Blood mercury concentrations are associated with decline in liver function in an elderly population: a panel study

Elements in trace amount with a significant role in human physiology: a tumor pathophysiological and diagnostic aspects

Cancer has a devastating impact globally regardless of gender, age, and community, which continues its severity to the population due to the lack of efficient strategy for the cancer diagnosis and treatment. According to the World Health Organisation report, one out of six people dies due to this deadly cancer and we need effective strategies to regulate it. In this context, trace element has a very hidden and unexplored role and require more attention from investigators. The variation in concentration of trace elements was observed during comparative studies on a cancer patient and a healthy person making them an effective target for cancer regulation. The percentage of trace elements present in the human body depends on environmental exposure, food habits, and habitats and could be instrumental in the early diagnosis of cancer. In this review, we have conducted inclusive analytics on trace elements associated with the various types of cancers and explored the several methods involved in their analysis. Further, intricacies in the correlation of trace elements with prominent cancers like prostate cancer, breast cancer, and leukaemia are represented in this review. This comprehensive information on trace elements proposes their role during cancer and as biomarkers in cancer diagnosis.

Heavy metals and metalloids exposure and liver function in Chinese adults - A nationally representative cross-sectional study

BACKGROUND

In China, the effects of heavy metals and metalloids (HMMs) on liver health are not consistently documented, despite their prevalent environmental presence.

OBJECTIVE

Our research assessed the association between HMMs and liver function biomarkers in a comprehensive sample of Chinese adults.

METHODS

We analyzed data from 9445 participants in the China National Human Biomonitoring survey. Blood and urine were evaluated for HMM concentrations, and liver health was gauged using serum albumin (ALB), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) metrics. Various statistical methods were employed to understand the relationship between 11 HMMs and liver function, adjusting for multiple factors. We also explored interactions with alcohol intake, gender, and age.

RESULTS

Among HMMs, selenium in blood [weighted geometric mean (GM) = 95.56 μg/L] and molybdenum in urine (GM = 46.44 μg/L) showed the highest concentrations, while lead in blood (GM = 21.92 μg/L) and arsenic in urine (GM = 19.80 μg/L) had the highest levels among risk HMMs. Manganese and thallium consistently indicated potential risk factor to liver in both sample types, while selenium displayed potential liver protection. Blood HMM mixtures were negatively associated with ALB (β = -0.614, 95% CI: -0.809, -0.418) and positively with AST (β = 0.701, 95% CI: 0.290, 1.111). No significant associations were found in urine HMM mixtures. Manganese, tin, nickel, and selenium were notable in blood mixture associations, with selenium and cobalt being significant in urine. The relationship of certain HMMs varied based on alcohol consumption.

CONCLUSION

This research highlights the complex relationship between HMM exposure and liver health in Chinese adults, particularly emphasizing metals like manganese, thallium, and selenium. The results suggest a need for public health attention to low dose HMM exposure and underscore the potential benefits of selenium for liver health. Further studies are essential to establish causality.

Association of serum five heavy metals level with all-cause and cause-specific mortality: a large population-based cohort study

The study aimed to explore the association between five heavy metals exposure (Cadmium, Lead, Mercury, Manganese, and Selenium) and mortality [all-cause, cardiovascular disease (CVD), and cancer-related]. We integrated the data into the National Health and Nutrition Examination Survey from 2011 to 2018 years. A total of 16,092 participants were recruited. The link between heavy metals exposure and mortality was analyzed by constructing a restricted cubic spline (RCS) curve, Cox proportional hazard regression model, and subgroup analysis. The RCS curve was used to show a positive linear relationship between Cadmium, Lead, and all-cause mortality. In contrast, there was a negative linear correlation between Mercury and all-cause mortality. Additionally, Manganese and Selenium also had a J-shaped and L-shaped link with all-cause mortality. The positive linear, positive linear, negative liner, J-shaped, and L-shaped relationships were observed for Cadmium, Lead, Mercury, Manganese, and Selenium and CVD mortality, respectively. Cadmium, Lead, Mercury, and Selenium were observed to exhibit positive linear, U-shaped, negative linear, and L-shaped relationships with cancer-related mortality, respectively. There was an increase and then a decrease in the link between Manganese and cancer-related morality. This study revealed the correlation between the content of different elements and different types of mortality in the U.S. general population.

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

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

Increase of blood mercury level with shark meat consumption: A repeated-measures study before and after Chuseok, Korean holiday

Sharks are known to contain high levels of mercury in their meat. However, few studies have directly assessed the changes in mercury concentration in the human body according to shark meat intake. One hundred and ninety-seven participants that traditionally consume shark meat during the Chuseok holiday were recruited from two areas of Gyeongsangbuk-do, South Korea to examine their blood mercury level before and after the holiday season. Blood mercury levels were measured before and after the holiday season. Characteristics such as the consumption of shark meat, intake amount, and the effect on mercury concentration were assessed during the survey. Univariable and multivariable analysis (Linear Mixed Model) were done for assessing the association between shark meat consumption of holiday season and blood mercury level. Among the total participants, 83 consumed shark meat during holiday. In the univariable analysis, a significant increase in blood mercury levels before and after Chuseok was observed only for the group that consumed shark meat during holiday. The multivariable analysis (adjusted for identified confounders that affect both exposure and outcome considering repeated measurements) showed that consuming shark meat was significantly associated with increased blood mercury levels by 3.56 μg/L (95% confidence interval [CI], 2.64-4.67 μg/L). In the model considering the amount consumed as two group, the level of increase was 2.61 μg/L (95% CI, 1.63-3.58 μg/L) for those consuming <100 g, and 6.20 μg/L (95% CI, 4.77-7.62 μg/L) for those consuming ≥100 g compared to group without consuming shark meat. Considering amount consumed as continuous value, 0.02 μg/L (95% CI, 0.01-0.02 μg/L) of blood mercury increase was significantly associated with consuming 1 g. Consumption of shark meat significantly elevated blood mercury levels, exceeding commonly suggested reference concentrations in less than 2 weeks. These findings suggest the need for public health warnings and regulations regarding shark meat consumption.

Quality assessment of hydroquinone, mercury, and arsenic in skin-lightening cosmetics marketed in Ilorin, Nigeria

Hydroquinone, Mercury (Hg), and Arsenic (As) are hazardous to health upon long-term exposure. Hydroquinone, Hg, and As were analysed in skin-lightening cosmetics randomly purchased from different cosmetic outlets within the Ilorin metropolis, Nigeria. The amount of hydroquinone in the samples was determined using a UV-spectrophotometry method at 290 nm. Hg and As were quantified using atomic absorption spectrophotometry (AAS). UV-spectrophotometry method validation showed excellent linearity (r2 = 0.9993), with limits of detection (0.75 µg/mL), limits of quantification (2.28 µg/mL), relative standard deviation (0.01-0.35%), and recovery (95.85-103.56%) in the concentration range of 5-50 µg/mL. Similarly, r2, LOD, and LOQ for Hg and As were 0.9983 and 0.9991, (0.5 and 1.0 µg/L) and 1.65 and 3.3 µg/L) respectively. All the samples contained hydroquinone, Hg and As in varying amounts. The amounts of hydroquinone, Hg and As present were in the ranges of 1.9-3.3%, 0.08-2.52 µg/g and 0.07-5.30 µg/g respectively. Only three of the analysed samples contained hydroquinone within the permissible limit of 2.0% w/w in cosmetic products. All the samples analysed contained mercury and arsenic in varying amounts. The need to periodically monitor the levels of hydroquinone, mercury, and arsenic in skin-lightening cosmetics marketed in Nigeria is recommended.

Multi-Year Monitoring of the Toxicological Risk of Heavy Metals Related to Fish Consumption by the Population of the Kendari Region (Southeast Sulawesi, Indonesia)

This study measured the concentrations of Hg, As, Ni, Cd, and Pb in six fish species commonly consumed in Kendari. Samples were bought within local markets from 2012 to 2017 at the end of the dry season. Results showed that mercury concentrations fluctuated between years and within species, except in the Caranx sexfasciatus, which showed no significant differences (Kruskall-Wallis, p-value > 0.05, df = 5) and an average concentration of 0.371 ± 0.162 µg g-1 DW. Arsenic was found in high concentrations across species and years and varied widely in C. sexfasciatus, the lowest value being 0.32 ± 0.01 µg g-1 DW in 2012 and the highest was 5.63 ± 1.89 µg g-1 DW in 2017. The highest nickel concentrations were found in 2016 across four of the six species. The fish samples displayed very low cadmium and lead concentrations throughout the study. In addition, the potential human health risk due to fish consumption was assessed. This showed that mercury is the only one of the five metals present in concentrations high enough to individually pose a potential hazard, the only metal likely to be accumulated beyond a safe concentration in Kendari. Chanos chanos never posed a toxicological risk based on the results of this research.

Association Between Serum Trace Heavy Metals and Liver Function Among Adolescents

BACKGROUND

Exposure to metals has been associated with liver-related disease. Few studies have explored the effect of sex stratification on adolescent liver function.

METHOD

From the National Health and Nutrition Examination Survey (2011-2016), 1143 subjects aged 12-19 years were selected for analysis. The outcome variables were the levels of alanine aminotransferase (ALT), aspartate aminotransferase, and gamma-glutamyl transpeptidase.

RESULTS

The results showed a positive association between serum zinc and ALT in boys (odds ratio [OR], 2.37; 95% confidence interval [CI], 1.11-5.06). Serum mercury was associated with an increase in ALT level in girls (OR, 2.73; 95% CI, 1.14-6.57). Mechanistically, the efficacy mediated by total cholesterol accounted for 24.38% and 6.19% of the association between serum zinc and ALT.

CONCLUSIONS

The results imply that serum heavy metals were associated with the risk of liver injury, possibly mediated by serum cholesterol, in adolescents.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association of Blood Mercury Level with Liver Enzymes in Korean Adults: An Analysis of 2015-2017 Korean National Environmental Health Survey

Increased liver enzymes as a result of exposure to mercury and their toxic effects are not well understood in Korea at the population level. The effect of blood mercury concentration on alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was evaluated after adjusting for sex, age, obesity, alcohol consumption habit, smoking, and exercise parameters in 3712 adults. The risk of abnormal liver function was measured using a multiple logistic regression analysis. Blood mercury concentration was divided into quartiles, and liver enzyme levels were compared for each quartile. ALT and AST levels were 10-20% higher in the second, third, and fourth quartiles compared to the first quartile. The risk of liver dysfunction or elevated liver enzymes was significantly higher in the second, third, and fourth quartiles than in the first quartile. As blood mercury levels increased, liver enzymes and mercury-induced hepatotoxicity increased. The increase in liver enzymes caused by mercury was more pronounced in the low-mercury concentration range. To reduce the long-standing problem of abnormal liver enzymes and liver function in Korea and other similar settings, it is important to decrease exposure to mercury through effective implementation of specific health and environmental strategies.

Associations of Dietary and Plasma Copper Levels with Liver Function in a Chinese Population

The potential mechanisms underlying the association between copper (Cu) exposure and impaired liver function are unclear. This study aimed to investigate the potential associations of dietary Cu intake and plasma Cu levels with liver function biomarkers. A cross-sectional study was performed to assess liver function biomarkers-namely, levels of total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), alanine transaminase (ALT), and aspartate transaminase (AST)-in 2376 subjects in Guangxi, China. Dietary Cu intake was determined from a food frequency questionnaire containing 109 common foods. Plasma Cu concentrations were determined by inductively coupled plasma‒mass spectrometry. Multiple linear regression and multivariate restricted cubic splines (RCS) were used to evaluate the correlations of plasma Cu levels and dietary Cu levels with liver function biomarkers. The covariate-adjusted results of the linear regression analysis showed that plasma Cu levels were significantly negatively correlated with serum IBIL (β =  - 0.37), DBIL (β =  - 0.22), and TBIL levels (β =  - 0.32) (all p < 0.05), and dietary Cu was negatively correlated with serum AST levels (β =  - 0.12, p < 0.05). The RCS analysis further indicated a negative linear relationship between dietary Cu levels and AST levels. In summary, our results suggested that the plasma Cu level is associated with serum bilirubin levels and that dietary Cu intake is associated with serum AST levels. Further studies are needed to validate these associations and elucidate the underlying mechanisms.

Cadmium, lead, and mercury mixtures interact with non-alcoholic fatty liver diseases

There is a scarcity of studies on the interactions between heavy metals and non-alcoholic fatty liver disease (NAFLD). Using a variety of statistical approaches, we investigated the impact of three common heavy metals on liver enzymes and NAFLD markers in a Korean adult population. We observed that cadmium, mercury, and lead all demonstrated positive correlations with liver enzymes and NAFLD indices. Our findings were mostly robust in secondary analysis, which included three novel mixture modeling approaches (WQS, qgcomp, and BKMR) as well as in silico investigation of molecular mechanisms (genes, miRNAs, biological processes, pathways, and illnesses). The 16 genes interacted with a mixture of heavy metals, which was linked to the development of NAFLD. Co-expression was discovered in nearly half of the interactions between the 18 NAFLD-linked genes. Key molecular pathways implicated in the pathogenesis of NAFLD generated by the heavy metal combination include activated oxidative stress, altered lipid metabolism, and increased cytokines and inflammatory response. Heavy metal exposure levels were related to liver enzymes and NAFLD indices, and cutoff criteria were revealed. More studies are needed to validate our findings and gain knowledge about the effects of chronic combined heavy metal exposure on adult and child liver function and the likelihood of developing NAFLD. To reduce the occurrence of NAFLD, early preventative and regulatory actions (half-yearly screening of workers at high-risk facilities; water filtration; avoiding excessive amounts of seafood, etc.) should be taken.

Associations between lead, cadmium, mercury, and arsenic exposure and alanine aminotransferase elevation in the general adult population: an exposure-response analysis

Cadmium, lead, mercury, and arsenic are among the most toxic environmental contaminants. Serum alanine aminotransferase (ALT) is the most common liver biomarker. This analysis aimed to explore the associations between blood cadmium, lead, mercury, urinary total arsenic, and dimethylarsinic acid and ALT elevation in adults. Data were extracted from 5 National Health and Nutrition Examination Survey cycles (NHANES) 2007-2016. Patients with chronic viral hepatitis and excessive alcohol consumption were excluded. ALT elevation was defined according to the 2017 American College of Gastroenterology Clinical Guideline. Logistic models and restricted cubic splines were adopted to assess the exposure-response relationships. Comparing the highest to lowest quintile of exposure, the multivariable-adjusted odds ratios (95% confidence intervals) of ALT elevation were 1.38 (1.07-1.78) for blood lead (P_{for trend} = 0.01), 1.37 (1.16-1.62) for blood mercury (P_{for trend} < 0.01), 0.94 (0.78-1.14) for blood cadmium (P_{for trend} = 0.64), 1.07 (0.79-1.45) for urinary total arsenic (P_{for trend} = 0.81), and 1.25 (0.94-1.66) for urinary dimethylarsinic acid (P_{for trend} = 0.18). The associations between blood lead and mercury and ALT elevation were only observed in women. In addition, the associations between urinary total arsenic [1.53 (1.02-2.29), P_{for trend} = 0.02] and dimethylarsinic acid [2.17 (1.05-4.49), P_{for trend} = 0.02] and ALT elevation were also observed in women. Dose-response analysis showed that there was no safe exposure threshold of blood lead and mercury's toxic effect on ALT elevation, respectively. In conclusion, lead, mercury and arsenic were associated with ALT elevation in adults, and the associations were mainly observed in women.

Mercury Contamination: A Growing Threat to Riverine and Urban Communities in the Brazilian Amazon

In recent decades, widespread and uncontrolled use of mercury (Hg) in artisanal small-scale gold mining has released thousands of tons of mercury-contaminated waste in the Amazon biome, endangering the largest tropical rainforest worldwide. In this study, we assessed and compared blood Hg levels in individuals living in urban and riverine areas in the lower Tapajós basin and examined the association between Hg exposure and specific biochemical parameters. In total, 462 adults from eight riverine communities and one urban area were assessed. Overall, 75.6% of the participants exhibited Hg concentrations exceeding the safe limit (10 µg/L). Hg exposure was higher in the riverine population (90%) than in urban areas (57.1%). Mean Hg levels were 21.8 ± 30.9 µg/L and 50.6 µg/L in urban and riverine residents, respectively. The mean Hg level was higher in those aged 41–60 years in both urban and riparian areas, with riparian residents exhibiting a mean double that of urban residents. The highest glucose and hepatic biomarker levels were detected in the urban area, whereas the highest levels of renal biomarker occurred in the riverine population. Our results indicate that Hg contamination remains a persistent challenge for the urban population of Santarém, a major city in the Brazilian Amazon.

Association between Pb, Cd, and Hg Exposure and Liver Injury among Korean Adults

BACKGROUND

Exposure to lead (Pb), cadmium (Cd), and mercury (Hg) has been reported to be associated with liver-related diseases. However, studies examining the association between heavy metal exposure and liver injury in a large population are scant and characterized by inconsistent results. This study aimed to evaluate the association between levels of heavy metal exposure and liver injury in the general population.

METHODS

Data for 2953 participants aged 19 years or more obtained from the Korean National Environmental Health Survey (KoNEHS) Cycle 3 (2015-2017) were used. The associations between levels of blood or urine heavy metals (Pb, Cd, and Hg) and liver function biomarkers [aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT)] were evaluated using multiple linear regression analysis.

RESULTS

Regarding the blood Pb (BPb), AST was higher in those of the 4th quartile, ALT was higher in those of the 2nd and 4th quartiles, and GGT was higher in those of the 3rd and 4th quartiles than in the 1st quartile. For urinary Cd (UCd), AST was higher in those of the 4th quartile; ALT was higher in those of the 2nd, 3rd, and 4th quartiles; and GGT was higher in the 4th quartile than in the 1st quartile. For the blood Hg (BHg), AST was higher in those of the 2nd and 4th quartile, ALT was higher in those of the 2nd, 3rd, and 4th quartiles; and GGT was higher in those of the 3rd and 4th quartiles than in the 1st quartile. There was no significant difference between urinary Hg (UHg) and liver function markers.

CONCLUSION

Heavy metal exposure showed an association with liver injury among the general adult population in Korea. Further studies are required to clarify the relationship between heavy metals and liver injury.

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.

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

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

Analysis of Cadmium, Mercury, and Lead Concentrations in Erythrocytes of Renal Transplant Recipients from Northwestern Poland

Simple Summary

The aim of this study is to determine the blood erythrocyte concentrations of toxic metals (Cd, Pb, and Hg) in renal transplant recipients. Additionally, we analyzed the effect of selected biological and environmental factors, including the intake of various immunosuppressive drug regimens and smoking, on these xenobiotic concentrations. In summary, our data suggest that, smoking is associated with Pb and Cd concentrations, and gender, age change depending on Pb concentration in erythrocytes of renal transplant recipients. Additionally, this is the first research that suggests that immunosuppressive regimen, depending on type of immunosuppressive drugs combination affects Pb concentration in erythrocytes of the mentioned group of patients. It seems to be crucial information for patients who use immunosuppressive drugs.

Abstract

Cadmium (Cd), mercury (Hg), and lead (Pb) exhibit highly nephrotoxic properties, and their high concentrations can lead to renal failure. Much research has been conducted on the concentrations of heavy metals, microelements, and macroelements in the blood, but little is known about the concentration of Cd, Pb, and Hg in erythrocytes of renal recipients. The aim of this study is to determine the blood erythrocyte concentrations of toxic metals (Cd, Pb, and Hg) in renal transplant recipients (RTRs). Additionally, we analyzed the effect of selected biological and environmental factors, including the intake of various immunosuppressive drug regimens and smoking, on these xenobiotic concentrations. The material consisted of erythrocyte samples from 115 patients of the Department of Nephrology, Transplantology, and Internal Medicine at Independent Public Clinical Hospital No. 2, Pomeranian Medical University, Szczecin, in northwestern Poland. Cd, Hg, and Pb levels in the erythrocytes were quantified by inductively coupled mass spectroscopy (ICP-MS). Equal concentrations of Cd were found in erythrocytes of both female and male transplant recipients. The highest level of Hg was seen in women, and women overall had statistically higher concentrations of Pb than men. Comparison of metal concentrations between those over 50 years and those under it showed that Pb concentration was also significantly higher in renal transplant recipients over 50. Pb concentration was almost twice as high in RTRs who used tacrolimus with mycophenolate mofetil than in RTRs who used cyclosporine A with mycophenolate mofetil. The highest level of Cd was seen in smokers, who had 3.25 µg/L. This value was significantly higher than in ex-smokers (p = 0.001) and with RTRs who had never smoked. There were significantly higher levels of Pb in the erythrocytes of RTRs who were ex-smokers than in those who had never smoked. A statistically significant correlation was found between Cd and Pb concentrations. Additionally, we have noticed significant positive correlation between Pb and age (R = 0.37), gender (R = 0.24) and significant negative correlation of Pb with GFR (R = −0.33). We have also found significant positive correlation between Hg and age (R = 0.21). In summary, our data suggest that, smoking is associated with Pb and Cd concentrations, and gender, age change depending on Pb concentration in erythrocytes of RTRs. Additionally, this is the first research that suggests that immunosuppressive regimen, depending on type of immunosuppressive drugs combination affects Pb concentration in erythrocytes of RTRs. It seems to be crucial information for patients who use immunosuppressive drugs.

Trace elements in different tissues in aging rats

BACKGROUND

Trace elements (TE) in the human body provide a connecting link between the environment, lifestyle and biochemical modulation of homeodynamics. On the other hand, many non-essential (toxic) elements are linked to numerous diseases. Our study tried to identify differences in TE levels between healthy old and young Wistar rats in blood and the tissues of kidney, liver, heart, and testicles. Furthermore, we wanted to see if there were age-related differences in correlations between essential and/or non-essential (toxic) TE within and between mentioned tissues.

METHODS

We used 28 healthy male Wistar rats which were divided into two age groups: young, aged 10 weeks (n = 15) and old, aged 36 months (n = 13). The animals were sacrificed under general anesthesia and the blood samples, and samples from the tissues of the heart, kidneys, testicles, and liver were used for the determination of TE content in them. Analysis of the 16 elements was performed by inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

Toxic elements in old rats (As, Hg, and Cd) were significantly higher in all of the tissues where the difference in levels of these elements was found. Tissues of the kidney and liver had the most correlations between TE in old and young rats, respectively. In both old and young rats, arsenic was the toxic element that had most of the correlations with other essential or non-essential elements. In old rats, most of the TE correlations were detected between the tissues of the kidney and heart (11 correlations), while in young rats most of the correlations were observed between the tissues of kidney and liver, and kidney and testicles (with 9 correlations both).

CONCLUSIONS

Our study has found significant changes in levels of trace elements in all of the mentioned tissues, with kidney and testicles being the tissues with the most TE differences between the two aged groups. This and other similar studies should encourage other investigators to evaluate the mutual connections between TE and physiological, or the "unhealthy" aging. More studies with more tissues included, more biomarkers of the systemic function, and even molecular methods are needed to provide the answers to numerous questions relating to TE and aging.

Blood mercury and liver enzymes: A pan-India retrospective correlation study

Mercury (Hg) is a toxic heavy metal, and the reported effects of exposure on liver function continue to be inconsistent. The objective of our study was to identify correlations between high blood Hg levels and liver enzymes in a pan-India population including adults ≥19 years of age. This retrospective study analyzed the data from 95,398 individuals tested for blood Hg levels and liver enzymes in our national laboratory. Testing for blood Hg was done by inductively coupled plasma-mass spectrometry, while testing for liver enzymes-aspartate aminotransferase (AST/SGOT), alanine aminotransferase (ALT/SGPT), and gamma-glutamyl transferase-was done by automated photometry systems. Data from all the individuals inclusive of 52,497 males and 42,901 females were studied. The frequency of high blood Hg levels (>5 µg/L) was found to be 0.6%, and the difference between males and females was not found to be significant. Further correlation by linear regression analysis found no relationship between high blood Hg levels and liver enzymes among females. However, among males, there was a significant correlation between high blood Hg levels, and increased AST as well as ALT. Our report suggested that for males but not females, Hg exposure may be one of the differentials for elevated liver enzymes.

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

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

United States Pharmacopeia (USP) comprehensive review of the hepatotoxicity of green tea extracts

As part of the United States Pharmacopeia's ongoing review of dietary supplement safety data, a new comprehensive systematic review on green tea extracts (GTE) has been completed. GTEs may contain hepatotoxic solvent residues, pesticide residues, pyrrolizidine alkaloids and elemental impurities, but no evidence of their involvement in GTE-induced liver injury was found during this review. GTE catechin profiles vary significantly with manufacturing processes. Animal and human data indicate that repeated oral administration of bolus doses of GTE during fasting significantly increases bioavailability of catechins, specifically EGCG, possibly involving saturation of first-pass elimination mechanisms. Toxicological studies show a hepatocellular pattern of liver injury. Published adverse event case reports associate hepatotoxicity with EGCG intake amounts from 140 mg to ∼1000 mg/day and substantial inter-individual variability in susceptibility, possibly due to genetic factors. Based on these findings, USP included a cautionary labeling requirement in its Powdered Decaffeinated Green Tea Extract monograph that reads as follows: "Do not take on an empty stomach. Take with food. Do not use if you have a liver problem and discontinue use and consult a healthcare practitioner if you develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes)."

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

Background

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

Objective

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

Materials and methods

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

Results

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

Conclusion

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

Multiple metal concentrations and gestational diabetes mellitus in Taiyuan, China

BACKGROUND

The association between multiple metal concentrations and gestational diabetes mellitus (GDM) is poorly understood.

METHODS

A total of 776 women with GDM and an equal number of controls were included in the study. Concentrations of metals in participants' blood (nickel (Ni), arsenic (As), cadmium (Cd), antimony (Sb), thallium (Tl), mercury (Hg), lead (Pb)) were measured using inductively coupled plasma-mass. We used unconditional logistical regression models to estimate the associations between metals and GDM. We also employed weighted quantile sum (WQS) regression and principal components analysis (PCA) to examine metal mixtures in relation to GDM.

RESULTS

An increased risk of GDM was associated with As (OR = 1.49, 95% CI: 1.11, 2.01 for the 2nd tertile vs. the 1st tertile) and Hg (OR = 1.43, 95% CI: 1.09, 1.88 for the 3rd tertile vs. the 1st tertile). In WQS analysis, the WQS index was significantly associated with GDM (OR = 1.20, 95% CI: 1.02, 1.41). The major contributor to the metal mixture index was Hg (69.2%), followed by Pb (12.8%), and As (11.3%). Based on PCA, the second principal component, which was characterized by Hg, Ni, and Pb, was associated with an increased risk of GDM (OR = 1.46, 95% CI: 1.02, 2.08 for the highest quartile vs. the lowest quartile).

CONCLUSIONS

Our study results suggest that high metal levels are associated with an increased risk of GDM, and this increased risk is mainly driven by Hg and, to a lesser extent, by Ni, Pb, and As.

Associations between mercury exposure and the risk of nonalcoholic fatty liver disease (NAFLD) in US adolescents

Little is known regarding the effects of environmental mercury (Hg) exposure on liver dysfunction in adolescents. We aimed to explore the association between Hg exposure and the risk of nonalcoholic fatty liver disease (NAFLD) in the adolescent population. The cross-sectional associations between blood Hg concentrations and serum alanine aminotransferase (ALT) levels, a surrogate for suspected NAFLD, were evaluated using data from adolescents (aged 12-17 years old) who participated in the National Health and Nutrition Examination Survey (NHANES), 1999-2014. A final sample of 6389 adolescents was analysed. Elevated ALT was defined as > 25 IU/L and > 22 IU/L for boys and girls ≤ 17 years old, respectively. Odds ratios (ORs) of Hg levels in association with serum ALT levels were estimated using a logistic regression after adjusting for gender, age, ethnicity, serum cotinine, body mass index, the poverty income ratio, and NHANES cycles. The median blood Hg level was 0.73 ± 0.91 μg/L amongst US adolescents. In the adjusted model, the ORs of elevated ALT levels of those in the 4th quartile were higher amongst non-Hispanic white adolescents (OR = 1.76, 95% CI 1.20, 2.59; P = 0.035) and those who were normal or underweight (OR = 1.41, 95% CI 1.08, 1.85; P = 0.020). No association was observed for the other variables. Our results indicate that the positive association between blood Hg exposure and the risk of NAFLD in US adolescents is the highest amongst non-Hispanic white and those who are normal or underweight, regardless of ethnicity. More research is necessary to confirm this association and to clarify the potential mechanisms.

A two-photon fluorescent probe for colorimetric and ratiometric monitoring of mercury in live cells and tissues

Owing to the extreme toxicity of mercury, methods for its selective and sensitive sensing in solutions, and in live cells and tissues are in great demand.

Mercury Exposure in Association With Decrease of Liver Function in Adults: A Longitudinal Study

Objectives

Although mercury (Hg) exposure is known to be neurotoxic in humans, its effects on liver function have been less often reported. The aim of this study was to investigate whether total Hg exposure in Korean adults was associated with elevated serum levels of the liver enzymes aspartate aminotransferase (AST), alanine transaminase (ALT), and gamma-glutamyltransferase (GGT).

Methods

We repeatedly examined the levels of total Hg and liver enzymes in the blood of 508 adults during 2010-2011 and 2014-2015. Cross-sectional associations between levels of blood Hg and liver enzymes were analyzed using a generalized linear model, and nonlinear relationships were analyzed using a generalized additive mixed model. Generalized estimating equations were applied to examine longitudinal associations, considering the correlations of individuals measured repeatedly.

Results

GGT increased by 11.0% (95% confidence interval [CI], 4.5 to 18.0%) in women and 8.1% (95% CI, -0.5 to 17.4%) in men per doubling of Hg levels, but AST and ALT were not significantly associated with Hg in either men or women. In women who drank more than 2 or 3 times per week, AST, ALT, and GGT levels increased by 10.6% (95% CI, 4.2 to 17.5%), 7.7% (95% CI, 1.1 to 14.7%), and 37.5% (95% CI,15.2 to 64.3%) per doubling of Hg levels, respectively, showing an interaction between blood Hg levels and drinking.

Conclusions

Hg exposure was associated with an elevated serum concentration of GGT. Especially in women who were frequent drinkers, AST, ALT, and GGT showed a significant increase, with a significant synergistic effect of Hg and alcohol consumption.