleviating Al toxicity

AIM

To assess the effectiveness of Lentilactobacillus parafarraginis A6-2 cell lysate for the removal of aluminum (Al), which induces neurotoxicity, and its protective effect at cellular level.

METHODS AND RESULTS

The cell lysate of the selected L. parafarraginis A6-2 strain demonstrated superior Al removal compared to live or dead cells. The Al removal efficiency of L. parafarraginis A6-2 cell lysate increased with decreasing pH and increasing temperature, primarily through adsorption onto peptidoglycan. Neurotoxicity mitigation potential of L. parafarraginis A6-2 was evaluated using C6 glioma cells. C6 cells exposed with increasing concentration of Al led to elevated toxicity and inflammation, which were gradually alleviated upon treatment with L. parafarraginis A6-2. Moreover, Al-induced oxidative stress in C6 cells showed a concentration-dependent reduction upon treatment with L. parafarraginis A6-2.

CONCLUSIONS

This study demonstrated that L. parafarraginis A6-2 strain, particularly in its lysate form, exhibited enhanced capability for Al removal. Furthermore, it effectively mitigated Al-induced toxicity, inflammation, and oxidative stress.

Antioxidant dihydrolipolic acid protects against in vitro aluminum-induced toxicity

Dihydrolipoic acid (DHLA) is a natural antioxidant known for its ability to counteract metal toxicity and oxidative stress. It has shown the potential to safeguard cells from harmful environmental substances. It may hold therapeutic benefits in treating neurodegenerative disorders by defending against oxidative damage and chronic inflammation. Thus, this study aimed to explore the potential neuroprotective effects of DHLA against aluminum (Al)-induced toxicity using an Alzheimer's disease (AD) model in vitro. The study focused on two important pathways: GSK-3β and the Wnt signaling pathways. The SH-SY5Y cell line was differentiated to establish AD, and the study group were as follows: control, Al, DHLA, Al-DHLA, AD, AD-Al, AD-DHLA, and AD-Al-DHLA. The impact of DHLA on parameters related to oxidative stress was assessed. The activity of the GSK-3β pathway was measured by evaluating the levels of PPP1CA, PP2A, GSK-3β, and Akt. The Wnt signaling pathway was assessed by measuring Wnt/β-catenin in the different study groups. Exposure to DHLA significantly reduced oxidative stress by effectively decreasing the levels of reactive oxygen species, thereby protecting against protein oxidation and limiting the production of malonaldehyde. Moreover, the DHLA-treated groups exhibited a remarkable increase in the total antioxidant capacity. Furthermore, the study observed an upregulation of the Wnt signaling pathway and a downregulation of the GSK-3β pathway in the groups treated with DHLA. In summary, the neuroprotective effects of DHLA, primarily achieved by reducing oxidative stress and modulating critical imbalanced pathways associated with AD, indicate its potential as a promising addition to the treatment regimens of AD patients.

Aluminum Concentrations in Male and Female Football Players during the Season

Aluminum (Al) is one of the most abundant trace mineral elements in the earth's crust. Al is considered a potent neurotoxicant. Physical exercise could cause modifications in some trace mineral elements. On the other hand, there could be sex differences in the exposure and deposits of toxic mineral elements. The aim of the present study was to compare sex and seasonal differences in extracellular and intracellular Al concentrations in football players. The study involved 22 male and 24 female football players from the fifth and second national category, respectively. Three assessments were carried out during the season (beginning, middle and end). Al concentrations in plasma, urine, erythrocytes and platelets were determined. Male football players ingested more Al (p < 0.05). Higher plasma Al concentrations were reported in male football players (p < 0.01). On the other hand, in both groups, increases and decreases in Al in the plasma and urine were observed in the second and third assessment, respectively (p < 0.01). There were sex differences in platelet Al concentrations (p < 0.05). Plasma and platelet Al concentrations may be different between the sexes. Al concentrations may change over the course of a season in football players.

Trace Elements Levels in Major Depressive Disorder-Evaluation of Potential Threats and Possible Therapeutic Approaches

The multifactorial etiology of major depressive disorder (MDD) includes biological, environmental, genetic, and psychological aspects. Recently, there has been an increasing interest in metallomic studies in psychiatry, aiming to evaluate the role of chosen trace elements in the MDD etiology as well as the progression of symptoms. This narrative review aims to summarize the available literature on the relationship between the concentration of chosen elements in the serum of patients with MDD and the onset and progression of this psychiatric condition. The authors reviewed PubMed, Web of Science, and Scopus databases searching for elements that had been investigated so far and further evaluated them in this paper. Ultimately, 15 elements were evaluated, namely, zinc, magnesium, selenium, iron, copper, aluminium, cadmium, lead, mercury, arsenic, calcium, manganese, chromium, nickel, and phosphorus. The association between metallomic studies and psychiatry has been developing dynamically recently. According to the results of current research, metallomics might act as a potential screening tool for patients with MDD while at the same time providing an assessment of the severity of symptoms. Either deficiencies or excessive amounts of chosen elements might be associated with the progression of depressive symptoms or even the onset of the disease among people predisposed to MDD.

Identification of potentially relevant metals for the etiology of autism by using a Bayesian multivariate approach for partially censored values

Heavy metals are known to be able to cross the placental and blood brain barriers to affect critical neurodevelopmental processes in the fetus. We measured metal levels (Al, Cd, Hg, Li, Pb and Zn) in the cord blood of newborns and in the serum of the same children at 5 years of age, and compared between individuals with or without (controls) autism spectrum disorder (ASD) diagnosis. The samples were from a biobank associated with the All Babies in Southeast Sweden (ABIS) registry. We proposed a Bayesian multivariate log-normal model for partially censored values to identify potentially relevant metals for the etiology of ASD. Our results in cord blood suggest prenatal Al levels could be indicative of later ASD incidence, which could also be related to an increased possibility of a high, potentially toxic, exposure to Al and Li during pregnancy. In addition, a larger possibility of a high, potentially beneficial, exposure to Zn could occur during pregnancy in controls. Finally, we found decisive evidence for an average increase of Hg in 5-year-old ASD children compared to only weak evidence for controls. This is concordant with previous research showing an impaired ability for eliminating Hg in the ASD group.

Risk Assessment of Chlorogenic and Isochlorogenic Acids in Coffee By-Products

Chlorogenic and isochlorogenic acids are naturally occurring antioxidant dietary polyphenolic compounds found in high concentrations in plants, fruits, vegetables, coffee, and coffee by-products. The objective of this review was to assess the potential health risks associated with the oral consumption of coffee by-products containing chlorogenic and isochlorogenic acids, considering both acute and chronic exposure. An electronic literature search was conducted, revealing that 5-caffeoylquinic acid (5-CQA) and 3,5-dicaffeoylquinic acid (3,5-DCQA) are the major chlorogenic acids found in coffee by-products. Toxicological, pharmacokinetic, and clinical data from animal and human studies were available for the assessment, which indicated no significant evidence of toxic or adverse effects following acute oral exposure. The current state of knowledge suggests that long-term exposure to chlorogenic and isochlorogenic acids by daily consumption does not appear to pose a risk to human health when observed at doses within the normal range of dietary exposure. As a result, the intake of CQAs from coffee by-products can be considered reasonably safe.

An ocular Th1 immune response promotes corneal nerve damage independently of the development of corneal epitheliopathy

Proper sight is not possible without a smooth, transparent cornea, which is highly exposed to environmental threats. The abundant corneal nerves are interspersed with epithelial cells in the anterior corneal surface and are instrumental to corneal integrity and immunoregulation. Conversely, corneal neuropathy is commonly observed in some immune-mediated corneal disorders but not in others, and its pathogenesis is poorly understood. Here we hypothesized that the type of adaptive immune response may influence the development of corneal neuropathy. To test this, we first immunized OT-II mice with different adjuvants that favor T helper (Th)1 or Th2 responses. Both Th1-skewed mice (measured by interferon-γ production) and Th2-skewed (measured by interleukin-4 production) developed comparable ocular surface inflammation and conjunctival CD4+ T cell recruitment but no appreciable corneal epithelial changes upon repeated local antigenic challenge. Th1-skewed mice showed decreased corneal mechanical sensitivity and altered corneal nerve morphology (signs of corneal neuropathy) upon antigenic challenge. However, Th2-skewed mice also developed milder corneal neuropathy immediately after immunization and independently of ocular challenge, suggestive of adjuvant-induced neurotoxicity. All these findings were confirmed in wild-type mice. To circumvent unwanted neurotoxicity, CD4+ T cells from immunized mice were adoptively transferred to T cell-deficient mice. In this setup, only Th1-transferred mice developed corneal neuropathy upon antigenic challenge. To further delineate the contribution of each profile, CD4+ T cells were polarized in vitro to either Th1, Th2, or Th17 cells and transferred to T cell-deficient mice. Upon local antigenic challenge, all groups had commensurate conjunctival CD4+ T cell recruitment and macroscopic ocular inflammation. However, none of the groups developed corneal epithelial changes and only Th1-transferred mice showed signs of corneal neuropathy. Altogether, the data show that corneal nerves, as opposed to corneal epithelial cells, are sensitive to immune-driven damage mediated by Th1 CD4+ T cells in the absence of other pathogenic factors. These findings have potential therapeutic implications for ocular surface disorders.

Role of aluminum exposure on Alzheimer's disease and related glycogen synthase kinase pathway

Aluminum (Al) is an environmentally abundant metal that is not essential for life. There is considerable evidence that Al as a neurotoxic xenobiotic may play a role in the pathogenesis of neurodegenerative diseases like Alzheimer's disease (AD). Exposure to aluminum has been shown to cause neuronal damage that resembles the symptoms of AD. In this review, we will summarize recent data about Al as the possible risk of incidence of AD. Then glycogen synthase kinase-3 beta (GSK3β) contributes to the hyperphosphorylation of Tau protein, the main component of neurofibrillary tangles, one of the hallmarks of AD as one of the mechanisms behind Al neurotoxicity will be covered. Overall, there is still a need for epidemiological studies and more in vivo and in vitro studies to determine the exact mechanisms of its neurotoxicity and the role of GSK3β in both Al toxic effect and AD.

The role of hypoxia-inducible factor 1 alpha (HIF-1α) modulation in heavy metal toxicity

Hypoxia-inducible factor 1 (HIF-1) is an oxygen-sensing transcriptional regulator orchestrating a complex of adaptive cellular responses to hypoxia. Several studies have demonstrated that toxic metal exposure may also modulate HIF-1α signal transduction pathway, although the existing data are scarce. Therefore, the present review aims to summarize the existing data on the effects of toxic metals on HIF-1 signaling and the potential underlying mechanisms with a special focus on prooxidant effect of the metals. The particular effect of metals was shown to be dependent on cell type, varying from down- to up-regulation of HIF-1 pathway. Inhibition of HIF-1 signaling may contribute to impaired hypoxic tolerance and adaptation, thus promoting hypoxic damage in the cells. In contrast, its metal-induced activation may result in increased tolerance to hypoxia through increased angiogenesis, thus promoting tumor growth and contributing to carcinogenic effect of heavy metals. Up-regulation of HIF-1 signaling is mainly observed upon Cr, As, and Ni exposure, whereas Cd and Hg may both stimulate and inhibit HIF-1 pathway. The mechanisms underlying the influence of toxic metal exposure on HIF-1 signaling involve modulation of prolyl hydroxylases (PHD2) activity, as well as interference with other tightly related pathways including Nrf2, PI3K/Akt, NF-κB, and MAPK signaling. These effects are at least partially mediated by metal-induced ROS generation. Hypothetically, maintenance of adequate HIF-1 signaling upon toxic metal exposure through direct (PHD2 modulation) or indirect (antioxidant) mechanisms may provide an additional strategy for prevention of adverse effects of metal toxicity.

Biomaterial-based platforms for modulating immune components against cancer and cancer stem cells

Immunotherapy involves the therapeutic alteration of the patient's immune system to identify, target, and eliminate cancer cells. Dendritic cells, macrophages, myeloid-derived suppressor cells, and regulatory T cells make up the tumor microenvironment. In cancer, these immune components (in association with some non-immune cell populations like cancer-associated fibroblasts) are directly altered at a cellular level. By dominating immune cells with molecular cross-talk, cancer cells can proliferate unchecked. Current clinical immunotherapy strategies are limited to conventional adoptive cell therapy or immune checkpoint blockade. Targeting and modulating key immune components presents an effective opportunity. Immunostimulatory drugs are a research hotspot, but their poor pharmacokinetics, low tumor accumulation, and non-specific systemic toxicity limit their use. This review describes the cutting-edge research undertaken in the field of nanotechnology and material science to develop biomaterials-based platforms as effective immunotherapeutics. Various biomaterial types (polymer-based, lipid-based, carbon-based, cell-derived, etc.) and functionalization methodologies for modulating tumor-associated immune/non-immune cells are explored. Additionally, emphasis has been laid on discussing how these platforms can be used against cancer stem cells, a fundamental contributor to chemoresistance, tumor relapse/metastasis, and failure of immunotherapy. Overall, this comprehensive review strives to provide up-to-date information to an audience working at the juncture of biomaterials and cancer immunotherapy. STATEMENT OF SIGNIFICANCE: Cancer immunotherapy possesses incredible potential and has successfully transitioned into a clinically lucrative alternative to conventional anti-cancer therapies. With new immunotherapeutics getting rapid clinical approval, fundamental problems associated with the dynamic nature of the immune system (like limited clinical response rates and autoimmunity-related adverse effects) have remained unanswered. In this context, treatment approaches that focus on modulating the compromised immune components within the tumor microenvironment have garnered significant attention amongst the scientific community. This review aims to provide a critical discussion on how various biomaterials (polymer-based, lipid-based, carbon-based, cell-derived, etc.) can be employed along with immunostimulatory agents to design innovative platforms for selective immunotherapy directed against cancer and cancer stem cells.

Evaluation of anti-Alzheimer activity of Echinacea purpurea extracts in aluminum chloride-induced neurotoxicity in rat model

Alzheimer's disease (AD) is one of the neurodegenerative illnesses that impair individual life & increase the demand for caregivers with no available curative medication right now. Therefore, there is a growing concern about employing herbal medicine to limit AD progression & improve patients' life quality, thus potentiating its add-on therapy. In addition, herbs are cost-effective & accessible with nearly no side effects. In the same vein, our study aimed to investigate the potency of Echinacea purpurea (EP) flower extracts to ameliorate the neurodegenerative effect of Aluminum chloride (AlCl3) in a rat model. Moreover, mechanistic studies, including impact on the cholinesterase activity, redox status, inflammatory mediators, behavior performance, glucose level & histopathology, were carried on. Our results showed that 250 mg/kg of Aqueous (AQ) & Alcoholic (AL) extracts of EP inhibited cholinesterase, restored oxidative balance, down-regulated IL-6 & TNF-α cytokines & improved behavior performance in vivo that was reflected in the brain picture by decreasing neuronal degeneration & amyloid plaques in cerebral cortex & hippocampus. The potency of both extracts was compared to reference drugs & AlCl3 positive control group. The AQ extract showed greater potency against COX-1, COX-2 & α-amylase in vitro, while the AL extract was more potent against cholinesterase in vitro, inflammatory cytokines, behavior & pathological improvement in vivo. Conclusively EP overcame AlCl3-induced neurobehavioral toxicity in the rat model via different pathways, which support its regular administration to postpone progressive neural damage in AD patients.

A Selective and ''Off-On'' Fluorescent Chemosensor Based on Fluorescein for Al3+: Synthesis, Characterization, Spectroscopy Analyses, and DFT Calculation

An efficient fluorescent cation chemosensor based on fluorescein L4 was well prepared and identified with spectroscopy analyses. UV-vis and fluorescence measurements examined the analyte complexation of the L4 with various cations, demonstrating a clear tendency to Al³⁺ ion. In the Job plot study, a stoichiometry ratio of a complex between L4 and Al³⁺ ion was determined to be 1: 2 (L4: Al³⁺). A stoichiometry ratio of complex between L4 and Al³⁺ ion was determined to be 1: 2 (L4: Al³⁺) using the Job plot. The association constant (K_a) of the L4-Al³⁺ complex was found 2.8 × 10⁷ M^-2. The obtained limit of detection (LOD) value (1.37 × 10^-6 M for Al³⁺) exhibited the considerable sensitivity of the chemosensor L4 to Al³⁺ ion. DFT/TD-DFT calculations have also been employed to support the binding mode and photophysical properties of the complexation of chemosensor L4 to Al³⁺ ion and also to investigate the enhancement of L4 fluorescence by Al³⁺ ion.

Protective effect of Allium atroviolaceum-synthesized SeNPs on aluminum-induced brain damage in mice

This study evaluated the possible neuroprotective effect of Allium atroviolaceum extract (AaE)-synthesized selenium nanoparticles (SeNPs) on aluminum (Al)-induced neurotoxicity in mice, explaining the likely mechanisms. Mice were divided into five groups: G1, control; G2, AaE group that received AaE (200 mg/kg) for 4 weeks; and groups 3, 4, and 5 received AlCl3 (100 mg/kg) for 3 weeks. After that, G4 received AaE (200 mg/kg), and G5 received SeNPs-AaE (0.5 mg/kg) for another 1 week. Exposure to AlCl3 boosted oxidative damage in brain tissue as evidenced by a reduction in glutathione concentrations and other antioxidant enzymes along with increased lipid peroxidation and nitric oxide levels. There was also a rise in the concentrations of interleukin-1β, TNF-α, and cyclooxygenase-II activities. AlCl3-treated mice showed reduced brain-derived neurotrophic factor (BDNF) and dopamine levels, increased acetylcholinesterase (AChE) activity, and reduced Bcl-2, and Bax, and caspase-3 activities. Treatment with SeNPs-AaE significantly reduced markers of oxidative stress, inflammation, and apoptosis. In addition, in SeNPs-AaE-treated rats, levels of BDNF and dopamine were significantly increased along with a reduction in AChE as compared with the AlCl3 group. Therefore, our results indicate that SeNPs-AaE has a potential neuroprotective effect against Al-mediated neurotoxic effects because of its powerful antioxidant, anti-inflammatory, anti-apoptotic, and neuromodulatory activities.

Surveillance of long-term environmental elements and PM2.5 health risk assessment in Yangtze River Delta, China, from 2016 to 2020

PM2.5 metal pollution significantly harms human health. The air quality in Wuxi is poor, especially in winter, and long-term monitoring of PM2.5 elements comprising has not been performed previously. In the present study, 420 PM2.5 samples were collected from January 2016 to December 2020. Eleven elements, including Al, Mn, Ni, Cr, As, Cd, Sb, Hg, Pb, Se, and Tl, were analyzed by inductively coupled plasma mass spectrometry. The mean PM2.5 level was 56.1 ± 31.0 μg/m3, with a tendency of yearly decreasing and a significant seasonal distribution variation. The concentration of 11 elements in the PM2.5 samples was 0.38 ± 0.33 μg/m3. Al was the highest element with a range of 37.5-2148 ng/m3. Meanwhile, the spatial distribution differences were compared by literatures review. Based on the Crystal Ball model, health risks were assessed dynamically using Monte Carlo uncertainty analysis. After 10,000 simulations, the mean value of the hazard index for nine elements was 0.743, and Mn contributed the most to the hazard index among elements, with a correlation of 0.3464. The average carcinogenic risk was 1.01 × 10-5, which indicated that the non-carcinogenic and carcinogenic risks were within the acceptable range. However, considerable attention should be paid to the potential health risks associated with long-term Al, Mn, and As exposure. This study provides detailed data on local atmospheric pollution characteristics, helps identify potential risk elements, and contributes to the development of effective regional air quality management.

Global Proteomic Profile of Aluminum-Induced Hippocampal Impairments in Rats: Are Low Doses of Aluminum Really Safe?

Hippocampus is the brain area where aluminum (Al) accumulates in abundance and is widely associated with learning and memory. In the present study, we evaluate behavioral, tissue, and proteomic changes in the hippocampus of Wistar rats caused by exposure to doses that mimic human consumption of aluminum chloride (AlCl₃) in urban areas. For this, male Wistar rats were divided into two groups: Control (distilled water) and AlCl₃ (8.3 mg/kg/day), both groups were exposed orally for 60 days. After the Al exposure protocol, cognitive functions were assessed by the Water maze test, followed by a collection for analysis of the global proteomic profile of the hippocampus by mass spectrometry. Aside from proteomic analysis, we performed a histological analysis of the hippocampus, to the determination of cell body density by cresyl violet staining in Cornu Ammonis fields (CA) 1 and 3, and hilus regions. Our results indicated that exposure to low doses of aluminum chloride triggered a decreased cognitive performance in learning and memory, being associated with the deregulation of proteins expression, mainly those related to the regulation of the cytoskeleton, cellular metabolism, mitochondrial activity, redox regulation, nervous system regulation, and synaptic signaling, reduced cell body density in CA1, CA3, and hilus.

Conjugated linoleic acid downregulates Alzheimer's hallmarks in aluminum mouse model through an Nrf2-mediated adaptive response and increases brain glucose transporter levels

Mitochondrial dysfunction, oxidative stress, inflammation and glucose dysmetabolism are pathological signs of Alzheimer's disease (AD). Dietary aluminum (Al) overload is often used to induce AD in rodents and trigger the onset of oxidative-stress hallmarks resembling those of the human disease. The Nuclear factor erythroid 2-related factor 2 (Nrf2), owing to its key role in redox homeostasis, mitochondrial function and inflammation, is a promising drug target for neurological disorders, but only a few data are available on its modulatory effects on glucose transporter expression levels. While it has been found that the protective effect of Conjugated linoleic acid (CLA) occurs through the activation of an Nrf2-mediated adaptive response, its beneficial effect on the considered pathological signs in the Al-induced model has not been established yet. Thirty-five male BalbC mice were divided into 5 groups: two Al-intoxicated groups were treated for 5 weeks with low or high Al doses (8 or 100 mg/kg/day in drinking water, respectively; L or H). Two groups of animals, orally supplemented with CLA (600 mg/kg bw/day) for 7 weeks (2 preliminary weeks plus the 5-week treatment with Al; CLA + L, CLA + H) were used to investigate its protective effect, while untreated mice were used as control (Cntr). We provide evidence that mitochondrial dysfunction, Nrf2 alteration, inflammation and Acetylcholinesterase (AChE) hyperactivation can occur even from L exposure. Interestingly, animal pre-treatment with an allometric CLA dose led to significant downregulation of the toxic effects elicited by L or H, likely through the activation of an adaptive response. In conclusion, CLA ability to increase the level of glucose transporters - along with its antioxidant and anti-inflammatory effect - expands the therapeutic targets of these molecules and comes out as an intriguing suitable candidate for the treatment of multifactorial disease.

Activation of PI3k/Akt/mTOR Signaling Induces Deposition of p-tau to Promote Aluminum Neurotoxicity

Aluminum neurotoxicity impairs learning and memory ability, but the molecular mechanism has not been elucidated. The aim of this study was to examine the role of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling in regulating the expression of synaptic plasticity-related proteins (PRPs) and p-tau deposition to explore the mechanism underlying aluminum-induced neurotoxicity. We constructed a sub-chronic aluminum-exposed Sprague Dawley (SD) rat model to assess aluminum neurotoxicity in vivo. The learning and memory abilities of rats were examined using the Morris water maze test. We also assessed the effect of aluminum in vitro using rat pheochromocytoma (PC12) cells. To explore the role of PI3K/Akt/mTOR signaling in aluminum neurotoxicity, we used the PI3K inhibitor wortmannin and the mTOR inhibitor rapamycin in aluminum-treated PC12 cells. Protein expression was examined by western blotting. Aluminum disrupted the learning and memory abilities of SD rats. Mechanistically, aluminum reduced the levels of the synaptic PRPs (cAMP-response element binding protein (CREB), glutamate receptor 1 (GluR1), glutamate receptor 2 (GluR2), and postsynaptic density protein 95 (PSD-95), and it increased p-tau deposition in the hippocampus of SD rats. We observed similar results in aluminum-treated PC12 cells. Further, PI3K/Akt/mTOR signaling was abnormally activated in aluminum-treated PC12 cells, and treatment with rapamycin reversed the decrease in synaptic PRPs levels and the increase in p-tau deposition. In conclusion, the activation of PI3K/Akt/mTOR signaling reduces the levels of synaptic PRPs and increases p-tau deposition induced by aluminum. Therefore, the PI3K/Akt/mTOR pathway participates in the mechanism of aluminum neurotoxicity.

Neuroprotective Effects of Phytochemicals against Aluminum Chloride-Induced Alzheimer’s Disease through ApoE4/LRP1, Wnt3/β-Catenin/GSK3β, and TLR4/NLRP3 Pathways with Physical and Mental Activities in a Rat Model

Background: Alzheimer’s disease (AD) is a neurodegenerative disorder that is associated with abnormal cognition. AD is aided in its initiation and progression by hereditary and environmental factors. Aluminum (Al) is a neurotoxic agent that causes oxidative stress, which is linked to AD progression. Additionally, Nrf2/HO-1, APOE4/LRP1, Wnt3/β-catenin, and TLR4/NLRP3 are the main signaling pathways involved in AD pathogenesis. Several phytochemicals are promising options in delaying AD evolution. Objectives: This study aimed at studying the neuroprotective effects of some phytochemicals as morin (MOR), thymol (TML), and thymoquinone (TMQ) on physical and mental activities (PhM) in Al chloride (AlCl₃)-induced AD rat model. Another objective was to determine the specificity of phytochemicals to AD signaling pathways using molecular docking. Methods: Eighty male Dawley rats were divided into eight groups. Each group received: saline (control group), AlCl₃, (ALAD), PhM, either alone or with a combination of MOR, TML, and/or TMQ for five weeks. Animals were then subjected to behavioral evaluation. Brain tissues were used for histopathological and biochemical analyses to determine the extent of neurodegeneration. The effect of phytochemicals on AlCl₃-induced oxidative stress and the main signaling pathways involved in AD progression were also investigated. Results: AlCl₃ caused a decline in spatial learning and memory, as well as histopathological changes in the brains of rats. Phytochemicals combined with PhM restored antioxidant activities, increased HO-1 and Nrf2 levels, blocked inflammasome activation, apoptosis, TLR4 expression, amyloide-β generation, and tau hyperphophorylation. They also brought ApoE4 and LRP1 levels back to normal and regulated Wnt3/β-catenin/GSK3β signaling pathway. Conclusions: The use of phytochemicals with PhM is a promising strategy for reducing AD by modulating Nrf2/HO-1, TLR4/NLRP3, APOE4/LRP1, and Wnt3/β-catenin/GSK-3β signaling pathways.

Endoplasmic reticulum stress and mitochondrial injury are critical molecular drivers of AlCl3-induced testicular and epididymal distortion and dysfunction: protective role of taurine

Aluminum, the third most plentiful metal in the Earth's crust, has potential for human exposure and harm. Oxidative stress plays an essential role in producing male infertility by inducing defects in sperm functions. We aimed to investigate the role of endoplasmic reticulum (ER) stress and mitochondrial injury in the pathogenesis of aluminum chloride (AlCl3)-induced testicular and epididymal damage at the histological, biochemical, and molecular levels, and to assess the potential protective role of taurine. Forty-eight adult male albino rats were separated into four groups (12 in each): negative control, positive control, AlCl3, and AlCl3 plus taurine groups. Testes and epididymis were dissected. Histological and immunohistochemical (Bax and vimentin) studies were carried out. Gene expression of vimentin, PCNA, CHOP, Bcl-2, Bax, and XBP1 were investigated via quantitative real-time polymerase chain reaction (qRT-PCR), besides estimation of malondialdehyde (MDA) and total antioxidant capacity (TAC). Light and electron microscopic examinations of the testes and epididymis revealed pathological changes emphasizing both mitochondrial injury and ER stress in the AlCl3 group. Taurine-treated rats showed a noticeable improvement in the testicular and epididymal ultrastructure. Moreover, they exhibited increased gene expression of vimentin, Bcl-2, and PNCA accompanied by decreased CHOP, Bax, and XBP1 gene expression. In conclusion, male reproductive impairment is a significant hazard associated with AlCl3 exposure. Both ER stress and mitochondrial impairment are critical mechanisms of the deterioration in the testes and epididymis induced by AlCl3, but taurine can amend this.

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

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

Impacts of Consumption of Ultra-Processed Foods on the Maternal-Child Health: A Systematic Review

Background and Aims

Changes in eating patterns have been leading to an increase in the consumption of ultra-processed foods (UPF), negatively impacting the quality of the diet and generating risk of harm to the health of the adult population, however, there is no systematized evidence of the impact of UPF in maternal-child health. Thus, in this study we aimed to evaluated the association between UPF consumption and health outcomes in the maternal-child population.

Methods

Systematic review registered on the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42021236633), conducted according to the PRISMA diagram in the following databases: PubMed, Medline, Scopus, Web of Science, Scielo, and CAPES thesis and dissertation directory. We included original cross-sectional, case-control and cohort studies in any language. Eligibility criteria were (a) food consumption assessment by the NOVA classification, (b) health outcome (nutritional or diseases), and (c) maternal-child population (pregnant, lactating women and infants/children). All data were analyzed and extracted to a spreadsheet structured by two independent reviewers. We evaluated the methodological quality of the studies included using the Newcastle-Otawa Scale and RoB 2.

Results

Searches retrieved 7,801 studies and 15 contemplated the eligibility criteria. Most studies included were cohort studies (n = 8, 53%), had children as their population (n = 9, 60%) and only one study evaluated UPF consumption in infants and lactating women. Panoramically, we observed that a higher participation of UPF in children’s diet has been associated with different maternal-child outcomes, such as increase of weight gain, adiposity measures, overweight, early weaning, lower diet quality, metabolic alterations, diseases, and consumption of plastic originated from packaging. Only one of the studies included did not present high methodological quality.

Conclusion

Despite the limited literature on UPF consumption and health outcomes in the maternal-child population, the highest UPF consumption negatively impacted nutrition and disease development indicators in pregnant, lactating women and children. Considering the expressive participation of these foods in the diet, other studies should be conducted to further investigate the impact of UPF consumption on different health indicators, especially in the lactation phase for this was the one to present the most important knowledge gap.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021236633], identifier [CRD42021236633].

Role of Environmental Toxicants on Neurodegenerative Disorders

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

Enzymatic Antioxidant Defense and Polymorphic Changes in Male Infertility

The intensification of oxidative stress and destabilization of the antioxidative defenses of an organism is a consequence of many environmental factors. We considered aspects conditioning male reproductive potential and the functionality of enzymatic antioxidative mechanisms, i.e., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR), and their correlations with Li, Be, B, Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Ag, Cd, Sn, Sb, Ba, Hg, Tl, Pb, and malondialdehyde (MDA), as well as genetic polymorphism IL-4v.C589T (rs2243250) in men with infertility (n = 76). A healthy normozoospermic control (n = 87) was also used. We assessed the impact of negative changes driven by oxidative stress on enzymatic antioxidative mechanisms as well as the role of MDA in the overall process. On this basis, we infer connections between disturbances in enzymatic antioxidative defense and reproductive potential. Based on a molecular analysis of the polymorphism of gene IL-4v.C589T (rs2243250) (chromosome 5) (PCR-RFLP), we considered the relationships among particular genotypes with the possibility of occurrence of male infertility. Concentrations of chemical elements were measured in the blood. The activity of antioxidants and MDA levels were measured in serum. In the infertile group, higher GPx activity was noted (6.56 nmoL·min-1·mL-1, control: 4.31 nmoL·min-1·mL-1; p = 0.004), while GR achieved a greater level in the control (17.74 nmoL·min-1·mL-1, infertile: 15.97 nmoL·min-1·mL-1, p = 0.043), which implies diversified efficiency of the first and second lines of defense. The polymorphism of IL-4v.C589T (rs2243250) was not directly connected with infertility because there were not any differences in the frequency of genotypes between the infertile and control group (p = 0.578). An analysis of genotypes CC and TT (polymorphism IL-4v.C589T (rs2243250)) indicated numerous correlations between antioxidants, chemical elements and MDA. Therefore, chemical economy, antioxidative defense and genetic conditions are connected and jointly shape male reproductive potential. Chemical elements influence antioxidative defense and male fertility; the most important modulators appeared to be Na, Ba, Al and B. The polymorphism of gene IL-4v.C589T (rs2243250) has a limited influence on antioxidative defense and the metabolism of chemical elements.

An Alternative Explanation for Alzheimer's Disease and Parkinson's Disease Initiation from Specific Antibiotics, Gut Microbiota Dysbiosis and Neurotoxins

The late onset neuropathologies, including Alzheimer's disease and Parkinson's disease, have become increasingly prevalent. Their causation has been linked to genetics, gut microbiota dysbiosis (gut dysbiosis), autoimmune diseases, pathogens and exposures to neurotoxins. An alternative explanatory hypothesis is provided for their pathogenesis. Virtually everyone has pervasive daily exposures to neurotoxins, through inhalation, skin contact, direct blood transmission and through the gastrointestinal tract by ingestion. As a result, every individual has substantial and fluctuating neurotoxin blood levels. Two major barriers to neurotoxin entry into the central nervous system are the blood-brain barrier and the intestinal wall, in the absence of gut dysbiosis. Inflammation from gut dysbiosis, induced by antibiotic usage, can increase the intestinal wall permeability for neurotoxins to reach the bloodstream, and also increase the blood-brain barrier permeability to neurotoxins. Gut dysbiosis, including gut dysbiosis caused by antibiotic treatments, is an especially high risk for neurotoxin entry into the brain to cause late onset neuropathologies. Gut dysbiosis has far-reaching immune system and central nervous system effects, and even a transient gut dysbiosis can act in combination with neurotoxins, such as aluminum, mercury, lead, arsenic, cadmium, selenium, manganese, organophosphate pesticides and organochlorines, to reach neurotoxin blood levels that can initiate a late onset neuropathology, depending on an individual's age and genetic vulnerability.

Activation of PINK1/Parkin-mediated mitophagy protects against apoptosis in kidney damage caused by aluminum

Aluminum (Al) induces apoptosis via oxidative stress and/or mitochondrial damage. Kidney is the main organ of Al excretion, but whether Al causes apoptosis in kidney of mice remains unclear. Mitophagy maintains cell homeostasis via clearing damaged mitochondria and reducing oxidative stress, but the role in kidney damage caused by Al has also not been investigated. In this study, firstly, forty wild type (WT) male C57 mice were randomly exposed to AlCl₃ at 0, 44.825, 89.65 or 179.3 mg/kg body weight in drinking water for 90 days, respectively. Our results confirmed that Al induced apoptosis, and activated PINK1 (phosphatase and tensin homolog (PTEN)-induced putative kinase1)/Parkin (E3 ubiquitin ligase PARK2)-mediated mitophagy with the dose increased. And secondly, to further assess the role of PINK1/Parkin-mediated mitophagy in Al-induced kidney damage, twenty Parkin knockout (Parkin^-/-) mice and twenty WT mice were divided into WT group, WT + Al group, Parkin^-/- group, and Parkin^-/- + Al group, and they were provided with AlCl₃ at a dose of 0 or 179.3 mg/kg body weight in drinking water for 90 days, respectively. The results showed that Parkin^-/- induced more severe kidney injury caused by Al. Besides, Parkin^-/- aggravated oxidative stress and apoptosis caused by Al. Overall, our findings indicate that the activation of PINK1/Parkin-mediated mitophagy protects against apoptosis in kidney damage caused by Al.

Autism Spectrum Disorder Initiation by Inflammation-Facilitated Neurotoxin Transport

Autism spectrum disorders have been linked to genetics, gut microbiota dysbiosis (gut dysbiosis), neurotoxin exposures, maternal allergies or autoimmune diseases. Two barriers to ingested neurotoxin transport into the central nervous system of a fetus or child are the gastrointestinal wall of the mother or child and the blood-brain barrier of the fetus or child. Inflammation from gut dysbiosis or inflammation from a disease or other agent can increase the gastrointestinal wall and the blood-brain barrier permeabilities to enable neurotoxins to reach the brain of a fetus or child. Postnatal gut dysbiosis is a particular inflammation risk for autism spectrum disorders caused by neurotoxin transport into a child's brain. An extensive gut dysbiosis or another source of inflammation such as a disease or other agent in combination with neurotoxins, including aluminum, mercury, lead, arsenic, cadmium, arsenic, organophosphates, and neurotoxic bacterial toxins and fungal toxins resulting from the gut dysbiosis, can elevate neurotoxin levels in a fetal or child brain to cause neurodevelopmental damage and initiate an autism spectrum disorder. The neurotoxins aluminum and mercury are especially synergistic in causing neurodevelopmental damage. There are three plausible causational pathways for autism spectrum disorders. They include inflammation and neurotoxin loading into the fetal brain during the prenatal neurodevelopment period, inflammation and neurotoxin loading into the brain during the postnatal neurodevelopment period or a two-stage loading of neurotoxins into the brain during both the prenatal and postnatal neurodevelopment periods.