Histochemical changes in muscle of rats exposed subchronically to low doses of heavy metals

Transplacental and genotoxicity effects of thallium(I) during organogenesis in mice

The increased concentration of thallium (Tl) in the environment is a cause for concern because the entire population, including pregnant women, is exposed, and this metal crosses the placenta and reaches the conceptus during development. In biological models such as mice, some abnormalities and delays in ossification occur in the fetuses of mice administered Tl on day 7 of gestation, but exposure to environmental Tl is constant during fetal development; therefore, in this study, the effects of several administrations of TI during organogenesis on the external morphology, skeletal development and genotoxicity of fetuses were evaluated. Four groups of 10 pregnant mice were administered 5.28, 6.16, 7.4 or 9.25 mg/kg body weight Tl(I) acetate intraperitoneally during fetal organogenesis. Additionally, samples were taken from fetuses from pregnant mice treated with 5.28 and 6.16 mg/kg body weight to evaluate the transplacental genotoxicity. The results revealed that the 9.25 mg/kg body weight dose produced maternal and fetal toxicity, and all of the treatment groups presented relatively high percentages of fetuses with external abnormalities, reduced bone ossification, and an increased percentage of liver cells with structural chromosomal aberrations (SCAs) and micronuclei (MNs) in blood cells. These results show that Tl(I) acetate administered during organogenesis produces abnormalities, including a delay in ossification and transplacental genotoxicity, in mouse fetuses. These findings are important because Tl has negative effects on development and may affect the health of offspring in the future because it can damage genetic material.

Integrating spatial heterogeneity and speciation dynamics in source apportionment of toxic metal(loid)s at an abandoned hydrometallurgical zinc smelting site

Zinc hydrometallurgy sites are critical hotspots for combined toxic metal(loid)s (TMs) pollution, yet the integration of spatial heterogeneity and migration dynamics into source apportionment remains underexplored. This study investigated the concentrations, speciation, and spatial distribution of nine TMs (As, Cd, Cu, Hg, Mn, Ni, Pb, Sb, Zn) in soils at an abandoned zinc smelter in southwest China. Multivariate statistical methods and the Positive matrix factorization (PMF) model were applied to disentangle primary sources and secondary redistribution. Spatial analysis revealed that As, Cd, Cu, Pb, Sb, and Zn shared similar contamination patterns, concentrated in slag storage and comprehensive recovery areas, whereas Hg and Mn exhibited distinct hotspots near sulfuric acid production and electrolysis zones. Vertical migration was most pronounced for Cd and Zn (> 8 m depth), followed by Hg and Mn (4-8 m), while As, Cu, Pb, and Sb were restricted to 0-4 m due to adsorption in clay-rich layers. Speciation analysis indicated high mobility of Cd and Zn (acid-soluble fraction: 66.96 and 52.10%, respectively), contrasting with reducible Pb and Mn (51.59 and 48.32%) and residual As, Hg, Ni, Sb (60.74-76.64%). The results from PMF model identified aqueous-phase (Cd, Zn, Mn) and solid-phase (As, Cu, Pb, Sb) migration pathways, validated by spatial correlations with topography and functional zones. Aqueous-phase contributions dominated low-lying areas, while solid-phase contributions aligned with elevated regions, reflecting topography-driven redistribution. This study advances source apportionment of TM in soil by unifying spatial heterogeneity, speciation dynamics, and receptor modeling, offering a framework for targeted risk assessment and remediation of industrial sites.

Selective fluorescent probe for Tl3+ ions through metal-induced hydrolysis and its application for direct assay of artificial urine

In this research, we report a simple fluorescent probe designed to detect thallium(iii) ions (Tl3+) in artificial urine samples. The Tl3+ signaling probe (TP-1) was readily prepared from 2-acetyl-6-methoxynaphthalene and hydrazine. In a pH 4.8 acetate buffer solution containing 1% (v/v) N,N-dimethylformamide as a solubilizer, probe TP-1 exhibited turn-on fluorescence signaling behavior in the presence of Tl3+. Other metal ions, anions, and major urine components such as uric acid, urea, and creatinine did not produce any noticeable fluorescence changes. The Tl3+ signaling of TP-1 was attributed to the hydrolysis of the hydrazone moiety, yielding the parent fluorophore 2-acetyl-6-methoxynaphthalene. The detection limit of TP-1 for Tl3+ sensing was 19 nM, and the signaling was completed within 2 min. Additionally, to further optimize the Tl3+ signaling of the hydrazone derivatives, we compared the effect of structural variations between the closely related ketone-hydrazone (TP-1) and aldehyde-hydrazone (TP-2) derivatives. We confirmed that the ketone-hydrazone (TP-1) demonstrated rapid and stable Tl3+ signaling behavior with satisfactory stability under the measurement conditions. Finally, as a practical application, a Tl3+ assay in artificial urine samples was performed using a smartphone as a portable signaling measurement and data analysis device.

Exposure to mixture of heavy metals and muscle strength in children and adolescents: a population-based study

Human beings are exposed to heavy metals through various ways in daily life. However, the effect of heavy metal mixtures on muscle strength in children and adolescents remains unclear. We aimed to investigate the relationship of exposure to heavy metal mixtures (barium, cadmium, cobalt, manganese, molybdenum, lead, antimony, strontium, tin, thallium, tungsten, uranium, and cesium) with muscle strength in children and adolescents. A total of 1357 (boys, 50.8%) participants aged between 8 and 17 were extracted from the National Health and Nutrition Examination Surveys 2011-2014. Urine metals were measured by inductively coupled plasma-mass spectrometry. Muscle strength was measured through a grip test using a handgrip dynamometer. Weighted quantile sum regression was performed to estimate the mixture effect of urinary metals on muscle strength. After adjusting for potential confounders, comparing participants in the highest versus lowest quartiles of cobalt, molybdenum, lead, antimony, strontium, thallium, and cesium, the handgrip strength decreased by - 4.48 kg (95% CI: - 6.93, - 2.03), - 6.13 kg (- 8.76, - 3.51), - 2.26 kg (- 4.22, - 0.30), - 2.38 kg (- 4.68, - 0.08), - 2.29 kg (- 4.45, - 0.13), - 4.78 kg (- 7.13, - 2.44), and - 5.68 kg (- 9.20, - 2.17), respectively. Furthermore, exposure to a mixture of metals were also significantly associated with decreased muscle strength (β: - 2.62 kg; 95% CI: - 3.71, - 1.54). Findings from the present study suggest that higher heavy metal exposure and the exposure levels of a mixture of metals in urine are inversely related to handgrip strength, implying that children's grip strength is not entirely explained by energy intake or lack of exercise, but may be related to environmental pollutants.

Effect on the offspring of pregnant females CD-1 mice treated with a single thallium(I) application

Thallium (Tl) is a highly toxic metal for human beings; higher amounts found in diverse fluids of pregnant women are associated with low birth weight and preterm birth. However, experimental data concerning their effects on the embryonic development of mammalian organisms are limited. Hence, in the present work, TI(I) acetate of 0, 4.6, 9.2, or 18.5 mg/kg body weight were administered by intraperitoneal injection to groups of 10 pregnant CD-1 mice on the 7th gestational day, and animals were sacrificed on day 18 of gestation. The fetuses obtained showed some variations, such as trunk bent over (18.5 mg/kg), tail variations (all doses), forelimbs malrotation and hind limbs (all doses). Skeletal examination of the fetuses showed a delay in the ossification of skull bones, ribs, and limbs (all doses). In conclusion, the Intraperitoneal injection of Tl(I) acetate to pregnant mice induced morphological variations and a delay of the fetus ossification.

Mercuric chloride poisoning: symptoms, analysis, therapies, and autoptic findings. A review of the literature

Among mercury-related intoxications, the re-emerging of mercuric chloride poisoning has been recently described in literature. Only sparse data, reporting the clinical symptoms, the anatomo-pathological findings, the analytical procedures or the treatment have been published and no exhaustive analysis of all these factors exists in literature. The classic symptoms associated with toxicity of mercuric chloride is a combination of renal, gastrointestinal (GI) and central nervous system (CNS) damages, eventually leading to death. Fatalities related to exposure to mercuric chloride have been reported since the nineteenth century. To date, there have been 45 published cases in the medical literature in which the intoxication or the death is attributed to mercuric chloride. In this review, we will describe the modern medical treatments, with particular attenztion to the developments of the lasts two decades, in order to provide an exhaustive description of the clinical symptoms, the post-mortem findings, and the analytical procedures to act out when mercuric chloride intoxication occurs. The analysis of the data obtained permitted us to accurately describe all the organs and apparatus involved in mercuric chloride intoxication. The target organs were the kidneys, the GI tract and the CNS. A description of the analytical procedures for the determination of mercuric chloride in biological materials, to carry out in vivo and in post-mortem samples has also been described.

Neurotoxicity Induced by Low Thallium Doses in Living Hippocampal Neurons: Evidence of Early Onset Mitochondrial Dysfunction and Correlation with Ethanol Production

The heavy metal thallium is an emerging pollutant among the most potentially toxic species to which human populations are exposed. Its harmful effects on living organisms are well-known at high doses, typical of acute intoxication. Its harmful effects at low doses are by far less known. In a previous paper, we reported a TlCl-induced metabolic shift to lactate and ethanol production in living hippocampal HN9.10e neurons that appeared after a single short exposure (48 h) at low doses (1-100 μg/L). This metabolic shift to lactate and ethanol suggests a marked impairment of cell bioenergetics. In this work, we provide detailed evidence for TlCl-induced changes of neuronal morphology and mitochondrial activity. Confocal microscopy and fluorescent probes were used to qualitatively and quantitatively analyze, at the subcellular level, living HN9.10e neurons during and after TlCl exposure. An early onset mitochondrial dysfunction appeared, associated with signs of cellular deregulation such as neurite shortening, loss of substrate adhesion, and increase of cytoplasmic calcium. The dose-dependent alteration of mitochondrial ROS (mtROS) level and of transmembrane mitochondrial potential (ΔΨ_m) has been observed also for very low TlCl doses (1 μg/L). The treatment with the ATP synthase inhibitor oligomycin revealed a severe impairment of the mitochondrial function, more significant than that measured by the simple quantification of the tetramethylrhodamine methyl ester (TMRM) fluorescence. These results highlight that mitochondria are a key subcellular target of TlCl neurotoxicity. The transmembrane mitochondrial potential was significantly correlated with the ethanol concentration in cell culture medium ( P < 0.001, r = -0.817), suggesting that ethanol could be potentially used as a biomarker of mitochondrial impairment.

Studies on analgesic, anti-inflammatory activities of stem and roots of Inula cuspidata C.B Clarke

The present study was carried out to evaluate analgesic and anti-inflammatory activities in Inula cuspidata stem and root extracts along with heavy metals estimation in stem and root powder.

Stem and roots were extracted with chloroform (ICSCE, ICRCE) and methanol (ICSME, ICRME). Acute oral toxicity of all extracts was determined by OECD guidelines 425. Analgesic activity was investigated by using hot plate and acetic acid induced writhing models. Anti-inflammatory activity (acute) of all extracts was evaluated by carrageenan induced paw edema model. In addition, root and stem powder was screened for heavy metals (As, Pb, Cd, Hg) estimation using atomic absorption spectroscopy. In acute toxicity study no mortality was observed when each extract was orally administered with 2.0 g/kg. At the doses (100 and 200 mg/kg) ICRME followed by ICSME showed significant and dose dependent analgesic and anti-inflammatory effects compared with chloroform extracts. The heavy metals concentration in stem and root powders was found to be within the permissible limits as recommended by WHO for herbal raw materials. The findings of the present study validated the folkloric use of Inula cuspidata as analgesic and anti-inflammatory. In addition, the results intimate that heavy metals present in raw material were found to be within the defined limits, and it exhibits that the therapeutic efficacy of plant may not be effected, which can be otherwise possibly effected if the plant sequester high concentration of heavy metals from the polluted environment as well as from the soil rich in pesticides and sewage sludge etc.

Toxicological effects of particulate matter (PM2.5) on rats: Bioaccumulation, antioxidant alterations, lipid damage, and ABC transporter activity

Previous studies have demonstrated the harmful effects of atmospheric pollutants on cardiac systems because of the presence of particulate matter (PM), a complex mixture of numerous substances including trace metals. In this study, the toxicity of PM2.5 from two regions, rural (PM2.5 level of 8.5 ± 4.0 μg m(-3)) and industrial (PM2.5 level of 14.4 ± 4.1 μg m(-3)) in Brazil, was investigated through in vivo experiments in rats. Metal accumulation and biochemical responses were evaluated after rats were exposed to three different concentrations of PM2.5 in saline extract (10× dilution, 5× dilution, and concentrated). The experimental data showed the bioaccumulation of diverse trace metals in the hearts of groups exposed to PM2.5 from both regions. Furthermore, mobilization of the antioxidant defenses and an increase in lipid peroxidation of the cardiac tissue was observed in response to the industrial and rural area PM2.5. Glutathione-S-transferase activity was increased in groups exposed to the 5× and concentrated rural PM2.5. Additionally, ATP-binding cassette (ABC) transporter activity in the cardiac tissue exposed to PM2.5 was reduced in response to the 5× dilution of the rural and industrial region PM2.5. Histological analysis showed a decrease in the percentage of cardiac cells in the heart at all tested concentrations. The results indicate that exposure to different concentrations of PM2.5 from both sources causes biochemical and histological changes in the heart with consequent damage to biological structures; these factors can favor the development of cardiac diseases.

Structural and functional changes in the zebrafish (Danio rerio) skeletal muscle after cadmium exposure

This report describes the alterations induced by an environmentally realistic concentration of cadmium in skeletal muscle fibre organization, composition, and function in the teleost zebrafish. Results demonstrate that the ion induces a significant quantitative and qualitative deterioration, disrupting sarcomeric pattern and altering glycoprotein composition. These events, together with a mitochondrial damage, result in a significant reduction in swimming performance. In conclusion, the evidence here collected indicate that in presence of an environmental cadmium contamination, important economic (yields in fisheries/aquaculture), consumer health (fish is an important source of proteins), and ecological (reduced fitness due to reduced swimming performance) consequences can be expected.

Preventive effects of ZPDC glycoprotein (24 kDa) on hepatotoxicity induced by mercury chloride in vitro and in vivo

Mercury is a potent environmental contaminant that exerts toxic effect on various vital organs in the human body. Recently, we isolated glycoprotein from Zanthoxylum piperitum DC (ZPDC), which has antioxidant and anticancer effects. In the present study, we determined the preventive effects of ZPDC glycoprotein on hepatic damage induced by mercury chloride (HgCl2 ). We evaluated the activities of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)], extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK), cyclo-oxygenase (COX-2), inducible nitric oxide synthetase (iNOS), and activator protein (AP-1) and the quantitative expressions of nuclear factor E2-related factor (Nrf2), heme oxygenase (HO-1), metallothionein (MT) and reduced glutathione (GSH) in mercury-chloride-exposed (50 μM and 10 mg/kg body weight) primary cultured hepatocytes and ICR mice, using biochemical assays, radioactivity and immunoblot analysis. The results demonstrated that ZPDC glycoprotein decreased the levels of LDH, ALT, HO-1 and MT, whereas it increased the activities of hepatic antioxidant enzymes (SOD, CAT and GPx) and reduced GSH in mercury-chloride-exposed primary cultured hepatocytes. Also, it suppressed arachidonic acid release and expression of ERK, p38 MAPK, COX-2, iNOS, AP-1 and Nrf-2 in primary cultured hepatocytes and ICR mice exposed to mercury chloride. Collectively, ZPDC glycoprotein may have potential applications to prevent hepatotoxicity induced by mercury chloride.