Gender differences in mercury-induced hepatotoxicity: Potential mechanisms

High-intensity interval training alleviates liver inflammation by regulating the TLR4/NF-κB signaling pathway and M1/M2 macrophage balance in female rats with cisplatin hepatotoxicity

Cisplatin (CDDP) is an antineoplastic drug whose adverse effects include hepatotoxicity. The inflammatory process is crucial in the progression of liver injuries. Exercise is known for its anti-inflammatory effects, but the influence of different training modalities on hepatoprotection is still unclear. This study aims to compare the impacts between preconditioning with high-intensity interval training (HIIT) and traditional continuous training of low (LT) and moderate (MT) intensities on inflammatory markers in Wistar female rats with CDDP-induced hepatotoxicity. Thirty-five rats were divided into five groups: control and sedentary (C + Sed), treated with CDDP and sedentary (CDDP + Sed), treated with CDDP and subjected to LT (CDDP + LT), treated with CDDP and subjected to MT (CDDP + MT), and treated with CDDP and subjected to HIIT (CDDP + HIIT). The training protocols consisted of treadmill running for 8 weeks before CDDP treatment. The rats were euthanized 7 days after the treatment. Liver samples were collected to evaluate the expression of various inflammatory markers and types of macrophages. Our results indicated that HIIT was the only protocol to prevent the increase in all analyzed pro-inflammatory cytokines and reduce the number of ED-1-positive cells, attenuating the TLR4/NF-κB signaling pathway in the liver. Additionally, HIIT increased the anti-inflammatory cytokine IL-10 and regulated M1/M2 macrophage polarization. Thus, this study suggests that preconditioning with HIIT is more effective in promoting hepatoprotective effects than LT and MT, regulating inflammatory markers through modulation of the TLR4/NF-κB signaling pathway and M2 macrophage polarization in the hepatic tissue of female rats treated with CDDP.

Development of a new series of thioacetal based fluorescence chemosensors for highly sensitive determination of Hg2+ in environmental samples and cell imaging

Mercury ion is one of the most harmful metal ions with significant hazards to the environment and human health. Thus, the development of innovative, sensitive, and selective sensors to help address the detrimental impacts of heavy metal contamination is necessary. In this work, we present three new chemosensors based on the deprotection reaction of the thioacetal group for distinguishing Hg2+ in environmental samples. These chemosensors show good photophysical properties with high quantum yield in aqueous medium. These prepared chemosensors were employed as fluorometric sensors for the determination of Hg2+ through the quenching of fluorescence emission due to the Hg2+-induced hydrolysis of the thioacetal to the aldehyde group. In the presence of Hg2+, chemosensors showed an emissive color transformation from blue fluorescence to non-fluorescence under UV light, which was readily seen by the visual eye. These chemosensors also exhibited highly distinctive selectivity toward Hg2+ over other interfering metal ions, with detection limits of 1.1 ppb, 13.4 ppb, and 12.7 ppb. Moreover, the practical applicability of chemosensor was successfully demonstrated in real water samples and herb extract samples.

Transcriptional and biochemical changes in mouse liver following exposure to a metal/drug cocktail. Attenuating effect of a selenium-enriched diet

Real-life pollution usually involves simultaneous co-exposure to different chemicals. Metals and drugs are frequently and abundantly released into the environment, where they interact and bioaccumulate. Few studies analyze potential interactions between metals and pharmaceuticals in these mixtures, although their joint effects cannot be inferred from their individual properties. We have previously demonstrated that the mixture (PC) of the metals Cd and Hg, the metalloid As and the pharmaceuticals diclofenac (DCF) and flumequine (FLQ) impairs hepatic proteostasis. To gain a deeper vision of how PC affects mouse liver homeostasis, we evaluated here the effects of PC exposure upon some biochemical and morphometric parameters, and on the transcriptional profiles of selected group of genes. We found that exposure to PC caused oxidative damage that exceeded the antioxidant capacity of cells. The excessive oxidative stress response resulted in an overabundance of reducing equivalents, which hindered the metabolism and transport of metabolites, including cholesterol and bile acids, between organs. These processes have been linked to metabolic and inflammatory disorders, cancer, and neurodegenerative diseases. Therefore, our findings suggest that unintended exposure to mixtures of environmental pollutants may underlie the etiology of many human diseases. Fortunately, we also found that a diet enriched with selenium mitigated the harmful effects of this combination of toxicants.

Selenium represses microRNA-202-5p/MICU1 aixs to attenuate mercuric chloride-induced kidney ferroptosis

Mercuric chloride (HgCl2) is a nephrotoxic contaminant that is widely present in the environment. Selenium (Se) can effectively antagonize the biological toxicity caused by heavy metals. Here, in vivo and in vitro models of Se antagonism to HgCl2-induced nephrotoxicity in chickens were established, with the aim of exploring the specific mechanism. Morphological observation and kidney function analysis showed that Se alleviated HgCl2-induced kidney tissue injury and cytotoxicity. The results showed that ferroptosis was the primary mechanism for the toxicity of HgCl2, as indicated by iron overload and lipid peroxidation. On the one hand, Se significantly prevented HgCl2-induced iron overload. On the other hand, Se alleviated the intracellular reactive oxygen species (ROS) levels caused by HgCl2. Subsequently, we focused on the sources of ROS during HgCl2-induced ferroptosis. Mechanically, Se reduced ROS overproduction induced by HgCl2 through mitochondrial calcium uniporter (MCU)/mitochondrial calcium uptake 1 (MICU1)-mediated mitochondrial calcium ion (Ca2+) overload. Furthermore, a dual luciferase reporter assay demonstrated that MICU1 was the direct target of miR-202-5p. Overall, Se represses miR-202-5p/MICU1 axis to attenuate HgCl2-induced kidney ferroptosis.

What does scientometry tell us about mercury toxicology and its biological impairments?

Mercury is a toxic pollutant that poses risks to both human and environmental health, making it a pressing public health concern. This study aimed to summarize the knowledge on mercury toxicology and the biological impairments caused by exposure to mercury in experimental studies and/or diagnosis in humans. The research was conducted on the main collection of Web of Science, employing as a methodological tool a bibliometric analysis. The selected articles were analyzed, and extracted data such as publication year, journal, author, title, number of citations, corresponding author's country, keywords, and the knowledge mapping was performed about the type of study, chemical form of mercury, exposure period, origin of exposure, tissue/fluid of exposure measurement, mercury concentration, evaluation period (age), mercury effect, model experiments, dose, exposure pathway, and time of exposure. The selected articles were published between 1965 and 2021, with Clarkson TW being the most cited author who has also published the most articles. A total of 38% of the publications were from the USA. These studies assessed the prenatal and postnatal effects of mercury, emphasizing the impact of methylmercury on neurodevelopment, including motor and cognitive evaluations, the association between mercury and autism, and an evaluation of its protective effects against mercury toxicity. In observational studies, the blood, umbilical cord, and hair were the most frequently used for measuring mercury levels. Our data analysis reveals that mercury neurotoxicology has been extensively explored, but the association among the outcomes evaluated in experimental studies has yet to be strengthened. Providing metric evidence on what is unexplored allows for new studies that may help governmental and non-governmental organizations develop guidelines and policies.

Assessment of thimerosal effects in sublethal concentrations on zebrafish (Danio rerio) embryos exploring NMR-based metabolomics profile

Thimerosal, a preservative commonly used in the pharmaceutical and cosmetic industry, has raised concerns regarding its potentially toxic effects as an organic mercury compound. Within this context, using an NMR-based metabolomics profile and chemometric analysis, zebrafish embryos were used as an in vivo model to study the effects of thimerosal in metabolic profiles after exposure to sublethal concentrations of the mercury compound. The thimerosal concentrations of 40 and 80 nM were employed, corresponding to 40% and 80% of the LC50, respectively, for zebrafish embryos. The most significant alterations in the metabolic profile included changes in carbohydrates, amino acids, nucleotides, trimethylamine-N-oxide, ethanolamine, betaine, and ethanol. Furthermore, thimerosal exposure affects various metabolic pathways, impairing the nervous system, disrupting protein metabolism, and potentially causing oxidative damage. Therefore, adopting a metabolomics approach in this investigation provided insights into the potentially implicated metabolic pathways contributing to the deleterious effects of thimerosal in biological systems.

Blood Concentrations of Lead, Cadmium, and Mercury Are Associated With Alcohol-Related Liver Disease

BACKGROUND

An association between environmental pollutants and alcohol-related liver disease (ALD) has not been determined until now. The objectives of this study were to examine the association of the pollutants with ALD, and whether the pollutants together increased the risk of ALD.

METHODS

Data were extracted from the Korea National Health and Nutrition Examination Survey (2010-2013 and 2016-2017; n = 11,993). Blood levels of lead, cadmium, and mercury were measured. ALD was defined by a combination of excessive alcohol consumption and ALD/non-alcoholic fatty liver disease index > 0. The aspartate aminotransferase-to-platelet ratio index and fibrosis (FIB)-4 score were used to evaluate ALD FIB.

RESULTS

The odds ratios (ORs) of ALD for the highest versus the lowest quartiles of exposure were for lead, 7.39 (95% confidence interval [CI], 5.51-9.91); cadmium, 1.68 (95% CI, 1.32-2.14); and mercury, 5.03 (95% CI, 3.88-6.53). Adjusting for age, gender, smoking, occupation, education, and personal income attenuated the associations but indicated significant positive trends (all Ptrend < 0.001). A positive additive interaction between cadmium and lead was observed. The relative excess OR due to the interaction was 0.96 (95% CI, 0.41-1.51); synergy index = 2.92 (95% CI, 0.97-8.80). Among 951 subjects with ALD, advanced FIB was associated with lead and cadmium (OR, 3.46, 95% CI, 1.84-6.53; OR, 8.50, 95% CI, 2.54-28.42, respectively), but not with mercury. The effect estimates for lead and cadmium remained significant even after adjustment for daily alcohol intake.

CONCLUSION

Blood levels of lead, cadmium, and mercury were significantly associated not only with the risk of ALD but also with ALD FIB. Cadmium and lead have synergistic effects that increase the risk of ALD.

Dissecting the role of cadmium, lead, arsenic, and mercury in non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

The objective of the present study was to review the existing epidemiological and laboratory findings supporting the role of toxic metal exposure in non-alcoholic fatty liver disease (NAFLD). The existing epidemiological studies demonstrate that cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) exposure was associated both with an increased risk of NAFLD and altered biochemical markers of liver injury. Laboratory studies demonstrated that metal exposure induces hepatic lipid accumulation resulting from activation of lipogenesis and inhibition of fatty acid β-oxidation due to up-regulation of sterol regulatory element-binding protein 1 (SREBP-1), carbohydrate response element binding protein (ChREBP), peroxisome proliferator-activated receptor γ (PPARγ), and down-regulation of PPARα. Other metabolic pathways involved in this effect may include activation of reactive oxygen species (ROS)/extracellular signal-regulated kinase (ERK) and inhibition of AMP-activated protein kinase (AMPK) signaling. The mechanisms of hepatocyte damage during development of metal-induced hepatic steatosis were shown to involve oxidative stress, endoplasmic reticulum stress, pyroptosis, ferroptosis, and dysregulation of autophagy. Induction of inflammatory response contributing to progression of NAFLD to non-alcoholic steatohepatitis (NASH) upon toxic metal exposure was shown to be mediated by up-regulation of nuclear factor κB (NF-κB) and activation of NRLP3 inflammasome. Moreover, epigenetic effects of the metals, as well as their effect on gut microbiota and gut wall integrity were also shown to mediate their role in NAFLD development. Despite being demonstrated for Cd, Pb, and As, the contribution of these mechanisms into Hg-induced NAFLD is yet to be estimated. Therefore, further studies are required to clarify the intimate mechanisms underlying the relationship between heavy metal and metalloid exposure and NAFLD/NASH to reveal the potential targets for treatment and prevention of metal-induced NAFLD.

N-Acetylcysteine Displaces Glutathionyl-Moieties from Hg2+ and MeHg+ to Form More Hydrophobic Complexes at Near-Physiological Conditions

The anthropogenic release of Hg is associated with an increased human exposure risk. Since Hg2+ and MeHg+ have a high affinity for thiols, their interaction with L-glutathione (GSH) within mammalian cells is fundamentally involved in their toxicological chemistry and excretion. To gain insight into the interaction of these mercurials with multiple small molecular weight thiols, we have investigated their competitive interactions with GSH and N-acetylcysteine (NAC) at near-physiological conditions, using a liquid chromatographic approach. This approach involved the injection of each mercurial onto a reversed-phase (RP)-HPLC column (37 °C) using a PBS buffer mobile phase containing 5.0 mM GSH to simulate cytosolic conditions with Hg being detected in the column effluent by an inductively coupled plasma atomic emission spectrometer (ICP-AES). When the 5.0 mM GSH mobile phase was amended with up to 10 mM NAC, gradually increasing retention times of both mercurials were observed. To explain this behavior, the experiment with 5.0 mM NAC and 5.0 mM GSH was replicated using 50 mM Tris buffer (pH 7.4), and the Hg-containing fractions were analyzed by electrospray ionization mass spectrometry. The results revealed the presence of Hg(GS)(NAC) and Hg(NAC)2 for Hg2+ and MeHg(GS) and MeHg(NAC) for MeHg+, which suggests that the coordination/displacement of GS-moieties from each mercurial by the more hydrophobic NAC can explain their retention behavior. Since the biotransformations of both mercurials were observed at near-physiological conditions, they are of toxicological relevance as they provide a biomolecular explanation for some results that were obtained when animals were administered with each mercurial and NAC.

Origin, dietary exposure, and toxicity of endocrine-disrupting food chemical contaminants: A comprehensive review

Endocrine-disrupting chemicals (EDCs) are a growing public health concern worldwide. Consumption of foodstuffs is currently thought to be one of the principal exposure routes to EDCs. However, alternative ways of human exposure are through inhalation of chemicals and dermal contact. These compounds in food products such as canned food, bottled water, dairy products, fish, meat, egg, and vegetables are a ubiquitous concern to the general population. Therefore, understanding EDCs' properties, such as origin, exposure, toxicological impact, and legal aspects are vital to control their release to the environment and food. The present paper provides an overview of the EDCs and their possible disrupting impact on the endocrine system and other organs.

Systemic impact of heavy metals and their role in cancer development: a review

Heavy metals are well-recognised as environmental hazards due to their toxicity, environmental persistence, and bioaccumulation in living organisms. Human health is a crucial concern related to terrestrial and aquatic ecosystems poisoned by harmful heavy metals. Most heavy metals pollute the air, water, and soil, which can be fatal to humans. Humans and other species can be exposed to heavy metals through the food chain if the metals oxidise or combine with other environmental elements (such as water, soil, or air). Their entry into the food chain assures interactions with biological macromolecules in living systems, including humans, resulting in undesirable outcomes. Human poisonings have typically been caused by mercury, lead, chromium, cadmium, and arsenic. The build-up of these metals in living organisms causes various harmful consequences on different organs and tissues. The gravitas of heavy metal toxicity regarding molecular impact and carcinogenesis needs in-depth understanding despite the plethora of available data. Hence, additionally, we attempt to elaborate on the multi-level impact of five heavy metals and emphasise their role in cancer development. The rationale of this essay is thus to understand the role of five heavy metals, viz., lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), and mercury (Hg), in carcinogenesis. Heavy metals interfere with various biological functions, including proliferation, differentiation, repair of damage, and apoptosis. By comparing their modes of action, we see that these metals share common mechanisms for inducing toxicity, such as reactive oxygen species (ROS) production, antioxidant defence weakening, enzyme inactivation, and oxidative stress.

Athelia rolfsii Exopolysaccharide Protection Against Kidney Injury in Lead-Exposed Mice via Nrf2 Signaling Pathway

This study aimed to explore protective efficacy of Athelia rolfsii exopolysaccharides (AEPS) to mice kidney against lead-exposed injury with a focus on the role of nuclear factor erythroid-2-related factor 2 (Nrf2) signaling pathway. Lead accumulation in the kidney induces oxidative stress which causes low antioxidant activity, abnormal pathological changes, and apoptosis. Here, the changes in lead levels in the kidney and whole blood proved that AEPS inhibited lead accumulation. It might be related to AEPS enhancing glutathione (GSH) levels and glutathione-s-transferase (GST) activities, as well as the protein abundances of multidrug resistance-associated protein 1 (MRP1) and multidrug resistance-associated protein 2 (MRP2). Moreover, AEPS increased antioxidant activity by upregulating superoxide dismutase (SOD), catalase (CAT) activities, downregulating malondialdehyde (MDA) levels. It also restored kidney function by decreasing blood urea nitrogen (BUN) and creatinine (CRE) levels in the serum. Histopathologic analysis showed that AEPS alleviated the kidney injury induced by lead, too. AEPS also showed anti-apoptosis effect by downregulating caspase-3 and bax expression and upregulating bcl-2 expression. Importantly, AEPS activated Nrf2 signaling pathway by promoting nuclear translocation of Nrf2. However, all-trans-retinoic acid (ATRA), an Nrf2 inhibitor, reversed the effects on AEPS to activation of Nrf2, enhancement of antioxidant, alleviation of kidney injury, restoration of kidney function, prevention of apoptotic, and facilitation of lead exclusion. In brief, AEPS showed kidney protective effect and facilitated lead-expulsion in an Nrf2-dependent manner.

Associations of blood metals with liver function: Analysis of NHANES from 2011 to 2018

BACKGROUND

Heavy metals have been reported to affect liver function. However, there is currently little and inconsistent knowledge about the effects of combined and individual blood metals on specific parameters of liver function in the general population. Hence, this study aimed to elucidate their associations.

METHODS

Data from National Health and Nutrition Examination Survey (NHANES) 2011-2018 were used in this cross-sectional study. Multivariate linear, and a quantile-based g-computation (qgcomp) were applied to explore the associations between blood metals [mercury (Hg), manganese (Mn), lead (Pb), cadmium (Cd), selenium (Se)], alone and in combination, and liver function parameters [alanine transaminase (ALT), aspartate transaminase (AST), ALT/AST, alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT) and serum total bilirubin (TBIL)].

RESULTS

A total of 15,328 were included. Multivariate linear models indicated that liver function was significantly associated with blood heavy metals. The most significant relationship was found between Se and AST (β 5.09, 95%CI (3.28,6.91), p＜0.001), Mn and ALT (β 1.24, 95%CI (0.57, 1.91), p＜0.001). Furthermore, the qgcomp analysis showed that the combination of five blood metals was positively associated with AST, ALT, GGT, TBIL and HSI. Cd contributed the most to the correlation of AST (weight = 0.447), Se contributed the most to the association of ALT (weight = 0.438) and HSI (weight = 0.570), Pb contributed the most to the association of GGT (weight = 0.421) and Hg contributed the most to the correlation of TBIL (weight = 0.331).

CONCLUSIONS

Blood heavy metal levels were significantly associated with liver function parameters. Further studies are required to clarify the relationship between heavy metals and liver function.

Associations of metal mixtures with metabolic-associated fatty liver disease and non-alcoholic fatty liver disease: NHANES 2003-2018

Objective

The hepatotoxicity of exposure to a single heavy metal has been examined in previous studies. However, there is limited evidence on the association between heavy metals mixture and non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD). This study aims to investigate the associations of 13 urinary metals, individually and jointly, with NAFLD, MAFLD, and MAFLD components.

Methods

This study included 5,548 adults from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Binary logistic regression was used to explore the associations between individual metal exposures and MAFLD, NAFLD, and MAFLD components. Bayesian kernel machine regression (BKMR) and Quantile-based g-computation (QGC) were used to investigate the association of metal mixture exposure with these outcomes.

Results

In single metal analysis, increased levels of arsenic [OR 1.09 (95%CI 1.03-1.16)], dimethylarsinic acid [1.17 (95%CI 1.07-1.27)], barium [1.22 (95%CI 1.14-1.30)], cobalt [1.22 (95%CI 1.11-1.34)], cesium [1.35 (95%CI 1.18-1.54)], molybdenum [1.45 (95%CI 1.30-1.62)], antimony [1.18 (95%CI 1.08-1.29)], thallium [1.49 (95%CI 1.33-1.67)], and tungsten [1.23 (95%CI 1.15-1.32)] were significantly associated with MAFLD risk after adjusting for potential covariates. The results for NAFLD were similar to those for MAFLD, except for arsenic, which was insignificantly associated with NAFLD. In mixture analysis, the overall metal mixture was positively associated with MAFLD, NAFLD, and MAFLD components, including obesity/overweight, diabetes, and metabolic dysfunction. In both BKMR and QGC models, thallium, molybdenum, tungsten, and barium mainly contributed to the positive association with MAFLD.

Conclusion

Our study indicated that exposure to heavy metals, individually or cumulatively, was positively associated with NAFLD, MAFLD, and MAFLD components, including obesity/overweight, diabetes, and metabolic dysfunction. Additional research is needed to validate these findings in longitudinal settings.

Aluminum, Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Copper, Iron, Lead, Mercury, Molybdenum, Nickel, Platinum, Thallium, Titanium, Vanadium, and Zinc: Molecular Aspects in Experimental Liver Injury

Experimental liver injury with hepatocelluar necrosis and abnormal liver tests is caused by exposure to heavy metals (HMs) like aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, mercury, molybdenum, nickel, platinum, thallium, titanium, vanadium, and zinc. As pollutants, HMs disturb the ecosystem, and as these substances are toxic, they may affect the health of humans and animals. HMs are not biodegradable and may be deposited preferentially in the liver. The use of animal models can help identify molecular and mechanistic steps leading to the injury. HMs commonly initiate hepatocellular overproduction of ROS (reactive oxygen species) due to oxidative stress, resulting in covalent binding of radicals to macromolecular proteins or lipids existing in membranes of subcellular organelles. Liver injury is facilitated by iron via the Fenton reaction, providing ROS, and is triggered if protective antioxidant systems are exhausted. Ferroptosis syn pyroptosis was recently introduced as mechanistic concept in explanations of nickel (Ni) liver injury. NiCl2 causes increased iron deposition in the liver, upregulation of cyclooxygenase 2 (COX-2) protein and mRNA expression levels, downregulation of glutathione eroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), nuclear receptor coactivator 4 (NCOA4) protein, and mRNA expression levels. Nickel may cause hepatic injury through mitochondrial damage and ferroptosis, defined as mechanism of iron-dependent cell death, similar to glutamate-induced excitotoxicity but likely distinct from apoptosis, necrosis, and autophagy. Under discussion were additional mechanistic concepts of hepatocellular uptake and biliary excretion of mercury in exposed animals. For instance, the organic anion transporter 3 (Oat3) and the multidrug resistance-associated protein 2 (Mrp2) were involved in the hepatic handling of mercury. Mercury treatment modified the expression of Mrp2 and Oat3 as assessed by immunoblotting, partially explaining its impaired biliary excretion. Concomitantly, a decrease in Oat3 abundance in the hepatocyte plasma membranes was observed that limits the hepatic uptake of mercury ions. Most importantly and shown for the first time in liver injury caused by HMs, titanium changed the diversity of gut microbiota and modified their metabolic functions, leading to increased generation of lipopolysaccharides (LPS). As endotoxins, LPS may trigger and perpetuate the liver injury at the level of gut-liver. In sum, mechanistic and molecular steps of experimental liver injury due to HM administration are complex, with ROS as the key promotional compound. However, additional concepts such as iron used in the Fenton reaction, ferroptosis, modification of transporter systems, and endotoxins derived from diversity of intestinal bacteria at the gut-liver level merit further consideration.

A simple colorimetric method based on "on-off-on" mode for detection of H2S and Hg2+ in water

It is of great significance to develop efficient platforms for the detection of hypertoxic Hg²⁺ and H₂S. Colorimetric have received much attention for the detection of H₂S and Hg²⁺ in the last decades. In this work, an "on-off-on" mode colorimetric method based on MnO₂/multi-wall carbon nanotubes (MnO₂/MWCNTs) composite was constructed. MnO₂/MWCNTs composite can oxidize TMB directly to form blue product (ox TMB) with a good simulated oxidase activity. In the presence of H₂S, it can decompose the MnO₂/MWCNTs composite causing the absorbance of the chromogenic system to decrease. When Hg²⁺ is introduced, the formation of Hg-S bond between Hg²⁺ and H₂S inhibited the decomposition ability of H₂S toward MnO₂ composite, thus resulting in a color change from colorless to blue. Based on this phenomenon, the proposed "on-off-on" colorimetric sensor can be used for detection of H₂S (off) and Hg²⁺ (on). Under optimized experimental conditions, this sensor showed a satisfactory linear relationship of H₂S and Hg²⁺ with pleasant repeatability, acceptable method accuracy and stability. More importantly, the proposed colorimetric sensor has been successfully applied to the detection of H₂S and Hg²⁺ in real samples, which not only provides a simple and cost-effective method to detect H₂S and Hg²⁺ but also hopefully makes a certain contribution to environmental protection.

In vivo evaluation of the potential protective effects of prolactin against damage caused by methylmercury

Non-biodegradable metals such as mercury accumulate in living organisms during life (bioaccumulation) and also within trophic webs (biomagnification) and may reach high concentrations in humans. The contamination of humans by mercury in drinking water and food may be common, in particular in riverside communities that have a diet rich in fish. In vitro studies of human cell lines exposed to the cytotoxic and mutagenic effects of methylmercury have shown that prolactin has potential cytoprotective properties and may act as a co-mitogenic factor and inhibitor of apoptosis. The present in vivo study investigated the protective potential of prolactin against the toxic effects of methylmercury in the mammal Mus musculus. Histological and biochemical analyses, together with biomarker of genotoxicity, were used to verify the protective potential of prolactin in mice exposed to methylmercury. The reduction in kidney and liver tissue damage was not significant. However, results of biochemical and genotoxic analyses were excellent. After prolactin treatment, a significant reduction was observed in biochemical parameters and mutagenic effects of methylmercury. The study results therefore indicated that prolactin has protective effects against the toxicity of methylmercury and allowed us to suggest the continuation of research to propose prolactin in the future, as an alternative to prevent the damage caused by mercury, especially in populations that are more exposed.

Aberrant Gene Expression of Selenoproteins in Chicken Spleen Lymphocytes Induced by Mercuric Chloride

Mercury (Hg) is a heavy metal widely distributed in ecological environment, poisoning the immune system of humans and animals. Selenium (Se) is an essential microelement and selenoproteins involved in the procedure of Se antagonizing organ toxicity induced by heavy metals. The aim of this research was to investigate the changes of gene expression profile of selenoproteins induced by mercuric chloride (HgCl₂) in chicken spleen lymphocytes. We established cytotoxicity model of chicken spleen lymphocytes by HgCl₂ exposure, the messenger RNA (mRNA) expression levels of 25 selenoproteins in spleen lymphocytes were analyzed by real-time quantitative PCR (qPCR), and the gene expression pattern of selenoproteins was revealed by principal component analysis (PCA). The results showed that the mRNA expression levels of 13 selenoproteins (GPX3, GPX4, TXNRD2, TXNRD3, DIO2, SELENOS, SELENON, SELENOT, SELENOO, SELENOP, SELENOP2, MSRB1, and SEPHS2) were decreased in HgCl₂ treatment group, and there was strong positive correlation between these selenoproteins and component 1 as well as component 2 of the PCA. At the same time, the protein expression levels of GPX4, TXNRD1, TXNRD2, SELENOM, SELENOS, and SELENON were detected by Western blotting, which were consistent with the changes of gene expression. The results showed that the expression levels of selenoproteins were aberrant in response to HgCl₂ toxicity. The information presented in this study provided clues for further research on the interaction between HgCl₂ and selenoproteins, and the possible mechanism of immune organ toxicity induced by HgCl₂.

Flaxseed oil ameliorates mercuric chloride-induced liver damage in rats

BACKGROUND

Mercury is a relentless pollutant, and its toxicity contributes to significant health problems due to exposure to the environment. The present study has determined the impact of flaxseed oil on mercuric chloride (HgCl2)-mediated hepatic oxidative toxicity in rats.

METHODS

Twenty-four healthy male Wistar rats were divided into four groups with six animals in each group. Group-A was the Control group treated with saline; Group-B received 1.0 ml oral dosage of flaxseed oil; Group-C was given 200 µl intraperitoneal injection of HgCl2, and Group-D received 1.0 ml oral dosage of flaxseed oil (one hour after treatment with 200 µl intraperitoneal injection of HgCl2.

RESULTS

Mercuric chloride (HgCl2) increased the production of malondialdehyde (MDA), reactive oxygen species (ROS), glutathione (GSH), and the concentration of HgCl2 in the liver tissue with a simultaneous decrease in the activities of Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Furthermore, serum HgCl2 elevated the activity of alanine transaminase (ALT) and Lactate dehydrogenase (LDH). Histopathological changes showed that liver injury was caused by mercuric chloride. Treatment with flaxseed oil ameliorated ROS production and reversed enzymes in serum and liver. Also, a noticeable improvement was observed in all the histopathological characteristics in the rats.

CONCLUSIONS

The findings of this study concluded that flaxseed oil had an outstanding remedial effect on mercuric chloride-mediated hepatic cytotoxicity.

Selenium alleviates mercury chloride-induced liver injury by regulating mitochondrial dynamics to inhibit the crosstalk between energy metabolism disorder and NF-κB/NLRP3 inflammasome-mediated inflammation

Mercury (Hg) is a persistent heavy metal contaminant with definite hepatotoxicity. Selenium (Se) has been shown to alleviate liver damage induced by heavy metals. Therefore, the present study aimed to explore the mechanism of the antagonistic effect of Se on mercury chloride (HgCl2)-induced hepatotoxicity in chickens. Firstly, we confirmed that Se alleviated HgCl2-induced liver injury through histopathological observation and liver function analyzation. The results also showed that Se prevented HgCl2-induced liver lipid accumulation and dyslipidemia by regulating the gene expression related to lipid as well as glucose metabolism. Moreover, Se blocked the nuclear factor kappa B (NF-κB)/NLR family pyrin domain containing 3 (NLRP3) inflammasome signaling pathway, which was the key to alleviate the inflammation caused by HgCl2. Mechanically, Se inhibited immoderate mitochondrial division, fusion, and biogenesis caused by HgCl2, and also improved mitochondrial respiration, which were essential for preventing energy metabolism disorder and inflammation. In conclusion, our results suggested that Se inhibited energy metabolism disorder and inflammation by regulating mitochondrial dynamics, thereby alleviating HgCl2-induced liver injury in chickens. These results are expected to provide potential intervention and therapeutic targets for diseases caused by inorganic mercury poisoning.

Antagonizing effects of curcumin against mercury-induced autophagic death and trace elements disorder by regulating PI3K/AKT and Nrf2 pathway in the spleen

Mercury is a naturally occurring element and highly toxic to humans even at a low dosage. Curcumin is a polyphenol found in turmeric (Curcuma longa), widely used as a treatment strategy to improve antioxidant and anti-inflammatory properties. The purpose of this study was to investigate the potential protective mechanisms of curcumin in spleen damage induced by HgCl₂. The mice were given curcumin by intragastric administration 2 h before HgCl₂ injection for 24 h. At first, splenic transcriptome analysis showed that 3334 genes (2134 up and 1200 down) were differently expressed in HgCl₂-induced spleen damage model. Notably, KEGG enrichment showed phosphatidylinositol 3-kinase (PI3K)-AKT might be a key signaling pathways in HgCl₂-induced spleen damage. Furthermore, our data demonstrated that HgCl₂ could induce autophagic cell death, evidenced by increases the protein expression of PI3K, AKT, LC3-II and p62 and the number of apoptotic cells. Furthermore, we found that curcumin significantly combated autophagic cell death, sodium overload and calcium leak induced by HgCl₂. Simultaneously, further studies demonstrated that curcumin significantly activated nuclear factor (erythroid-derived-2)-like 2 (Nrf2) signaling pathway, and subsequent enhancing antioxidant defenses. Taken together, our data indicated that inorganic mercury could result in autophagic cell death, which may be related to the regulation of PI3K-AKT signaling cascades. Furthermore, Nrf2-mediated antioxidant defenses may be the target of curcumin to confers an adaptive survival response to resist spleen damage induced by HgCl₂. The present study perfects the mechanism theory of HgCl₂-induced spleen damage and provides a way for pharmacological intervention to prevent spleen injury.

In Utero Exposure to Mercury Is Associated With Increased Susceptibility to Liver Injury and Inflammation in Childhood

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent cause of liver disease in children. Mercury (Hg), a ubiquitous toxic metal, has been proposed as an environmental factor contributing to toxicant-associated fatty liver disease.

APPROACH AND RESULTS

We investigated the effect of prenatal exposure to Hg on childhood liver injury by combining epidemiological results from a multicenter mother-child cohort with complementary in vitro experiments on monocyte cells that are known to play a key role in liver immune homeostasis and NAFLD. We used data from 872 mothers and their children (median age, 8.1 years; interquartile range [IQR], 6.5-8.7) from the European Human Early-Life Exposome cohort. We measured Hg concentration in maternal blood during pregnancy (median, 2.0 μg/L; IQR, 1.1-3.6). We also assessed serum levels of alanine aminotransferase (ALT), a common screening tool for pediatric NAFLD, and plasma concentrations of inflammation-related cytokines in children. We found that prenatal Hg exposure was associated with a phenotype in children that was characterized by elevated ALT (≥22.1 U/L for females and ≥25.8 U/L for males) and increased concentrations of circulating IL-1β, IL-6, IL-8, and TNF-α. Consistently, inflammatory monocytes exposed in vitro to a physiologically relevant dose of Hg demonstrated significant up-regulation of genes encoding these four cytokines and increased concentrations of IL-8 and TNF-α in the supernatants.

CONCLUSIONS

These findings suggest that developmental exposure to Hg can contribute to inflammation and increased NAFLD risk in early life.

Comparison of the Effects of Intraperitoneal Injection with Carbon Tetrachloride on Acute Liver Toxicity in Male and Female Kunming Mice

Background

Acute chemical liver injury needs to be further explored. The present study aimed to compare the effects of intraperitoneal injection with carbon tetrachloride on acute liver toxicity after 24 h in male and female Kunming mice.

Material/Methods

In this study, female and male mice were simultaneously divided into 3 different groups. Each group was treated differently, and after 24 h, blood samples were collected to check for changes in the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which were used to assess liver toxicity. Liver samples were used for hematoxylin-eosin staining, and periodic acid Schiff reagent staining was performed to detect the pathological changes of each group. The expression level of biomarker molecules in liver cells was also systematically analyzed.

Results

Our results showed that, compared with male mice, female mice showed more serious damage: reduced glycogen and higher degree of necrosis, and the levels of heatshock protein 27 (HSP27), heat-shock protein 70 (HSP70), proliferating cell nuclear antigen (PCNA) and B cell lymphoma/lewkmia-2 (Bcl-2) were significantly lower than in the male group (P<0.05 or P<0.01), while the results of Bcl-2-associated X protein (Bax), cysteinyl aspartate specific proteinase 3 (Caspase3), and cytochrome P450 2E1 (CYP2E1) were the opposite (P<0.05 or P<0.01).

Conclusions

The findings from this study showed that, compared with male mice, at 24 h after CCl₄ toxicity, female mice showed more severe changes of hepatocyte necrosis and PAS-positivity, with significantly reduced expression of HSP27, HSP70, PCNA, and Bcl-2, and significantly increased expression of Bax, caspase-3, and CYP2E1.

Hepatic and renal expression of Oatp1 in obstructive uropathy. First detection of Oatp1 in urine, a potential biomarker

Obstructive renal diseases affect renal function and kidney integrity. Nevertheless, little is known about its systemic or extra-renal effects. The organic anion transporting polypeptide 1 (Oatp1) is a carrier expressed in liver and kidneys. In this study, the hepatic and renal expression of Oatp1 was evaluated in rats with obstructive nephropathy. Moreover, the urinary excretion of Oatp1 (Oatp1u ) was evaluated as a potential biomarker for this pathology. Male Wistar rats with bilateral ureteral obstruction for 5 hours (BUO5), 24 hours (BUO24) or sham operated were used. After 24 hours of ureteral releasing, liver and kidney functional parameters, histopathology, Oatp1 tissular expression and Oatp1u were evaluated. For Oatp1u evaluation two groups were added; BUO1 and BUO2 (1 and 2 hours of ureteral obstruction, respectively). Both liver and kidney functional parameters and histopathological studies showed alterations in BUO5 and BUO24. In hepatic homogenates, Oatp1 significantly decreased in BUO groups and in total liver membranes no modifications were observed. In renal homogenates, Oatp1 significantly decreased in BUO groups, but in apical kidney membranes, its expression was increased. Oatp1u was only detected in BUO groups, even in those (BUO1, BUO2) in which no alterations in the traditional parameters of renal function were observed. Modulations in liver and renal expression of Oatp1 could be an organism strategy to attenuate the effects of the disease and an attempt to maintain the complex organ cross-talk between liver and kidneys. Oatp1u could be a new, early and specific biomarker of obstructive nephropathy.

Toxic Mechanisms of Five Heavy Metals: Mercury, Lead, Chromium, Cadmium, and Arsenic

The industrial activities of the last century have caused massive increases in human exposure to heavy metals. Mercury, lead, chromium, cadmium, and arsenic have been the most common heavy metals that induced human poisonings. Here, we reviewed the mechanistic action of these heavy metals according to the available animal and human studies. Acute or chronic poisonings may occur following exposure through water, air, and food. Bioaccumulation of these heavy metals leads to a diversity of toxic effects on a variety of body tissues and organs. Heavy metals disrupt cellular events including growth, proliferation, differentiation, damage-repairing processes, and apoptosis. Comparison of the mechanisms of action reveals similar pathways for these metals to induce toxicity including ROS generation, weakening of the antioxidant defense, enzyme inactivation, and oxidative stress. On the other hand, some of them have selective binding to specific macromolecules. The interaction of lead with aminolevulinic acid dehydratase and ferrochelatase is within this context. Reactions of other heavy metals with certain proteins were discussed as well. Some toxic metals including chromium, cadmium, and arsenic cause genomic instability. Defects in DNA repair following the induction of oxidative stress and DNA damage by the three metals have been considered as the cause of their carcinogenicity. Even with the current knowledge of hazards of heavy metals, the incidence of poisoning remains considerable and requires preventive and effective treatment. The application of chelation therapy for the management of metal poisoning could be another aspect of heavy metals to be reviewed in the future.

Ziziphus spina-christi leaf extract attenuates mercuric chloride-induced liver injury in male rats via inhibition of oxidative damage

Heavy metal contamination including mercury (Hg) has become one of the most serious environmental problems facing humans and other living organisms. Here, the hepatoprotective effects of Z. spina-christi leaf extract (ZCE) against inorganic mercury salt (mercuric chloride; HgCl₂)-induced hepatotoxicity model was investigated in rats. Mercury concentration, liver function markers, oxidative stress markers, inflammation, cell death indicators, and histopathology were assessed. ZCE protected against HgCl₂-induced hepatotoxicity, decreased Hg concentration, lipid peroxidation, and nitric oxide, increased glutathione, superoxide dismutase, catalase, and glutathione recycling enzymes (peroxidase and reductase), and upregulated nuclear factor-erythroid 2-related factor 2 (Nrf2) gene expression in HgCl₂-intoxicated rat hepatic tissue. Nrf2 downstream gene and heme oxygenase-1 were also upregulated, confirming that hepatoprotection by ZCE against HgCl₂-induced liver damage involved activation of the Nrf2/antioxidant response element pathway. ZCE also decreased the expression and production of pro-inflammatory cytokines and pro-apoptotic proteins and increased anti-apoptotic protein Bcl-2. Immunohistochemical analysis of liver tissues of HgCl₂-treated rats confirmed the alternations of apoptotic-related protein expression. Our data demonstrated that post-administration of ZCE attenuated HgCl₂-induced liver damage by activating the Nrf2/HO-1 signaling pathway. Therefore, administering this extract may be a novel therapeutic strategy for inorganic mercury intoxication.

Effect of erythropoietin on mercury-induced nephrotoxicity: Role of membrane transporters

Mercury is a widespread pollutant. Mercuric ions uptake into tubular cells is supported by the Organic anion transporter 1 (Oat1) and 3 (Oat3) and its elimination into urine is through the Multidrug resistance-associated protein 2 (Mrp2). We investigated the effect of recombinant human erythropoietin (Epo) on renal function and on renal expression of Oat1, Oat3, and Mrp2 in a model of mercuric chloride (HgCl2)-induced renal damage. Four experimental groups of adult male Wistar rats were used: Control, Epo, HgCl2, and Epo + HgCl2. Epo (3000 IU/kg, b.w., i.p.) was administered 24 h before HgCl2 (4 mg/kg, b.w., i.p.). Experiments were performed 18 h after the HgCl2 dose. Parameters of renal function and structure were evaluated. The protein expression of Oat1, Oat3 and Mrp2 in renal tissue was assessed by immunoblotting techniques. Mercury levels were determined by cold vapor atomic absorption spectrometry. Pretreatment with Epo ameliorated the HgCl2-induced tubular injury as assessed by histopathology and urinary biomarkers. Immunoblotting showed that pretreatment with Epo regulated the renal expression of mercury transporters in a way to decrease mercury content in the kidney. Epo pretreatment ameliorates HgCl2-induced renal tubular injury by modulation of mercury transporters expression in the kidneys.

Di-(2-ethylhexyl) phthalate-induced hepatotoxicity exacerbated type 2 diabetes mellitus (T2DM) in female pubertal T2DM mice

Di-(2-ethylhexyl) phthalate (DEHP), one of the most common plasticizers, is closely associated with a high prevalence of pubertal type 2 diabetes mellitus (T2DM). Numerous studies have indicated that DEHP-induced metabolic toxicity exhibits sex differences. In this study, the sex differences in the effect of DEHP on pubertal T2DM (P-T2DM) mice, the susceptibility of female P-T2DM mice to DEHP-induced metabolic toxicity, and the underlying mechanisms were investigated. DEHP exposure exacerbated metabolic disorders in female P-T2DM mice. Factorial analysis showed that female P-T2DM mice were more sensitive to DEHP exposure than female normal mice and male P-T2DM mice. It was determined by integrated biomarker response results that female P-T2DM mice had higher risks of developing T2DM, metabolic disorders, cardiovascular events and hepatotoxicity than male P-T2DM mice. Moreover, hepatic transcriptome analysis emphasized the effects of DEHP on the expression of oxidative injury- and metabolic function-related genes. Western blotting indicated that DEHP activated Jun-N-terminal kinase (JNK) and impaired insulin sensitivity in the liver, which were the main causes of DEHP-exacerbated metabolic abnormalities in P-T2DM mice. Our study revealed that compared with normal mice and male P-T2DM mice, female P-T2DM mice tend to suffer from increased DEHP-induced metabolic toxicity, which was primarily attributed to hepatotoxicity.

The sex-specific effects of blood lead, mercury, and cadmium levels on hepatic steatosis and fibrosis: Korean nationwide cross-sectional study

AIM

The potential effects of heavy metals on non-alcoholic fatty liver disease (NAFLD) remain unknown. We investigated the sex-specific relationships of blood lead (BPb), mercury (BHg), and cadmium (BCd) levels with hepatic steatosis (HS) and fibrosis (HF).

METHOD

We included 4420 participants from the 2016-2017 Korea National Health and Nutrition Examination Survey. High-risk alcoholics and patients with chronic hepatitis B or C infections or liver cirrhosis were excluded. We calculated the hepatic steatosis index (HSI) and fibrosis-4 index (FIB-4) values; we defined the presence of HS and HF as an HSI ≥ 36 and FIB-4 score >2.67, respectively. We adjusted for age, smoking and alcohol consumption statuses, hypertension, obesity, diabetes, hypertriglyceridemia, and BPb, BHg, and BCd levels.

RESULT

In males (n = 1860), the HSI was correlated negatively with the BPb level and positively with the BHg level (both p < 0.01). The FIB-4 score was correlated positively with the BPb and BCd levels (both p < 0.01). In females (n = 2560), the HSI and FIB-4 score were correlated positively with the BPb, BHg, and BCd levels (all p < 0.01). After adjustments, the BHg level increased the risk of HS in both males (OR = 1.065, p = 0.003) and females (OR = 1.061, p = 0.048), and the BCd level increased the risk of HF in females (OR = 1.668, p = 0.012).

CONCLUSION

Blood heavy metal levels were generally correlated positively with the HSI and FIB4 score, more so in females than males. The BHg level was associated with HS in males and females, and the BCd level was associated with HF in females. Further studies on NAFLD progression according to heavy metal status and sex are warranted.

Sex differences in renal handling of inorganic mercury in aged rats

The sex of an individual/animal has been shown to play an important role in many biological processes. Furthermore, sex may also be a factor in the way environmental toxicants, such as heavy metals, are handled by organisms. However, the effect of sex on the handling and disposition of heavy metals, such as mercury (Hg), has not been shown. Aging has also been shown to be a factor in the accumulation of heavy metals in that older individuals tend to have higher burdens of these metals. Therefore, the purpose of the current study was to evaluate the effect of sex on the accumulation of mercury in aged animals. Aged male and female rats were injected intravenously with 0.5 μmol or 2.0 μmol·kg⁻¹ HgCl₂ (containing radioactive Hg) and organs were harvested after 24 h. In general, the renal accumulation of Hg was significantly greater in males than in females. Similarly, urinary excretion of Hg was greater in males than in females. There were no significant differences between males and females in the burden of Hg in other organs. Sex differences in the renal accumulation of Hg may be related to differences in the expression of membrane transporters involved in the uptake of mercuric species into tubular epithelial cells. The results of the current study illustrate the need to evaluate both sexes when assessing the renal effects of environmental toxicants.

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Renal accumulation of mercury is greater in aged male rats than aged female rats.

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Mercury accumulation differed among zones of the kidney.

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Sex did not appear to alter accumulation of mercury in other organs studied.

Nanozyme-based sensing platforms for detection of toxic mercury ions: An alternative approach to conventional methods

Mercury (Hg) is known as a poisonous heavy metal which stimulates a wide range of adverse effects on the human health. Therefore, development of some feasible, practical and highly sensitive platforms would be desirable in determination of Hg²⁺ level as low as nmol L^-1 or pmol L^-1. Different approaches such as ICP-MS, AAS/AES, and nanomaterial-based nanobiosensors have been manipulated for determination of Hg²⁺ level. However, these approaches suffer from expensive instruments and complicated sample preparation. Recently, nanozymes have been assembled to address some disadvantages of conventional methods in the detection of Hg²⁺. Along with the outstanding progress in nanotechnology and computational approaches, pronounced improvement has been attained in the field of nanozymes, recently. To accentuate these progresses, this review presents an overview on the different reports of Hg²⁺-induced toxicity on the different tissues followed by various conventional approaches validated for the determination of Hg²⁺ level. Afterwards, different types of nanozymes like AuNPs, PtNPs for quantitative detection of Hg²⁺ were surveyed. Finally, the current challenges and the future directions were explored to alleviate the limitation of nanozyme-based platforms with potential engineering in detection of heavy metals, namely Hg²⁺. The current overview can provide outstanding information to develop nano-based platforms for improvement of LOD and LOQ of analytical methods in sensitive detection of Hg²⁺ and other heavy metals.

Tissue distribution of mercury and copper after Aarogyavardhini Vati treatment in rat model of CCl4 induced chronic hepatotoxicity

Background

Aarogyavardhini Vati is a classical Ayurvedic herbomineral formulation. It contains mercury and copper compounds as principal minerals along with other minerals and herbal ingredients. Aarogyavardhini Vati is indicated in chronic liver ailments. However, safety concerns are often raised regarding the use of mercury containing ayurvedic drugs in disease conditions due to the risk of mercury and copper toxicity.

Objective

This study was performed to address the safety concerns regarding mercury and copper toxicity from Ayurvedic herbomineral formulations by investigating accumulation of these minerals in tissues and subsequent toxicity in chronic hepatotoxicity rat model.

Materials and methods

Quantification of mercury and copper in Aarogyavardhini Vati was done. Chronic hepatotoxicity was induced in the Wistar rats by repeated administration of CCl₄ for 8 weeks. Animals were treated with Aarogyavardhini Vati for various durations. Post treatment of 8 weeks, serum biochemical marker estimations was done. Estimation of mercury and copper from the liver, kidney and brain tissues was done after animal sacrifice. Histopathology evaluation of visceral organs was also performed.

Results

Treatment with Aarogyavardhini Vati exhibited significant accumulation of mercury in the kidney but not in the brain and liver. Similarly, no significant accumulation of copper was observed in liver, kidney, and brain due to the treatment of Aarogyavardhini Vati. Serum biochemical and histopathological changes were not affected by the treatment with Aarogyavardhini Vati.

Conclusion

Aarogyavardhini Vati did not show any biologically significant potential to cause toxicity due to its mercury and copper content when administered for prolonged duration to rats with chronic hepatotoxicity.

EASL clinical practice guidelines for the management of occupational liver diseases

The Clinical Practice Guidelines (CPG) on Occupational Liver Diseases (OLD) of the European Association for the Study of the Liver (EASL) have been developed to increase awareness, recognition and improve management of patients with OLD. Indeed, although workplace exposure has been associated with virtually the entire spectrum of acute and chronic liver diseases, data on the epidemiology of OLD are scarce. These diseases may be a result of high-level accidental exposure or prolonged lower level exposure to a variety of chemicals including solvents, pesticides, metals and other agents. While acute liver diseases related to OLD are uncommon and easily recognized, chronic liver diseases are relatively more frequent but often overlooked because of their asymptomatic course and an insidious onset which is often accompanied by comorbidities. Because of the absence of data in observational studies and meta-analyses or systematic reviews, the evidence and recommendations in these guidelines have been graded according to the Oxford Centre for Evidence-based Medicine, which assesses evidence according to diagnostic, prevalence, aetiological, prognostic or preventive categories. They can still generate grades of recommendation even when the evidence is inconclusive.

Unravelling the fibrillation mechanism of ovalbumin in the presence of mercury at its isoelectric pH

The intriguing resemblances of amyloid fibrils and spider silk in protein aggregation diseases have instigated the exploration of identical structural features if any in their oligomeric pathways. The serpin group protein, ovalbumin, on defolding in HgCl₂ shares commonness to the micellar pathway of spidroins for their aggregation in response to a pH trigger. The structural feature changes from monomer to worm like fibril with a shift in the primary protein pH to slightly acidic pH (4.5), and then proceeds through a secondary nucleation pathway to ‘hillock’ and ‘hydra’ like protofibrils rich in β-sheet and random coil conformers upon exposure to mercury. The findings are backed by atomic force microscopy, confocal Raman spectroscopy and fluorescence measurements. Unlocking such structural features can favorably assist in the design of therapeutics.

Mercuric chloride triggered ovalbumin aggregation pathway and its resemblance to Nephila clavipes.

EASL Clinical Practice Guideline: Occupational liver diseases

A variety of chemicals have been linked to occupational liver diseases, including several solvents and mixtures thereof, pesticides, and metals. Workplace exposures have been associated with virtually the entire spectrum of acute and chronic liver diseases. However, their prevalence is inadequately quantified and their epidemiology limited. Occupational liver diseases may result from high accidental or from prolonged lower level exposures. Whereas the former is uncommon and easily recognised, the latter are relatively more frequent but often overlooked because they may display normal values of conventional markers, have an insidious onset and be asymptomatic or be obfuscated and confounded by concurrent conditions. In addition, specific tests of toxicity are not available, histopathology may not be revealing and the assessment of internal dose of chemicals is usually not decisive. Given these circumstances, the diagnosis of these liver disorders is challenging, one of exclusion and often requires an interdisciplinary approach. These recommendations offer a classification of the type of liver injuries associated with occupational exposures - based in part on the criteria for drug-induced liver injury - a grading of their severity, and the diagnostic and preventive criteria for chemically induced occupational liver disease.

Mechanisms of Environmental Contributions to Fatty Liver Disease

PURPOSE

Fatty liver disease (FLD) affects over 25% of the global population and may lead to liver-related mortality due to cirrhosis and liver cancer. FLD caused by occupational and environmental chemical exposures is termed "toxicant-associated steatohepatitis" (TASH). The current review addresses the scientific progress made in the mechanistic understanding of TASH since its initial description in 2010.

RECENT FINDINGS

Recently discovered modes of actions for volatile organic compounds and persistent organic pollutants include the following: (i) the endocrine-, metabolism-, and signaling-disrupting chemical hypotheses; (ii) chemical-nutrient interactions and the "two-hit" hypothesis. These key hypotheses were then reviewed in the context of the steatosis adverse outcome pathway (AOP) proposed by the US Environmental Protection Agency. The conceptual understanding of the contribution of environmental exposures to FLD has progressed significantly. However, because this is a new research area, more studies including mechanistic human data are required to address current knowledge gaps.

L-α-Phosphatidylcholine attenuates mercury-induced hepato-renal damage through suppressing oxidative stress and inflammation

The potential ameliorative effects of L-α-phosphatidylcholine (PC) against mercuric chloride (HgCl₂)-induced hematological and hepato-renal damage were investigated. Rats were randomly allocated into four groups (n = 12): control, PC (100 mg/kg bwt, intragastrically every other day for 30 consecutive days), HgCl₂ (5 mg/kg bwt, intragastrically daily), and PC plus HgCl₂. Hematological and hepato-renal dysfunctions were evaluated biochemically and histopathologically. Hepatic and renal oxidative/antioxidative indices were evaluated. The expression of proinflammatory cytokines (tumor necrosis factor-α and interleukin-6) was also detected by ELISA. HgCl₂ significantly increased serum aminotransferases (ALT, AST), urea, and creatinine levels that are indicative of hepato-renal damage. HgCl₂ also induced a significant accumulation of malondialdehyde (+ 195%) with depletion of glutathione (- 43%) levels in the liver and renal tissues. The apparent hepato-renal oxidative damage was associated with obvious organ dysfunction that was confirmed by impairments in the liver and kidney histoarchitecture. Furthermore, HgCl₂ significantly attenuated the expression of proinflammatory cytokines named tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Conversely, PC treatment attenuated these effects, which improved the hematological and serum biochemical alternations, reduced the oxidative stress and proinflammatory cytokine levels, and ameliorated the intensity of the histopathological alterations in livers and kidneys of HgCl₂-treated rats. It could be concluded that PC displayed potential anti-inflammatory and antioxidant activities against HgCl₂-induced hepato-renal damage via suppression of proinflammatory cytokines and declining oxidative stress.

Renal expression of organic anion transporters is modified after mercuric chloride exposure: Gender-related differences

Mercuric ions (Hg⁺²) gain access to proximal tubule cells primarily by the Organic Anion Transporter 1 (Oat1) and 3 (Oat3) in the basolateral plasma membrane. The removal process of Hg⁺² ions from cells into the lumen involves an efflux process mainly mediated by the Multidrug Resistance-Associated Protein 2 (Mrp2). The aim of this study was to compare the sex-related differences in the renal expression of Oat1, Oat3, and Mrp2 after mercuric chloride (HgCl₂) treatment and analyze their relevance in the mercury-induced nephrotoxicity. Control and Hg-treated male and female Wistar rats were used. Animals received a dose of HgCl₂ (4 mg/kg bw, ip) 18 h before the experiments. Tubular injury was assessed by histopathological studies. The renal expression of Oat1, Oat3, and Mrp2 was analyzed by Western Blotting. Mercury levels were determined in urine by cold vapour atomic absorption spectroscopy. HgCl₂ treatment increased the expression of renal Oat1 and Mrp2 in both sexes, being more evident in females than in males. The Oat3 renal expression only increased in female rats. The higher expressions of Oat1, Oat3, and Mrp2 could explain the higher renal excretion of mercury and consequently, the lesser renal tubular damage in female rats than in male rats.