Effect of chronic exposure to cadmium on serum lipid, lipoprotein and oxidative stress indices in male rats

N-Dimethyl chalcone facilitated augmentation of IL-10 and diminution of TNF-α, IL-1β, IL-6, NFκB, and COX-2 in FCA-induced arthritic rat model

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent inflammation and chronic pain due to the degradation of subchondral bone and the loss of cartilage function. The present study was designed to evaluate the activity of 1N,N-dimethyl chalcone (DGCHAL) against RA. A primary 28-day investigation was conducted on adjuvant-induced arthritic rats with DGCHAL (10 mg/kg, 20 mg/kg, and 30 mg/kg) and methotrexate (STDMTX). The therapeutic effect was estimated on the basis of measurements of paw diameter, fluctuations in body weight, oxidative stress biomarkers, and hematological parameters. In addition, the study sought to quantify the expression of key cytokines, including TNFα, IL-6, IL-10, IL-1β, and NFκβ, using qRT-PCR and ELISA techniques. Treatment with DGCHAL significantly restored the paw volume, body weight, arthritis-induced anemia, and leukocyte count. The tested compound remarkably downregulated the expression of COX-2, TNFα, IL-6, IL-1β, and NFκB and upregulated the expression of IL-10. The treatment groups increased the activities of SOD, CAT, and GSH, whereas they reduced the formation of MDA and NO as compared to the arthritic group. These findings provide an evident basis for the anti-arthritic potential of DGCHAL in a chronic arthritis rat model and should be further studied for dosage form design.

Association of Different Doses and Routes of Acute Cadmium Exposure With Bone Marrow Hypoplasia, Cellular and Biochemical Alterations in Male Wistar Rats

Cadmium is a widespread and non-biodegradable pollutant that is dangerous to living organisms. The routes of exposure and doses of pollutants are different, and it is extremely important to assess their toxicity. Three experimental groups received a single treatment of CdCl2 (15 and 30 mg/kg orally; 15 OR and 30 OR group and 15 mg/kg intraperitoneally; 15 IP group) and one control group (Ctr). The toxic effects of Cd were examined on hematological and biochemical parameters, and histopathological observation of hepatocytes and bone marrow. Leukocytopenia and granulopenia were recorded in 30-OR, and thrombocytopenia in 15-OR and 15-IP. 30-OR causes a decrease in RBC, and 15-IP causes changes in RBC count. Renal markers (CRE and BUN) show a correlation with 15-OR dose, inflammatory marker CRP shows a positive correlation with 15-IP dose, LDH as a biomarker of oxidative stress and CK as a biomarker of membrane damage were significantly increased in all experimental groups. The hepatocyte membrane and the size of the nucleolus have changed in all groups, and the highest degree in 15-IP. Bone marrow hypoplasia was noted with oral doses, and basophilia and an increased number of lymphoblasts and myeloblasts and immature hematopoietic cells with toxic granulations in 15-IP. Single doses of Cd cause serious toxicological changes in blood and tissues. Oral doses cause significant tissue-specific microscopic lesions observed in the liver during histopathology and bone marrow hypoplasia compared with intraperitoneal administration. Intraperitoneal administration shows a strong correlation with renal, inflammatory and stress markers compared to oral administration.

Association of heavy metals and bio-elements blood level with metabolic syndrome: a systematic review and meta-analysis of observational studies

Background and objectives

The literature has reported heavy metals might alter the physiological and biochemical functions of body organs and cause several health problems. So, the present systematic review and meta-analysis aimed to investigate the association of blood levels of essential or non-essential metals with metabolic syndrome (MetS).

Methods

In this systematic review, some international databases including PubMed, Embase, Scopus, and Web of Science were searched up to February 2024. All observational studies which assessed the association of three heavy metals (cadmium, mercury, lead) and bio-elements (chromium, iron, manganese, and magnesium, copper) with the risk of MetS were included. There was no limitation in the time of publication and language. A random-effects meta-analysis was performed to estimate the pooled effect sizes. Possible sources of heterogeneity were explored by meta-regression analysis.

Results

Totally, 29 studies were eligible for meta-analysis. Our results showed that increased level of cadmium (pooled OR: 1.24, 95% CI: 1.05, 1.46) and mercury (pooled OR: 1.22, 95% CI: 1.08, 1.38) significantly increased the risk of MetS. In contrast, increased level of chromium significantly reduced the risk of developing MetS (pooled OR: 0.68, 95% CI: 0.56, 0.83). Moreover, association between lead, iron, copper, magnesium, and manganese with MetS was not statistically significant (P > 0.05). However, elevated lead levels in men increased the odds of MetS.

Conclusion

Our results show a significant association between blood levels of some heavy metals, including cadmium, mercury, and lead, with increased odds of MetS. On the other hand, chromium as a biometal decreased the odds of MetS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01500-9.

Mechanisms of Metal-Induced Hepatic Inflammation

PURPOSE OF REVIEW

Worldwide, there is an increasing prevalence of hepatic diseases. The most common diseases include alcoholic-associated liver disease (ALD), metabolic dysfunction-associated fatty liver disease/ metabolic dysfunction-associated steatohepatitis (MAFLD/MASH) and viral hepatitis. While there are many important mediators of these diseases, there is increasing recognition of the importance of the inflammatory immune response in hepatic disease pathogenesis.

RECENT FINDINGS

Hepatic inflammation triggers the onset and progression of liver diseases. Chronic and sustained inflammation can lead to fibrosis, then cirrhosis and eventually end-stage cancer, hepatocellular carcinoma. Importantly, growing evidence suggest that metal exposure plays a role in hepatic disease pathogenesis. While in recent years, studies have linked metal exposure and hepatic steatosis, studies emphasizing metal-induced hepatic inflammation are limited. Hepatic inflammation is an important hallmark of fatty liver disease. This review aims to summarize the mechanisms of arsenic (As), cadmium (Cd) and chromium (Cr)-induced hepatic inflammation as they contribute to hepatic toxicity and to identify data gaps for future investigation.

The therapeutic efficacy of adipose mesenchymal stem cell-derived microvesicles versus infliximab in a dextran sodium sulfate induced ulcerative colitis rat model

Ulcerative colitis (UC) is a chronic relapsing intestinal inflammation that is becoming of increasing incidence worldwide and has insufficient treatment. Therefore, finding effective therapies remains a priority. A dextran sodium sulfate colitis model was established to elucidate colonic layers alterations and compare adipose mesenchymal stem cell-derived microvesicles (MSC-MVs) versus infliximab (IFX) efficacy through biochemical, light, and electron microscope studies. Fifty-four rats were allocated to 4 groups: Control (Con), UC, UC+IFX, and UC+MSC-MVs groups. End body weights (BW) and serum malondialdehyde (MDA) levels were recorded. Colitis severity was estimated by disease activity index (DAI). Colonic specimens were processed to evaluate the histological structure, collagen content, surface mucous and goblet cells, CD44, TNF-α, and GFAP immune expression. Morphometric and statistical analyses were performed. The UC group revealed congested, stenosed colons, a significant decline in end BW, and a significant increase in serum MDA and DAI. Furthermore, disturbed histoarchitecture, inflammatory infiltration, depletion of surface mucous and goblet cells, increased collagen, and TNF-α expression and decreased GFAP expression were observed. Alterations were partially attenuated by IFX therapy, whereas MSC-MVs significantly improved all parameters. In conclusion, MSC-MVs were a superior therapeutic option, via attenuating oxidative stress and inflammatory infiltration, in addition to restoring intestinal epithelial integrity and mucosal barrier.

Cadmium toxicity on endoplasmic reticulum functioning

Cadmium (Cd) is a heavy metal pollutant widely distributed in the environment due to industrial activities, mining, and agricultural practices. Cadmium-induced Toxicity exerts profound effects on ER functioning through multiple mechanisms, leading to cellular dysfunction and pathological consequences. Cadmium disrupts protein folding and activates the unfolded protein response (UPR). Cd exposure leads to the accumulation of misfolded proteins, triggering UPR pathways mediated by critical ER transmembrane sensors: IRE1, PERK, and ATF6. The subsequent UPR aims to restore ER homeostasis but can also induce apoptosis under severe stress conditions. Cd disrupts ER calcium homeostasis by inhibiting the SERCA pump, further exacerbating ER stress. The generation of reactive oxygen species (ROS also plays a critical role in Cd toxicity, damaging ER-resident proteins and amplifying UPR activation). Cadmium also affects the lipid metabolism. This review examines the mechanisms by which Cd toxicity impairs ER functioning, disruption of protein folding and quality control mechanisms, and dysregulation of calcium signaling and lipid metabolism. The subsequent cellular consequences, including oxidative stress, apoptosis, and inflammation, are discussed in the context of Cd-induced pathogenesis of diseases such as Cancer and neurodegenerative and cardiovascular disorders. Finally, potential therapeutic strategies must be explored to mitigate the adverse effects of Cd on ER functioning and human health.

Internal Flames: Metal(loid) Exposure Linked to Alteration of the Lipid Profile in Czech Male Firefighters (CELSPAC-FIREexpo Study)

Increased wildfire activity increases the demands on fire rescue services and firefighters' contact with harmful chemicals. This study aimed to determine firefighters' exposure to toxic metal(loid)s and its association with the lipid profile. CELSPAC-FIREexpo study participants (including 110 firefighters) provided urine and blood samples to quantify urinary levels of metal(loid)s (arsenic, cadmium (Cd), mercury, and lead (Pb)), and serum lipid biomarkers (cholesterol (CHOL), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglycerides (TG)). The associations were investigated by using multiple linear regression and Bayesian weighted quantile sum (BWQS) regression. Higher levels of Pb were observed in firefighters. Pb was positively associated with CHOL and TG. Cd was negatively associated with HDL. In the BWQS model, the mixture of metal(loid)s was associated positively with CHOL (β = 14.75, 95% CrI = 2.45-29.08), LDL (β = 15.14, 95% CrI = 3.39-29.35), and TG (β = 14.79, 95% CrI = 0.73-30.42), while negatively with HDL (β = -14.96, 95% CrI = -25.78 to -1.8). Pb emerged as a key component in a metal(loid) mixture. The results suggest that higher exposure to lead and the mixture of metal(loid)s is associated with the alteration of the lipid profile, which can result in an unfavorable cardiometabolic profile, especially in occupationally exposed firefighters.

Metal mixture exposures and serum lipid levels in childhood: the Rhea mother-child cohort in Greece

BACKGROUND

Growing evidence suggests that cardiovascular disease develops over the lifetime, often beginning in childhood. Metal exposures have been associated with cardiovascular disease and important risk factors, including dyslipidemia, but prior studies have largely focused on adult populations and single metal exposures.

OBJECTIVE

To investigate the individual and joint impacts of multiple metal exposures on lipid levels during childhood.

METHODS

This cross-sectional study included 291 4-year-old children from the Rhea Cohort Study in Heraklion, Greece. Seven metals (manganese, cobalt, selenium, molybdenum, cadmium, mercury, and lead) were measured in whole blood using inductively coupled plasma mass spectrometry. Serum lipid levels included total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol. To determine the joint and individual impacts of child metal exposures (log2-transformed) on lipid levels, Bayesian kernel machine regression (BKMR) was employed as the primary multi-pollutant approach. Potential effect modification by child sex and childhood environmental tobacco smoke exposure was also evaluated.

RESULTS

BKMR identified a positive association between the metal mixture and both total and LDL cholesterol. Of the seven metals examined, selenium (median 90.6 [IQR = 83.6, 96.5] µg/L) was assigned the highest posterior inclusion probability for both total and LDL cholesterol. A difference in LDL cholesterol of 8.22 mg/dL (95% CI = 1.85, 14.59) was observed when blood selenium was set to its 75th versus 25th percentile, holding all other metals at their median values. In stratified analyses, the positive association between selenium and LDL cholesterol was only observed among boys or among children exposed to environmental tobacco smoke during childhood.

IMPACT STATEMENT

Growing evidence indicates that cardiovascular events in adulthood are the consequence of the lifelong atherosclerotic process that begins in childhood. Therefore, public health interventions targeting childhood cardiovascular risk factors may have a particularly profound impact on reducing the burden of cardiovascular disease. Although growing evidence supports that both essential and nonessential metals contribute to cardiovascular disease and risk factors, such as dyslipidemia, prior studies have mainly focused on single metal exposures in adult populations. To address this research gap, the current study investigated the joint impacts of multiple metal exposures on lipid concentrations in early childhood.

Integrating Transcriptomics and Proteomics to Characterize the Intestinal Responses to Cadmium Exposure Using a Piglet Model

Cadmium (Cd) is a heavy metal element with a wide range of hazards and severe biotoxicity. Since Cd can be easily accumulated in the edible parts of plants, the exposure of humans to Cd is mainly through the intake of Cd-contaminated food. However, the intestinal responses to Cd exposure are not completely characterized. Herein, we simulated laboratory and environmental Cd exposure by feeding the piglets with CdCl2-added rice and Cd-contaminated rice (Cdcr) contained diet, as piglets show anatomical and physiological similarities to humans. Subsequent analysis of the metal element concentrations showed that exposure to the two types of Cd significantly increased Cd levels in piglets. After verifying the expression of major Cd transporters by Western blots, multi-omics further expanded the possible transporters of Cd and found Cd exposure causes wide alterations in the metabolism of piglets. Of significance, CdCl2 and Cdcr exhibited different body distribution and metabolic rewiring, and Cdcr had stronger carcinogenic and diabetes-inducing potential. Together, our results indicate that CdCl2 had a significant difference compared with Cdcr, which has important implications for a more intense study of Cd toxicity.

Associations of cadmium exposure with risk of metabolic syndrome and its individual components: a meta-analysis

Data directly associating cadmium (Cd) with metabolic syndrome (MetS) are sparse and inconsistent. We aimed to quantitatively assess the association of Cd exposure with risk of MetS and its individual components. Literature searching was performed in PubMed, EMBASE, and MEDLINE-OVID through September, 2021. Weighted odds ratios (ORs) for MetS and its components were pooled by comparing the highest to the lowest category of Cd exposure using random-effects models. Eleven (10 from Asia and 1 from the US) cross-sectional studies (33,887 participants and 7176 cases) were identified. Overall, Cd exposure was not associated with risk of MetS [OR: 1.08, 95% confidence interval (CI): 0.92, 1.28]. However, the association became significant when pooling Asian studies (OR: 1.18, 95% CI: 1.02, 1.35), and it was more pronounced with Cd measured in blood (OR: 1.24, 95% CI: 1.05, 1.45). Additionally, Cd exposure was significantly associated with reduced HDL-cholesterol (OR: 1.27, 95% CI: 1.05, 1.54) and elevated triglyceride (OR: 1.17, 95% CI: 1.05, 1.30), but not other components. This meta-analysis indicates that Cd exposure is associated with risk of MetS among Asian populations, which is mainly explained by Cd's association with dyslipidemia. Further studies are needed to better understand the mechanism of action.

Exposure to acute waterborne cadmium caused severe damage on lipid metabolism of freshwater fish, revealed by nuclear lipid droplet deposition in hepatocytes of rare minnow

Cadmium (Cd) is a widely distributed aquatic toxic heavy metal with the potential to disrupt fish metabolism; however, more research is needed to clarify the underlying mechanisms. In the present study, rare minnows (Gobiocypris rarus) were used to detect the effects of cadmium on freshwater fish lipid metabolism and its underlying mechanism by histopathological observation, measurement of serum and liver biochemical indexes, and analysis of gene expression in terms of lipid oxidation, synthesis and transport. Here, severe damage, such as cytoplasmic lipid droplet (LD) accumulation, ectopic deposition of LDs, and the appearance of nuclear LDs (nLDs), was detected after exposure to 2.0 mg/L or higher concentrations (2.5 and 2.8 mg/L CdCl₂) for 96 h. Other damage included abnormal increases in rough endoplasmic reticulum (RER) lamellae in a fingerprint or concentric circle pattern and necrosis of hepatocytes, and which was observed in the livers of fish exposed to 2.0 mg/L CdCl_2.. Both hepatic and serum lipids, such as triglycerides and total cholesterol, were significantly increased after exposure to 2.0 mg/L CdCl₂, as was serum lipase (LPS). Hepatic lipase and lipoprotein lipase remained unchanged, in accordance with the unchanged hepatic mRNA transcripts of PPARɑ. Furthermore, the mRNA transcripts of both SCD and SQLE were significantly decreased. Moreover, hepatic and serum low-density and high-density lipoprotein cholesterol showed significant changes, which were accompanied by a significant increase and decrease in hepatic APOAI and APOB100 mRNA levels, respectively. All the results indicate the presence of severe damage to hepatic lipid metabolism and that disrupted lipid transport may play a key role in the accumulation of hepatic LDs. In addition, the hepatic nLDs of nonmammalian vertebrates and their location across the nuclear envelope are intriguing, suggesting that large-size nLDs are a common marker for severe liver damage.

Does maternal low-dose cadmium exposure increase the risk of offspring to develop metabolic syndrome and/or type 2 diabetes?

Cadmium is a hazardous metal with multiple organ toxicity that causes great harm to human health. Cadmium enters the human body through occupational exposure, diet, drinking water, breathing, and smoking. Cadmium accumulation in the human body is associated with increased risk of developing obesity, cardiovascular disease, diabetes, and metabolic syndrome (MetS). Cadmium uptake is enhanced during pregnancy and can cross the placenta affecting placental development and function. Subsequently, cadmium can pass to fetus, gathering in multiple organs such as the liver and pancreas. Early-life cadmium exposure can induce hepatic oxidative stress and pancreatic β-cell dysfunction, resulting in insulin resistance and glucose metabolic dyshomeostasis in the offspring. Prenatal exposure to cadmium is also associated with increasing epigenetic effects on the offspring's multi-organ functions. However, whether and how maternal exposure to low-dose cadmium impacts the risks of developing type 2 diabetes (T2D) in the young and/or adult offspring remains unclear. This review collected available data to address the current evidence for the potential role of cadmium exposure, leading to insulin resistance and the development of T2D in offspring. However, this review reveals that underlying mechanisms linking prenatal cadmium exposure during pregnancy with T2D in offspring remain to be adequately investigated.

Correlative study on heavy metal-induced oxidative stress and hypertension among the rural population of Malwa Region of Punjab, India

Heavy metal-induced toxicity contributes to the progression of various metabolic disorders and possible mechanisms involved in disease progression are not well established. In this study, the correlation of  heavy metal exposure and  hypertension have been demonstrated. The results showed that in hypertensive subjects, the lipid profiles (triglycerides, LDL-C, HDL-C, and total cholesterol) and cardiac markers (CK-MB and LDH) were altered abruptly. As a consequence of heavy- induced oxidative stress, the oxidants (TBARS and protein carbonyls) and antioxidants (SOD, GSH, and TAC) were significantly increased and decreased, respectively in hypertension subjects. The concentrations of heavy metals (Pb, Cd, and As) exceeded the permissible limits in hypertensive subjects. The Nrf-2 genotyping indicated that heavy metals may induce mutations at molecular level. The results of correlation analysis revealed that the heavy metals interact with cellular components and interfere with metabolic processes which then results in disturbed lipid profile, enhanced oxidative stress, and reduced antioxidant status. The current study systematically estimated the association of hair and nail heavy metal concentrations with hypertension among the population residing in the Malwa region of Punjab. The proposed study highlighted that heavy metals act as a silent risk factor in the hypertension progression in the population of Malwa region. Future studies are required to confirm current findings and further scrutinize the effect of heavy metals exposure in early adulthood, early, and late mid-life to develop metabolic complications such as hypertension.

Cadmium perturbed lipid profile and induced liver dysfunction in mice through phosphatidylcholine remodeling and promoting arachidonic acid synthesis and metabolism

Cadmium ion (Cd²⁺) exposure has been reported to associate with the prevalence of dyslipidemia, and contribute to the initiation and progression of nonalcoholic fatty liver disease (NAFLD). However, Cd²⁺ exposure perturbed specific metabolic pathways and underlying mechanisms are still unclear. In the present study, through lipidomics analyses of differential metabolites in serum between the Cd²⁺-exposed mice and the control group, 179 differential metabolites were identified, among which phosphatidylcholines (PCs) accounted for 49 % metabolites. Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment assay indicates that PCs participate in the metabolic pathways, including the Arachidonic Acid (AA) metabolism, which also could be potential NAFLD biomarkers. Moreover, in vivo and in vitro results suggested that Cd²⁺ exposure induced PC synthesis and remodeling, and increased AA level by promoting fatty acid desaturase 1 (FADS1) to catalyze synthesis process instead of cytosolic phospholipase A2 (cPLA2) mediated release pathway. Inhibition of FADS1 by T3364366 could reverse Cd-induced AA, prostaglandin E2 (PGE2) and triglyceride (TAG) levels, and it also reduce cisplatin resistance in HepG2 cells. This study provides new evidence of Cd²⁺-induced dyslipidemia and reveals underlying molecular mechanism involved in liver dysfunction of Cd²⁺ exposure.

Effects of heavy metals on cardiovascular diseases in pre and post-menopausal women: from big data to molecular mechanism involved

To assess the link between a mixed heavy metal (cadmium, lead, and mercury) and the 10-year risk of cardiovascular diseases (CVDs) in pre- and post-menopausal Korean women aged ≥20 years, as well as identify potential molecular mechanisms of mixed heavy metal-induced CVDs. Multivariate linear regression, weighted quantile sum (WQS) regression, quantile g-computation (gqcomp), and Bayesian kernel machine regression (BKMR) models were used to examine the effects of mixed heavy metals and the 10-year risk of CVDs. The Comparative Toxicogenomics Database, MicroRNA ENrichment TURned NETwork, and the microRNA sponge generator and tester were used as the key data-mining approaches. In our BKMR analysis, we found that the overall effect of mixed heavy metals was linked to the 10-year risk of CVDs in postmenopausal women in the upper 20^th percentiles and in premenopausal women in the upper 55^th percentiles. Mercury was identified as the key chemical for the 10-year risk of CVDs in pre- and postmenopausal women. In silico analysis revealed that a heavy metal mixture interacted with six genes associated with CVD development. Physical interactions (77.6%) were found to be the most common among CVD-related genes induced by the heavy metals studied. Several pathways have been identified as the main molecular mechanisms that could be affected by studied heavy metals and are implicated in the development of CVDs (e.g., lipid and lipoprotein metabolism, lipoprotein metabolism, cholesterol metabolism, and cardiovascular disease). ALB, APOE, ATF5, and CREB3L3 were the key genes and transcription factors related to CVDs induced by the mixture of the investigated heavy metals, respectively. The two miRNAs with the highest interaction and expression in the development of CVDs were hsa-miR-199a-5p and hsa-miR-199a-3p. We also designed and tested miRNA sponge sequences for these miRNAs. The cutoff thresholds for each heavy metal level linked with the 10-year risk of CVDs were described. A mixture of heavy metal exposures, especially mercury, was more strongly linked with the 10-year risk of CVDs in postmenopausal women than in premenopausal women. Early interventions in postmenopausal women should be considered to reduce CVD risks.

The Beneficial Impact of Zinc Supplementation on the Vascular Tissue of the Abdominal Aorta under Repeated Intoxication with Cadmium: A Study in an In Vivo Experimental Model

In an in vivo rat model of human exposure to cadmium (Cd; 5 and 50 mg/L, 6 months), whether the supplementation with zinc (Zn; 30 and 60 mg/L, increasing its daily intake by 79% and 151%, respectively) protects against the unfavourable impact of this xenobiotic on the vascular tissue of the abdominal aorta was investigated. The treatment with Cd led to oxidative stress and increased the concentrations of pro-inflammatory interleukin 1β (IL-1β), total cholesterol (TC), triglycerides (TG), and endothelial nitric oxide synthase (eNOS) and decreased the concentration of anti-inflammatory interleukin 10 (IL-10) in the vascular tissue. Cd decreased the expression of intercellular adhesion molecule-1 (ICAM-1), platelet endothelial cell adhesion molecule-1 (PECAM-1), and L-selectin on the endothelial cells. The administration of Zn prevented most of the Cd-induced alterations or at least weakened them (except for the expression of adhesive molecules). In conclusion, Zn supplementation may protect from the toxic impact of Cd on the blood vessels and thus exert a beneficial influence on the cardiovascular system. The increase in the intake of Zn by 79% may be sufficient to provide this protection and the effect is related to the antioxidative, anti-inflammatory, and antiatherogenic properties of this essential element.

Association between plasma cadmium and renal stone prevalence in adults in rural areas of Guangxi, China: a case-control study

Background

Kidney stones have become a worldwide public health problem. The purpose of this research is to study the relationship between plasma cadmium level and the prevalence of kidney stones in an adult population.

Methods

The data of this study were based on a current survey conducted from December 2018 to November 2019 in Gongcheng Yao Autonomous County, Guangxi, China. A total of 940 study subjects of the same sex and age (within 2 years of each other) according to 1:1 matching were selected for a case–control study. The diagnosis of kidney stones was based on the presence of strong light spots, patches, clusters, or bands within the renal sinus region, followed by an echo-free bundle of acoustic images. Plasma metal elements were determined by the metal plasma method. The relationship between plasma cadmium concentration and the prevalence of kidney stones was assessed using logistic regression and restricted cubic spline regression.

Results

The crude ratio for kidney stones in the highest quartile of plasma cadmium was 1.164 (95% CI, 1.121 to 2.324) compared with the lowest quartile. A positive correlation was found between the two (P for trend = 0.039). After adjusting for potential confounders, the ratio of plasma cadmium to kidney stones in the highest quartile was 1.606 (95% CI, 1.100 to 2.344) compared with the lowest quartile, and the findings remained unchanged.

Conclusion

The odds of kidney stones in adults increased with increasing plasma cadmium exposure, and high plasma cadmium may be a risk factor for kidney stones.

The mechanism of the cadmium-induced toxicity and cellular response in the liver

Cadmium is a toxic element to which man can be exposed at work or in the environment. Cd's most salient toxicological property is its exceptionally long half-life in the human body. Once absorbed, Cd accumulates in the human body, particularly in the liver. The cellular actions of Cd are extensively documented, but the molecular mechanisms underlying these actions are still not resolved. The liver manages the cadmium to eliminate it by a diverse mechanism of action. Still, many cellular and physiological responses are executed in the task, leading to worse liver damage, ranging from steatosis, steatohepatitis, and eventually hepatocellular carcinoma. The progression of cadmium-induced liver damage is complex, and it is well-known the cellular response that depends on the time in which the metal is present, ranging from oxidative stress, apoptosis, adipogenesis, and failures in autophagy. In the present work, we aim to present a review of the current knowledge of cadmium toxicity and the cellular response in the liver.

Misuse of Cardiac Lipid upon Exposure to Toxic Trace Elements-A Focused Review

Heavy metals and metalloids like cadmium, arsenic, mercury, and lead are frequently found in the soil, water, food, and atmosphere; trace amounts can cause serious health issues to the human organism. These toxic trace elements (TTE) affect almost all the organs, mainly the heart, kidney, liver, lungs, and the nervous system, through increased free radical formation, DNA damage, lipid peroxidation, and protein sulfhydryl depletion. This work aims to advance our understanding of the mechanisms behind lipid accumulation via increased free fatty acid levels in circulation due to TTEs. The increased lipid level in the myocardium worsens the heart function. This dysregulation of the lipid metabolism leads to damage in the structure of the myocardium, inclusive fibrosis in cardiac tissue, myocyte apoptosis, and decreased contractility due to mitochondrial dysfunction. Additionally, it is discussed herein how exposure to cadmium decreases the heart rate, contractile tension, the conductivity of the atrioventricular node, and coronary flow rate. Arsenic may induce atherosclerosis by increasing platelet aggregation and reducing fibrinolysis, as exposure interferes with apolipoprotein (Apo) levels, resulting in the rise of the Apo-B/Apo-A1 ratio and an elevated risk of acute cardiovascular events. Concerning mercury and lead, these toxicants can cause hypertension, myocardial infarction, and carotid atherosclerosis, in association with the generation of free radicals and oxidative stress. This review offers a complete overview of the critical factors and biomarkers of lipid and TTE-induced cardiotoxicity useful for developing future protective interventions.

The Combination of Tamarindus indica and Coenzyme Q10 can be a Potential Therapy Preference to Attenuate Cadmium-Induced Hepatorenal Injury

Cadmium (Cd) is a hazardous environmental pollutant that menaces human and animal health and induces serious adverse effects in various organs, particularly the liver and kidneys. Thus, the current study was designed to look into the possible mechanisms behind the ameliorative activities of Tamarindus indica (TM) and coenzyme Q10 (CoQ) combined therapy toward Cd-inflicted tissue injury. Male Wistar rats were categorized into seven groups: Control (received saline only); TM (50 mg/kg); CoQ (40 mg/kg); Cd (2 mg/kg); (Cd + TM); (Cd + CoQ); and (Cd + TM + CoQ). All the treatments were employed once daily via oral gavage for 28 consecutive days. The results revealed that Cd exposure considerably induced liver and kidney damage, evidenced by enhancement of liver and kidney function tests. In addition, Cd intoxication could provoke oxidative stress evidenced by markedly decreased glutathione (GSH) content and catalase (CAT) activity alongside a substantial increase in malondialdehyde (MDA) concentrations in the hepatic and renal tissues. Besides, disrupted protein and lipid metabolism were noticed. Unambiguously, TM or CoQ supplementation alleviated Cd-induced hepatorenal damage, which is most likely attributed to their antioxidant and anti-inflammatory contents. Interestingly, when TM and CoQ were given in combination, a better restoration of Cd-induced liver and kidney damage was noticed than was during their individual treatments.

Association between urinary cadmium concentrations and liver function in adolescents

Evidence from previous studies has shown that exposure to cadmium (Cd) is associated with cardiovascular disease, kidney disease, and osteoporosis, but the effects of Cd on liver toxicity in adolescents are unclear. The data of 4411 adolescents who participated in the US The National Health and Nutrition Examination Survey (NHANES) during 1999-2016 was analyzed. Liver function was indicated by the levels of alanine aminotransferase (ALT) and aspartate amino transferase (AST). The associations between the levels of urinary Cd and liver function were evaluated using multivariate logistic regression models adjusted for covariates. The results showed that the odds ratios of ALT and AST in the highest quartiles of urinary Cd were 1.40 (95% confidence interval [CI], 1.07-1.82) and 1.64 (95% CI, 1.10-2.44), respectively, compared with the lowest quartiles, which were similar to using urinary creatinine as the covariate. We also found linear regression of associations of urinary Cd with elevated ALT and AST levels in boys. In addition, one augmented urinary Cd concentration unit (Log₁₀) was associated with a 0.04-mg/dL increase in C-reactive protein and a 0.53-mg/dL decrease in HDL cholesterol in the fully adjusted model. Our results add novel evidence that exposure to Cd might be positively associated with indicators of liver injury, indicating the potential toxic effect of Cd exposure on the adolescent liver. Further confirmatory studies are needed.

Intrauterine exposure of mice to arsenite induces abnormal and transgenerational glycometabolism

The adverse, transgenerational effects on health caused by environmental pollutants are receiving increasing attention. For humans and mice, inorganic arsenic (iAs), a widespread environmental contaminant, is associated with diabetic phenotypes. However, the transgenerational effects of arsenite-induced changes in glucose metabolism in mice have not been fully investigated. In the present study, F0 pregnant mice were exposed to arsenite via drinking water (0, 0.5, 5, or 50 ppm NaAsO₂) from gestational day 0 (GD0) until parturition. We examined the effects of arsenite exposure on the metabolic phenotypes and the levels of proteins and genes related to glucose metabolism of dams and their offspring (F1∼F4). Arsenite exposure altered the glucose tolerance of offspring. Notably, glucose transporter-2 (GLUT2) and insulin receptor substrate-1 (IRS1), which are related to the maintenance of glucose homeostasis, were also changed. The homeostasis assessment-insulin resistance (HOMA-IR), an indicator of insulin resistance, was higher in the offspring from the F0 female mice exposed to arsenite. Furthermore, imprinted genes, insulin-like growth factor 2 (IGF2) and potassium voltage-gated channel subfamily Q member 1 (KCNQ1), related to glycometabolism across multiple generations, were lower in the offspring. In sum, arsenite exposure during pregnancy transgenerationally affects glucose metabolism, which is related to altered levels of IGF2 and KCNQ1.

Higher Blood Cadmium Concentration Is Associated With Increased Likelihood of Abdominal Aortic Calcification

Aims

This study aimed to evaluate the association between blood cadmium concentration (BCC) and abdominal aortic calcification (AAC) in adults aged ≥40 years in the United States.

Methods

Data were obtained from the 2013–2014 National Health and Nutrition Examination Survey (NHANES). Participants without data about BCC and AAC scores were excluded. BCC was directly measured using inductively coupled plasma mass spectrometry (ICP–MS). AAC scores were quantified by the Kauppila scoring system, and severe AAC was defined as an AAC score >6. Weighted multivariable regression analysis and subgroup analysis were conducted to explore the independent relationship between cadmium exposure with AAC scores and severe AAC.

Results

A total of 1,530 participants were included with an average BCC of 0.47 ± 0.02 μg/L and AAC score of 1.40 ± 0.10 [mean ± standard error (SE)]. The prevalence of severe AAC was 7.96% in the whole subjects and increased with the higher BCC tertiles (Tertile 1: 4.74%, Tertile 2: 9.83%, and Tertile 3: 10.17%; p = 0.0395). We observed a significant positive association between BCC and the AAC score (β = 0.16, 95% CI: 0.01~0.30) and an increased risk of severe AAC [odds ratio (OR) = 1.45; 95% CI: 1.03~2.04]. Subgroup analysis and interaction tests revealed that there was no dependence for the association between BCC and AAC.

Conclusion

Blood cadmium concentration was associated with a higher AAC score and an increased likelihood of severe AAC in adults in the United States. Cadmium exposure is a risk factor for AAC, and attention should be given to the management of blood cadmium.

Cadmium exposure and growth differentiation factor-15 (GDF-15) levels in non-smoking older adults

BACKGROUND

Cadmium (Cd) exposure is a risk factor for cardiovascular disease (CVD); however, understanding the effects of Cd at the cellular level remains incomplete. Since growth differentiation factor-15 (GDF-15) is a cytokine produced in many cell types in response to tissue injury and inflammation that may capture several pathways between Cd and CVD, this study examined the relationship between blood Cd levels and serum GDF-15 concentrations in community-dwelling older adults.

METHODS

Cd and GDF-15 were measured in 1942 non-smoking individuals aged 65+ with no previous history of CVD. The association of Cd with GDF-15 was evaluated in linear regression models that adjusted for sociodemographic, lifestyle and biological risk factors, inflammatory biomarkers (IL-6, C-reactive protein and neutrophil to lymphocyte ratio), and markers of vascular damage (NTproBNP and cTnT-hs).

RESULTS

Geometric mean Cd exposure was 0.11 μg/L (0.09 in never- and 0.15 in former-smokers) and geometric mean GDF-15 was 1186.21 pg/mL (1182.67 in never- and 1191.66 in former-smokers). In multivariable analyses, we found a dose-response association between Cd levels and GDF-15: adjusted mean percentage differences in GDF-15 (95% confidence interval) per 2-fold increase in Cd concentrations in the overall non-smoking population and in never smokers were, respectively, 2.54% (1.01, 4.06) and 2.50% (0.47, 4.54). In spline regression, the dose-response relationship was progressive over the range of Cd concentrations with no significant departures from linearity.

CONCLUSIONS

Cd exposure may be related to enhanced GDF-15 expression. Future studies with repeated GDF-15 measurements should confirm the present findings to better understand the biological mechanisms underlying this association.

An exploratory identification of biological markers of chronic musculoskeletal pain in the low back, neck, and shoulders

Objectives

This study was an in-depth exploration of unique data from a nationally representative sample of adults living in the United States to identify biomarkers associated with musculoskeletal pain.

Methods

We performed secondary analyses of 2003–2004 NHANES data. After a first screening of 187 markers, analyses of 31 biomarkers were conducted on participants aged ≥20 years identified in all counties using the 2000 Census Bureau data (n = 4,742). To assess the association of each biomarker with each pain outcome (acute, subacute and chronic low back, neck, and shoulder pain), analyses were carried out using multivariable logistic regression with adjustments for sex, age and body mass index. Biomarkers were considered as continuous variables and categorized at the median of their distributions.

Results

Pain at any site for ≥24 hours during the past month was reported by 1,214 participants. Of these, 779 mentioned that the pain had lasted for ≥3 months (“chronic pain”). α-carotene, ascorbic acid, β-carotene, mercury and total protein had a statistically significant, inverse association with ≥2 chronic pain sites. Acrylamide, alkaline phosphatase, cadmium, cotinine, glycidamide, homocysteine, retinol, triglycerides and white blood cell count were positively associated with ≥2 chronic pain sites. Few biological markers were associated with acute and subacute pain.

Conclusions

This study identified some biomarkers that were strongly and consistently associated with musculoskeletal pain. These results raise new hypotheses and could have tremendous implications for advancing knowledge in the field. Research on musculoskeletal pain needs to put more effort on the biological dimension of the biopsychosocial model of pain.

Whole Transcriptome Profiling of the Effects of Cadmium on the Liver of the Xiangxi Yellow Heifer

Cadmium (Cd) is a major heavy metal toxicant found in industrial zones. Humans and animals are exposed to it through their diet, which results in various physiological problems. In the current study, the toxic effects of Cd on the liver were investigated by whole-transcriptome sequencing (RNA-seq) of the livers of Xiangxi heifers fed a diet with excess Cd. We randomly divided six healthy heifers into two groups. The first group received a control diet, whereas the second group received Cd-exceeding diets for 100 days. After 100 days, the livers were collected. A total of 551 differentially expressed mRNAs, 24 differentially expressed miRNAs, and 169 differentially expressed lncRNAs were identified (p < 0.05, |log2FC| >1). Differentially expressed genes (DEGs) were analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. We found that under Cd exposure, DEGs were enriched in the adenosine 5'-monophosphate-activated protein kinase pathway, which is involved in autophagy regulation, and the peroxisome proliferator-activated receptor pathway, which is involved in lipid metabolism. In addition, the apolipoprotein A4 gene, which has anti-inflammatory and antioxidant effects, the anti-apoptotic gene ATPase H+/K+ transporting the nongastric alpha2 subunit, and the cholesterol metabolism-associated gene endothelial lipase gene were significantly downregulated. C-X-C motif chemokine ligand 3, cholesterol 7α-hydroxylase, and stearoyl-CoA desaturase, which are involved in the development of fatty liver, were significantly upregulated. These genes revealed the main effects of Cd on the liver of Xiangxi yellow heifers. The current study provides insightful information regarding the DEGs involved in autophagy regulation, apoptosis, lipid metabolism, anti-inflammation, and antioxidant enzyme activity. These may serve as useful biomarkers for predicting and treating Cd-related diseases in the future.

Autophagy as a molecular target of quercetin underlying its protective effects in human diseases

Autophagy, known as a "self-eating" process, is associated with degradation of aged or damaged components and organelles. Generally, autophagy is a survival mechanism that provides energy during nutritional deprivation. This mechanism plays a remarkable role during the physiological condition by maintaining homeostasis and energy balance and several pathological conditions, particularly neurological disorders. Due to the critical role of autophagy in cancer, much attention has been made in the regulation of autophagy using both naturally occurring and synthetic drugs. Quercetin is a plant-derived chemical belonging to the family of flavonoids. Quercetin has valuable biological and therapeutic effects such as anti-tumor, antioxidant, anti-inflammatory, anti-diabetic, hepatoprotective, and cardioprotective. At the present review, we first provide an introduction about quercetin and autophagy with its related molecular pathways. We also describe how quercetin modulates autophagy mechanism to exert its therapeutic effects.

Increased serum levels of cadmium are associated with an elevated risk of cardiovascular disease in adults

Previous studies have determined the effects of exposure to certain heavy metals on cardiovascular disease (CVD); however, the association between cadmium exposure and CVD in adults remains unclear. The relationship between serum levels of cadmium and the risk of CVD was studied by analyzing available data from 38,223 different participants of the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2016. After adjusting for all covariates, we found that higher serum cadmium concentrations were positively related to both the overall risk of CVD (odds ratio (OR): 1.45; 95% confidence interval (CI): 1.22, 1.72; p for trend <0.001) and the risks of its subtypes, including congestive heart failure, coronary heart disease, heart attack, and stroke. Elevated cadmium levels were associated with increased levels of lipids and inflammatory factors, including blood triglycerides, total cholesterol, white blood cells (WBCs), and C-reactive protein (CRP). Our study provided epidemiological evidence that cadmium may increase the risk of CVD by elevating blood lipids and inflammation.

Immunomodulation by heavy metals as a contributing factor to inflammatory diseases and autoimmune reactions: Cadmium as an example

Cadmium (Cd) represents a unique hazard because of the long biological half-life in humans (20-30 years). This metal accumulates in organs causing a continuum of responses, with organ disease/failure as extreme outcome. Some of the cellular and molecular alterations in target tissues can be related to immune-modulating potential of Cd. This metal may cause adverse responses in which components of the immune system function as both mediators and effectors of Cd tissue toxicity, which, in combination with Cd-induced alterations in homeostatic reparative activities may contribute to tissue dysfunction. In this work, current knowledge concerning inflammatory/autoimmune disease manifestations found to be related with cadmium exposure are summarized. Along with epidemiological evidence, animal and in vitro data are presented, with focus on cellular and molecular immune mechanisms potentially relevant for the disease susceptibility, disease promotion, or facilitating development of pre-existing pathologies.

Mitochondrial dysfunction and oxidative stress in liver of male albino rats after exposing to sub-chronic intoxication of chlorpyrifos, cypermethrin, and imidacloprid

The adverse effects of chlorpyrifos, cypermethrin, and imidacloprid on mitochondrial dysfunction and oxidative stress biomarkers were studied in rat liver. The liver deficiency was also confirmed by histological analysis and gel electrophoresis. Each insecticide was administered orally with five doses per week for 28 days to male albino rats at 1/50 of the LD₅₀ per insecticide. The results demonstrated that the mitochondrial dysfunction was confirmed by a significant decrease in NADH dehydrogenase and ATPase activities. Oxidative stress biomarkers include malondialdehyde (MDA), and protein carbonyl content (PCC) were significantly increased. However, superoxide dismutase (SOD) and glutathione S-transferase (GST) as antioxidant enzymes were significantly decreased in the mitochondria of the rat liver. HPLC analysis showed a significant increase of the 8-hydroxy-2'-deoxyguanosine (8-OH-2DG) as a biomarker of the DNA damage in rat liver. In addition, the residue levels of 0.96 and 0.29 μg/mL serum were found for cypermethrin and imidacloprid, respectively. However, chlorpyrifos not detected using the HPLC analysis. Blue native polyacrylamide gel electrophoresis (BN-PAGE) analysis showed a change in the pattern and sequence of complexions of the electron transport chain in liver mitochondria with treatment by such insecticides. The hepatic histological examination also showed symptoms of abnormalities after exposure to these insecticides.

Puerarin attenuates cadmium-induced hepatic lipid metabolism disorder by inhibiting oxidative stress and inflammation in mice

Cadmium (Cd) is a common environmental pollutant with known toxic effects on the liver. Puerarin (PU), a natural flavonoid, has been shown to exert protective effect in numerous pathological processes. However, whether PU affords protection in Cd-induced liver damage is still equivocal. Therefore, 40 mice were treated with Cd and/or PU by gavage for 9 weeks, then the serum and liver samples were collected to verify this issue. In this study, Cd exposure triggered hepatic lipid metabolism disorders and resultant liver damage as evidenced by Oil Red O staining and total cholesterol (TC) and triglyceride (TG) levels in serum and liver, aspartate transaminase (AST) and alanine transaminase (ALT) levels in serum, and histopathology, which were significantly improved by PU. Moreover, PU also normalized the expression of Cd-disturbed lipid metabolism-related proteins to improve lipid accumulation, contributing to the alleviation of liver injury. Moreover, Cd-decreased antioxidative indices superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) as well as glutathione (GSH) in hepatic tissues were significantly attenuated by PU administration, while Cd-elevated hepatic malondialdehyde (MDA) and reactive oxygen species (ROS) levels were markedly down-regulated by PU treatment, demonstrating the antioxidant effect of PU against Cd exposure. In addition, PU supplementation increased the anti-inflammatory potential, and normalized the levels of proinflammatory cytokines during Cd exposure. In conclusion, these observations demonstrate that PU treatment decreases oxidative stress and inflammation response, which may contribute to prevent Cd-induced lipid metabolism disorder and consequent liver damage.

Effect of electroacupuncture on inhibition of inflammatory response and oxidative stress through activating ApoE and Nrf2 in a mouse model of spinal cord injury

INTRODUCTION

Electroacupuncture protects neurons and myelinated axons after spinal cord injury by mitigating the inflammatory response and oxidative stress, but how it exerts these effects is unclear.

METHODS AND RESULTS

Spinal cord injury was induced in C57BL/6 wild-type and apolipoprotein E (ApoE) knockout (ApoE^-/- ) mice, followed by electroacupuncture or ApoE mimetic peptide COG112 treatment. Mice with spinal cord injury suffered loss of myelinated axons and hindlimb motor function through the detections of Basso mouse scale, histology, and transmission electron microscopy; electroacupuncture partially reversed these effects in wild-type mice but not in ApoE^-/- mice. Combining exogenous ApoE administration with electroacupuncture significantly mitigated the effects of spinal cord injury in both mouse strains, and these effects were associated with up-regulation of anti-inflammatory cytokines and down-regulation of pro-inflammatory cytokines which were detected by quantitative reverse transcription-polymerase chain reaction. Combination treatment also reduced oxidative stress by up-regulating ApoE and Nrf2/HO-1 signaling pathway through the detections of immunofluorescence and western blot analysis.

CONCLUSIONS

These results suggest that electroacupuncture protects neurons and myelinated axons following spinal cord injury through an ApoE-dependent mechanism.

A Pivotal Role of the Nrf2 Signaling Pathway in Spinal Cord Injury: A Prospective Therapeutics Study

The nuclear erythroid 2-related factor 2 (Nrf2) signaling pathway has a main role against oxidative stress and inflammation. Spinal Cord Injury (SCI) leads to the high secretion of inflammatory cytokines and reactive oxygen species, which disturbs nervous system function and regeneration. Several studies have indicated that the activation of the Nrf2 signaling pathway may be effective against inflammation after SCI. The experimental studies have indicated that many chemical and natural agents act as Nrf2 inducer, which inhibits the SCI progression. Thus, the finding of novel Nrf2- inducer anti-inflammatory agents may be a valuable approach in drug discovery. In the present review, we discussed the Nrf2 signal pathway and crosstalk with the NF-κB pathway and also the impact of this pathway on inflammation in animal models of SCI. Furthermore, we discussed the regulation of Nrf2 by several phytochemicals and drugs, as well as their effects on the SCI inhibition. Therefore, the current study presented a new hypothesis of the development of anti-inflammatory agents that mediate the Nrf2 signaling pathway for treating the SCI outcomes.

Association between heavy metals, high-sensitivity C-reaction protein and 10-year risk of cardiovascular diseases among adult Korean population

The prevalence of cardiovascular diseases (CVDs) in Korea tends to be increasing. It has worsened during the COVID-19 pandemic. Increasing evidence shows heavy metals are associated with increased CVD risk. We aimed to determine the association between the serum heavy metal levels and 10-year risk of CVDs and to predict risks of CVDs based on marginal effects. Heavy metals were measured by a graphite furnace atomic absorption spectrometry and direct mercury analyzer. The results show a significant relationship between the increase in cadmium, lead, mercury, hs-CRP levels and the 10-year risk of CVD after adjustment for serum cotinine, age group, sex, body mass index, a family history of CVDs, diabetes or hyperlipidemia, high-risk drinking, physical activity, and diabetes. A doubling of serum cadmium, lead, mercury, and hs-CRP was associated with the increase in the 10-year risk of CVD by 0.14%, 0.10%, 0.11% and 0.22%, respectively. Therefore, a special concern should be given to the harmful impacts of heavy metals on the 10-year risk of CVD. It is important to develop a prevention strategy targeting the high-risk population to slow down this progression to risk factors related to heavy metals and reduce prevalence. Remarkedly, hs-CRP is the most validated and widely used inflammatory marker, and could be a potential clinical value in predicting and monitoring CVDs.

Relationship between urinary heavy metals with metabolic syndrome and its components in population from Hoveyzeh cohort study: A case-control study in Iran

BACKGROUND

The incidence of Metabolic Syndrome (MetS) has been growing rapidly and is rising to pandemic proportions. Although obesity is a primary risk factor for the enhancement of these conditions, not all obese individuals develop metabolic syndrome, indicating that the risk for developing MetS is impacted by other genetic and/or environmental factors such as heavy metals. Therefore, the present study focused on the association between exposures to heavy metal and MetS.

METHODS

Urine samples were collected from 150 participants (75 patients with MetS and 75 healthy participants), which were used from Hoveyzeh Cohort center. To make a quantitative comparison between the two groups, Man-Whitney nonparametric test was used. The logistic regression was performed adjusted for age, demographic, lifestyle factor, physical activity, occupational history and urine creatinine.

RESULTS

The results of logistic regression showed that OR and 95 % CI for Cd, Pb, Sr, As and Fe concentration were still significant after adjusting for urine creatinine. Moreover, there was a relationship between Cd and Pb levels and waist circumstance (WC). After adjusting for urine creatinine, age, sex, occupation, smoking status, education and place of residence, only Pb concentration was showed a significant association with systolic blood pressure (SBP). The subjects with high urine level of Cd had the high odds (OR: 6.273; 95 % Cl: 1.783-22.070) of MetS and low high-density lipoprotein (HDL-C). The relationship between As concentration and high fasting blood sugars confirmed the previous evidence suggesting that high As level can cause diabetes.

CONCLUSION

These results indicated that outbreak of MetS and its component are associated with heavy metal concentrations in urine.

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

Heavy metals pose a serious threat if they go beyond permissible limits in our bodies. Much heavy metal's viz. Lead, Chromium, Arsenic, Mercury, Nickel, and Cadmium pose a serious threat when they go beyond permissible limits and cause hepatotoxicity. They cause the generation of ROS which in turn causes numerous injuries and undesirable changes in the liver. Epidemiological studies have shown an increase in the levels of such heavy metals in the environment posing a serious threat to human health. Epigenetic alterations have been seen in the event of exposure to such heavy metals. Apoptosis, caspase activation as well as ultrastructural changes in the hepatocytes have also been seen due to heavy metals. Inflammation involving TNF-alpha, pro-inflammatory cytokines, MAPK, ERK pathways have been seen in the event of heavy metal hepatotoxicity. All these have shown that these heavy metals pose a serious threat to human health in particular and the environment as a whole.

The effect of toxic components on metabolomic response of male SD rats exposed to fine particulate matter

PM_2.5 pollution was associated with numerous adverse health effects. However, PM_2.5 induced toxic effects and the relationships with toxic components remain largely unknown. To evaluate the metabolic toxicity of PM_2.5 at environmentally relevant doses, investigate the seasonal variation of PM_2.5 induced toxicity and the relationship with toxic components, a combination of general pathophysiological tests and metabolomics analysis was conducted in this study to explore the response of SD rats to PM_2.5 exposure. The result of general toxicology analysis revealed unconspicuous toxicity of PM_2.5 under environmental dose, but winter PM_2.5 at high dose caused severe histopathological damage to lung. Metabolomic analysis highlighted significant metabolic disorder induced by PM_2.5 even at environmentally relevant doses. Lipid metabolism and GSH metabolism were primarily influenced by PM_2.5 exposure due to the high levels of heavy metals. In addition, high levels of organic compounds such as PAHs, PCBs and PCDD/Fs in winter PM_2.5 bring multiple overlaps on the toxic pathways, resulting in larger pulmonary toxicity and metabolic toxicity in rats than summer.

A longitudinal study of rural Bangladeshi children with long-term arsenic and cadmium exposures and biomarkers of cardiometabolic diseases

There is growing interest in understanding the contribution of environmental toxicant exposure in early life to development of cardiometabolic diseases (CMD) in adulthood. We aimed to assess associations of early life exposure to arsenic and cadmium with biomarkers of CMD in children in rural Bangladesh. From a longitudinal mother-child cohort in Matlab, Bangladesh, we followed up 540 pairs. Exposure to arsenic (U-As) and cadmium (U-Cd) was assessed by concentrations in urine from mothers at gestational week 8 (GW8) and children at ages 4.5 and 9 years. Blood pressure and anthropometric indices were measured at 4.5 and 9 years. Metabolic markers (lipids, glucose, hemoglobin A1c, adipokines, estimated glomerular filtration rate (eGFR) were determined in plasma/blood of 9 years old children. In linear regression models, adjusted for child sex, age, height-for-age z score (HAZ), BMI-for-age z score (BAZ), socioeconomic status (SES) and maternal education, each doubling of maternal and early childhood U-Cd was associated with 0.73 and 0.82 mmHg increase in systolic blood pressure (SBP) respectively. Both early and concurrent childhood U-Cd was associated with diastolic (D)BP (β = 0.80 at 4.5 years; β = 0.75 at 9 years). Each doubling of U-Cd at 9 years was associated with decrements of 4.98 mg/dL of total cholesterol (TC), 1.75 mg/dL high-density lipoprotein (HDL), 3.85 mg/dL low-density lipoprotein (LDL), 0.43 mg/dL glucose and 4.29 units eGFR. Each doubling of maternal U-Cd was associated with a decrement of 1.23 mg/dL HDL. Both maternal and childhood U-As were associated with decrement in TC and HDL. Multiple comparisons were checked with family-wise error rate Bonferroni-type-approach. The negative associations of arsenic and cadmium with biomarkers of CMD in preadolescent children indicated influence of both metal(loid)s on fat and carbohydrate metabolism, while cadmium additionally influenced kidney function and BP. Thus, fewer outcomes were associated with U-As compared to U-Cd at preadolescence.

Associations between metabolic syndrome and four heavy metals: A systematic review and meta-analysis

Four most concerned heavy metal pollutants, arsenic, cadmium, lead, and mercury may share common mechanisms to induce metabolic syndrome (MetS). However, recent studies exploring the relationships between MetS and metal exposure presented inconsistent findings. We aimed to clarify the relationship between heavy metal exposure biomarkers and MetS using a meta-analysis and systematic review approach. Literature search was conducted in international and the Chinese national databases up to June 2020. Of selected studies, we extracted the relevant data and evaluated the quality of each study's methodology. We then calculated the pooled effect sizes (ESs), standardized mean differences (SMDs), and their 95% confidence intervals (CIs) using a random-effect meta-analysis approach followed by stratification analyses for control of potential confounders. Involving 55,536 participants, the included 22 articles covered 52 observational studies reporting ESs and/or metal concentrations on specific metal and gender. Our results show that participants with MetS had significantly higher levels of heavy metal exposure [pooled ES = 1.16, 95% CI: 1.09, 1.23; n = 42, heterogeneity I2 = 75.6%; and SMD = 0.22, 95% CI: 0.15, 0.29; n = 32, I2 = 94.2%] than those without MetS. Pooled ESs in the subgroups stratified by arsenic, cadmium, lead, and mercury were 1.04 (95% CI: 0.97, 1.10; n = 8, I2 = 61.0%), 1.10 (0.95, 1.27; 11, 45.0%), 1.21 (1.00, 1.48; 12, 82.9%), and 1.26 (1.06, 1.48; 11, 67.7%), respectively. Pooled ESs in the subgroups stratified by blood, urine, and the other specimen were 1.22 (95% CI: 1.08, 1.38; n = 26, I2 = 75.8%), 1.06 (1.00, 1.13; 14, 58.1%), and 2.41 (1.30, 4.43; 2, 0.0%), respectively. In conclusion, heavy metal exposure was positively associated with MetS. Further studies are warranted to examine the effects of individual metals and their interaction on the relationship between MetS and heavy metals.

Subacute cadmium exposure disrupts the hypothalamic-pituitary-gonadal axis, leading to polycystic ovarian syndrome and premature ovarian failure features in female rats

Cadmium (Cd), a toxic heavy metal, is a known endocrine disruptor that is associated with reproductive complications. However, few studies have explored the effects of Cd exposure on features of polycystic ovary syndrome (PCOS) and premature ovary failure (POF). In this study, we assessed whether doses found in workers occupationally exposed to Cd and subacute exposure result in hypothalamic-pituitary-gonadal (HPG) axis and other irregularities. We administered CdCl₂ to female rats (100 ppm in drinking water for 30 days) and then assessed Cd levels in the blood, HPG axis and uterus. Metabolic features, HPG axis function, reproductive tract (RT) morphophysiology, inflammation, oxidative stress (OS), and fibrosis were evaluated. Cd exposure increased Cd levels in the serum, HPG axis, and uterus. Cd rats displayed metabolic impairments, such as a reduction in adiposity, dyslipidemia, and insulin resistance (IR). Cd exposure also caused improper functioning in the HPG. Specifically, Cd exposure caused irregular estrous cyclicity, abnormal hypothalamic gene expression (upregulated - Kiss1, AR and mTOR; downregulated - Kiss1R, LepR and TNF-α), high LH levels, low AMH levels and abnormal ovarian follicular development, coupled with a reduction in ovarian reserve and antral follicle number was observed, suggesting ovarian depletion. Further, Cd exposure caused a reduction in corpora lutea (CL) and granulosa layer thickness together with an increase in cystic/atretic follicles. In addition, Cd exposure caused RT inflammation, OS and fibrosis. Finally, strong positive correlations were observed between serum, RT Cd levels, IR, dyslipidemia and estrous cycle length, cystic, atretic follicles, LH levels, and RT inflammation. Thus, these data suggest that subacute Cd exposure using doses found in workers occupationally exposed to Cd disrupt the HPG axis function, leading to PCOS and POF features and other abnormalities in female rats.

Some data on the comparative and combined toxic activity of nanoparticles containing lead and cadmium with special attention to their vasotoxicity

Moderate subchronic intoxication was induced in rats by repeated intraperitoneal injections of PbO (49.6 ± 16.0 nm) and/or CdO (57.0 ± 13.0 nm) nanoparticles (NP) three times a week during 6 weeks. In particular, there was a reduction in arterial blood pressure and in blood concentrations of a number of factors controlling vasoconstriction and vasodilation, particularly of endothelin 1 (ET-1). This toxic effect was attenuated with a bioprotective complex administered in the background. The study confirmed as well that the combined binary action typology varies depending on which effect it is estimated by.

Molecular mechanism-based therapeutic properties of honey

Honey and its phenolic compounds specifically chrysin are focused as nutritional supplements and likewise as valued phytochemicals, nutraceuticals, and phytopharmaceuticals alone, or adjuvant with some conventional medications to cause synergistic therapeutic or cytotoxic effects. Through the verified beneficial strategies combat several disturbances, phenolic compounds play fundamental functions in the avoidance and treatment of disorders. Oxidative stress, inflammation, and apoptosis are the three most imperative physiological reactions in the prevalence of numerous ailments. Honey, chrysin, and other phenolic compounds detected in honey can modify clinical conditions via modulation of these contrivances and correlated signaling pathways. The current study desires to review the therapeutic effects of honey and its allied molecular mechanisms. Evidenced-base studies show that honey would represent therapeutic potential against various types of cancer and tumor proliferation (colorectal cancer, breast cancer, bladder cancer, leukemia, glioma, hepatocellular cancer, pancreatic cancer, and melanoma), wounds, diabetes mellitus, neurological (depression, Parkinson disease, and Alzheimer's disease), respiratory, gastrointestinal (peptic ulcer and ulcerative colitis), cardiovascular disorders, renal injuries, liver diseases and many other kinds of physiological dysfunctionalities through various molecular mechanisms contributed with oxidative stress, inflammatory process, and apoptosis.

Green tea catechins inhibit microglial activation which prevents the development of neurological disorders

The over-activated microglial cells induce neuroinflammation which has the main role in neurological disorders. The over-activated microglia can disturb neuronal function by releasing inflammatory mediators leading to neuronal dysfunctions and death. Thus, inhibition of over-activated microglia may be an effective therapeutic approach for modulating neuroinflammation. Experimental studies have indicated anti-neuroinflammatory effects of flavonoids such as green tea catechins. The current research was aimed to review the effect of green tea catechins in inhibiting microglial cells, inflammatory cascades, and subsequent neurological diseases.

Oxidative stress and mitochondrial dysfunction in organophosphate pesticide-induced neurotoxicity and its amelioration: a review

Organophosphorus pesticides (OPs) are widely used for controlling pests worldwide. The inhibitory effects of these pesticides on acetylcholinesterase lead to neurotoxic damages. The oxidative stress is responsible for several neurological diseases, including Parkinson's disease, seizure, depression, and Alzheimer's disease. Strong evidence suggests that dysfunction of mitochondria and oxidative stress are involved in neurological diseases. OPs can disturb the function of mitochondria by inducing oxidative stress. In the present study, we tried to highlight the role of dysfunction of mitochondria and the induction of oxidative stress in the neurotoxicity induced by OPs. Additionally, the amelioration of OP-induced oxidative damage and mitochondrial dysfunctional through the chemical and natural antioxidants have been discussed.

Organophosphorus Compounds and MAPK Signaling Pathways

The molecular signaling pathways that lead to cell survival/death after exposure to organophosphate compounds (OPCs) are not yet fully understood. Mitogen-activated protein kinases (MAPKs) including the extracellular signal-regulated protein kinase (ERK), the c-Jun NH2-terminal kinase (JNK), and the p38-MAPK play the leading roles in the transmission of extracellular signals into the cell nucleus, leading to cell differentiation, cell growth, and apoptosis. Moreover, exposure to OPCs induces ERK, JNK, and p38-MAPK activation, which leads to oxidative stress and apoptosis in various tissues. However, the activation of MAPK signaling pathways may differ depending on the type of OPCs and the type of cell exposed. Finally, different cell responses can be induced by different types of MAPK signaling pathways after exposure to OPCs.

Endocrine disruption and obesity: A current review on environmental obesogens

Obesity represents an important public health concern because it substantially increases the risk of multiple chronic diseases and thereby contributing to a decline in both quality of life and life expectancy. Besides unhealthy diet, physical inactivity and genetic susceptibility, environmental pollutants also contribute to the rising prevalence of obesity epidemic. An environmental obesogen is defined as a chemical that can alter lipid homeostasis to promote adipogenesis and lipid accumulation whereas an endocrine disrupting chemical (EDC) is defined as a synthetic chemical that can interfere with the endocrine function and cause adverse health effects. Many obesogens are EDCs that interfere with normal endocrine regulation of metabolism, adipose tissue development and maintenance, appetite, weight and energy balance. An expanding body of scientific evidence from animal and epidemiological studies has begun to provide links between exposure to EDCs and obesity. Despite the significance of environmental obesogens in the pathogenesis of metabolic diseases, the contribution of synthetic chemical exposure to obesity epidemic remains largely unrecognised. Hence, the purpose of this review is to provide a current update on the evidences from animal and human studies on the role of fourteen environmental obesogens in obesity, a comprehensive view of the mechanisms of action of these obesogens and current green and sustainable chemistry strategies to overcome chemical exposure to prevent obesity. Designing of safer version of obesogens through green chemistry approaches requires a collaborative undertaking to evaluate the toxicity of endocrine disruptors using appropriate experimental methods, which will help in developing a new generation of inherently safer chemicals.

•

Many environmental obesogens are endocrine disrupting chemicals that interfere with normal endocrine regulation of metabolism.

•

Understanding the role of environmental obesogens in the epidemics of obesity is in an infant stage.

•

Green chemistry approach aims to design a safer version of these chemicals by understanding their hazardous effects.

•

Further studies are necessary to fully establish the hazardous effects of obesogens and their association to human obesity.

Effect of Prepubertal Exposure to CdCl2 on the Liver, Hematological, and Biochemical Parameters in Female Rats; an Experimental Study

The examination chemical factors including industrial toxins and heavy metals seem to be crucial during the prepubertal period. In order to investigate the effects of prepubertal exposure to toxic doses of Cd on liver, hematological, and biochemical parameters in the serum, 16 female rats weaned on postnatal day (PND) 21 were randomly divided into four groups with four rats in each (n = 4). The treatments were as follows: control (0.5 mL distilled water), 25, 50, and 75 mg/kg/day received cadmium chloride (CdCl2). The CdCl2 were administered orally from PND 21 days until observed first vaginal opening (VO). The result showed that the treatment of 75 mg/kg CdCl2 dramatically increased the serum level of LDL (P < 0.0001) and LDL/HDL ratio (P = 0.0004). Conversely, treatment of 75 mg/kg CdCl2 considerably decreased the serum level of HDL in comparison with control group (P = 0.0002). Nevertheless, the rats that received different doses of CdCl2 showed no significant differences in Glu, TG, and TC compared to control group. Number of RBC and Hb of rats treated with 75 mg/kg CdCl2 were significantly less than the other groups (P < 0.0001), whereas a number of WBCs in rats treated with 75 mg/kg CdCl2 (5.27 ± 0.13 10³/μL) showed significant difference (P < 0.0001) compared to control group (4.23 ± 0.09 10³/μL). Histopathological exams showed nodular accumulation of lymphocytes in the liver (lymphocytic hepatitis) of rats, treated with 75 mg/kg CdCl2. These results showed that CdCl2 could cause change in serum lipidome and hematological parameters. What is more, exposure to Cd triggers liver injury and cardiovascular disease during the prepubertal period.

Arsenite-induced transgenerational glycometabolism is associated with up-regulation of H3K4me2 via inhibiting spr-5 in caenorhabditis elegans

Arsenic (As) is a toxic element that is highly abundant in the environment. However, there has not been sufficient research into the mechanisms of arsenic-induced transgenerational effects. In biomedical and environmental toxicology research field, C. elegans are often used as the ideal model. In this study, F0 generation animals were cultured with arsenite, while subsequent generations animals (F1 - F6) were cultured in the absence of arsenic. Experiments were performed to examine the transgenerational glycometabolism and the associated mechanisms in all seven generations (F0 - F6) of C. elegans. Results show that arsenite exposure increased total glucose content but reduced glucose metabolites in F0 generation C. elegans. The total glucose content was also elevated in subsequent generations probably due to transgenerational downregulation of fgt-1. In addition, arsenite exposure induced transgenerational downregulation of histone demethyltransferase spr-5 and elevated histone dimethylation in F0 generation. This study highlights that single generation exposure to arsenite causes transgenerational changes in glycometabolism in C. elegans, which may be caused by downregulation of spr-5 and elevation of H3K4me2.