Molecular mechanism of heavy metals (Lead, Chromium, Arsenic, Mercury, Nickel and Cadmium) - induced hepatotoxicity - A review

Associations of non-essential metal mixture with biological aging and the mediating role of inflammation in Chinese older adults

BACKGROUND

Individual non-essential metals (NMs) have been linked with biological aging. However, the effects of NM mixture and their mechanisms remain unclear.

OBJECTIVE

To characterize the relationships of individual NMs and their mixture to biological aging, and to explore the mediating roles of inflammatory factors.

METHODS

This cross-sectional study recruited 3251 individuals aged 60 years or above in China. Urine gallium, arsenic, cadmium, cesium, thallium, and barium were tested using ICP-MS. The Klemera-Doubal method was used to construct the KDMAge, reflecting the estimation of biological age, and ΔKDMAge, defined as the difference between KDMAge and chronological age, reflecting the deviation in aging rate. Four blood cell counts, including neutrophil, lymphocyte, platelet, and monocyte, were used to calculate inflammatory indices: neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and systemic immune-inflammation index. Linear regression, generalized additive model (GAM), weighted quantile sum (WQS), quantile-based computation (QGC), and Bayesian kernel machine regression (BKMR) were employed to assess the associations between the NMs and ΔKDMAge. Mediation analysis was further performed to examine the roles of inflammatory factors.

RESULTS

KDMAge strongly correlated with chronological age (r = 0.863). Linear regression showed significant positive associations of Gallium (β = 0.88, 95 % CI = 0.30, 1.46), arsenic (β = 1.11, 95 % CI = 0.54, 1.69), and cesium (β = 0.75, 95 % CI = 0.19, 1.30) with ΔKDMAge. GAMs further exhibited a "J-shaped" relationship for gallium, arsenic with ΔKDMAge, a linear trend for cesium, and a "U-shaped" relationship for barium. The mixture models demonstrated a positive association between the NM mixture and ΔKDMAge, with gallium, arsenic, and cesium identified as the primary contributors. Mediation analyses further suggested that neutrophil-to-lymphocyte ratio and systemic immune-inflammation index partially mediated this association.

CONCLUSIONS

The NM mixture accelerates biological aging, mainly driven by gallium, arsenic, and cesium, with partial mediation by inflammation. Future longitudinal studies are necessary to verify these findings.

Synergistic human health risks of microplastics and co-contaminants: A quantitative risk assessment in water

The pervasive presence of microplastics (MPs) in aquatic environments, coupled with their potential to act as vectors for toxic contaminants, raises significant concerns for human health. This study quantifies the health risks associated with the ingestion of microplastics and their co-contaminants in aquatic medium, considering both individual and interactive effects. The analysis encompasses four MP types (PP, PS, PET, PE) and prevalent contaminants including heavy metals (Cr, Cu, Ni, Pb), polycyclic aromatic hydrocarbons (PAHs, expressed as BaP equivalents), and plastic additives (DEHP, DBP, BPA)-to calculate individual Hazard Quotient (HQ), interaction-based Hazard Index (HIint), individual Incremental Lifetime Cancer Risk (ILCR), and interaction-based ILCR (ILCRint). The mean concentration of MPs in aqueous media was determined to be 2.19 mg/L (95 % CI), and Chronic Daily Intake (CDI) values were derived from particle counts converted to mass using polymer-specific densities. Reference Dose (RfD) values were calculated using the Weight of Evidence (WoE) approach, which integrates findings from rodent toxicity studies, identifying PP and PS as having low RfD values 25 × 10⁻⁴ mg/kg bw/day and 8 × 10⁻⁴ mg/kg bw/day, respectively. HQ-based toxicity rankings indicated the order of risk as PP > PS > PE > PET. Findings revealed a pronounced HIint of 18.646 × 10³ and 16.649 × 10⁶ at the 50th and 90th percentiles in children, underscoring significant synergistic effects from combined exposure to MPs and leached plastic additives. Co-contaminant scenarios further escalated health risks, with HI values reaching 52.236 in the presence of heavy metals and 53.141 with PAHs. The maximum allowable MP concentration, considering additive leaching, was estimated at 0.011 mg/L. This research highlights the need for firstly understanding the transformations of microplastic in the aquatic medium along with co-contaminants and framing regulatory measures and improved monitoring to protect human health from the growing threat of microplastic pollution. By integrating exposure modeling, dose-response assessment, and Monte Carlo simulations, the study delivers a robust framework for environmental health guidelines. It emphasizes the complex, multifaceted risks MPs pose and their associated contaminants, calling for innovative solutions to safeguard public health against this pervasive environmental challenge.

Association between Mixed Heavy Metal Exposure and Arterial Stiffness, with Alkaline Phosphatase Identified as a Mediator

Elevated arterial stiffness has been associated with exposure to heavy metals such as lead (Pb) and cadmium (Cd). However, the collective impact of multiple metals and the underlying mechanisms are not fully elucidated. The purpose of this study was to assess the combined effects of exposure to nine heavy metals on arterial stiffness and explore whether serum alkaline phosphatase (ALP) acts as a mediator in this relationship. In the retrospective analysis, data from 8,700 participants were retrieved from the National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2018. Arterial stiffness was measured by estimated pulse wave velocity (ePWV). The cumulative impact of exposure to multiple metals was examined using adaptive elastic-net, environmental risk score, weighted quantile sum regression, and quantile g-computation. Additionally, mediation analysis was conducted to explore the potential mediating role of serum ALP. We found that combined exposure to multiple metals was consistently associated with elevated ePWV, with Ba, Pb, and Sb exhibiting the greatest contributions. Notably, serum ALP partially mediated the associations between individual (Pb, Sb) and mixed metal exposure with ePWV, with mediation proportions at 10.76% for Pb, 18.22% for Sb, and 11.07% for mixed metal exposure. In conclusion, this study demonstrates a clear association between exposure to heavy metals, either individually or in combination, and heightened arterial stiffness. Furthermore, the findings suggest that serum ALP activity may act as a mediator in these relationships.

Health-related reference intervals for heavy metals in non-exposed young adults

OBJECTIVES

Heavy Metals (HMs) concentrations vary with living environments, diet, and personal habits. This study aims to establish health-related reference intervals (RIs) for selected HMs in healthy, non-occupationally exposed young adults living in an urban environment.

METHODS

The Uni4Me study enrolled 154 healthy university volunteers (median age: 23 years) to assess the concentrations of seven heavy metals (lead, nickel, cadmium, zinc, chromium, cobalt, and mercury) using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-EOS). CLSI guidelines were followed to estimate the 2.5th and 97.5th percentiles as RIs.

RESULTS

Most metals were detected at low concentrations. Zinc showed consistent physiological levels in all participants. Mercury and chromium were the most frequently detected, indicating potential environmental or dietary exposure.

CONCLUSIONS

This study defines baseline values for HMs in an urban, healthy, young adult population. These results may support future biomonitoring efforts and public health initiatives targeting subclinical exposure in non-occupationally exposed populations.

Association between heavy metal exposure and pregnancy loss: evidence from NHANES 2011-2016

OBJECTIVE

Previous research suggests that heavy metal exposure may lead to pregnancy loss, but findings have varied. This study focuses on examining the relationship between heavy metal exposure (manganese, selenium, cadmium, lead, mercury) and pregnancy loss.

METHODS

Utilizing data from the 2011-2016 National Health and Nutrition Examination Survey (NHANES), this study included women between 20-80 years with complete pregnancy history, heavy metal exposure data, and covariate information. Pregnancy loss was self-reported by participants. Blood levels of manganese, selenium, cadmium, lead, and mercury were measured using mass spectrometry. Logistic regression, smooth curve fitting, and weighted quantile sum (WQS) regression were employed to investigate the association between heavy metal exposure and pregnancy loss. Subgroup analyses were conducted to verify the heterogeneity of the results.

RESULTS

A total of 3623 eligible women were included, with 1607 reporting pregnancy loss. Blood mercury levels were positively correlated with a higher risk of pregnancy loss (odds ratio 1.06, 95% confidence interval 1.03-1.09, P < 0.001), which remained significant in the two adjusted models. A nonlinear association between mercury levels and pregnancy loss was identified. The heterogeneity in this association was influenced by race, education level, body mass index, and age at menarche. No significant links were detected between pregnancy loss and cadmium, lead, manganese, and selenium. WQS regression highlighted the critical role of mercury in pregnancy loss.

CONCLUSION

Mercury exposure may contribute to a higher risk of pregnancy loss. Reducing heavy metal pollution and minimizing mercury exposure could potentially help improve pregnancy outcomes.

G-Quadruplex and DNAzyme dual-driven DNA detection system for real-time quantitative detection of environmental lead ions

Lead is a major heavy metal pollutant resulting from industrial activities, such as mining and battery manufacturing. Residual Pb ions pose serious health risks, highlighting the need for accurate monitoring to ensure environmental safety. Although traditional methods, such as inductively Coupled Plasma Mass Spectrometry (ICP-MS), are reliable, they require costly equipment, skilled operators, and are time-consuming, making them impractical for rapid field detection. Consequently, research is focused on developing simpler, faster, and more cost-effective detection methods for environmental monitoring and food safety. In this study, we developed a novel G-quadruplex-based detection system using bioenzyme-driven DNA molecular machines aiming to address the complexities of environmental detection and the need for timely monitoring. The unique spatial folding characteristics of G-quadruplexes can significantly accelerate amplification cycles, thereby reducing the dependence on bioenzymes, lowering detection costs, and enhancing the system's resistance to interference in complex environments. Specifically, we designed a dual-drive DNA detection system based on Pb²⁺-specific DNAzyme and G-quadruplex embedded fluorescent probes. In the presence of Pb²⁺, this system responded rapidly, inducing multiple amplification reactions to achieve high sensitivity and high selectivity detection of Pb²⁺. This detection method can detect Pb²⁺ as low as 1.062 × 10-4 mg/L, with a detection linear range of 3.793 × 10-5-1.897 × 10-2 mg/L. Additionally, this platform demonstrated excellent Pb²⁺ specificity and stability in complex samples. We also compared this technology with ICP-MS, and the results showed a high consistency between the two methods for the detection of actual samples. Furthermore, we expanded the application of this technology for quantitative detection in lake water, fish, and soil, providing a new solution for the rapid detection of Pb²⁺ in daily environmental and food samples.

Targeting TLR4/NF-κB signaling, oxidative stress, and apoptosis by farnesol mitigates cadmium-induced testicular toxicity in rats

Cadmium (Cd) is a highly toxic heavy metal, and its detrimental effects on reproductive health pose a significant risk to the general population. Farnesol (FAR), a sesquiterpene alcohol, exhibits anti-inflammatory, antioxidant, and anticancer properties. This study investigated the protective effects of FAR against Cd-induced testicular toxicity, focusing on its antioxidant and anti-inflammatory mechanisms. Rats were randomly divided into four experimental groups: control, FAR (10 mg/kg), Cd (1.2 mg/kg), and Cd + FAR. Cd administration caused testicular tissue damage, altered hormone levels, oxidative stress and apoptosis, upregulated TLR4/NF-κB signaling and diminished antioxidants. FAR ameliorated gonadotropins and testosterone, prevented tissue damage, and attenuated oxidative stress. Additionally, FAR significantly attenuated the inflammatory response triggered by Cd, as evidenced by reduced levels of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and suppression of the TLR4/NF-κB signaling pathway. FAR inhibited testicular apoptosis by upregulating the anti-apoptotic protein Bcl-2 and downregulating the pro-apoptotic markers Bax and caspase-3. These results suggest that FAR mitigates Cd-induced testicular toxicity through upregulation of antioxidants, suppression of TLR4/NF-κB signaling, and inhibition of apoptotic pathways. Thus, FAR represents a promising therapeutic agent for protecting against Cd-induced reproductive damage.

CoFe2O4/TiO2-Nb2O5 magnetic catalysts synthesized by chemical and physical mixture applied in the reduction of Cr(VI)

Among heavy metals, chromium stands out, given the high toxicity and carcinogenicity of Cr(VI). The use of magnetic photocatalysts has opened up new possibilities for their large-scale application, given the ease of catalyst separation. The present work was dedicated to the synthesis and characterization of CoFe2O4/TiO2-Nb2O5 magnetic catalysts and their application in the photocatalytic reduction of chromium. Cobalt ferrite and TiO2-Nb2O5 were combined through chemical (sol-gel synthesis) or physical (mortar and pestle) mixing. In preliminary tests to assess the catalytic activity, approximately 60% of salicylic acid degradation was achieved using CoFe2O4/TiO2-Nb2O5. For the tests with chromium, both a synthetic solution and a real effluent were considered, under different reaction conditions. Sodium formate used as a hole scavenger made it possible to achieve chromium removal percentages above 90% in 60 min. Cobalt ferrite stood out for its Cr(VI) removal capacity, but only pure TiO2-Nb2O5 showed considerable total chromium removal capacity. As for the CoFe2O4/TiO2-Nb2O5 combination, only the catalyst obtained by physical mixing was able to remove both Cr(VI) and total chromium. CoFe2O4/TiO2-Nb2O5 catalyst also exhibited considerable magnetic properties. In effluent tests, this catalyst achieved 33.9% removal of total chromium in 60 min of irradiation.

Rebalancing redox homeostasis: A pivotal regulator of the cGAS-STING pathway in autoimmune diseases

Autoimmune diseases (ADs) arise from the breakdown of immune tolerance to self-antigens, leading to pathological tissue damage. Proinflammatory cytokine overproduction disrupts redox homeostasis across diverse cell populations, generating oxidative stress that induces DNA damage through multiple mechanisms. Oxidative stress-induced alterations in membrane permeability and DNA damage can lead to the recognition of double-stranded DNA (dsDNA), mitochondrial DNA (mtDNA) and micronuclei-DNA (MN-DNA) by DNA sensors, thereby initiating activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. While previous reviews have characterized cGAS-STING activation in autoimmunity, the reciprocal regulation between redox homeostasis and cGAS-STING activation remains insufficiently defined. This narrative review examines oxidative stress-mediated DNA damage as a critical driver of pathological cGAS-STING signaling and delineates molecular mechanisms linking redox homeostasis to autoimmune pathogenesis. Furthermore, we propose therapeutic strategies that combine redox restoration with the attenuation of aberrant cGAS-STING activation, thereby establishing a mechanistic foundation for precision interventions in autoimmune disorders. METHODS: The manuscript is formatted as a narrative review. We conducted a comprehensive search strategy using electronic databases such as PubMed, Google Scholar and Web of Science. Various keywords were used, such as "cGAS-STING," "Redox homeostasis," "Oxidative stress," "pentose phosphate pathway," "Ferroptosis," "mtDNA," "dsDNA," "DNA damage," "Micronuclei," "Reactive oxygen species," "Reactive nitrogen species," "Nanomaterial," "Autoimmune disease," "Systemic lupus erythematosus," "Type 1 diabetes," "Rheumatoid arthritis," "Multiple sclerosis," "Experimental autoimmune encephalomyelitis," "Psoriasis," etc. The titles and abstracts were reviewed for inclusion into this review. After removing duplicates and irrelevant studies, 174 articles met inclusion criteria (original research, English language).

Molecular mechanistic approach to reveal decitabine's effect on DNMT gene modulation and its inhibitory role in heavy metal-induced proliferation in urinary bladder cancer cell line

Heavy metals are pervasive environmental and occupational carcinogens known to induce uncontrolled cell proliferation. They influence a number of cellular processes, including proliferation, metabolism, apoptosis, and carcinogenesis. Among the several underlying mechanisms of carcinogenesis, metal-induced aberrant modulation of DNA methyltransferase (DNMT) activity may play crucial role. In this context, our study explored the proliferative and/or cytotoxic effects of heavy metals on the T24 urinary bladder cancer cell line. Additionally, we evaluated the effects of heavy metals and the chemotherapeutic agent decitabine on DNMT expression and activity. For investigative purposes, T24 cells were exposed to different heavy metals; namely, lead (Pb), chromium (Cr), cadmium (Cd), nickel (Ni), and arsenic (As) at concentrations ranging from 0.5 to 32 μM for 24, 48, and 72 h, as well as to decitabine (1 to 64 μM) for 72 h. Post-incubation, cell proliferation and migration increased, and mitochondrial membrane potential decreased significantly in the presence of heavy metals, especially Cr and Cd. Moreover, in the presence of Cr and Cd, expression of DNMT1 and DNMT3b genes enhanced significantly. Furthermore, decitabine treatment effectively inhibited Cd- and Cr-induced proliferation and downregulated expression of DNMT genes. In conclusion, heavy metals such as Cd and Cr may contribute to urinary bladder carcinogenesis through DNMT upregulation, while decitabine showedprotective effects by suppressing DNMT expression and inhibiting cell proliferation.

Quantification of an integrated approach to heavy metal source apportionment and probabilistic health risk assessment in the black soil region of central Jilin Province, China

The northeast black soil region is critical for grain production in China but has experienced significant heavy metals (HMs) contamination due to intensive agriculture. This study investigates the levels of Cr, Ni, Cu, Zn, Cd, As, Pb, and Hg in agricultural soils within the black soil region of central Jilin Province. Enrichment factor (EF) and geo-accumulation index (Igeo) indicate that Ni and Cr are significantly affected by human activities, with notable pollution levels. The Positive Matrix Factorization (PMF) model identifies four primary pollution sources: coal combustion, traffic emissions, and soil parent material (24.70 %); fertilizers and pesticides (24.50 %); mining (27.81 %); and organic fertilizers combined with soil parent material (22.99 %). The potential ecological risk assessment results reveal a generally low potential ecological risk in the study area, although Hg and Cd contribute notably to the overall risk. The human health risk assessment (HHRA) results show that non-carcinogenic risk for all populations are below the threshold of 1, while the average carcinogenic risk for all populations exceed the acceptable threshold of 1E-6. Children face higher non-carcinogenic and carcinogenic risks compared to adults. By integrating the PMF results with potential ecological and health risk assessments, it was found that coal combustion and mining activities contribute most significantly to potential ecological and health risks, respectively. This study investigates the pollution characteristics, sources, and ecological and health risks of HMs in agricultural soils in the black soil region. The findings offer valuable insights for policymakers in developing effective environmental management strategies.

Machine learning prediction model with shap interpretation for chronic bronchitis risk assessment based on heavy metal exposure: a nationally representative study

BACKGROUND

Chronic bronchitis (CB), as a core precursor of Chronic Obstructive Pulmonary Disease (COPD), is crucial for global disease burden prevention and control. Although the association between heavy metal exposure and respiratory damage has been preliminarily demonstrated, traditional linear models are difficult to resolve the nonlinear interactions and dose-response heterogeneity. The aim of this study was to construct the first heavy metal exposure-chronic bronchitis risk prediction model by integrating exposureomics data through machine learning (ML).

METHODS

Weighted logistic regression was used to assess the association of 14 blood and urine heavy metals with CB based on nationally representative samples from the 2005-2015 National Health and Nutrition Examination Survey (NHANES). The Boruta algorithm was further applied to screen the characteristic variables and construct 10 ML models. The best model was selected by four evaluation metrics: accuracy, specificity, sensitivity, and area under the ROC curve (AUC), and the best model was visually interpreted using Shapley's additive interpretation (SHAP).

RESULTS

The multifactorial logistic regression model showed that urinary cadmium (OR = 1.53, 95% CI = 1.17-1.98) versus blood cadmium (OR = 1.36, 1.13-1.65) was an independent risk factor for CB. The CatBoost model had the best predictive performance (AUC = 0.805), with smoking as the most significant predictor, followed by blood cadmium concentration and gender.

CONCLUSION

In this research, the first risk prediction diagnostic model for heavy metal-chronic bronchitis was developed, in which CatBoost model had the best performance, and it provides a referenceable prediction model for the screening of high-risk groups.

Development of chitosan based recyclable bionanocomposite for the efficient removal of heavy metal ions from aqueous solution

Chitosan/cellulose/titania (CS/cellulose/TiO2) bionanocomposite film was fabricated via solvent casting strategy for removing Cr(VI) and Mn(VII) ions from aqueous solution. XRD, FTIR and SEM studies confirm the incorporation of cellulose and nano TiO2 into chitosan matrix. It has been observed that the mechanical characteristics of neat CS has been enhanced by cellulose and nano TiO2 embedding. The developed nanocomposite showed antibacterial properties and higher resistance is towards gram positive bacteria (S. aureus) than gram negative bacteria (E. coli). The nanocomposite film showed a removal efficiency of 98.3 % and 99.4 % for Cr(VI) and Mn(VII) ions respectively. Maximum adsorption capacity of the adsorbent for Cr(VI) and Mn(VII) ion adsorption has been found to 136.98 mg/g and 137.50 mg/g respectively. Adsorption isotherm has been found to be best fitted by Freundlich model and the pseudo second order kinetic model governs the kinetics of adsorption. The enthalpy change for adsorption of Cr(VI) and Mn(VII) ions has been determined to be -21.78 and -28.70 kJ/mol respectively. The negative values of enthalpy change point out exothermic nature of adsorption. The system can be easily recovered after treatment and can be reuse for 5 cycles in multicycle experiments.

Associations of non-essential metal/metalloids and their mixture with liver function in Chinese older adults: the mediating roles of lipid profiles

The liver is vulnerable to damage from environmental pollutants, but evidence on the effects of non-essential metal/metalloid (NEM) mixture on liver function and their mechanisms remains limited. The study aimed to explore the correlations between individual NEMs and their combinations with liver function, and the mediating roles of lipid profiles. The research involved 2642 individuals aged 60 and older in China. Urine concentrations of arsenic (As), cesium (Cs), barium (Ba), thallium (Tl), and cadmium (Cd) were analyzed using ICP-MS. Liver function was assessed based on the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin (ALB). To evaluate the individual and combined effects of these NEMs on liver function, linear regression, restricted cubic splines (RCS), weighted quantile sum (WQS), quantile g-computation (QGC), and Bayesian kernel machine regression (BKMR) models were utilized. Mediation analyses were conducted to explore the potential role of lipid profiles in NEM-liver function relations. Adjusted linear regression revealed positive associations of Tl with ALT (β = 0.044, 95 % CI: 0.022 to 0.066) and AST (β = 0.019, 95 % CI: 0.004 to 0.035), and negative associations of Cs (β = -0.015, 95 % CI: -0.020 to -0.010), Tl (β = -0.010, 95 % CI: -0.015 to -0.005), and Cd (β = -0.019, 95 % CI: -0.024 to -0.014) with ALB. The RCS model confirmed these linear relationships. Mixture models consistently demonstrated a positive association between the NEM mixture and ALT/AST, primarily driven by Tl, and a negative association with ALB, predominantly influenced by Cd. Mediation analyses suggested triglycerides and total cholesterol partially mediated the associations between Tl, the NEM mixture, and liver function. In conclusion, the NEM mixture, mainly driven by Tl and Cd, is linked to liver function impairment, with lipid profiles potentially mediating these effects. More research is needed to confirm these findings and clarify the mechanisms.

Case Report: Heavy metal poisoning and acute liver failure following use of a folk remedy in a child with a burn

Introducion

Folk remedies for the treatment of burns are widely used in China, often due to the belief that they can prevent scarring. However, these remedies may contain complex and unregulated ingredients that can worsen wound conditions, increase infection risk, and lead to systemic heavy metal poisoning.

Methods

We report the case of a 1-year-and-8-month-old boy with a burn injury who received treatment with a folk remedy. This treatment led to worsening wound edema and hospital admission. The child developed acute liver failure, requiring plasma exchange and surgical debridement. Laboratory analyses of blood, urine, wound samples, and the folk remedy identified high levels of heavy metals, including chromium, nickel, tin, and lead.

Results

The toxicological risks associated with the heavy metal content in folk remedies significantly contributed to the patient's condition. Following standardized medical treatment, liver enzyme levels and coagulation function returned to normal, and the child made a full recovery after 37 days.

Conclusion

This case highlights the serious health risks associated with the use of folk remedies in burn management, particularly the potential for wound aggravation and systemic heavy metal poisoning. Clinicians should maintain a high index of suspicion for heavy metal toxicity and apply early, targeted interventions. Furthermore, the optimization of treatment experience for heavy metal poisoning is crucial to improving outcomes for children affected by such exposure, and providing valuable insights for future cases.

Association of exposure to urinary and blood heavy metals with visual disability among U.S. adults in NHANES 2013-2018

Background

Heavy metals exposure has been widely referred to as a risk factor for human health. However, studies on the potential impact of heavy metals on visual disability are limited. Herein, this study aims to investigate the associations of urinary and blood heavy metals with visual disability in adults.

Methods

A total of 4,284 eligible participants in the 2013-2018 National Health and Nutrition Examination Survey (NHANES) were enrolled in our cross-sectional study. The urinary barium (Ba), cadmium (Cd), cesium (Cs), cobalt (Co), molybdenum (Mo), lead (Pb), antimony (Sb), thallium (Tl), tin (Sn), tungsten (Tu), and mercury (Hg) and blood Pb, Cd, and Hg were included for analysis. We used multivariate logistic regression, weighted quantile sum (WQS) regression, quantile-based gcomputation (qgcomp) regression, and Bayesian kernel machine regression (BKMR) to assess the mixed-metal effect on visual disability. The subgroup analysis was stratified by age.

Results

In the single metal exposure model, the risk of visual disability increased by 39.2%, 22.6%, 25.6%, and 17.9% for each unit increase in urinary Cd, Pb, Sn, and Tu, respectively (all p < 0.05). Meanwhile, the risk of visual disability increased by 40.6% and 22.7% per unit increase in blood Ln-Pb and Ln-Cd, respectively (p = 0.034 and 0.018). In mixed metal effect analysis, WQS, qgcomp, and BKMR models consistently demonstrated a positive association between blood and urine metal co-exposure and visual disability. Furthermore, we found that Cd and Pb were the top-weighted metals responsible for the overall effect. However, these associations were not pronounced in the older adults.

Conclusions

Our findings suggested that Cd, Pb, Sn, and Tu were identified as independent risk factors for visual disability. Furthermore, exposure to mixed metals could increase the risk of visual disability, to which Cd and Pb were the greatest contributors.

Attenuating effects of vitamin C on lead (Pb)-induced toxicological and endocrine responses in male Wistar rats

The aim of this study was to investigate the attenuating effect of vitamin C (VC) on lead (Pb)-induced toxicity in male Wistar rats. Twenty-four mature male rats were divided into 4 groups consisting of 6 animals using a completely randomized design. Rats were treated orally with either 60 mg/kg body weight (BW) Pb acetate or 100 mg/kg BW VC singly or combination. Controls group received water (vehicle control). After 65 days exposure, testes and epididymis of the animals were measured for testicular weight, epididymal weight and sperm estimations, while blood and liver samples were collected for liver function, hormonal assays, and oxidative stress responses including transcript expression using real-time PCR. Lead initiated significant increases in expression and activities of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD,) glutathione peroxidase (Gpx) and levels of malondialdehyde (MDA) and nitric oxide (NO). Liver function enzyme activities for alkaline phosphatase (ALP,) aspartate aminotransferase (AST), and alanine aminotransferase (ALP) were also elevated in Pb exposed rats. In contrast, a significant decrease was noted in reproductive hormones testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), sperm variables including motility, viability and counts, as well as testes and epididymis weights following Pb treatment. However, the oxidative stress responses and liver function enzymes were reduced in the combined Pb and VC exposure group, while reproductive hormones and sperm profile increased significantly compared to Pb alone. Data indicate that VC exerts an attenuating effect. Our findings showed the attenuating potential of VC on Pb-induced toxicity of male rats.

Nano-Manganese and H2S Signalling Improve Rapeseed Tolerance to Chromium Stress by Regulating Cellular Metabolism and Downstream Pathways

A cutting-edge smart nano-hybrid technology, offering potential benefits for plants, has recently been developed to address the pervasive issue of heavy metal pollution. This study explored the potential of this technology in mitigating chromium (Cr) stress in rapeseed using a nano-based system that integrates 100 μM hydrogen sulphide (H2S) and 50 μM manganese nanoparticles (Mn-NPs). This strategy reveals Cr-stress tolerance mechanisms through physiological assessments and transcriptome data analysis. The results demonstrated that Cr stress substantially inhibited rapeseed growth while increasing oxidative damage markers (MDA and ROS levels). Conversely, Mn-NP and H2S co-treatment significantly mitigated these effects, as shown by: (1) restored growth metrics, (2) improved photosynthetic performance and membrane integrity, (3) optimized Mn/H2S homeostasis, and (4) reduced tissue Cr accumulation. The reduction in Cr content was attributed to enhanced Cr-detoxification mechanisms, driven by the upregulation of enzymatic antioxidant activities, like superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase. Transcriptomic profiling revealed marked upregulation of genes involved in core metabolic processes, including photosynthetic pathways, carbon assimilation, secondary metabolite biosynthesis, inositol/phosphatidylinositol signalling systems, and stress-response networks. Under Cr stress, Mn-NP and H2S co-treated rapeseed plants displayed enhanced tolerance, highlighting the crucial role of these signalling agents in activating Cr-defence mechanisms. Our findings demonstrate that the integration of nanotechnology and gasotransmitter signalling molecule H2S presents a novel strategy for enhancing heavy metal tolerance and plant productivity in contaminated soils.

Cu(OH)2 nanopesticide induced liver dysfunction in mice by targeting lipoylated tricarboxylic acid cycle proteins via ferredoxin 1

Copper hydroxide [Cu(OH)2] nanopesticide is an emerging agrochemical known for its ability to mitigate bacterial and fungal damage to host organisms. However, its environmental exposure and potential toxicological effects have garnered significant attention. The liver is regarded as the primary organ for copper storage and utilization within the body. Here, the potential hepatic dyshomeostasis and metabolic dysfunction resulting from exposure to Cu(OH)2 nanopesticide for a month were investigated using the C57BL/6 mouse model. The findings demonstrated that Cu(OH)2 nanopesticide induced damage to the core functions of the mouse liver, evidenced by an impaired tissue microstructure, attenuated biochemical function, as well as disturbed bile acid synthesis and energy metabolism. The regulatory manner of Cu(OH)2 nanopesticide on the lipoylated proteins in the tricarboxylic acid (TCA) cycle by targeting ferredoxin 1 (FDX1) and its associated lipoic acid and iron-sulfur pathways, also shared genetic characteristics with the recently identified cuproptosis mechanism, providing a deeper understanding of the hepatoxic effects induced by this copper nanopesticide. These findings contribute valuable data for evaluating the hepatotoxicity of Cu(OH)2 nanopesticide, and further research into the molecular mechanisms is anticipated to enhance the identification of therapeutic targets for hepatic diseases related to copper metabolism.

Artichoke water extract protects against Lead-induced hepatotoxicity by activating Nrf2 signaling and inhibiting NLRP3/caspase-1/GSDMD-mediated pyroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Lead (Pb), a predominant heavy metal in the environment, causes significant harm to mammalian organs by activating oxidative stress and inflammation. Artichoke (Cynarascolymus L.) is a conventional edible botanical remedy known for its diverse pharmacological attributes, including antioxidant and anti-inflammatory properties.

AIM

In this study, we aimed to investigate the effects of artichoke water extract (AWE) on Pb-induced liver toxicity and the potential underlying mechanisms.

MATERIALS AND METHODS

We identified and quantified the chemical compounds in AWE using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Fifty male C57BL/6J mice (8-week-old) were randomly divided into five groups with ad libitum access to a standard diet and water. Over six weeks of experiments, the control group was orally administered 100 μL/day of distilled water. The Pb group received orally a Pb solution at 25 mg/kg body weight (BW)/day. The Pb + AWE (0.8) group received a combination of Pb solution (25 mg/kg BW) and AWE (0.8 g/kg BW) daily. Next, the Pb + AWE (1.6) group received a combination of Pb solution (25 mg/kg BW) and AWE (1.6 g/kg BW) daily. The Pb + vitamin C group received a combination of Pb solution (25 mg/kg BW) and vitamin C (50 mg/kg BW) daily. We evaluated tissue Pb levels, serum biochemical indices, liver function parameters, and histopathology post-experiment. HepG2 cells were cultured to investigate AWE's role and underlying mechanism of action on Pb-induced pyroptosis.

RESULTS

Ninety-six major compounds were identified and quantified in AWE using UPLC-MS/MS. Treatment with AWE at 0.8 and 1.6 g/kg body weight (BW) significantly reduced tissue Pb accumulation, induced fecal Pb excretion, improved lipid profiles, and attenuated liver injury. In addition, AWE treatment increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity and decreased malondialdehyde (MDA), 8-OHdG production, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-1 beta expression in Pb-exposed mice and HepG2 cells. Mechanistically, the in vivo and in vitro results showed that AWE's antioxidant role was related to the activation of nuclear factor-E2-related factor 2 (Nrf2) signaling. Its anti-inflammatory effect was associated with the inhibition of Pb-induced pyroptosis by inhibiting the nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3 (NLRP3)/caspase-1/gasdermin D (GSDMD) pathway.

CONCLUSION

These findings indicate that AWE protects against Pb-induced liver toxicity potentially through its chelating, antioxidant, and anti-inflammatory properties.

Effects of minimal arsenic, lead, and cadmium exposure on biological pathways in Brazilian informal workers welding fashion jewelry

INTRODUCTION

This study complements previous research about informal workers occupational exposure by investigating the whole blood transcriptome of women engaged in informal home-based jewelry production in the city of Limeira, Sao Paulo, Brazil, focusing on associations between gene expression and arsenic (As), cadmium (Cd), and lead (Pb) concentrations in blood, as well as on identifying transcriptome profiles linked to self-reported health outcomes.

METHODS

Participants were divided into two groups: an exposed group comprising informal workers engaged in domestic jewelry welding activities (n = 22) and a control group composed of neighbors without occupational exposures (n = 19). Linear regression modeling assessed the association between the blood concentration of toxic elements, gene expression, and reported health outcomes. Pathway analysis was performed using ConsensusPathDB.

RESULTS

269 differentially expressed genes (DEGs) associated with As exposure and 43 with Cd exposure were found in this study, revealing significant health impacts on these workers. DEGs were also significantly associated with respiratory illness (bronchitis and asthma), neurological manifestations (sleep problems, migraines, or frequent headaches), shortness of breath, blood glucose, cholesterol, and triglyceride levels. Pathway analysis indicates genes related to inflammatory processes, alterations in intestinal permeability, and neurological outcomes.

CONCLUSION

The results shed light on the transcriptomic changes in this occupational context and contribute to a better understanding of the challenges faced by informal workers. Even with low doses of toxic elements in the blood, it was possible to observe differences in gene expression linked to self-reported outcomes. Additional studies should clarify the biological processes associated with toxic elements exposure.

RNA Methylation and Transcriptome Analysis Reveal Key Regulatory Pathways Related to Cadmium-Induced Liver Damage

Cadmium (Cd) is a prevalent environmental and industrial contaminant that causes significant damage to liver function. However, the role of m6A methylation─a critical epigenetic modification─in Cd-induced liver injury remains poorly understood. This study aimed to investigate the effects of m6A methylation in Cd-induced liver damage. A mouse model of Cd-induced liver injury was established, and exposure to CdCl2 (20 mg/kg) for 90 days resulted in reduced m6A methylation levels. Using methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-Seq), we characterized the m6A methylation profiles in both control and Cd-exposed groups. A total of 8355 unique m6A peaks and 1,101 unique m6A-modified genes were identified. Among these, 673 genes exhibited differential m6A methylated modifications, including 463 hyper-methylated and 210 hypo-methylated genes. Conjoint analysis of MeRIP-seq and RNA-Seq data unveiled genes that showed both differential methylation and expression. These genes were significantly enriched in the AGE-RAGE and PI3K-Akt signaling pathway. Through bioinformatics screening, five key genes (Il-1β, Ccl2, Tlr2, Itgax, and Ccr2) were identified, and expression validation indicated that Itgax and Ccr2 may play pivotal roles in Cd-induced liver injury. Notably, elevated expression of methyltransferase-like 14 (METTL14) was observed in both in vivo and in vitro models. Inhibition of Mettl14 can regulate Cd-induced liver inflammation through m6A-dependent regulation of Ccr2 expression. Collectively, our findings highlight the crucial role of Mettl14 and Ccr2 in Cd-induced liver injury, providing novel insights into the epigenetic mechanisms underlying liver diseases and potential biomarkers for diagnosis and therapy.

Heavy metals and cardiovascular health: Uncovering links and health challenges

BACKGROUND

Heavy metals, including lead, mercury, cadmium, and arsenic, along with emerging contaminants, pose significant threats to cardiovascular health. These metals are linked to oxidative stress, endothelial dysfunction, inflammation, and epigenetic alterations, contributing to various cardiovascular diseases.

AIM

This review synthesizes current research on the pathways by which heavy metal exposure affects cardiovascular health, highlighting epidemiological trends, vulnerable populations, and potential preventive strategies.

METHODS

A comprehensive review of molecular mechanisms, epidemiological studies, and public health data was conducted to elucidate the links between heavy metal exposure and cardiovascular health.

RESULTS

Mechanisms of Toxicity: Heavy metals induce oxidative stress and inflammation, impair endothelial function, and disrupt calcium signaling. These effects culminate in hypertension, atherosclerosis, myocardial dysfunction, and other cardiovascular pathologies. Epidemiological Trends: Evidence links even low-level exposures to increased Cardio Vascular Disease risk. Regional trends show elevated risks in areas with significant industrial activity or contaminated water supplies. Vulnerable Populations: Children, the elderly, and individuals in low-income or industrially polluted regions exhibit heightened susceptibility. Preventive Strategies: Regulatory actions, improved water safety, dietary interventions, and community awareness are critical in mitigating exposure and its health impacts.

CONCLUSIONS

Environmental exposure to heavy metals significantly elevates cardiovascular disease risk, particularly among vulnerable groups. Urgent public health measures and further research are needed to address the cumulative and synergistic effects of these toxicants.

Elevated Metal Levels in U.S. Honeys: Is There a Concern for Human Health?

Honey is a bioactive food used for millennia to improve health and treat diseases. More recently, researchers employ honey as a tool to assess local environmental pollution. Honeybees effectively 'sample' their environment within a ~ 7 km radius, actively collecting nectar, pollen, and water to bring to their hive. Foraging honeybees also sample the air as dust particles accumulate on their pubescence, adding to the hive's contaminant load. Many studies from around the world report elevated metal levels in honey, with the most reports from Iran, Italy, and Turkey, but only two reports have measured metal levels in honey from the United States (U.S.). We report levels of 20 metals from 28 honeys collected from 15 U.S. states between 2022-2023. We then focus on four toxic metals recognized as hazards in foodstuffs when the concentrations are above safety recommendations - lead, cadmium, arsenic, and mercury. Two of these metals (lead and mercury) are regulated in honey by the European Union (EU), though the U.S. currently lacks defined regulations for metal levels in honey. We consider the levels of these toxic metals by state, then compare the U.S. mean honey level for these metals against the provisional tolerable weekly intake (PTWI). Our results suggest U.S. honey have levels metal that exceed the PWTI and EU regulations and may be hazardous to human health. Further research is needed to determine if the effects of these toxic metal at measured levels outweigh the health benefits from consumption of honey.

Inflammation factors mediate the association between heavy metal and Homa-IR index: An integrated approach from the NHANES (2011∼2016)

INTRODUCTION

The interplay between heavy metals exposure and insulin resistance (IR), specifically through the mediation of inflammation factors, is crucial for understanding metabolic disturbances. This study utilizes data from the NHANES (2011∼2016) to investigate these relationships in a large, diverse U.S.

POPULATION

METHODS

The study analyzed the associations between heavy metals (cadmium (Cd), lead (Pb), mercury (Hg), manganese (Mn)) and the Homeostatic Model Assessment for Insulin Resistance (Homa-IR) index. The analyses included descriptive statistics, Pearson's correlations, linear and non-linear regression models, and advanced statistical models such as Weighted Quantile Sum (WQS) regression and Bayesian Kernel Machine Regression (BKMR). Inflammation factors were assessed for their mediating role in these associations.

RESULTS

The findings highlighted significant positive correlations between specific heavy metals and the Homa-IR index. Both linear and non-linear associations were evident, with certain metals showing a more pronounced impact in the presence of high inflammation markers. It was found that the Homa-IR index was negatively associated with Pb (β (95 %CI) = -0.0126 (-0.0238 ∼ -0.0015), P = 0.0268) and Hg (β (95 %CI) = -0.0090 (-0.0180 ∼ -0.0001), P = 0.0487). The WQS regression indicated an overall positive relationship between heavy metal mixtures (Estimate: 0.0050, P < 0.05) and the Homa-IR index where Cu had the highest weights (0.7741), while BKMR analyses detailed the varying effects of individual metals at different exposure levels. In the mediation analysis, it can be found that monocyte (Mono) mediated the association between Pb and Homa-IR index (direct effect:0.0546, indirect effect:0.0082) and neutrophil (Neu) (direct effect:0.0521, indirect effect:0.0047) can mediate the association between Hg and Homa-IR index.

CONCLUSIONS

This study confirms that exposure to heavy metals is associated with increased insulin resistance and that inflammation significantly mediates this relationship. Understanding these pathways is essential for developing targeted interventions to mitigate the metabolic consequences of environmental exposures.

Honey: Inorganic Composition as Possible Marker for Botanical and Geological Assignment

Honey can be classified based on its geographical or botanical origin according to Directive 2001/110/EC. Geographical origin is determined when the pollen collection occurs entirely in a specific location, allowing producers to label the honey with the name of the region. Verification typically involves melissopalynological analysis to match the pollen spectrum with regional vegetation. Botanical origin applies when honey predominantly comes from a single floral species, characterized by specific organoleptic, physico-chemical, and microscopic properties. However, defining "predominantly" and identifying distinct physico-chemical parameters remain ambiguous. This review evaluates the use of chemical analysis as a complement or alternative to melissopalynological methods for determining honey's origin. The focus is on inorganic composition, particularly metals and semimetals, as potential fingerprints to identify botanical or geographical provenance. Relevant studies were reviewed, with data reprocessed and analyzed using chemometric techniques, including Principal Component Analysis and Agglomerative Cluster Analysis. These methods reveal common traits distinguishing honeys by origin. Chemical analysis combined with chemometric processing enhances honey identification, prevents fraud, assesses environmental pollution in collection areas, and evaluates the impact of processing on the final product.

Lactiplantibacillus plantarum FEED8 Biosynthesis of Pyranoanthocyanin (Cyanidin-3-glucoside-4-vinylcatechol) Improves Oxidative Stress and Inflammation of the Gut Microbiome in Cadmium-Exposed Mice

The study is to explore the biosynthesis of cyanidin-3-glucoside-4-vinylcatechol (C3G_VC) through Lactiplantibacillus plantarum-fermented caffeic acid and cyanidin-3-glucoside (C3G) extract (molar ratio = 1:30) in the model medium. C3G_VC was isolated and purified by a venusil ASB-C18 column with a medium-pressure liquid chromatography (MPLC) system. The chemical structure of C3G_VC was identified by high-performance liquid chromatography (HPLC), which showed the maximum absorption wavelength of 505.57 nm. This study showed that Cd exposure of mice induced liver damage, oxidative stress, and inflammation of the gut microbiome. Our findings demonstrated that C3G_VC intervention in Cd-exposed mice significantly mitigated oxidative stress injury by declining the malondialdehyde (MDA) level and increasing the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) in the liver, meanwhile alleviating liver injury by decreasing the bile acid (BA) level and accelerating the excretion of fecal BA. Moreover, the Cd_C3G_VC group showed elevated levels of mRNA expression of pro-inflammatory cytokines (IL6, IL1β, and TNF-α) and inhibited BA synthesis (CYP7A1) in Cd-exposed mice. The fermentation results in vitro showed that C3G_VC had a higher residue than that of cyanidin-3-glucoside. The 16S rRNA high-throughput sequencing disclosed that C3G_VC intervention in Cd-exposed mice significantly increased the abundance of Faecalibaculum and unidentified_Lachnospiraceae. It is noteworthy that the C3G_VC supplement increased the abundance of Akkermansia. Overall, this study demonstrated that C3G_VC intervention in Cd-exposed mice had the potential to decrease the occurrence of inflammatory and oxidative stress and maintain bile acid homeostasis by regulating gut microflora.

Combination of 10-hydroxy-decanoic acid and ZnO nanoparticles abrogates lead acetate-induced nephrotoxicity in rats: targeting oxidative stress and inflammatory signalling

Lead is a heavy metal contaminant that can cause significant alterations in renal structure and function, resulting in nephrotoxicity. The fatty acids of royal jelly exhibit immunoregulatory, anticancer, anti-inflammatory, and antioxidant properties, which have garnered significant interest. The most prevalent among them is 10-hydroxydecanoic acid (10-HDA). Zinc oxide nanoparticles (ZnONPs) demonstrate a renoprotective effect, likely due to their antioxidant, anti-inflammatory, and antiapoptotic properties. This study evaluated the therapeutic efficacy of 10-HDA and ZnONPs, administered either as monotherapy or in combination, against lead-induced nephrotoxicity. Male rats were orally administered lead acetate (PbAc) for three months, followed by the administration of 10-HDA and/or ZnONPs for one month. Exposure to PbAc resulted in elevated renal lead concentration, as well as increased serum levels of urea, creatinine, and cystatin C. The condition resulted in damage to the renal parenchyma, characterised by degenerative glomeruli and tubules, and exhibited the highest lesion score. Nrf2 and HO-1 exhibited reduced expression and diminished antioxidant enzyme levels subsequent to PbAc poisoning. Additionally, there was an increase in the inflammatory and apoptotic signalling through the p-IKK/NF-κB axis. The administration of 10-HDA and ZnONPs significantly decreased renal lead levels and improved antioxidant capacity. Moreover, renal inflammatory markers (TNF-α, p-IKK, IL-1β, IL-6, and IL-8) and proapoptotic indicators (Bax and Caspase-3) were significantly suppressed. The combined therapy demonstrated a synergistic effect (combination index < 1). In conclusion, the results indicated that 10-HDA and ZnONPs have the potential to be a supplement or even an effective treatment to alleviate the adverse effects of lead poisoning. This is potentially attributed to their potent ameliorative actions against oxidation, inflammation, and apoptosis.

Human health risk assessment of toxic metals in Nass smokeless tobacco in Iran

Smokeless tobacco (ST) products create a deadly combination of addiction to nicotine and exposure to toxic substances. Nass is the predominant smokeless tobacco (ST) product consumed in Iran. This study was conducted to evaluate the levels of arsenic (As), lead (Pb), nickel (Ni), and cadmium (Cd) in Nass brands available in the Iranian market. A total of 42 samples were analyzed for the levels of heavy metals using flame atomic absorption spectrometry. The study also evaluated the risk associated with carcinogenic and non-carcinogenic toxic metal contamination in smokeless tobacco in Iran. The level of heavy metals measured in various Nass samples was ranked as Pb > Ni > Cd > As .The mean levels (range) of Pb, Cd, As, and Ni in Nass samples were determined to be 38.71 µg/g (17.60-57.70), 2.90 µg/g (1.20-3.65), 0.71 µg/g (0.25-1.17), and 23.24 µg/g (4.95-44.65), respectively. The levels of Pb, Cd, As and Ni in handmade samples are higher than products manufactured at the plant. The levels of Pb, Cd and Ni in all samples were higher than the Swedish Match recommended limits. While the levels of As in 12% of samples were lower than the standard defined by the Swedish Match. The Estimated daily intake (EDI) values for As, Cd, Ni and Pb are below the reference dose (RfD) established by the Environmental Protection Agency. The findings indicate that the target hazard quotient (THQ) and the hazard index (HI) values in the study were below 1. In this study, for the first time demonstrated that Nass consumers in Iran are at risk of exposure to Pb, As, Cd, and Ni. Consequently, the health system should prioritize raising public awareness about the health risks associated to Nass.

Covalent organic frameworks as superior adsorbents for the removal of toxic substances

Developing new materials capable of the safe and efficient removal of toxic substances has become a research hotspot in the field of materials science, as these toxic substances pose a serious threat to human health, both directly and indirectly. Covalent organic frameworks (COFs), as an emerging class of crystalline porous materials, have advantages such as large specific surface area, tunable pore size, designable structure, and good biocompatibility, which have been proven to be a superior adsorbent design platform for toxic substances capture. This review will summarize the synthesis methods of COFs and the properties and characteristics of typical toxicants, discuss the design strategies of COF-based adsorbents for the removal of toxic substances, and highlight the recent advancements in COF-based adsorbents as robust candidates for the efficient removal of various types of toxicants, such as animal toxins, microbial toxins, phytotoxins, environmental toxins, etc. The adsorption performance and related mechanisms of COF-based adsorbents for different types of toxic substances will be discussed. The complex host-guest interactions mainly include electrostatic, π-π interactions, hydrogen bonding, hydrophobic interactions, and molecular sieving effects. In addition, the adsorption performance of various COF-based adsorbents will be compared, and strategies such as reasonable adjustment of pore size, introduction of functionalities, and preparation of composite materials can effectively improve the adsorption efficiency of toxins. Finally, we also point out the challenges and future development directions that COFs may face in the field of toxicant removal. It is expected that this review will provide valuable insights into the application of COF-based adsorbents in the removal of toxicants and the development of new materials.

A Case-Control Study of Association Between Serum Levels of 19 Trace Elements with Prostate Cancer in Southwest China

Prostate cancer (PCa) is the most prevalent urological malignancy, exhibiting the highest incidence and the second-highest mortality among all male cancers. The incidence of PCa in men in China is consistently rising. Studies have shown that elemental exposure levels are associated with the occurrence of PCa. However, epidemiological data are limited, and more researches on different regions and races are needed. To clarify the relationship between the occurrence of PCa and serum levels of 19 trace elements. Serum samples from 79 PCa patients and 74 male healthy controls were obtained, and the levels of 19 trace elements were measured using inductively coupled plasma mass spectrometry (ICP-MS). Baseline matching of key demographic characteristics was performed between the two groups. The relationship between serum trace elements levels and PCa, prostate-specific antigen (PSA), and PCa staging were evaluated using the Mann-Whitney U test, logistic regression, and Spearman's correlation analysis. Statistical analysis of the test results revealed that the low levels of Cu, Zn, and Se in serum may be associated with the development of PCa. Moreover, the changes in the interrelationship of trace elements may play a role in the development of PCa.

Interactive and joint effects of toxic metals and oxidative balance score on the risk of mortality in adults with NAFLD

BACKGROUND

High oxidative balance score (OBS) may mitigate inflammation levels and thereby alleviate the adverse health effects induced by toxic metals. We assessed the independent, joint effects as well as their interactions of toxic metals and OBS on mortality among individuals with non-alcoholic fatty liver diseases (NAFLD).

METHODS

Participants with NAFLD from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 were included. Mortality and underlying causes of death were certain by National Death Index records through 31 December 2019. Cox regression models were used to estimate hazard ratios (HRs) for all-cause and disease-specific mortality. Additionally, we assessed multiplicative and additive interactions of OBS and toxic metals on mortality.

RESULTS

Among 5263 patients with NAFLD, 1097 deaths occurred during a mean follow-up of 10.27 years. Compared with those in the OBS tertile 1, participants in tertile 3 had lower risk of all-cause mortality (HR=0.79, 95 %CI: 0.64, 0.96). Compared with individuals in the lowest lead concentration in blood, those in the highest had an increased risk of mortality, with the HRs (95 %CIs) being 1.23 (1.01, 1.51), 1.53(1.06, 2.20) and 1.94(1.25, 3.01) for all-cause, CVD and cancer mortality, respectively. Similar results were also found for blood cadmium level. Joint associations analyses found that individuals with low lead and high-OBS levels had the lowest risk of all-cause, CVD and cancer mortality, with the HRs(95 %CIs) being 0.58(0.40, 0.85), 0.45(0.21, 0.93) and 0.35(0.15, 0.81), respectively. Multiplicative interactions between OBS and blood cadmium on all-cause death (HR=0.87, 95 %CI: 0.78, 0.97) and CVD death (HR=0.81, 95 %CI: 0.67, 0.99) were found.

CONCLUSIONS

High OBS and low exposure to toxic metals were associated with lower risk of mortality among participants with NAFLD. Adopting anti-oxidative lifestyle could alleviate the harmful effects of toxic metals in NAFLD patients. Comprehensive strategies are essential to decrease the risk of mortality and potentially mitigate the overall burden of NAFLD.

Impact of iron oxide nanoparticles on cadmium toxicity mitigation in Brassica napus

Cadmium (Cd) contamination greatly hinders plant productivity. Nanotechnology offers a promising solution for Cd phytotoxicity. The novelty of this study lies in the limited research on the effects of nanoiron (Fe3O4NPs) in regulating Cd toxicity in oilseed crops. This study examined how Fe3O4NPs regulated the Cd-exposure in B. napus. Foliar spray of 10 mg L-1 Fe3O4NPs was applied to 50 μM Cd-stressed B. napus seedlings via leaf exposure in hydroponic system. Under Cd stress, Fe3O4NPs decreased the Cd-accumulation (25-37%) due to adsorption followed by more root Cd-immobilization, and increased the plant height (23-31%) and biomass (17-24%). These findings were directly correlated with better photosynthetic activity (chlorophylls, gas exchanges and photosynthetic efficiency), leaf stomata opening and nutrients accumulation (20-29%). Subcellular localization revealed that Fe3O4NPs enhanced the binding capacity of cell wall for Cd to hinder its entry into cell organalles and facilitated vacoular sequestration. Additionally, Fe3O4NPs decreased the oxidative stress (21-33%) and peroxidation of lipids (24-31%) by regulating the genes-associated to superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, glutathione reductase, reduced glutathione, phytochelation, chlorophyll synthesis and Cd-transporters. Fe3O4NPs protected plant roots from Cd-induced cell structural damages and cell death. Among studied parameters, ZD 635 exhibited greater tolerance to Cd stress when compared to ZD 622 cultivar. Findings revealed that Fe3O4NPs effectively mitigate Cd toxicity by improving the photosynthesis, antioxidant defense mechanisms, cellular protection, nutrients accumulation and limiting Cd accumulation. This research offers a benchmark for the practical applicability of Fe3O4NPs to enhance the quality of canola production in Cd-contaminated soils.

Multiple biological responses and transcriptome plasticity of the model unicellular eukaryote paramecium for cadmium toxicity aggravated by freshwater acidification

Cadmium (Cd) pollution is a widespread threat to aquatic life, and ongoing freshwater acidification (FA) can be expected to interact with Cd compounds to disrupt freshwater ecosystems. However, the effects of FA on Cd biotoxicity remain unclear. Herein, the model ciliate Paramecium tetraurelia, a model unicellular eukaryotic organism, was used to explore the response to environmental relevant concentrations of Cd under acidification conditions. We show for the first time that exposure to acidified freshwater accelerated Cd bioaccumulation and enhanced Cd bioavailability in P. tetraurelia, suggesting the synergistic interaction of Cd and FA. The co-exposure greatly reduced the abundance and carbon biomass, altered lysosomal membrane stability, induced oxidative stress, and consumed more ATP in exposed ciliates. Transcriptome plasticity enabled P. tetraurelia to develop a Cd stress-adaptive transcriptional profile (upregulation of transport and detoxification and downregulation of energy metabolism) under acidification. With a concomitant inhibition in energy production, the exposed ciliates might have diverted the energy from growth and cell replication to compensate for the energetic cost from stress response and detoxification. Collectively, acidified freshwater could aggravate Cd toxicity, which, in turn, arouses the response strategy of ciliates to cope with stress, providing a mechanistic understanding of the interaction between freshwater acidification and Cd pollution in the basic trophic level ciliated protozoa in freshwater ecosystems.

Activity pattern of antioxidant enzymes in relation to the time of exposure of hexavalent chromium to Nile tilapia Oreochromis niloticus

Hexavalent chromium (Cr (VI)), a toxicant of environmental concern, frequently enters into water bodies and produces oxidative stress in fish. The antioxidant enzymes, Superoxide dismutase (SOD), Catalase (CAT), and Glutathion S-transferase (GST) are activated to counteract the oxidative stress in fish. This study explores the pattern of activation of these enzymes in gill, muscle, liver, and kidney tissues of Nile tilapia Oreochromis niloticus exposed to 9.35 mg/L and 18.70 mg/L of Cr (VI) for 96 h. The optimal hour of activity of these enzymes was revealed through extensive regression analysis. The results indicate a bell-shaped time response curve in the activity of the enzymes in both the treatments, except CAT in the gill of fish exposed to 18.70 mg/L Cr (VI) and GST in the gill, liver, and kidney of fish exposed to 18.70 mg/L Cr (VI). The results indicate that the optimal hour of activity of SOD changes in tandem with CAT, SOD responding first followed by CAT, both diminishing within 96 h. However, deviating from the bell-shaped pattern, the activity of CAT in gill and GST in gill, liver, and kidney in fish exposed to 18.70 mg/L Cr (VI) continued to rise even at 96 h, indicating that these antioxidant enzymes could not diminish the oxidative stress produced by the higher dose of Cr (VI). It was concluded that the activity of SOD, CAT, and GST between 30 and 70 h in the gill, liver, and kidney of Nile tilapia could serve as excellent biomarkers of oxidative stress under low doses of Cr (VI).

Effect of glucose selenol on hepatic lipid metabolism disorder induced by heavy metal cadmium in male rats

This study used 24 male rats to determine the protective effects of a new selenium molecule (glucose selenol) on cadmium (Cd) induced hepatic toxicity. The rats were randomly divided into four groups: control group, Cd group, Cd + 0.15 Se group, and Cd + 0.4 Se group. The results showed that glucose selenol supplementation alleviated the adverse impact of Cd on lipid metabolism, including decreased serum triacylglycerol and cholesterol levels. Transcriptome analysis revealed that, compared to the control group, Cd changed the expression of 1379 genes - discernibly affecting lipid metabolism pathways. Proteomic analysis primarily indicated alterations in lipid metabolism-related pathways. In conclusion, glucose selenol restored lipid metabolism disorders induced by Cd, thus rescuing hepatic damage. This integrated analysis identified the influence of glucose selenol on Cd-induced hepatic toxicity and provided its potential application prospects in alleviating the impact of heavy metal pollution, such as Cd, on human health.

Assessing Chronic Heavy Metal Exposure by Analysis of Human Cataract Specimens and the Relationship to Metabolic Profiles

PURPOSE

With age, the mammalian lens forms successive layers of crystallin protein fibers which infoliate with lens growth and development. As heavy metals generally bind to tissue protein, heavy metals are posited to sequester within the lens with age. Therefore, this study aims to compare heavy metals in human crystalline lens of older adults to known physiologic blood and urine levels and assess the association between concentrations in the lens and metabolic biomarkers.

METHODS

Consecutive lens specimens obtained during cataract surgery by phacoemulsification were subjected to atomic spectrometry for heavy metal content. A one-sample t-test compared heavy metals in lens to known physiologic blood and urine concentrations. Linear regression models assessed the association between heavy metals and biomarkers of metabolic function. Linear discriminant analysis assessed the classification of gender and smoking status based on multiple and individual heavy metals.

RESULTS

All heavy metal levels were elevated in lens specimens compared to blood and urine with the exception of iron (p < 0.0001). Lens titanium and copper were positively associated with blood-urea nitrogen (Titanium: β ̂ = 1.14, p = 0.04, Copper: β ̂ = 1.12, p = 0.03. Lens copper was positively associated with creatinine (β ̂ = 1.10; p = 0.02), but negatively associated with glomerular filtration rate (β ̂ = 0.89; p = 0.02). Lens chromium and lead were positively associated with albumin (Chromium: β ̂ = 1.03, p = 0.03; Lead: β ̂ = 1.02, p = 0.04). Lens nickel was positively associated with bilirubin (β ̂ = 1.14; p = 0.03). Classification based on multiple or individual heavy metals for gender and smoking status was not statistically significant.

CONCLUSIONS

Our results suggest the human crystalline lens accumulates heavy metals with age and demonstrate the correlation between abnormality of metabolic function and heavy metal deposition in older adult lens.

Combined Effect of Gamma Radiation and Heavy Metals on Some Living Organisms

The purpose of this study was to systematise scientific publications on the combined effect of gamma radiation and heavy metals on living organisms. For this purpose, the method of analysis was applied, by means of which scientific papers in PubMed, Google Scholar, and other related databases were analysed for compliance with the inclusion criteria, where the objects of research were toxic effects of radiation and heavy metals on cells and adaptation processes. The results revealed that the study of the problem was carried out on organisms such as microalgae, fungi, weed and agricultural plants, fish, laboratory rats, and human cell cultures. In most studies, an antagonistic effect between low doses of gamma radiation and heavy metal salts was reported, which was manifested by a reduction in the cytotoxicity of isolated exposure to each agent separately. However, there are studies showing additive effects, especially in heavy metals. At the molecular level, heavy metal accumulation in combination with low doses of radiation (typically defined as less than 0.1 Gy or sievert) induces the expression of metallothionein proteins, which can bind free radicals. At the metabolic level, this is manifested by a decrease in lipid peroxidation products, activation of antioxidant enzymes, and a decrease in apoptosis. The study proved both a direct relationship between zinc and cadmium accumulation in cells and inhibition of caspases and an indirect one, by maintaining mitochondrial membrane integrity through metallothionein.

Transcriptome alterations in long-term mining region residents: Insights into immune response and molecular pathways

Pollution with metals and metalloids is a global problem that adversely affects human health and environment. Although several studies have reported gene expression changes in response to human exposures to metals, there are a limited number of studies exploring the effect of long-term residence in mining areas. The evidence of increased levels of several essential and non-essential metals in soil, water, and plants in Kapan mining area (Armenia) has been previously demonstrated in several environmental studies. Our study investigated the impact of long-term residence in this mining area on the transcriptome state of human peripheral blood mononuclear cells and the possible association of transcriptome changes with the blood metallome. In total, 58 participants including 27 mining region residents (MRR) and 31 non-mining region residents (NMR) were selected for our study. Transcriptomic analysis of peripheral blood mononuclear cells was performed by mRNA sequencing. Differential expression analyses were conducted using generalized linear modeling, optimized for participant demographics, cell types, and sequencing technical factors, followed by pathway analysis. The study revealed that long-term residence in a mining area is correlated with alterations in the blood transcriptome, with responses varying by sex. The identified transcriptome changes were enriched for pathways related to immune response and RNA translation. These changes correlated with higher blood levels of a mixture of non-essential metals, including arsenic, antimony, nickel, thallium, and beryllium. Additionally, the study identified differences in the transcriptome response between male and female MRR. While females exhibited a stronger immune response, males show dysregulation in ion transport and epigenetic modifications. Our findings contribute to understanding the effects of long-term residence in mining regions and can aid in developing more effective risk assessment and mitigation approaches in target populations.

Evaluation of Heavy Metal and Specific Trace Elements Levels Among Fast-Food Workers and Their Susceptibility to Atherosclerosis

Fast-food workers in Iraq face significant health risks due to exposure to heavy metals from fumes and dust during cooking activities. Heavy metals, such as lead (Pb), cadmium (Cd), and nickel (Ni), are toxic to cells even at low concentrations and can cause health risks, including atherosclerosis, due to oxidative stress and reduced antioxidant activity. To the best of our knowledge, this is the first study assess the levels of heavy metals in fast-food workers and investigate their potential link to atherosclerosis development by monitoring the levels of copper (Cu), zinc (Zn), magnesium (Mg), manganese (Mn), and iron (Fe). A total of 120 male participants aged between 20 and 40 years were included in the study, with 40 fast-food workers, 40 patients with atherosclerosis, and 40 healthy individuals evaluated. The levels of Pb, Cd, Ni, Cu, Zn, Mg, Mn, and Fe in all blood samples were determined using atomic absorption spectrometry. Results showed that the fast-food worker group had significantly higher levels of Pb, Cd, Cu, and Fe compared to the healthy control group, with increases of 57%, 75%, 30%, and 55%, respectively. Conversely, their levels of Zn and Mg were significantly lower, decreasing by 15% and 16%, respectively. On the other hand, the atherosclerosis patients' group had significantly higher levels of Pb, Cd, Cu, and Fe, with increases of 47%, 74%, 34%, and 28%, respectively, as well as significantly lower levels of Zn and Mg, decreasing by 17% and 21%, respectively, compared to the control group. These findings suggest that fast-food workers are at risk of developing atherosclerosis due to exposure to high levels of heavy metals and imbalances in essential trace elements. The results showed a significant increase in the levels of Pb and Cd in the sera of these workers, which was expected because of the long duration and high intensity of exposure to toxic heavy metals. This is a serious indicator that must be considered, as it has been previously established that increased levels of Pb and Cd in the body are linked to the risk of atherosclerosis. Additionally, an association between Pb and Cd levels and an imbalance in trace element levels (Cu, Zn, Mg, and Fe) were observed. The Implementation of stricter regulations and guidelines for maintaining cleanliness and safety in fast-food restaurants may be crucial for protecting workers and preventing long-term health complications.

Associations between serum metal mixtures and systemic inflammation indices among Chinese early adolescents: A prospective cohort study

BACKGROUND

Research has demonstrated a link between metal exposure and inflammation. However, little is known about this relationship among adolescents, especially in prospective cohort studies. The aim of this study was to investigate the relationship between serum metal exposure and inflammatory status in Chinese early adolescents.

METHODS

In this study, 12 serum metals were detected at baseline in 1551 participants from the Chinese Early Adolescents Cohort. The participants' inflammatory status was assessed via three systemic inflammation indices (neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII)) at both baseline and follow-up. Generalized linear mixed models and restricted cubic splines regression were used to examine the linear and nonlinear relationships between single metal concentrations and systemic inflammation indices. Multiple mixture models were implemented to assess the relationships of mixed metals with systemic inflammation indices. Additionally, sex subgroup analyses were conducted to explore the sex-specific associations between serum metals and inflammatory status.

RESULTS

Single-exposure analysis revealed that exposure to multiple serum metals, such as chromium, cobalt, copper and lead, was positively associated with the NLR and SII, whereas iron was negatively correlated with the three systemic inflammation indices (PFDR<0.05). Additionally, inverted U-shaped associations were observed between vanadium, manganese and systemic inflammation indices. According to the mixture models, high levels of the serum metal mixture were positively correlated with the NLR and the SII. Cobalt had the highest positive weight in the mixed samples, whereas iron had the greatest negative weight in the serum-metal mixtures. Subgroup analyses revealed that serum exposure to the metal mixture had a more significant effect on systemic inflammation markers in females than in males.

CONCLUSIONS

This study reveals the impact of real-world mixed metal exposure on adolescents' inflammatory levels, which is of primary significance for protecting the healthy development of early adolescents.

Chronic Cr(VI) exposure-induced biotoxicity involved in liver microbiota-gut axis disruption in Phoxinus lagowskii Dybowski based on multi-omics technologies

Cr(VI) is widely used in industry and has high toxicity, making it one of the most common environmental pollutants. Long-term exposure to Cr(VI) can cause metabolic disorders and tissue damage. However, the effects of Cr(VI) on liver and gut microbes in fish have rarely been reported. In this study, 240 fish were randomly divided into 3 groups: the control group, low-dose Cr(VI) group (0.5 mg/L), and high-dose Cr(VI) group (2 mg/L). The mechanism by which Cr(VI) affects the enterohepatic axis of common carp was elucidated via multiomic analysis, serology, histomorphology, and physiological and biochemical indices. The results revealed that Cr(VI) stress led to hepatocyte damage, nuclear lysis, inflammatory cell infiltration, and vacuolated degeneration. The structure of the intestinal villi was severely damaged, and the length and width of the intestinal villi were significantly reduced. We also found that the accumulation of Cr(VI) in tissues increased in a concentration-dependent manner, and the content of Cr(VI) in each tissue increased in the order of gut > gill > liver > muscle. Multiple omics studies have revealed that chronic Cr(VI) stress leads to disturbances in the intestinal flora, with a significant reduction in the abundance of the beneficial bacterium Akkermansia and a significant increase in the abundance of the harmful bacterium Escherichia/Shigella. Intestinal injury and dysbiosis lead to an increase in blood LPS levels, further inducing metabolic disorders in the liver. The metabolites in the liver, including geniposide, leucine, C17 sphingosine, and 9,10-DiHODE, were significantly increased, whereas the beneficial metabolites, such as carnitine propionate and palmitoyl ethanolamide, were significantly reduced. In conclusion, our results suggest that chronic Cr(VI) stress leads to disturbances in gut microbial homeostasis and disturbed fatty acid and amino acid metabolism in the liver. LPS released into the bloodstream reaches the liver through the portal circulation, further exacerbating Cr(VI) stress-induced hepatotoxicity. This study revealed the mechanism of Cr(VI) toxicity to the liver-microbiota-gut axis of common carp. Our study provides new insights into the effects of Cr(VI) on the liver-microbiota-gut axis.

Effects of Nanosilica Priming on Rapeseed (Brassica napus) Tolerance to Cadmium and Arsenic Stress by Regulating Cellular Metabolism and Antioxidant Defense

The mechanisms by which seed-primed silicon dioxide nanoparticles (nSi) alleviated arsenic (As) and cadmium (Cd) toxicity in Brassica napus L. remain unclear. A pot study examined the physico-biochemical, cellular, and molecular responses of B. napus exposed to Cd (10 mg/kg soil) and As (50 mg/kg soil) doses with or without nSi priming. The results showed that nSi priming improved photosynthesis, seedling biomass, and metabolite accumulation, and restored the cell structure. Upon Cd and As stress, nSi diminished oxidative stress by downplaying H2O2 (24-32%) and O2•- (29-36%), MDA, and activating antioxidant defenses. Also, nSi relieved Cd and As accumulation (27-36%) by enhancing root-vacuolar sequestration (upregulating BnHMA3, BnPCs, and BnABCC1), cell wall chelation, and downregulating root transporters (BnNRAMP5, BnIRTI, BnHMA2, BnHMA4, BnPHT1.1, and BnPHT1.4). Our findings revealed that nSi priming effectively enhanced canola tolerance to Cd and As toxicity by strengthening multiple oxidative defense mechanisms and limiting their accumulation.

Ecological and human health risks of potentially toxic elements (PTEs) in street dust of Al-Hillah City, Iraq using Monte Carlo simulation

Street dust is a primary source of metal pollution in urban environments, posing a significant threat to human health through chronic exposure via inhalation, ingestion, and skin contact. This study used deterministic and Monte Carlo simulation to assess the health risks of potential toxic elements (PTEs) in the street dust of Al-Hillah City. The average concentrations of elements in the samples followed the order: Al > Fe > S > K > Sr > Mn > Cr > Ba > Zn > Ni > Pb > Cu > Co > As > Sn > Sb > Cd. In the study area, all the measured elements exceeded UCC values except for Al, Ba, Fe, and K. The results for the enrichment factor (EF), geo accumulation index (Igeo), and contamination factor (CF) revealed that the most sampled locations were polluted with sulfur (S), arsenic (As), and chromium (Cr). The highest values of the pollution load index were not for a solely land use class; they were identified at different sampling stations. According to the potential ecological risk rating, As and Cd pose a medium risk, while Cr, Cu, Ni, Pb, and Zn have low risks. The probabilistic Monte Carlo simulation highlighted the significant health risks from PTEs in street dust, especially for children, with HI values of 2.01, 3.24, and 5.26 at the 5th, 50th, and 95th percentiles, respectively. In comparison, HI values for adults were much lower at 0.29, 0.41, and 0.58, remaining within safe limits. Lifetime Cancer Risk (LTCR) estimates showed that 99.7 % of adults and 97 % of children exposed to levels exceeding the safe threshold 1E-4. Sensitivity analysis revealed that chromium (Cr) and nickel (Ni) were the main PTEs contributing to health risks in children and adults' groups.

Association between blood heavy metals exposure with uterine fibroids among American women: a cross-sectional analysis from NHANES data

BACKGROUND

Excessive exposure to heavy metals has been linked to various health problems, including organ damage, neurological disorders, and reproductive and developmental abnormalities. However, the relationship between heavy metals exposure and uterine fibroids remains uncertain. To explore this association, we conducted a cross-sectional study among American women.

METHODS

We utilized data from three cycles of the National Health and Nutrition Examination Survey (NHANES, 1999-2006) to evaluate the association between uterine fibroids and blood heavy metal levels, including lead (Pb), cadmium (Cd), and mercury (Hg). Weighted logistic regression, restricted cubic spline (RCS), Bayesian kernel machine regression (BKMR), and subgroup analyse were used to examine the potential relationships between blood heavy metals and uterine fibroids.

RESULTS

Of the 4502 American women studied, 542 (12.04%) had uterine fibroids. Elevated levels of all heavy metals were significantly more common in women with uterine fibroids (P < 0.001). Blood Hg levels were notably associated with uterine fibroid prevalence in the adjusted model (OR = 1.41, 95% CI: 1.06-1.89, p = 0.03). Similar patterns were partly observed for blood Pb and Cd. Age and marital status were significant interaction factors concerning Hg exposure (P for interaction < 0.05). A dose-response relationship with an inflection point at 7µmol/L was identified for Hg, and BKMR models indicated a positive association between mixed heavy metal exposure and uterine fibroid risk.

CONCLUSIONS

Exposure to blood heavy metals, particularly Hg, is significantly associated with an elevated risk of uterine fibroids. Further prospective studies are necessary to confirm these findings.

Bioaccumulation of Lead and Mercury in Water, Sediment, and Fish Samples of Baraila Lake, Vaishali, Bihar

In the current study, a protected subtropical wetland in Bihar (India), Baraila Lake, was investigated for heavy metal (Pb and Hg) status. These metals tend to bioaccumulate in fish, posing a concern to human health. This study reported the concentration of lead and mercury in water, sediment, and fish muscles of Baraila Lake in the year 2022. The samples were collected from pre-monsoon and post-monsoon seasons at four sampling locations, i.e., Loma, Dhulwar, Chakaiya, and Kawai Baraila, and were analyzed in triplicates. Lead concentration in water samples of all four sites of Baraila Lake observed during pre-monsoon and post-monsoon season exceeded the permissible limit for drinking water, while the mercury concentration of all sites was under the permissible limit in both seasons as prescribed by WHO. The extent of elemental pollution was evaluated using the Geo-accumulation index (Igeo), contamination factor (CF), contamination degree (Cd), ecological risk factor (Er), and the potential ecological risk index (Ri). Lead concentration in fish muscles of both seasons exceeded the permissible limit, while the concentration of mercury exceeded in Xenentodon cancila (0.55 ± 0.07 µg/g) during the pre-monsoon season. Also, estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) were calculated in different fish muscles to assess potential human health risks. A higher THQ value of 1.303 was observed in carnivore fish during the pre-monsoon season.

Helicobacter pylori promotes intestinal flora imbalance and hepatic metabolic disorders under arsenic stress

Environmental arsenic contamination is a serious issue that cannot be ignored, since arsenic levels in drinking water frequently exceed safety standards, and there is an increased prevalence of Helicobacter pylori (H. pylori) infection. This results in an increasing population at risk of simultaneous exposure to both harmful agents, yet whether a synergistic interaction exists between them remains unclear. Therefore, this study aims to investigate the combined effects and underlying pathogenic mechanisms of concurrent exposure to these two hazardous factors by establishing a mouse model that is infected with H. pylori and exposed to inorganic arsenic through drinking water. Analysis of intestinal flora revealed significant alterations in the composition, relative abundance (Akkermansia, Faecalibaculum, Ilieibacterium, etc.), and metabolic potential of the intestinal microflora (amino acid metabolism and energy metabolism) in the combinatory exposure group. Non-targeted metabolomics analysis identified that the combinatory exposure group exhibited greater fluctuations in metabolite content, particularly in triacylglycerol, fatty-acid, peptide and amino acid. Moreover, H. pylori infection and arsenic exposure had increased levels of metabolites associated with the intestinal microbiota in their livers (4-Ethylphenyl sulfate and Phenylacetylglycine). Further analysis revealed significant correlations between changes in the intestinal flora and alterations in liver metabolic profiles. Herein, we hypothesize that H. pylori infection may exacerbate the intestinal flora imbalance and hepatic metabolic disturbances caused by arsenic exposure, which may disrupt enterohepatic homeostasis and potentially increase biological susceptibility to heavy metal toxicity.

Rhizosphere microbial community structure and PICRUSt2 predicted metagenomes function in heavy metal contaminated sites: A case study of the Blesbokspruit wetland

This study investigated the microbial diversity inhabiting the roots (rhizosphere) of macrophytes thriving along the Blesbokspruit wetland, South Africa's least conserved Ramsar site. The wetland suffers from decades of pollution from mining wastewater, agriculture, and sewage. The current study focused on three macrophytes: Phragmites australis (common reed), Typha capensis (bulrush), and Eichhornia crassipes (water hyacinth). The results revealed a greater abundance and diversity of microbes (Bacteria and Fungi) associated with the free-floating E. crassipes compared to P. australis and T. capensis. Furthermore, the correlation between microbial abundance and metals, showed a strong correlation between fungal communities and metals such as nickel (Ni) and arsenic (As), while bacterial communities correlated more with lead (Pb) and chromium (Cr). The functional analysis predicted by PICRUSt2 identified genes related to xenobiotic degradation, suggesting the potential of these microbes to break down pollutants. Moreover, specific bacterial groups - Proteobacteria, Verrucomicrobia, Cyanobacteria, and Bacteroidetes - were linked to this degradation pathway. These findings suggest a promising avenue for microbe-assisted phytoremediation, a technique that utilizes plants and their associated microbes to decontaminate polluted environments.

Hepatoprotective Potential of Murraya koenigii (Curry Leaves) against Xenobiotics, Heavy Metals, and Hepatotoxic Agents: A Comprehensive Review

Liver disease, responsible for two million annual deaths, causes Chronic Liver Disease (CLD) and cirrhosis, causing roughly a million deaths yearly. Treatment options for liver injury induced by hepatotoxicity vary, including medication (N-acetylcysteine, corticosteroids, and ursodeoxycholic acid), lifestyle changes, and sometimes liver transplant. However, effectiveness varies, and some treatments carry risks and side effects, highlighting the need for improved therapeutic approaches. Murraya koenigii (MK) is known for its hepatoprotective, antioxidant, anti-inflammatory, anti-microbial, nephroprotective, hepatoprotective, gastroprotective, cardioprotective, neuroprotective, wound-healing, anti-cancerous and immunomodulatory effects, etc. This review highlights the effectiveness of MK against liver damage induced by heavy metals, drug abuse, xenobiotics, etc. A comprehensive search across multiple databases like PubMed, Google Scholar, and others for articles on various hepatotoxicants and hepatoprotective activity of MK was conducted. The researchers applied specific search terms and limits, resulting in 149 eligible articles for final analysis, meeting predetermined inclusion criteria and excluding irrelevant studies. According to the available literature, the phytochemical components of MK, such as flavonoids, tannins, and alkaloids present in various extracts, play a crucial role in reversing the hepatotoxic effects by modifying oxidative and ER stresses, re-establishing the hepatic biochemical markers and enzymes involved in metabolism denoting ameliorative activity, and controlling the expression of pro-inflammatory cytokines. To conclude, this review highlights that MK has great potential as a natural hepatoprotective agent, providing a versatile defense against a range of injuries caused by heavy metals, xenobiotics, and common hepatotoxic agents.

Understanding and using Animal Models of Hepatotoxicity

Hepatotoxicity is a critical health hazard, primarily contributing to the increased incidence of deaths globally. The liver is one of the major and extremely vital organs of the human body. Autoimmune diseases, viruses, exposure to toxicants such as carcinogens, and changes in eating habits can all cause liver problems, among other things. Free radical generation, together with raised enzyme levels including SGOT, SGPT, and total bilirubin, are among the pathological changes set off by liver injury. Hepatotoxicity causes changes in cells, such as eosinophilic cytoplasm, nuclear pyknosis, fatty degeneration, too many liver lesions, and hepatic centrilobular necrosis due to lipid peroxidation. Researchers have used animal models to investigate liver diseases and toxicities. Drugs such as azathioprine, alcoholism, paracetamol intoxication, and anti-tuberculosis drugs are some of the most common causes of liver toxicity. These toxins cause calcium ions (Ca2+), reactive oxygen species (ROS), and inflammatory mediators to be released inside cells. This activates immune cells like NK cells, NKT cells, and Kupffer cells. These signaling pathways also play roles in hepatotoxicity. Due to its pathogenesis, no effective drug is currently available for hepatotoxicity due to a lack of understanding related to the signaling factors involved in it. The paper primarily examines different experimental models of hepatotoxicity, including non-invasive and invasive methods, as well as genetic models. As such, these models are crucial tools in advancing our understanding of hepatotoxicity, thus paving the way for new therapeutic interventions.