Role of oxidative stress in cadmium toxicity and carcinogenesis

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.

Preventive Effects of Vanillic Acid Against Lung Inflammation and Oxidative Stress Induced by Dust Particles in Wistar Rats

To evaluate dose-dependent cytotoxicity effects of indoor dust particles (DPs) collected from Neyshabur, Iran, in vitro on A545 cells and in vivo on lungs of healthy male Wistar rats, as well as the antioxidant effects of vanillic acid (VA) against DP inhalation. Heavy metal levels in DPs collected from high-traffic (HT), medium-traffic, low-traffic or rural (LT) zones were measured, and their cytotoxicity effects were evaluated by MTT assay. In vivo evaluations were conducted after rats were exposed to DPs collected from HT or LT in the presence or absence of VA. Exposure to DPs increased the activity of serum superoxide dismutase; the serum level of malondialdehyde; and mRNA expression of TNFα, IL6, CXCL15 and CYP1A1 in the lung homogenate groups receiving HT and LT compared to the control group. DP effects in the groups receiving HT were higher than those of LT. Concomitant VA intake attenuated the adverse effects mediated by DPs in the HT and LT groups. DPs had adverse effects on the lungs of healthy rats, probably because of the accumulated oxidative stress agents. VA could ameliorate the effects of DPs and may be considered as a protective substance against the undesirable effects of DPs.

Elucidating the interaction and toxicity of cadmium and cerium on the growth of maize seedlings: Insights from morpho-physiological and biochemical analysis

The exploitation of rare earth elements (REEs) is often accompanied by heavy metal contamination. However, our understanding regarding the growth responses of plants to the co-existence of REEs and heavy metals (HMs), remains limited. In this study, cerium (Ce) and cadmium (Cd) were selected as representatives of REEs and HMs to investigate their interactive effects on maize growth through multiple model analyses. The results revealed that both Cd and Ce induce oxidative injuries by increasing reactive oxygen species (ROS) content in a dose-dependent manner. Ce can enhance chlorophyll content while reducing leaf yellowing induced by Cd. The addition of 10 and 100 mg· L-1 Ce significantly increased the Chla content in 50 μM Cd sets by 52.2 % and 50.2 % compared to Cd50Ce0 treatment, respectively. Evaluation of the physiological and biochemical effect level index (PBELI) showed that the primary interaction mode of Cd and Ce was antagonism. The co-existence of Cd (50 μM) and Ce (100 mg· L-1) poses a higher ecological risk than Ce alone. These results demonstrated that combined exposure to Cd and Ce exhibited diverse effects in mitigating the inhibition of maize growth, thereby improving our understanding of phytotoxicity resulting from metal mixtures in the environment.

Alpha-lipoic acid, as an effective agent against toxic elements: a review

This review aims to evaluate the efficacy of alpha-lipoic acid (ALA) in combating toxic elements, such as aluminum, arsenic, lead, mercury, and cadmium. The primary research question addressed is whether ALA can effectively mitigate the toxic effects of these metals through its antioxidant and chelating properties. Articles published between 1995 and 2024 were collected from Scopus, PubMed, Google Scholar, and Web of Science. Using Boolean (AND and OR), English-language publications were selected based on medical subject headings, titles, or abstracts that contained keywords related to ALA, metals, toxicity, antioxidants, and chelation. ALA supplementation significantly enhances cellular defense mechanisms and antioxidant enzyme activity. It effectively mitigates the adverse effects of aluminum exposure, counters arsenic toxicity in various cells and organs, and reduces cadmium toxicity, resulting in lower mortality rates among treated groups. Although ALA acts as a lead chelator, its efficacy is less than standard chelators. In the case of mercury, ALA shows beneficial effects in long-term therapy, although its capacity to reduce mercury concentration is limited. Overall, ALA emerges as a promising alternative for alleviating metal toxicity by enhancing antioxidant defenses, chelating toxic metals, and reversing their harmful effects. Further research in this area is encouraged to explore the full potential of ALA in mitigating the toxic effects of metals on biological systems.

BRD4 Mediates Cadmium-Induced Oxidative Stress and Kidney Injury in Mice via Disruption of Redox Homeostasis

Cadmium (Cd) is a toxic heavy metal that threatens public health, with kidney injury being one of the common manifestations after Cd exposure. Oxidative stress plays a crucial role in Cd-induced kidney injury, arising from an imbalance between cellular oxidation and antioxidation processes. Bromodomain-containing protein 4 (BRD4) has been identified as a significant factor in the initiation and advancement of multiple diseases, primarily due to its regulatory role in oxidative stress. Nevertheless, the specific role of BRD4 in Cd-induced kidney oxidative injury remains poorly understood. The present study demonstrates that BRD4 is activated in the kidney after Cd exposure, while JQ1 (a BRD4 inhibitor) treatment inhibits Cd-induced oxidative stress and kidney injury. Subsequently, we investigate the mechanisms by which Cd regulates oxidative stress both in vivo and in vitro. The results indicate that JQ1 treatment reduces the expression levels of NADPH oxidase 4 (Nox4), thereby alleviating mitochondrial damage and reducing reactive oxygen species (ROS) generation. Furthermore, JQ1 treatment facilitates nuclear translocation levels of Nuclear factor erythroid-derived 2-like 2 (Nrf2), thereby enhancing the antioxidant defense system in the kidney after Cd exposure. In conclusion, this study reveals that BRD4 is significantly involved in the process of Cd-induced oxidative damage in the kidney, while inhibiting BRD4 is observed to attenuate ROS generation by regulating Nox4 and enhance ROS scavenging by regulating Nrf2, which, in turn, suppresses the oxidative stress level in the kidney after Cd exposure. These findings suggest that targeting BRD4 may represent an effective strategy for the prevention and treatment of Cd-induced kidney diseases.

The Effect of the Combination of Probiotics and Heavy Metals From Various Aspects in Humans: A Systematic Review of Clinical Trial Studies

Background and Aims

Probiotics usually have beneficial effects on the absorption of trace elements and detoxification of toxic metals in human. Hence, the aim of the systematic review was to evaluate various aspects of the effect of the combination of probiotics and heavy metals in human clinical trial studies.

Methods

Nine databases were searched for clinical trials up to June 2024 investigating probiotics for heavy metal exposure in humans. Two reviewers independently screened records and extracted data on study characteristics, interventions, outcomes, and results. Risk of bias was assessed.

Results

The analysis included 31 clinical trials with a total of 4,611 participants, focusing on the effects of probiotics, prebiotics, and synbiotics. Among the trials, 23 investigated probiotics, five looked at prebiotics, and three explored synbiotics, with probiotic doses ranging from 107 to 2.5 × 1010 CFU/day. Results indicated that probiotics combined with zinc significantly reduced the time to resolution of vomiting and diarrhea compared to zinc alone, improved the treatment efficacy of antibiotic-associated diarrhea linked to pneumonia, and shortened hospital stays relative to probiotics alone. Probiotics did not show significant effects on blood parameters compared to placebo; however, prebiotic galactooligosaccharides enhanced iron absorption in women and children. The addition of probiotics to bismuth quadruple therapy did not improve Helicobacter pylori eradication rates but reduced side effects like diarrhea and vomiting. One trial reported a decrease in toxic metal levels in pregnant women due to probiotics, but no similar effects were observed in children.

Conclusions

Probiotics are one of the new methods employed to improve or eliminate the adverse effects of heavy metals in the body. Although many studies have investigated the effects of probiotics on heavy metals, there is still a need for more in-depth and extensive studies.

Disentangling the role of selenium in antagonizing the toxicity of arsenic and cadmium

Cadmium (Cd) and inorganic arsenic (As) compounds are considered to be among the major public health hazards. This is due to both the high intrinsic toxicity of these substances and the often difficult to avoid exposure of the general population through contaminated water and food. One proposed method to reduce the toxic effects of As and Cd on animals and humans is the use of selenium (Se). As discussed in our previous article, laboratory studies show that this micronutrient can have a beneficial effect on the detoxification of As and Cd in the body through the formation of non-toxic complexes with these elements, as well as through the antioxidant effects of selenoproteins. New data that have emerged in recent years allow for a clearer description of the interaction between Se and As and Se and Cd. Human studies show that optimal levels of Se can have a beneficial effect in reducing the toxic effects associated with exposure to As or Cd. However, as Se levels in the body increase, the protective effects of Se may be reversed. Recent laboratory studies confirm the antagonistic effects of medium doses of Se toward Cd and As through the formation of nontoxic complexes, antioxidant, anti-inflammatory effects, and induction of pro-survival pathways in cells. In conclusion, Se has a complex effect on As and Cd toxicity, with both benefits and potential risks, depending on the form of Se and its dose as a supplement or the status (level) of this micronutrient in the body.

Heavy metals: toxicity and human health effects

Heavy metals are naturally occurring components of the Earth's crust and persistent environmental pollutants. Human exposure to heavy metals occurs via various pathways, including inhalation of air/dust particles, ingesting contaminated water or soil, or through the food chain. Their bioaccumulation may lead to diverse toxic effects affecting different body tissues and organ systems. The toxicity of heavy metals depends on the properties of the given metal, dose, route, duration of exposure (acute or chronic), and  extent of bioaccumulation. The detrimental impacts of heavy metals on human health are largely linked to their capacity to interfere with antioxidant defense mechanisms, primarily through their interaction with intracellular glutathione (GSH) or sulfhydryl groups (R-SH) of antioxidant enzymes such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GR), and other enzyme systems. Although arsenic (As) is believed to bind directly to critical thiols, alternative hydrogen peroxide production processes have also been postulated. Heavy metals are known to interfere with signaling pathways and affect a variety of cellular processes, including cell growth, proliferation, survival, metabolism, and apoptosis. For example, cadmium can affect the BLC-2 family of proteins involved in mitochondrial death via the overexpression of antiapoptotic Bcl-2 and the suppression of proapoptotic (BAX, BAK) mechanisms, thus increasing the resistance of various cells to undergo malignant transformation. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of antioxidant enzymes, the level of oxidative stress, and cellular resistance to oxidants and has been shown to act as a double-edged sword in response to arsenic-induced oxidative stress. Another mechanism of significant health threats and heavy metal (e.g., Pb) toxicity involves the substitution of essential metals (e.g., calcium (Ca), copper (Cu), and iron (Fe)) with structurally similar heavy metals (e.g., cadmium (Cd) and lead (Pb)) in the metal-binding sites of proteins. Displaced essential redox metals (copper, iron, manganese) from their natural metal-binding sites can catalyze the decomposition of hydrogen peroxide via the Fenton reaction and generate damaging ROS such as hydroxyl radicals, causing damage to lipids, proteins, and DNA. Conversely, some heavy metals, such as cadmium, can suppress the synthesis of nitric oxide radical (NO·), manifested by altered vasorelaxation and, consequently, blood pressure regulation. Pb-induced oxidative stress has been shown to be indirectly responsible for the depletion of nitric oxide due to its interaction with superoxide radical (O2·-), resulting in the formation of a potent biological oxidant, peroxynitrite (ONOO-). This review comprehensively discusses the mechanisms of heavy metal toxicity and their health effects. Aluminum (Al), cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), and chromium (Cr) and their roles in the development of gastrointestinal, pulmonary, kidney, reproductive, neurodegenerative (Alzheimer's and Parkinson's diseases), cardiovascular, and cancer (e.g. renal, lung, skin, stomach) diseases are discussed. A short account is devoted to the detoxification of heavy metals by chelation via the use of ethylenediaminetetraacetic acid (EDTA), dimercaprol (BAL), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercapto-1-propane sulfonic acid (DMPS), and penicillamine chelators.

Screening Methods to Discover the FDA-Approved Cancer Drug Encorafenib as Optimally Selective for Metallothionein Gene Loss Ovarian Cancer

BACKGROUND/OBJECTIVES

All 11 metallothionein protein-coding genes are located on human chromosome 16q13. It is unique among human genetics to have an entire pathway's genes clustered in a short chromosomal region. Since solid tumors, particularly high-grade serous ovarian cancer (HGSC), exhibit high rates of monoallelic aneuploidy, this region is commonly lost. Studies have not yet been performed to determine what vulnerability may be created in cancer cells with low metallothionein expression. Here, a screen of FDA-approved cancer small molecule drugs for those best targeting low metallothionein ovarian cancer was completed.

METHODS

Screening methods were tested and compared using vehicle-treated negative controls and cadmium chloride, a positive control for cell loss selective for low metallothionein cells. CAOV3 cells, which are unique in their expression of only two metallothionein isoforms, were used, with or without shRNA knockdown of the predominantly expressed MT2A gene. A library of FDA-approved molecules was then screened.

RESULTS

The optimal assay utilized Hoechst 33342 nuclear staining and mechanized fluorescent microscope counting of cell content. Encorafenib, an RAF inhibitor, was identified as the most selective for enhanced cytotoxicity in MT2A knockdown cells compared to scrambled controls.

CONCLUSIONS

The nuclear stain Hoechst 33342, assessed by fluorescence microscopy, provides a low variance, moderate throughput platform for cancer cell loss screens. Low metallothionein ovarian cancer cells exhibit a vulnerability to the RAF inhibitor encorafenib.

Analysis of the Cadmium Removal Mechanism of Human Gut Bacteria Enterococcus faecalis Strain ATCC19433 from a Genomic Perspective

Cadmium (Cd) is one of the most well-known toxic metals capable of entering the human body via the food chain, leading to serious health problems. Human gut microbes play a pivotal role in controlling Cd bioavailability and toxicity within the human gastrointestinal tract, primarily due to their capacity for Cd adsorption and metabolism. In this work, a Cd-resistant bacterial strain, Enterococcus faecalis strain ATCC19433 was isolated from human gut microbiota. Cd binding assays and comprehensive characterization analyses were performed, revealing the ability of strain ATCC19433 to remove Cd from the solution. Cd adsorption primarily occurred on the bacterial cell walls, which was ascribed to the exciting of functional groups on the bacterial surfaces, containing alkyl, amide II, and phosphate groups; meanwhile, Cd could enter cells, probably through transport channels or via diffusion. These results indicated that Cd removal by the strain was predominantly dependent on biosorption and bioaccumulation. Whole-genome sequencing analyses further suggested the probable mechanisms of biosorption and bioaccumulation, including Cd transport by transporter proteins, active efflux of Cd by cadmium efflux pumps, and mitigating oxidative stress-induced cell damage by DNA repair proteases. This study evaluated the Cd removal capability and mechanism of Enterococcus faecalis strain ATCC19433 while annotating the genetic functions related to Cd removal, which may facilitate the development of potential human gut strains for the removal of Cd.

Coenzyme Q10 Attenuates Kidney Injury Induced by Titanium Dioxide Nanoparticles and Cadmium Co-exposure in Rats

This study examined the possible defensive role of coenzyme Q10 (CQ10) against the impact of cadmium (Cd) and titanium dioxide nanoparticle (TNP) exposure on rat kidneys. Distilled water (1 mL/rat), corn oil (1 mL/rat), 10 mg CQ10/kg b.wt, 50 mg TNP/kg b.wt, 5 mg Cd/kg b.wt, TNP + Cd, or TNP + Cd + CQ10 was administered orally to seven groups of 70 male Sprague Dawley rats for 60 days. The findings demonstrated that TNP and/or Cd exposure considerably raised serum levels of several renal damage products, disturbed electrolyte balance including sodium, potassium, and calcium, decreased antioxidant enzyme concentration in the kidneys, and elevated malondialdehyde. In addition, rats exposed to TNP and/or Cd had significantly higher levels of renal titanium and Cd. In addition, rats exposed to TNP and/or Cd showed significant histopathological lesions and collagen deposition as revealed by H and E and Masson trichrome staining, respectively. The kidneys were severely damaged by the combined effects of TNP and Cd, although CQ10 greatly mitigated these effects. According to the study, exposure to TNP and Cd can damage the kidneys' function and structure, especially when combined. However, CQ10 can protect against TNP and Cd's nephrotoxic effects.

Dynamics of metal/metalloid bioaccumulation and sensitivity in post-larvae shrimp (Macrobrachium rosenbergii) exposed to settleable atmospheric particulate matter from an industrial source

The metallurgy industry is a potent global source of particulate matter (PM) atmospheric emissions. A portion of this PM may settle in aquatic (SePM) carrying metal/metalloid particles and metallic nanoparticles. Surprisingly, this form of contamination has not received due attention from most environmental monitoring agencies. We analyzed the effect of exposure to SePM on shrimp post-larvae, a critical stage for the viability of shrimp populations and for the trophic chain. After acclimation, shrimp were exposed to contaminants using a randomized experimental design-a 4 × 4 factorial arrangement with 2 factors: exposure time (24, 48, 72, and 96 h) and SePM concentration (0.00, 0.01, 0.10, and 1.00 g L-1). The bioaccumulation of metals, contamination rates, mortality, and ROS-related biomarkers (lipid peroxidation - LPO; DNA strand breakage DNA SB and metallothionein content - MTs;) were evaluated. After contamination, the water contained 27 different metals/metalloids. Post-larvae accumulated metals, such as Cd, Pb, Al, As, Se, Sr, Zr, Ba, La, Ce, W, and Hg. However, the rise in SePM did not result in a proportional bioaccumulation rise, indicating that effective biological barriers may work for some metals. Although the different levels of SePM changed mortality dynamics, they resulted in a similar final lethality (60-80 %). SePM caused significant damage to lipids (increased LPO), genetic material (DNA SB), and increased Mts. Such effects may reflect a particularly deleterious ecological problem as it is present at such an early stage of life. These results identified a clear environmental risk since the lower level of exposure used was 102 times lower than that measured in the habitats affected by local industry. Consequently, our results emphasize the need for clear protocols for monitoring the effects of SePM in aquatic environments.

Analysis of Toxic Element Levels and Health Risks in Different Soybean Species (Glycine max, Vigna radiata, Vigna angularis, Vigna mungo)

Background: Soybeans are a widely consumed legume, essential in Western diets and especially prominent in vegan and vegetarian nutrition. However, environmental contamination from anthropogenic sources, such as industrial emissions, wastewater, and pesticide use, has led to the accumulation of non-essential and toxic elements in legumes, potentially impacting human health. Method: This study quantified the levels of 11 potential toxic elements (Al, B, Ba, Cd, Co, Cr, Li, Ni, Pb, Sr, V) in 90 samples of four soybean species (Glycine max, Vigna radiata, Vigna angularis, Vigna mungo) using inductively coupled plasma optical emission spectrometry (ICP-OES). Results: Results showed that boron had the highest mean content (9.52 mg/kg ww), followed by aluminum (6.73 mg/kg ww). Among the toxic metals, cadmium was most concentrated in green soybeans (0.03 mg/kg ww), and black soybeans had the highest level of lead (0.07 mg/kg ww). Based on an average soybean consumption of 50 g/day, no immediate health risk was detected. However, lithium and nickel were present in substantial amounts, with lithium contributing 31.43-48.57% and nickel 6.81-39.56% of their respective provisional daily intake limits, especially from red soybeans (V. angularis). Conclusions: This study highlights the importance of monitoring toxic elements in soybeans and calls for stricter environmental management practices to minimize contamination, ensuring the safety of soy products as their global consumption rises.

Diallyl disulfide prevents cadmium-induced testicular injury by attenuating oxidative stress, apoptosis, and TLR-4/NF-κB and JAK1/STAT3 signaling and upregulating SIRT1 in rats

BACKGROUND

Cadmium (Cd) is a heavy metal environmental pollutant that can cause serious health problems. Cd can cause structural changes in the testes and exposure to this heavy metal is associated with the loss of sperms and male infertility. The role of oxidative stress and inflammation in Cd toxicity has been acknowledged. Diallyl disulfide (DADS), an organo-sulfur compound found in garlic, possesses antioxidant, anti-inflammatory, and cytoprotective effects. This study evaluated the protective effect of DADS against Cd reproductive toxicity in male rats, emphasizing the involvement of redox imbalance, TLR-4/NF-κB and JAK1/STAT3 signaling, and SIRT1.

METHODS

DADS (10 mg/kg body weight) was administered orally to rats for 14 days and a single dose of Cd (1.2 mg/kg) was injected intraperitoneally on day 7. Blood and samples from the testes were collected for analysis.

RESULTS

Cd caused testicular injury manifested by multiple histopathological changes and loss of sperms from seminiferous tubules. Circulating levels of gonadotropins and testosterone were decreased in Cd-administered rats. DADS prevented Cd-induced testicular injury and ameliorated serum levels of gonadotropins and testosterone. Cd increased testicular reactive oxygen species (ROS) and malondialdehyde (MDA) and upregulated TLR-4, NF-κB, pro-inflammatory cytokines, JAK1 and STAT3 phosphorylation, Bax and caspase-3, while decreased antioxidants and Bcl-2. DADS effectively decreased ROS and MDA, downregulated TLR-4, NF-κB, JAK1, STAT3, pro-inflammatory cytokines and pro-apoptosis markers in Cd-administered rats. In addition, DADS enhanced antioxidants, Bcl-2, SIRT1 and cytoglobin in the testis of Cd-administered rats.

CONCLUSION

DADS prevents Cd-induced testicular injury by attenuating oxidative stress, apoptosis, and TLR-4/NF-κB and JAK1/STAT3 signaling, and upregulating SIRT1 and antioxidants.

Determination of Toxic Elements in Cannabinoid and Opioid Drugs and Their Impact on Addicts' Health: A Comparative Study

Drug addiction is associated with significant health risks, including cardiovascular complications, cancer, and mental disorders. Illicit drugs, such as cannabinoids and opioids, including prescription medications, are widely consumed and have profound health consequences. Understanding the health effects of the toxic elements in these substances is critical for overdose prevention and effective recovery strategies. This study aimed to determine toxic elements, including arsenic (As), cadmium (Cd), mercury (Hg), and nickel (Ni), in cannabinoid and opioid drugs and in biological samples (whole blood, scalp hair, and serum) from 311 male drug abuse patients aged 15-60 years with a history of drug abuse. The participants were categorized into three age groups. The comparative analysis involved 113 reference subjects of the same age groups. The sample preparation employed microwave-assisted acid digestion, and the toxic elements were quantified using atomic absorption spectrophotometry. Accuracy was ensured using certified reference materials for hair, whole blood, and serum samples. Drug-addicted subjects had significantly higher concentrations of toxic elements (arsenic, cadmium, mercury, and nickel) in biological samples than referent subjects (p > 0.001). Elevated levels of these toxic elements may increase susceptibility to infections, possibly due to malnutrition, drug-related effects, and additional contaminants. These findings necessitate further studies to explore the long-term health outcomes, potential treatment options, and broader socioeconomic impacts of substance abuse. This study serves as a baseline for future research in this critical public health field.

Attenuation of inflammation, oxidative stress and TGF-β1/Smad3 signaling and upregulation of Nrf2/HO-1 signaling mediate the protective effect of diallyl disulfide against cadmium nephrotoxicity

Heavy metals are toxic environmental pollutants with serious health effects on humans and animals. Cadmium (Cd) is known for its serious nephrotoxic effect and its toxicity involves oxidative stress (OS) and inflammation. Diallyl disulfide (DADS), a main constituent of garlic, exhibites cytoprotective and antioxidant activities. This study investigated the effect of DADS on OS, inflammation, and fibrosis induced by Cd in rat kidney, pointing to the involvement of transforming growth factor-β (TGF-β)/Smad3 and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling, and peroxisome proliferator-activated receptor gamma (PPARγ). Rats received DADS for 14 days and Cd on day 7 and blood and kidney samples were collected. Cd elevated serum creatinine, urea and uric acid, provoked kidney histopathological alterations and collagen deposition, increased kidney malondialdehyde (MDA) level, and decreased glutathione (GSH) and antioxidant enzymes. Nuclear factor-kappaB (NF-κB) p65, interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1β, and CD68 were upregulated in Cd-administered rat kidney. DADS prevented kidney injury, mitigated OS, suppressed NF-κB, CD68 and pro-inflammatory mediators, and boosted antioxidants. DADS downregulated TGF-β1, Smad3 phosphorylation and Kelch-like ECH-associated protein-1 (Keap1), and increased Nrf2, HO-1, cytoglobin, and PPARγ. In conclusion, DADS protects the kidney against Cd toxicity by attenuating OS, inflammation, and TGF-β1/Smad3 signaling, and enhancement of Nrf2/HO-1 signaling, antioxidants, and PPARγ.

E-waste in the environment: Unveiling the sources, carcinogenic links, and sustainable management strategies

E-waste refers to the electrical and electronic equipment discarded without the intent of reuse or at the end of its functional lifespan. In 2022, approximately 62 billion kg of e-waste, equivalent to 7.8 kg per capita, was generated globally. With an alarming annual growth of approximately 2 million metric tonnes, e-waste production may exceed 82 billion kg by 2030. Improper disposal of e-waste can be detrimental to human health and the entire biosphere. E-waste encompasses a wide range of materials, including heavy metals, Polychlorinated Biphenyls (PCBs), Per- and Polyfluoroalkyl Substances (PFAS), Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Dibenzo-dioxins and -furans (PCDD/Fs), Polybrominated Diphenyl Ethers (PBDEs), and radioactive elements. E-waste, when disposed inappropriately can directly contaminate the aquatic and terrestrial environment, leading to human exposure through ingestion, inhalation, dermal absorption, and trans-placental transfer. These detrimental contaminants can directly enter the human body from the environment and may fuel carcinogenesis by modulating cell cycle proteins, redox homeostasis, and mutations. Heavy metals such as cadmium, mercury, arsenic, lead, chromium, and nickel, along with organic pollutants like PAHs, PCBs, PBDEs, PFAS, and radioactive elements, play a crucial role in inducing malignancy. Effective collection, sorting, proper recycling, and appropriate disposal techniques are essential to reduce environmental contamination with e-waste-derived chemicals. Hence, this comprehensive review aims to unravel the global environmental burden of e-waste and its links to carcinogenesis in humans. Furthermore, it provides an inclusive discussion on potential treatment approaches to minimize environmental e-waste contamination.

Heavy metals altered the xenobiotic metabolism of rats by targeting the GST enzyme: An in vitro and in silico study

Among all the heavy metals, Pb, Cd, and As are the most harmful pollutants in the environment. They reach into the organisms via various levels of food chains i.e. air and water. Glutathione-s-transferase (GST, E.C. 2.5.1.18), a key enzyme of xenobiotics metabolism, plays an important role in the removal of several toxicants. The present study aimed to evaluate any inhibitory action of these heavy metals on the GST enzyme isolated from the hepatic tissues of rats. A 10 % (w/v) homogenate of rat liver was prepared in cold and centrifuged at 4 °C at 9000xg for 30 min. The supernatant was collected and kept frozen at -20 °C or used fresh for carrying out different experiments. The activity of GST was monitored spectrophotometrically at 340 nm using 220 μg of soluble protein with varying equal substrate concentrations (0.125-2 mM) in phosphate buffer (50 mM, pH 6.5). To assess the impact of heavy metals on the enzyme activity, different concentrations of Cd (0-0.6 mM) and Pb (0-2 mM) were added to the reaction mixture followed by monitoring the residual activity. The optimum temperature and pH of rat liver GST were found to be 37 °C and 6.5, respectively. The Km value for GST was 0.69 mM and the Vmax was found to be 78.67 U/mg. The Cd and Pb significantly altered the kinetic behaviour of the enzyme. The Vmax and Kcat/Km parameters of GST were recorded to be decreased after interaction with Cd and Pb individually and showed a mixed type of inhibition pattern suggesting that these inhibitors may have a greater binding affinity either for the free enzyme or the substrate-enzyme complex. These metals showed a time-dependent enzyme inhibition profile. Cd was found to be the most potent inhibitor when compared to other treated metals; the order of inhibitory effect of metal ions was Cd>Pb>As. The in silico ion docking analysis for determining the probable interactions of Cd and Pb with fragmented GST validated that Cd exhibited higher inhibition potential for the enzyme as compared to Pb. The results of the present study indicated that exposure of both the Cd and Pb may cause significant inhibition of hepatic GST; the former with higher inhibitory potential than the later. However, As proved to be least effective against the enzyme under the aforesaid experimental conditions.

Mitochondrial Dysfunction in Environmental Toxicology: Mechanisms, Impacts, and Health Implications

Mitochondria, pivotal to cellular metabolism, serve as the primary sources of biological energy and are key regulators of intracellular calcium ion storage, crucial for maintaining cellular calcium homeostasis. Dysfunction in these organelles impairs ATP synthesis, diminishing cellular functionality. Emerging evidence implicates mitochondrial dysfunction in the etiology and progression of diverse diseases. Environmental factors that induce mitochondrial dysregulation raise significant public health concerns, necessitating a nuanced comprehension and classification of mitochondrial-related hazards. This review systematically adopts a toxicological perspective to illuminate the biological functions of mitochondria, offering a comprehensive exploration of how toxicants instigate mitochondrial dysfunction. It delves into the disruption of energy metabolism, the initiation of mitochondrial fragility and autophagy, and the induction of mutations in mitochondrial DNA by mutagens. The overarching objective is to enhance our understanding of the repercussions of mitochondrial damage on human health.

Therapeutic Efficacy of Selenium Pre-treatment in Mitigating Cadmium-Induced Cardiotoxicity in Zebrafish (Danio rerio)

Cardiovascular diseases are a rampant public health threat. Environmental contaminants, such as Cadmium (Cd), a toxic metal, are risk factors for cardiovascular diseases. Given that human exposure to Cd is increasing, there is a need for therapies to ameliorate Cd toxicity. Selenium (Se), an essential trace element, has been proposed to rescue the effects of Cd toxicity, with mixed effects. Se's narrow therapeutic window necessitates precise dosing to avoid toxicity. Here, we assessed the effects of various waterborne Cd and Se concentrations and sequences on cardiac function using zebrafish (Danio rerio). We showed that Cd induced pericardial edemas and modified heart rates in zebrafish larvae in a concentration-dependent manner. To identify the therapeutic range of Se for Cd-induced cardiotoxicity, zebrafish embryos were treated with 0, 10, 50, 100, 150, or 200 μg/L Se for 1-4 days prior to exposure to 2.5 and 5 μg/L Cd. We found that a 50 µg/L Se pre-treatment before 2.5 μg/L Cd, but not 5 μg/L Cd, reduced the prevalence of pericardial edemas and ameliorated Cd-induced bradycardia in zebrafish. Zebrafish exposed to 10 and 50 μg/L of Se for up to 4 days showed typical heart morphology, whereas other Se-exposed and control fish presented pericardial edemas. Longer Se pre-treatment durations led to fewer incidences of pericardial edemas. Overall, this study highlights the importance of optimizing Se concentrations and pre-treatment periods to harness its protective effects against Cd-induced cardiotoxicity. These findings provide insights into potential therapeutic strategies for reducing Cd-related cardiovascular damage in humans.

Strengthening bioremediation potential: Enterobacter ludwigii ES2 for combined nicosulfuron and Cd contamination through whole genome and microbial diversity community analysis

Nicosulfuron and Cd are common pollutants that pose significant threats to the environment and human health, particularly under combined stress. This study is the first to remediate environmental nicosulfuron and Cd under combined stress using microbiological techniques. Enterobacter ludwigii ES2 was isolated, characterized, and demonstrated to degrade 93.80 % of nicosulfuron and remove 59.64 % of Cd within 4 d. Potential functional genes, including nicosulfuron degradation genes gstA, gstB, glnQ, glnP, mreB, and sixA, and Cd tolerance/removal-related genes mntA, mntB, mntH, dnaK, znuA, and zupt, were predicted by sequencing the whole genome of strain ES2, and their expression was verified by qRT-PCR. Strain ES2 managed oxidative stress induced by Cd through superoxide dismutase, glutathione, catalase, peroxidase, and malondialdehyde. Furthermore, to repair compound stress, up to 90.48 % of nicosulfuron and 67.74 % of Cd were removed. The community structure analysis indicated that Enterobacteriaceae, Sphingomonadaceae, and Gemmatimonadaceae were dominant populations, with ES2 stably colonizing and becoming the dominant bacterium. In summary, ES2 demonstrated significant potential in remediating nicosulfuron and Cd pollution from various perspectives, providing a solid theoretical foundation.

Farnesol attenuates cadmium-induced kidney injury by mitigating oxidative stress, inflammation and necroptosis and upregulating cytoglobin and PPARγ in rats

Heavy metals are environmental pollutants that can harm animals and humans even at low concentrations. Cadmium (Cd) is known for its serious health effects on different organs and its toxicity is associated with oxidative stress (OS) and inflammation. Farnesol (FAR), a sesquiterpene alcohol found in many vegetables and fruits, possesses promising anti-inflammatory and antioxidant activities. This study evaluated the effect of FAR on Cd-induced kidney injury, pinpointing its effect of the redox status, inflammation, fibrosis and necroptosis. Rats in this study received FAR for 14 days and Cd on day 7. Elevated serum creatinine, urea and uric acid, and several kidney histopathological alterations were observed in Cd-administered rats. Cd increased MDA, decreased antioxidants, downregulated PPARγ and upregulated NF-κB p65, IL-6, TNF-α, and IL-1β. Necroptosis mediators (RIP1, RIP3, MLKL, and caspase-8) and α-SMA were upregulated, and collagen deposition was increased in Cd-administered rats. FAR ameliorated kidney injury markers and tissue damage, attenuated OS, suppressed NF-κB and inflammatory mediators, and enhanced antioxidants. In addition, FAR suppressed RIP1, RIP3, MLKL, caspase-8, and α-SMA, and enhanced kidney cytoglobin and PPARγ. In conclusion, FAR protects against Cd nephrotoxicity by suppressing OS, inflammatory response and necroptosis, effects associated with enhanced antioxidants, cytoglobin, and PPARγ.

Xeroderris stuhlmannii (Taub.) Mendonça & E.P.Sousa (Fabaceae): Evidence of the antihypertensive and antioxidant activities of its leaf aqueous extract in cadmium chloride hypertensive rats

Xeroderris stuhlmannii (Fabaceae) is a medicinal reported in Cameroonian herbal medicine to treat hypertension. The aim of the study was to assess the antihypertensive and antioxidant activities of X. stuhlmannii aqueous leaf extract (AEXS) on cadmium chloride-induced hypertensive rats. The in vitro antioxidant activities of AEXS were investigated for their radical scavenging potency using 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric reducing antioxidant power (FRAP), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS), Nitric oxide (NO) and OH- assays completed with oxidative stress markers analyses. Antihypertensive activity of AEXS (35, 100, and 300 mg/kg) was assessed in CdCl2 induced-hypertensive rats. Antihypertensive activities performed include systolic (SBP), diastolic blood pressure (DBP) and heart rate (HR) variation, followed by evaluation of selected biochemical parameters in urine, blood (Alanine aminotransferase (ALT), aspartate aminotransferase (AST)), creatinine, urea and total protein) and histological examination of tissue samples (aorta, heart, kidneys and liver). The amount of the phenols of the leaf extract was estimated in mg gallic acid equivalent and identification of some compounds was done by UPLC-UV-ESI-TOF-MS. Accordingly, the identified phenols were stuhlmannione A (1), formononetin (2), stuhlmarotenoid A (3), 9-methoxymaackiain (4), 4-hydroxymaackiain (5) and 7-hydroxy-3',4'-methylenedioxy-isoflavone (6). The extract exhibited a significant (P < 0.05-0.001) decrease of SBP, DBP and HR when compare to control. AEXS also reduced (P < 0.05) serum rates of ALT, AST, and urea. The extract showed beneficial effects on alterations observed in the histological structures of the aorta, heart, kidneys and liver. AEXS highlighted high level of phenols (26.48 ± 2.89 mg GAE/g) and a strong antiradical activity on DPPH, ABTS+, OH- and NO with IC50 of 148.8 μg/mL, 27.83 μg/mL, 22.29 μg/mL, 29.84 μg/mL respectively. An optical density of 1.79 nm was obtained with FRAP test. Thus, X. stuhlmannii leaf extract has in vitro antioxidant and antihypertensive effects that may support its use against hypertension.

The Association Between the Non-essential Metal Mixture and Handgrip Strength in Chinese Community-Dwelling Older Adults

There is limited research on the effects of non-essential metal (NEM) mixture on handgrip strength in the elderly. This study aimed to assess the associations of single NEMs and their mixture with handgrip strength in Chinese community-dwelling older adults. A total of 3807 elderly people aged 60 years or above were included in this study. Measurement of urinary aluminum (Al), arsenic (As), barium (Ba), cadmium (Cd), and gallium (Ga) concentrations was conducted by inductively coupled plasma mass spectrometry (ICP-MS). Handgrip strength was measured using a hand dynamometer. Four statistical models, including general linear regression and generalized additive models (GAMs), as well as Bayesian kernel machine regression (BKMR) and quantile-based computation regression (QGC) models, were used to assess the individual and joint effects of urine NEMs with handgrip strength, respectively. After adjusting for covariates, Ga (ß = - 0.27; 95% CI, - 0.54 ~  - 0.01) and As ( β  = - 0.34; 95% CI, - 0.61 ~  - 0.07) were negatively associated with handgrip strength. The GAMs and BKMR further suggested that the negative associations of Ga and As with handgrip strength were linear and inverted U-shaped, respectively. The BKMR and QGC models showed that the NEM mixture was negatively related to handgrip strength, with Ga and As contributing the most within the mixture. Moreover, we also observed an interaction between As and Ga on handgrip strength. Longitudinal studies are needed to verify these findings.

Mechanistic insights into cadmium exacerbating 2-Ethylhexyl diphenyl phosphate-induced human keratinocyte toxicity: Oxidative damage, cell apoptosis, and tight junction disruption

Organophosphate flame retardants 2-ethylhexyldiphenyl phosphate (EHDPP) and cadmium (Cd) are ubiquitous in environmental matrices, and dermal absorption is a major human exposure pathway. However, their detrimental effects on the human epidermis remain largely unknown. In this study, human keratinocytes (HaCaT cells) were employed to examine the toxicity and underlying mechanisms of co-exposure to EHDPP and Cd. Their influence on cell morphology and viability, oxidative damage, apoptosis, and tight junction were determined. The results showed that co-exposure decreased cell viability by >40 %, induced a higher level of oxidative damage by increasing the generation of reactive oxygen species (1.3 folds) and inhibited CAT (79 %) and GPX (90 %) activities. Moreover, Cd exacerbated EHDPP-induced mitochondrial disorder and cellular apoptosis, which was evidenced by a reduction in mitochondrial membrane potential and an elevation of cyt-c and Caspase-3 mRNA expression. In addition, greater loss of ZO-1 immunoreactivity at cellular boundaries was observed after co-exposure, indicating skin epithelial barrier function disruption, which may increase the human bioavailability of contaminants via the dermal absorption pathway. Taken together, oxidative damage, cell apoptosis, and tight junction disruption played a crucial role in EHDPP + Cd triggered cytotoxicity in HaCaT cells. The detrimental effects of EHDPP + Cd co-exposure were greater than individual exposure, suggesting the current health risk assessment or adverse effects evaluation of individual exposure may underestimate their perniciousness. Our data imply the importance of considering the combined exposure to accurately assess their health implication.

Foliar application of selenium and gibberellins reduce cadmium accumulation in soybean by regulating interplay among rhizosphere soil metabolites, bacteria community and cadmium speciation

Both selenium (Se) and gibberellins (GA3) can alleviate cadmium (Cd) toxicity in plants. However, the application of Se and GA3 as foliar spray to against Cd stress on soybean and its related mechanisms have been poorly explored. Herein, this experiment evaluated the effects of Se and GA3 alone and combined application on soybean rhizosphere microenvironment, Cd accumulation and growth of soybean seedlings. The results revealed that both Se and GA3 can effectively decrease the accumulation of Cd in soybean seedlings. Foliar application of Se, GA3 and their combination reduced Cd contents in soybean seedlings respectively by 21.70 %, 27.53 % and 45.07 % when compared with the control treatment, suggest a synergistic effect of Se and GA3 in decreasing Cd accumulation. Se and GA3 also significantly increased diversity and abundance of the metabolites in rhizosphere, which consequently played an important role in shaping rhizosphere bacteria community and improve rhizosphere soil physicochemical properties of Cd contaminated soil, as well as decreased the Cd available forms contents but enhance the immobilized form levels. Overall, this study affords a novel approach on mitigating Cd accumulation in soybean seedlings which is attributed to Se and GA3 regulated interplay among rhizosphere soil metabolites, bacteria community and cadmium speciation.

Epigenetic alterations in bioaccumulators of cadmium: Lessons from mammalian kidneys and plants

Faced with unpredictable changes in global weather patterns, release and redistribution of metals through land erosion and water movements add to the increasing use of metals in industrial activities causing high levels of environmental pollution and concern to the health of all living organisms. Cadmium is released into the environment by smelting and mining, entering the food chain via contaminated soils, water, and phosphate fertilizers. Bioaccumulation of cadmium in plants represents the first major step into the human food chain and contributes to toxicity of several organs, especially the kidneys, where biomagnification of cadmium occurs over decades of exposure. Even in small amounts, cadmium brings about alterations at the molecular and cellular levels in eukaryotes through mutagenicity, molecular mimicry at metal binding sites and oxidative stress. The epigenome dictates expression of a gene's output through a number of regulatory steps involving chromatin remodeling, nucleosome unwinding, DNA accessibility, or nucleic acid modifications that ultimately impact the transcriptional and translational machinery. Several epigenetic enzymes exhibit zinc-dependence as zinc metalloenzymes and zinc finger proteins thus making them susceptible to deregulation through displacement by cadmium. In this review, we summarize the literature on cadmium-induced epigenetic mechanisms in mammalian kidneys and plants, compare similarities in the epigenetic defense between these bioaccumulators, and explore how future studies could advance our understanding of the cadmium-induced stress response and disruption to biological health.

Understanding heavy metal toxicity: Implications on human health, marine ecosystems and bioremediation strategies

Heavy metals are constituents of the natural environment and are of great importance to both natural and artificial processes. But in recent times the indiscriminate use of heavy metals especially for human purposes has caused an imbalance in natural geochemical cycles. This imbalance has caused contamination of heavy metals into natural resources and such as soil and a marine ecosystem. Long exposure and higher accumulation of given heavy metals are known to impose detrimental and even lethal effects on humans. Conventional remediation techniques of heavy metals provide good results but have negative side effects on surrounding environment. The role played by microbes in bioremediation of heavy metals is well reported in the literature and understanding the role of molecules in the process of metal accumulation its reduction and transformation into less hazardous state, has myriads of biotechnological implications for bioremediation of metal-contaminated sites. The current review presents the implications of heavy metals on human health and marine ecosystems, conventional methods of heavy metal removal and their side effects on the environment. Bioremediation approaches have been discussed as well in this review, proving to be a more sustainable and eco-friendly approach towards remediation of heavy metals.

Fe Crystalline Phases in Fe/C Composites Modulated the Selective Adsorption of Pb(II) from Industrial Wastewater with Cd(II): An Electronic-Scale Perspective

Fe oxide or Fe0-based materials display weak removal capacity for Pb(II), especially in the presence of Cd(II), and the electronic-scale mechanisms are not reported. In this study, Fe3C(220) modified black carbon (BC) [Fe3C(220)@BC] with high adsorption and selectivity for Pb(II) from industrial wastewater with Cd(II) was developed. The quantitative experiment suggested that Fe species accounted for 80.5-100 and 18.4-33.8% of Pb(II) and Cd(II) removal, respectively. Based on X-ray absorption near-edge structure analysis, 57.3% of adsorbed Pb2+ was reduced to Pb0; however, 61.6% of Cd2+ existed on Fe3C@BC. Density functional theory simulation unraveled that Cd(II) adsorption was attributed to the cation-π interaction with BC, whereas that of Pb(II) was ascribed to the stronger interactions with different Fe phases following the order: Fe3C(220) > Fe0(110) > Fe3O4(311). Crystal orbital bond index and Hamilton population analyses were innovatively applied in the adsorption system and displayed a unique discovery: the stronger Pb(II) adsorption on Fe phases was mediated by a combination of covalent and ionic bonding, whereas ionic bonding was mainly accounted for Cd(II) adsorption. These findings open a new chapter in understanding the functions of different Fe phases in mediating the fate and transport of heavy metals in both natural and engineered systems.

Mechanism of Mitochondrial Kinetic Imbalance and Nrf2 Signaling Pathway-Mediated Oxidative Stress in Nickel and/or Chromium-Induced Kidney Injury in Mice

Nickel and chromium are both common heavy metals that pose serious environmental and health hazards. However, the exact mechanism by which nickel and/or chromium cause renal injury is unclear. Therefore, we explored the molecular mechanisms of renal injury caused by nickel and/or chromium poisoning from the perspective of mitochondrial dynamics and the Nrf2 antioxidant pathway. In this study, eighty 6-week-old C57BL/6J mice were randomly divided into four groups: control (Con, untreated), nickel (Ni, 110 mg/L Ni2+), chromium (Cr, 50 mg/L Cr6+), and combined nickel-chromium (Ni + Cr, 110 mg/L Ni2+, 50 mg/L Cr6+). The results showed that chronic nickel and/or chromium exposure inhibited body weight gain and impaired kidney function and structure in mice. Chronic nickel and/or chromium exposure led to the disruption of mitochondrial dynamics and thus induced oxidative stress. On the other hand, the Nrf2 antioxidant pathway may play an important regulatory role in mitigating oxidative stress-induced oxidative damage in kidney. The present study partially elucidated the molecular mechanism of renal injury induced by nickel and/or chromium exposure in mice and the regulatory role of the Nrf2 pathway in inducing oxidative injury from the perspective of mitochondrial dynamics. This provides a theoretical basis for the development of prevention and control strategies, and environmental protection measures.

Is Cadmium Genotoxicity Due to the Induction of Redox Stress and Inflammation? A Systematic Review

The transition metal cadmium (Cd) is toxic to humans and can induce cellular redox stress and inflammation. Cd is a recognized carcinogen, but the molecular mechanisms associated with its genotoxicity and carcinogenicity are not defined. Therefore, a systematic review was undertaken to examine the scientific literature that has covered the molecular mechanism of Cd genotoxicity and its relationship to cellular redox stress and inflammation. An electronic database search of PubMed, Scopus, and the Web of Science Core Collection was conducted to retrieve the studies that had investigated if Cd genotoxicity was directly linked to the induction of redox stress and inflammation. Studies included exposure to Cd via in vitro and in vivo routes of administration. Of 214 publications retrieved, 10 met the inclusion criteria for this review. Preclinical studies indicate that Cd exposure causes the induction of reactive oxygen species (ROS) and, via concomitant activity of the transcription factor NF-κβ, induces the production of pro-inflammatory cytokines and a cytokine profile consistent with the induction of an allergic response. There is limited information regarding the impact of Cd on cellular signal transduction pathways, and the relationship of this to genotoxicity is still inconclusive. Nevertheless, pre-incubation with the antioxidants, N-acetylcysteine or sulforaphane, or the necroptosis inhibitor, necrostatin-1, reduces Cd toxicity; indicative that these agents may be a beneficial treatment adjunct in cases of Cd poisoning. Collectively, this review highlights that Cd-induced toxicity and associated tissue pathology, and ultimately the carcinogenic potential of Cd, may be driven by redox stress and inflammatory mechanisms.

Therapeutic Efficacy of Selenium Pre-treatment in Mitigating Cadmium-Induced Cardiotoxicity in Zebrafish (Danio rerio)

Cardiovascular diseases are a rampant public health threat. Environmental contaminants, such as Cadmium (Cd), a toxic metal, have been linked to increased risk for cardiovascular diseases. Given that human exposure to Cd is increasing overtime, there is a need to develop new therapies to ameliorate Cd toxicity. Selenium (Se), an essential trace element, has been proposed to rescue the effects of Cd toxicity, with mixed effects. Se's narrow therapeutic window necessitates precise dosing to avoid toxicity. Here, we assessed the effects of various waterborne Cd and Se concentrations and sequences on cardiac function using zebrafish (Danio rerio). We showed that Cd induced pericardial edemas and modified heart rates in a concentration-dependent manner. To identify the therapeutic range of Se for Cd-induced cardiotoxicity, zebrafish embryos were treated with 0, 10, 50, 100, 150, or 200 μg/L Se for 1-4 days prior to exposure to Cd at 2.5, and 5 μg/L. We found that a 50 μg/L Se pre-treatment prior to Cd at 2.5 μg/L, but not at 5 μg/L, reduced the prevalence of pericardial edemas and ameliorated Cd-induced bradycardia in zebrafish. Embryos exposed to 10 and 50 μg/L of Se showed typical heart morphology, whereas other Se-exposed and Se-deficient fish presented pericardial edemas. Longer Se pre-treatment durations led to fewer incidences of pericardial edemas. Overall, this study highlights the importance of optimizing Se concentration and pre-treatment periods to harness its protective effects against Cd-induced cardiotoxicity. These findings provide insights into potential therapeutic strategies for reducing Cd-related cardiovascular damage in humans.

Comprehensive analysis of environmental exposure to hazardous trace elements and lung function: a national cross-sectional study

BACKGROUND

There is growing interest in the joint effects of hazardous trace elements (HTEs) on lung function deficits, but the data are limited. This is a critical research gap given increased global industrialisation.

METHODS

A national cross-sectional study including spirometry was performed among 2112 adults across 11 provinces in China between 2020 and 2021. A total of 27 HTEs were quantified from urine samples. Generalised linear models and quantile-based g-computation were used to explore the individual and joint effects of urinary HTEs on lung function, respectively.

RESULTS

Overall, there were negative associations between forced expiratory volume in 1 s (FEV1) and urinary arsenic (As) (z-score coefficient, -0.150; 95% CI, -0.262 to -0.038 per 1 ln-unit increase), barium (Ba) (-0.148, 95% CI: -0.258 to -0.039), cadmium (Cd) (-0.132, 95% CI: -0.236 to -0.028), thallium (Tl) (-0.137, 95% CI: -0.257 to -0.018), strontium (Sr) (-0.147, 95% CI: -0.273 to -0.022) and lead (Pb) (-0.121, 95% CI: -0.219 to -0.023). Similar results were observed for forced vital capacity (FVC) with urinary As, Ba and Pb and FEV1/FVC with titanium (Ti), As, Sr, Cd, Tl and Pb. We found borderline associations between the ln-quartile of joint HTEs and decreased FEV1 (-20 mL, 95% CI: -48 to +8) and FVC (-14 mL, 95% CI: -49 to+2). Ba and Ti were assigned the largest negative weights for FEV1 and FVC within the model, respectively.

CONCLUSION

Our study investigating a wide range of HTEs in a highly polluted setting suggests that higher urinary HTE concentrations are associated with lower lung function, especially for emerging Ti and Ba, which need to be monitored or regulated to improve lung health.

Cadmium transport by mammalian ATP-binding cassette transporters

Cellular responses to toxic metals depend on metal accessibility to intracellular targets, reaching interaction sites, and the intracellular metal concentration, which is mainly determined by uptake pathways, binding/sequestration and efflux pathways. ATP-binding cassette (ABC) transporters are ubiquitous in the human body-usually in epithelia-and are responsible for the transfer of indispensable physiological substrates (e.g. lipids and heme), protection against potentially toxic substances, maintenance of fluid composition, and excretion of metabolic waste products. Derailed regulation and gene variants of ABC transporters culminate in a wide array of pathophysiological disease states, such as oncogenic multidrug resistance or cystic fibrosis. Cadmium (Cd) has no known physiological role in mammalians and poses a health risk due to its release into the environment as a result of industrial activities, and eventually passes into the food chain. Epithelial cells, especially within the liver, lungs, gastrointestinal tract and kidneys, are particularly susceptible to the multifaceted effects of Cd because of the plethora of uptake pathways available. Pertinent to their broad substrate spectra, ABC transporters represent a major cellular efflux pathway for Cd and Cd complexes. In this review, we summarize current knowledge concerning transport of Cd and its complexes (mainly Cd bound to glutathione) by the ABC transporters ABCB1 (P-glycoprotein, MDR1), ABCB6, ABCC1 (multidrug resistance related protein 1, MRP1), ABCC7 (cystic fibrosis transmembrane regulator, CFTR), and ABCG2 (breast cancer related protein, BCRP). Potential detoxification strategies underlying ABC transporter-mediated efflux of Cd and Cd complexes are discussed.

Egg White Hydrolysate Mitigates Cadmium-induced Neurological Disorders and Oxidative Damage

We aimed to investigate whether the consumption of Egg White Hydrolysate (EWH) acts on nervous system disorders induced by exposure to Cadmium (Cd) in rats. Male Wistar rats were divided into (a) Control (Ct): H2O by gavage for 28 days + H2O (i.p. - 15th - 28th day); (b) Cadmium (Cd): H2O by gavage + CdCl2 - 1 mg/kg/day (i.p. - 15th - 28th day); (c) EWH 14d: EWH 1 g/kg/day by gavage for 14 days + H2O (i.p.- 15th - 28th day); (d) Cd + EWH cotreatment (Cd + EWHco): CdCl2 + EWH for 14 days; (e) EWH 28d: EWH for 28 days; (f) EWHpre + Cd: EWH (1st - 28th day) + CdCl2 (15th - 28th day). At the beginning and the end of treatment, neuromotor performance (Neurological Deficit Scale); motor function (Rota-Rod test); ability to move and explore (Open Field test); thermal sensitivity (Hot Plate test); and state of anxiety (Elevated Maze test) were tested. The antioxidant status in the cerebral cortex and the striatum were biochemically analyzed. Cd induces anxiety, and neuromotor, and thermal sensitivity deficits. EWH consumption prevented anxiety, neuromotor deficits, and alterations in thermal sensitivity, avoiding neuromotor deficits both when the administration was performed before or during Cd exposure. Both modes of administration reduced the levels of reactive species, and the lipid peroxidation increased by Cd and improved the striatum's antioxidant capacity. Pretreatment proved to be beneficial in preventing the reduction of SOD activity in the cortex. EWH could be used as a functional food with antioxidant properties capable of preventing neurological damage induced by Cd.

Metal toxicity in Bryum coronatum Schwaegrichen: impact on chlorophyll content, lamina cell structure, and metal accumulation

This research examined the impact of heavy metals, including Cd, Pb, and Zn, on chlorophyll content and lamina cell structure in Bryum coronatum. After exposure to varying metal concentrations (0.015, 0.065, 0.250, 1, and 4 mg/L), chlorophyll content, chloroplast numbers, lamina cell change, and metal accumulation were investigated. Chlorophyll content was assessed using spectrophotometry, whereas chloroplast numbers and lamina cell changes were examined under a light microscope. Metal accumulation was quantified through ICP-MS. The findings revealed that Cd notably reduced chlorophyll a content, while Pb and Zn showed minimal influence. Cd and Pb exposure decreased the number of chloroplasts in lamina cells, with no impact from Zn. The moss's capacity to absorb metals increased with higher exposure levels, indicating its potential as a biomonitor for heavy metal pollution. Cell mortality occurred in response to Cd and Pb, primarily in the median and apical lamina regions, while Zn had no effect. This study sheds light on heavy metal toxicity in B. coronatum, underscoring its significance for environmental monitoring. Further research on the mechanisms and consequences of heavy metal toxicity in bryophytes is essential for a comprehensive understanding of this critical issue.

Co-exposure to PVC microplastics and cadmium induces oxidative stress and fibrosis in duck pancreas

PVC microplastics (PVC-MPs) are environmental pollutants that interact with cadmium (Cd) to exert various biological effects. Ducks belong to the waterfowl family of birds and therefore are at a higher risk of exposure to PVC-MPs and Cd than other animals. However, the effects of co-exposure of ducks to Cd and PVC-MPs are poorly understood. Here, we used Muscovy ducks to establish an in vivo model to explore the effects of co-exposure to 1 mg/L PVC-MPs and 50 mg/kg Cd on duck pancreas. After 2 months of treatment with 50 mg/kg Cd, pancreas weight decreased by 21 %, and the content of amylase and lipase increased by 25 % and 233 %. However, exposure to PVC-MPs did not significantly affect the pancreas. Moreover, co-exposure to PVC-MPs and Cd worsened the reduction of pancreas weight and disruption of pancreas function compared to exposure to either substance alone. Furthermore, our research has revealed that exposure to PVC-MPs or Cd disrupted mitochondrial structure, reduced ATP levels by 10 % and 18 %, inhibited antioxidant enzyme activity, and increased malondialdehyde levels by 153.8 % and 232.5 %. It was found that exposure to either PVC-MPs or Cd can induce inflammation and fibrosis in the duck pancreas. Notably, co-exposure to PVC-MPs and Cd exacerbated inflammation and fibrosis, with the content of IL-1, IL-6, and TNF-α increasing by 169 %, 199 %, and 98 %, compared to Cd exposure alone. The study emphasizes the significance of comprehending the potential hazards linked to exposure to these substances. In conclusion, it presents promising preliminary evidence that PVC-MPs accumulate in duck pancreas, and increase the accumulation of Cd. Co-exposure to PVC-MPs and Cd disrupts the structure and function of mitochondria and promotes the development of pancreas inflammation and fibrosis.

Mechanisms of microbial resistance against cadmium - a review

The escalating cadmium influx from industrial activities and anthropogenic sources has raised serious environmental concerns due to its toxic effects on ecosystems and human health. This review delves into the intricate mechanisms underlying microbial resistance to cadmium, shedding light on the multifaceted interplay between microorganisms and this hazardous heavy metal. Cadmium overexposure elicits severe health repercussions, including renal carcinoma, mucous membrane degradation, bone density loss, and kidney stone formation in humans. Moreover, its deleterious impact extends to animal and plant metabolism. While physico-chemical methods like reverse osmosis and ion exchange are employed to mitigate cadmium contamination, their costliness and incomplete efficacy necessitate alternative strategies. Microbes, particularly bacteria and fungi, exhibit remarkable resilience to elevated cadmium concentrations through intricate resistance mechanisms. This paper elucidates the ingenious strategies employed by these microorganisms to combat cadmium stress, encompassing metal ion sequestration, efflux pumps, and enzymatic detoxification pathways. Bioremediation emerges as a promising avenue for tackling cadmium pollution, leveraging microorganisms' ability to transform toxic cadmium forms into less hazardous derivatives. Unlike conventional methods, bioremediation offers a cost-effective, environmentally benign, and efficient approach. This review amalgamates the current understanding of microbial cadmium resistance mechanisms, highlighting their potential for sustainable remediation strategies. By unraveling the intricate interactions between microorganisms and cadmium, this study contributes to advancing our knowledge of bioremediation approaches, thereby paving the way for safer and more effective cadmium mitigation practices.

Cadmium Exposure: Mechanisms and Pathways of Toxicity and Implications for Human Health

Cadmium (Cd), a prevalent environmental contaminant, exerts widespread toxic effects on human health through various biochemical and molecular mechanisms. This review encapsulates the primary pathways through which Cd inflicts damage, including oxidative stress induction, disruption of Ca2+ signaling, interference with cellular signaling pathways, and epigenetic modifications. By detailing the absorption, distribution, metabolism, and excretion (ADME) of Cd, alongside its interactions with cellular components such as mitochondria and DNA, this paper highlights the extensive damage caused by Cd2+ at the cellular and tissue levels. The role of Cd in inducing oxidative stress-a pivotal mechanism behind its toxicity-is discussed with emphasis on how it disrupts the balance between oxidants and antioxidants, leading to cellular damage and apoptosis. Additionally, the review covers Cd's impact on signaling pathways like Mitogen-Activated Protein Kinase (MAPK), Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB), and Tumor Protein 53 (p53) pathways, illustrating how its interference with these pathways contributes to pathological conditions and carcinogenesis. The epigenetic effects of Cd, including DNA methylation and histone modifications, are also explored to explain its long-term impact on gene expression and disease manifestation. This comprehensive analysis not only elucidates the mechanisms of Cd toxicity but also underscores the critical need for enhanced strategies to mitigate its public health implications.

The Protective Effects of Ganoderma lucidum Active Peptide GLP4 on Lung Injury Induced by Cadmium Poisoning in Mice

Ganoderma triterpenes and spore powder have shown promising results in mitigating cadmium-induced renal and hepatic injuries. Ganoderma lucidum active peptide GLP4 is a natural protein with dual antioxidant activities derived from the mycelium of Ganoderma lucidum. However, its efficacy in alleviating cadmium-induced lung injury remains unexplored. This study aims to investigate the protective effects of GLP4 against cadmium-induced lung injury in mice. Mice were exposed to cadmium chloride via nebulization to induce lung injury. The protective effect of GLP4 was assessed by measuring the total cell count in BALF, levels of inflammatory cytokines, and the expression of NLRP3 in lung tissues a through histopathological examination of lung tissue changes. The results showed that GLP4 significantly mitigated histopathological damage in lung tissues, decreased the secretion of inflammatory cytokines, and reduced the expression of NLRP3, which was elevated in cadmium-exposed mice. In vitro studies further revealed that GLP4 inhibited the cadmium-induced activation of the NLRP3 inflammasome. Notably, acute cadmium exposure by the respiratory tract did not affect the liver and kidneys of the mice. The findings suggest that GLP4 reduces cadmium-induced lung injury in mice by inhibiting the activation of the NLRP3 inflammasome, which provides a theoretical foundation for using Ganoderma lucidum as a preventive and therapeutic agent against cadmium poisoning.

Unlocking the potential of biochar: an iron-phosphorus-based composite modified adsorbent for adsorption of Pb(II) and Cd(II) in aqueous environments and response surface optimization of adsorption conditions

In this work, iron-phosphorus based composite biochar (FPBC) was prepared by modification with potassium phosphate and iron oxides for the removal of heavy metal ions from single and mixed heavy metal (Pb and Cd) solutions. FTIR and XPS characterization experiments showed that the novel modified biochar had a greater number of surface functional groups compared to the pristine biochar. The maximum adsorption capacities of FPBC for Pb(II) and Cd(II) were 211.66 mg·g-1 and 94.08 mg·g-1 at 293 K. The adsorption of Pb(II) and Cd(II) by FPBC followed the proposed two-step adsorption kinetic model and the Freundlich isothermal adsorption model, suggesting that the mechanism of adsorption of Pb(II) and Cd(II) by FPBC involved chemical adsorption of multiple layers. Mechanistic studies showed that the introduction of -PO4 and -PO3 chemisorbed with Pb(II) and Cd(II), and the introduction of -Fe-O increased the ion exchange with Pb(II) and Cd(II) during the adsorption process and produced precipitates such as Pb3Fe(PO4)3 and Cd5Fe2(P2O7)4. Additionally, the abundant -OH and -COOH groups also participated in the removal of Pb(II) and Cd(II). In addition, FPBC demonstrated strong selective adsorption of Pb(II) in mixed heavy metal solutions. The Response Surface Methodology(RSM) analysis determined the optimal adsorption conditions for FPBC as pH 5.31, temperature 26.01 °C, and Pb(II) concentration 306.30 mg·L-1 for Pb(II). Similarly, the optimal adsorption conditions for Cd(II) were found to be pH 5.66, temperature 39.34 °C, and Cd(II) concentration 267.68 mg·L-1. Therefore, FPBC has the potential for application as a composite-modified adsorbent for the adsorption of multiple heavy metal ions.

The dynamic face of cadmium-induced Carcinogenesis: Mechanisms, emerging trends, and future directions

Cadmium (Cd) is a malleable element with odorless, tasteless characteristics that occurs naturally in the earth's crust, underground water, and soil. The most common reasons for the anthropological release of Cd to the environment include industrial metal mining, smelting, battery manufacturing, fertilizer production, and cigarette smoking. Cadmium-containing products may enter the environment as soluble salts, vapor, or particle forms that accumulate in food, soil, water, and air. Several epidemiological studies have highlighted the association between Cd exposure and adverse health outcomes, especially renal toxicity, and the impact of Cd exposure on the development and progression of carcinogenesis. Also highlighted is the evidence for early-life and even maternal exposure to Cd leading to devastating health outcomes, especially the risk of cancer development in adulthood. Several mechanisms have been proposed to explain how Cd mediates carcinogenic transformation, including epigenetic alteration, DNA methylation, histone posttranslational modification, dysregulated non-coding RNA, DNA damage in the form of DNA mutation, strand breaks, and chromosomal abnormalities with double-strand break representing the most common DNA form of damage. Cd induces an indirect genotoxic effect by reducing p53's DNA binding activity, eventually impairing DNA repair, inducing downregulation in the expression of DNA repair genes, which might result in carcinogenic transformation, enhancing lipid peroxidation or evasion of antioxidant interference such as catalase, superoxide dismutase, and glutathione. Moreover, Cd mediates apoptosis evasion, autophagy activation, and survival mechanisms. In this review, we decipher the role of Cd mediating carcinogenic transformation in different models and highlight the interaction between various mechanisms. We also discuss diagnostic markers, therapeutic interventions, and future perspectives.

Distinct concentration-dependent oxidative stress profiles by cadmium in a rat kidney proximal tubule cell line

Levels and chemical species of reactive oxygen/nitrogen species (ROS/RNS) determine oxidative eustress and distress. Abundance of uptake pathways and high oxygen consumption for ATP-dependent transport makes the renal proximal tubule particularly susceptible to cadmium (Cd2+)-induced oxidative stress by targeting ROS/RNS generation or antioxidant defence mechanisms, such as superoxide dismutase (SOD) or H2O2-metabolizing catalase (CAT). Though ROS/RNS are well-evidenced, the role of distinct ROS profiles in Cd2+ concentration-dependent toxicity is not clear. In renal cells, Cd2+ (10-50 µM) oxidized dihydrorhodamine 123, reaching a maximum at 2-3 h. Increases (up to fourfold) in lipid peroxidation by TBARS assay and H2O2 by Amplex Red were evident within 30 min. ROS and loss in cell viability by MTT assay with 50 µM Cd2+ could not be fully reversed by SOD mimetics Tempol and MnTBAP nor by SOD1 overexpression, whereas CAT expression and α-tocopherol were effective. SOD and CAT activities were attenuated below controls only with >6 h 50 µM Cd2+, yet augmented by up to 1.5- and 1.2-fold, respectively, by 10 µM Cd2+. Moreover, 10 µM, but not 25-50 µM Cd2+, caused 1.7-fold increase in superoxide anion (O2•-), detected by dihydroethidium, paralled by loss in cell viability, that was abolished by Tempol, MnTBAP, α-tocopherol and SOD1 or CAT overexpression. H2O2-generating NADPH oxidase 4 (NOX4) was attenuated by ~50% with 10 µM Cd2+ at 3 h compared to upregulation by 50 µM Cd2+ (~1.4-fold, 30 min), which was sustained for 24 h. In summary, O2•- predominates with low-moderate Cd2+, driving an adaptive response, whereas oxidative stress by elevated H2O2 at high Cd2+ triggers cell death signaling pathways.Highlights Different levels of reactive oxygen species are generated, depending on cadmium concentration. Superoxide anion predominates and H2O2 is suppressed with low cadmium representing oxidative eustress. High cadmium fosters H2O2 by inhibiting catalase and increasing NOX4 leading to oxidative distress. Superoxide dismutase mimetics and overexpression were less effective with high versus low cadmium. Oxidative stress profile could dictate downstream signalling pathways.

Redox mechanisms of environmental toxicants on male reproductive function

Humans and wildlife, including domesticated animals, are exposed to a myriad of environmental contaminants that are derived from various human activities, including agricultural, household, cosmetic, pharmaceutical, and industrial products. Excessive exposure to pesticides, heavy metals, and phthalates consequently causes the overproduction of reactive oxygen species. The equilibrium between reactive oxygen species and the antioxidant system is preserved to maintain cellular redox homeostasis. Mitochondria play a key role in cellular function and cell survival. Mitochondria are vulnerable to damage that can be provoked by environmental exposures. Once the mitochondrial metabolism is damaged, it interferes with energy metabolism and eventually causes the overproduction of free radicals. Furthermore, it also perceives inflammation signals to generate an inflammatory response, which is involved in pathophysiological mechanisms. A depleted antioxidant system provokes oxidative stress that triggers inflammation and regulates epigenetic function and apoptotic events. Apart from that, these chemicals influence steroidogenesis, deteriorate sperm quality, and damage male reproductive organs. It is strongly believed that redox signaling molecules are the key regulators that mediate reproductive toxicity. This review article aims to spotlight the redox toxicology of environmental chemicals on male reproduction function and its fertility prognosis. Furthermore, we shed light on the influence of redox signaling and metabolism in modulating the response of environmental toxins to reproductive function. Additionally, we emphasize the supporting evidence from diverse cellular and animal studies.

The detoxification of cadmium in Japanese quail by pomegranate peel powder

Environmental pollution and exposure to toxic metals such as cadmium (Cd) can cause severe and chronic diseases and have significant side effects on vital organs. The present study aimed to evaluate the effect of pomegranate peel on biochemical factors and lipid peroxidation in intoxication by Cd in Japanese quail. Two hundred seventy quails in different groups were fed diets containing Cd and pomegranate peel from 6 to 35 days old. Then, serum biochemical parameters were assessed, including liver enzymes, urea, and thiobarbituric acid. In the quails, Cd significantly increased MDA, urea, and AST (P < 0.05). Adding pomegranate peel at 1.5 and 2% levels decreased these parameters significantly (P < 0.05). In conclusion, dietary enrichment using pomegranate peel reduced the adverse effects of Cd by improving lipid peroxidation, aspartate aminotransferase (AST), and urea in Japanese quail.

Assessment of salivary cadmium levels and breast density in the Marin Women's Study

BACKGROUND

We aimed to determine if salivary cadmium (Cd) levels had any association with breast density, hoping to establish a less invasive cost-effective method of stratifying Cd burden as an environmental breast cancer risk factor.

METHODS

Salivary Cd levels were quantified from the Marin Women's Study, a Marin County, California population composite. Volumetric compositional breast density (BDsxa ) data were measured by single x-ray absorptiometry techniques. Digital screening mammography was performed by the San Francisco Mammography Registry. Radiologists reviewed mammograms and assigned a Breast Imaging-Reporting and Data System score. Early morning salivary Cd samples were assayed. Association analyses were then performed.

RESULTS

Cd was quantifiable in over 90% of saliva samples (mean = 55.7 pg/L, SD = 29). Women with higher saliva Cd levels had a non-significant odds ratio of 1.34 with BI-RAD scores (3 or 4) (95% CI 0.75-2.39, p = 0.329). Cd levels were higher in current smokers (mean = 61.4 pg/L, SD = 34.8) than former smokers or non-smokers. These results were non-significant. Pilot data revealed that higher age and higher BMI were associated with higher BI-RAD scores (p < 0.001).

CONCLUSION

Salivary Cd is a viable quantification source in large epidemiologic studies. Association analyses between Cd levels and breast density may provide additional information for breast cancer risk assessment, risk reduction plans, and future research directions. Further work is needed to demonstrate a more robust testing protocol before the extent of its usefulness can be established.

Interactive effects of cadmium and titanium dioxide nanoparticles on hepatic tissue in rats: Ameliorative role of coenzyme 10 via modulation of the NF-κB and TNFα pathway

This study investigated the effect of oral dosing of titanium dioxide nanoparticles (TNPs) and cadmium (Cd2+) on rat liver and the potential protective role of coenzyme Q10 (CQ10) against TNPs and Cd2+-induced hepatic injury. Seventy male Sprague Dawley rats were divided into seven groups and orally given distilled water, corn oil, CQ10 (10 mg/kg b.wt), TNPs (50 mg/kg b.wt), Cd2+ (5 mg/kg b.wt), TNPs + Cd2+, or TNPs + Cd2++CQ10 by gastric gavage for 60 successive days. The results showed that individual or mutual exposure to TNPs and Cd2+ significantly increased the serum levels of various hepatic enzymes and lipids, depleted the hepatic content of antioxidant enzymes, and increased malondialdehyde. Moreover, the hepatic titanium and Cd2+ content were increased considerably in TNPs and/or Cd2+-exposed rats. Furthermore, marked histopathological perturbations with increased immunoexpression of tumor necrosis factor-alpha and nuclear factor kappa B were evident in TNPs and/or Cd2+-exposed rats. However, CQ10 significantly counteracted the damaging effect of combined exposure of TNPs and Cd2+ on the liver. The study concluded that TNPs and Cd2+ exposure harm hepatic function and its architecture, particularly at their mutual exposure, but CQ10 could be a candidate protective agent against TNPs and Cd2+ hepatotoxic impacts.

Effect of lactoferrin supplement on cadmium chloride induced toxicity to male rats: Toxicopathological, ultrastructural and immunological studies

This study sought to determine whether lactoferrin supplementation could counteract the harm that cadmium (Cd) induced to the rats. The effect of Cd and lactoferrin were investigated in hematological, biochemical, histological, immunohistochemical expression and ultrastructural studies. After 30 days of treatment, rats exposed to Cd had significantly higher levels of Cd in their blood, more oxidized lipids, and less antioxidant capacity overall. Supplemental lactoferrin also significantly undoes that effect. Hematological and biochemical parameters changed along with the increase in blood Cd levels. The histological integrity of the liver, kidney, spleen, and (axillary, cervical, mesenteric and popliteal) lymph nodes that had been damaged by Cd exposure was also restored by lactoferrin supplementation. Moreover, the liver and spleen ultrastructure showed the same improvement. In addition, the spleen of Lf/Cd group showed less immunohistochemical expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in comparison to the Cd group. In conclusion, the current study showed that supplementing with lactoferrin improved immune response and restored biochemical and oxidative stability induced by Cd.

Arrestin domain-containing protein 1-mediated microvesicles (ARMMs) protect against cadmium-induced neurotoxicity

Exposure to environmental heavy metals such as cadmium (Cd) is often linked to neurotoxicity but the underlying mechanisms remain poorly understood. Here we show that Arrestin domain-containing protein 1 (ARRDC1)-mediated microvesicles (ARMMs)--an important class of extracellular vesicles (EVs) whose biogenesis occurs at the plasma membrane--protect against Cd-induced neurotoxicity. Cd increased the production of EVs, including ARMMs, in a human neural progenitor cell line, ReNcell CX (ReN) cells. ReN cells that lack ARMMs production as a result of CRISPR-mediated ARRDC1 knockout were more susceptible to Cd toxicity as evidenced by increased LDH production as well as elevated level of oxidative stress markers. Importantly, adding ARMMs back to the ARRDC1-knockout ReN cells significantly reduced Cd-induced toxicity. Consistent with this finding, proteomics data showed that anti-oxidative stress proteins are enriched in ARMMs secreted from ReN cells. Together our study reveals a novel protective role of ARMMs in Cd neurotoxicity and suggests that ARMMs may be used therapeutically to reduce neurotoxicity caused by exposure to Cd and potentially other metal toxicants.

Heavy metal levels and flavonoid intakes are associated with chronic obstructive pulmonary disease: an NHANES analysis (2007-2010 to 2017-2018)

BACKGROUND

The association between exposure to environmental metals and chronic obstructive pulmonary disease (COPD) is preventing chronic lung diseases. However, little is currently known about the interaction between heavy metals and flavonoids in relation to the risk of COPD. This study aims to bridge this knowledge gap by leveraging The National Health and Nutrition Examination Survey (NHANES) database to evaluate thecorrelation between blood levels of heavy metals (cadmium, lead, mercury) and the intake of various flavonoid compounds (isoflavones, anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, total flavonoids). Additionally, appropriate dietary recommendations are provided based on the study findings.

MATERIALS AND METHODS

Cross-sectional analysis was conducted using the 2007-2010 and 2017-2018 NHANES data. Specialized weighted complex survey design analysis software was used for data analysis. Multivariate logistic regression models and restricted cubic splines (RCS) were used to evaluate the relationship between blood heavy metal levels, flavonoids intake, and COPD incidence in all participants, and to explore the effect of different levels of flavonoids intake on COPD caused by heavy metal exposure.

RESULTS

A total of 7,265 adults aged ≥ 40 years were analyzed. Higher levels of blood cadmium (Cd), blood lead and Anthocyanidin (AC) intake were independently associated with an increased risk of COPD (Cd highest quantile vs. lowest: OR = 1.73, 95% CI, 1.25-2.3; Lead highest quantile vs. lowest quantile: OR = 1.44, 95% CI, 1.11-1.86; AC highest quantile vs. lowest: OR = 0.73, 95% CI, 0.54-0.99). When AC intake exceeded 11.56 mg/d, the effect of Cd exposure on COPD incidence decreased by 27%, and this finding was more significant in smokers.

CONCLUSION

Higher levels of Cd (≥ 0.45ug/L) and lead (≥ 0.172 ug/L) were positively correlated with the risk of COPD among participants aged 40 years and above, while AC intake (≥ 11.56 mg/d) could reduce the risk related to blood Cd.