Dietary strategies for the treatment of cadmium and lead toxicity

Bioaccumulated trace element toxicity in commercially harvested bronze whaler sharks (Carcharhinus brachyurus) of South Africa

Shark meat consumption may pose a significant risk to human health as high levels of toxic pollutants bioaccumulate in muscular tissue. Commercial harvest of Carcharhinus brachyurus meat in South Africa is estimated at 100-300 filleted tons per annum. Muscle tissue samples from 41 sharks were collected from the southern and eastern coastlines of South Africa in 2022 and analysed for 10 trace elements and 8 polychlorinated biphenyl congeners. All trace elements were found to be lower than the regulatory maximum limits for human consumption in most samples irrespective of shark length, sex, and sampling region. However, the estimated daily intake for Mercury and Arsenic exceeded the oral reference dose set by international agencies. The meat from this shark may be consumed due to its low toxic potential for human health, however long-term exposure to C. brachyurus meat should be avoided as it could pose detrimental health risks to consumers.

Low-level, chronic ingestion of lead and cadmium: The unspoken danger for at-risk populations

The long-term effects of low-level, chronic exposure to lead and cadmium through ingestion are often overlooked, despite the urgency surrounding the clinical onset and worsening of certain pathologies caused by these metals. This work reviews current legislation, global ingestion levels, and blood levels in the general population to emphasize the need for reactivity towards this exposure, especially in at-risk populations, including patients with early-stage renal and chronic kidney disease. Global data indicates persistent chronic ingestion of lead and cadmium, with no decreasing trend in recent years, and a daily consumption of tens of micrograms worldwide. Moreover, the average blood lead and cadmium levels in the general population are concerning in many countries with some significantly exceeding healthy limits, particularly for children. Technologies developed to cleanse soil and prevent heavy metal contamination in food are not yet applicable on a global scale and remain financially inaccessible for many communities. Addressing this chronic ingestion at the human level may prove more beneficial in delaying the onset of associated clinical pathologies or preventing them all together.

Cadmium exposure in infants and children: toxicity, health effects, dietary risk assessment and mitigation strategies

As a non-essential metal, cadmium (Cd) poses a significant threat to food safety and public health. This risk is particularly pronounced for infants and young children due to their high food consumption relative to body weight and immature physiological systems. This review examines the health risks associated with Cd exposure, particularly during the prenatal period through adolescence. It evaluates the prevalence of Cd-rich foods in children's diets and their intake levels across various countries. The review demonstrates that Cd exposure is associated with neurodevelopmental disorders, immune dysfunction, and cardiovascular diseases. It also highlights geographic differences in exposure, with some Asian countries, such as Thailand and China, exhibiting higher overall levels of Cd intake among children compared to other regions. This review presents several recommendations to mitigate Cd intake during early childhood, including reducing the Cd content in food, inhibiting Cd absorption, and promoting its excretion from the body. To minimize the risk of dietary Cd intake in children, it is recommended that stringent regulations of Cd limits in children's food be implemented, alongside a coordinated multi-stakeholder effort. This review provides important insights into effective public health policy development, laying the foundation for achieving broader public health goals.

Association Between Combined Polymetallic Exposure and Osteoporosis

Combined polymetallic exposure may be an influential factor in osteoporosis. This study aimed to explore the association between polymetallic combined exposure and osteoporosis. A total of 2115 participants were included. Plasma concentrations of 22 metals were determined by inductively coupled plasma mass spectrometry. Osteoporosis was defined as a T ≤  - 2.5. The least absolute shrinkage and selection operator (LASSO) regression, binary logistics regression, and Bayesian kernel machine regression (BKMR) model were used to explore the association between plasma metals and osteoporosis. LASSO regression showed that 10 metals were associated with osteoporosis in the total population (magnesium, calcium, manganese, nickel, cobalt, arsenic, selenium, rubidium, cadmium, aluminum) and women (magnesium, calcium, molybdenum, nickel, cobalt, arsenic, selenium, rubidium, cadmium, aluminum), and four metals associated with men (magnesium, cobalt, aluminum, iron). Logistics regression showed that in total population, magnesium (ORQ3 = 0.653, 95% CI = 0.446-0.954) was negatively correlated with osteoporosis, while aluminum (ORQ2 = 1.569, 95% CI = 1.095-2.248, ORQ4 = 1.616, 95% CI = 1.109-2.354) and cadmium (ORQ4 = 1.989, 95% CI = 1.379-2.870) were positively correlated; in women, magnesium (ORQ3 = 0.579, 95% CI = 0.379-0.883) was negatively correlated with osteoporosis, while aluminum (ORQ2 = 1.563, 95% CI = 1.051-2.326, ORQ4 = 1.543, 95% CI = 1.024-2.326) and cadmium (ORQ3 = 1.482, 95% CI = 1.003-2.191, ORQ4 = 1.740, 95% CI = 1.167-2.596) were positively correlated. BKMR model showed that combined polymetallic exposure had an overall positive effect on osteoporosis, magnesium was negatively associated with osteoporosis, and cadmium, selenium, and aluminum were positively associated with osteoporosis. Metal mixtures in plasma were associated with osteoporosis risk. Magnesium may reduce the risk of osteoporosis, while cadmium, selenium, and aluminum may increase the risk of osteoporosis. Future studies needed to explore correlations and mechanisms.

Naringenin Against Cadmium Toxicity in Fibroblast Cells: An Integrated Network Pharmacology and In Vitro Metabolomics Approach

Cadmium, a heavy metal, disrupts cellular homeostasis and is highly toxic, with no effective treatments currently available against its toxicity. According to studies, phytochemicals provide a promising strategy for mitigating cadmium toxicity. Naringenin (NG), a potent antioxidant found primarily in citrus fruits, showed protective properties against cadmium toxicity in rats. Nonetheless, the precise mechanism of cadmium cytotoxicity in fibroblasts remains unknown. This study evaluated NG against cadmium (CdCl2) toxicity utilizing network pharmacology and in silico molecular docking, and was further validated experimentally in rat fibroblast F111 cells. Using network pharmacology, 25 possible targets, including the top 10 targets of NG against cadmium, were identified. Molecular docking of interleukin 6 (IL6), the top potential target with NG, showed robust binding with an inhibition constant (Ki) of 58.76 μM, supporting its potential therapeutic potential. Pathway enrichment analysis suggested that "response to reactive oxygen species" and "negative regulation of small molecules metabolic process" were the topmost pathways targeted by NG against cadmium. In vitro analysis showed that NG (10 μM) attenuated CdCl2-induced oxidative stress by reducing altered intracellular ROS, mitochondrial mass, and membrane potential. Also, NG reversed CdCl2-mediated nuclear damage, G2/M phase arrest, and apoptosis. GC/MS-based metabolomics of F111 cells revealed CdCl2 reduced cholesterol levels, which led to alterations in primary bile acid, steroid and steroid hormone biosynthesis pathways, whereas, NG restored these alterations. In summary, combined in silico and in vitro analysis suggested that NG protected cells from CdCl2 toxicity by mitigating oxidative stress and metabolic pathway alterations, providing a comprehensive understanding of its protective mechanisms against cadmium-induced toxicity.

Individual and combined effects of cadmium and lead exposure in rats

The exposure of humans and animals to environmental compounds is rarely restricted to a single chemical. Cadmium (Cd) and lead (Pb) are two heavy metals known to be the most toxic. Deleterious effects of each metal alone are well documented. Unfortunately, very few studies were conducted to determine their combined effect. Four groups of Wistar rats were treated intravenously for 15 days. The control group received physiological saline solution; groups 2 and 3 were treated with Cd chloride and lead acetate, respectively ; and the treatment group 4 received a combined treatment of Cd and Pb . A significant decrease was recorded for hematological parameters , with an increase in white blood cells and an inhibition in δ-ALAD level. Cell injury in the livers and kidneys was clearly shown by the significant elevation of the biochemical markers. Cd and Pb induced oxidative stress and had adverse health effects at lower exposure levels than previously thought.

Evaluating the Impact of Airborne Fine Particulate Matter and Heavy Metals on Oxidative Stress via Vitamin Supplementation

This cross-sectional study aimed to assess the interrelationships between PM2.5 exposure, heavy metal concentrations, and oxidative stress indicators, while evaluating the impact of antioxidant intake, such as vitamins, on these associations. PM2.5 exposure assessments were conducted using portable sensor-based monitors; biomarker analyses for heavy metals and oxidative stress were performed in 114 non-smoking adults. We observed that personal or ambient PM2.5 exposure levels were not associated with increased levels of heavy metals in blood and urine, nor with oxidative stress levels in urine. However, the concentrations of cadmium and lead in blood, and those of chromium and nickel in urine, were significantly associated with the urinary malondialdehyde (MDA) concentration. Additionally, increases in blood cadmium, urinary chromium, and nickel levels were significantly associated with higher urinary MDA concentrations in the non-vitamin-supplement group, but this trend was not observed in the regular vitamin supplement group. Our findings suggest that a regular intake of vitamin supplements might modulate the relationship between heavy metal exposure and oxidative stress, indicating potential protective effects against oxidative damage induced by PM2.5 and heavy metals. This study highlights the complexity of environmental pollutant exposure and its impact on human health, emphasizing the need for further research to elucidate the underlying mechanisms and explore potential protective strategies.

Addressing the Missing Links in Cardiovascular Aging

The aim of this manuscript is to provide a review of available options to enhance cardiovascular health and prevent cardiovascular disease (CVD) in the aging population using a systems-biology approach. These include the role of the gut microbiome, the early identification and removal of environmental toxins, and finally age related sex hormones and supplement replacement which all influence aging. Implementing such a comprehensive approach has the potential to facilitate earlier risk assessment, disease prevention, and even improve mortality. Further study in these areas will continue to advance our understanding and refine therapeutic interventions for a healthier cardiovascular aging process.

Effect of cadmium on polystyrene transport in parsley roots planted in a split-root system and assessment of the combined toxic effects

Micro and nanoplastics (MPs/NPs) coupled with heavy metals are prevalent in both aquatic and terrestrial ecosystems. Their ecological toxicity and combined adverse effects have obtained significant concern. Past studies primarily focused on how MPs/NPs influence the behavior of heavy metals. Yet, the possible effects of heavy metals on MP/NP transport and toxicity within co-contaminated systems are still not well-understood. In this study, we conducted split-root experiments to explore the transport and toxicity of polystyrene (PS) particles of varying sizes in parsley seedlings, both with and without the addition of cadmium (Cd). Both the PS-NPs (100 nm) and PS-MPs (300 nm) traveled from the PS-spiked roots (Roots-1) to the non-PS-spiked roots (Roots-2), with or without Cd, possibly because of phloem transport. Furthermore, the presence of Cd reduced the accumulation and movement of PS-NP/MP in the roots, likely due to the increased positive charge (Cd2+) on the PS surface. PS-NPs/MPs in both Roots-1 and Roots-2 were observed using transmission electron microscopy (TEM). When Cd was added to either Roots-1 (PS + Cd|H) or Roots-2 (PS|Cd), there was a minor reduction in the chlorophyll a and carotenoids content in leaves with PS|H. The adverse impacts of MPs|H on both indicators were influenced by the MP concentration. However, chlorophyll b significantly increased in the PS|H, PS + Cd|H, and PS|Cd treatments. Consequently, the chlorophyll a/b ratio declined, indicating inhibition of photosynthesis. The dehydrogenase content showed a minor change in Roots-1 and Roots-2 without Cd stress, whereas it significantly decreased on the Cd-spiked side and subsequently inhibited root growth. In contrast, the marked rise in glutathione (GSH) levels within Cd-spiked roots suggested, based on Gaussian analysis, that GSH and Cd chelation were instrumental in mitigating Cd toxicity. When Cd was introduced to both Roots-1 and Roots-2 simultaneously (PS + Cd|Cd), the aforementioned index showed a notable decline.

Evaluation of the effect of cannabidiol on the THLE-2 liver cell line exposed to lead

Environmental and soil pollution increase the likelihood of human exposure to toxic metals. Therefore, there is a need for new methods and substances to protect individuals against the harmful effects caused by toxic metals. The study is the first to aim at determining the protective effect of cannabidiol (CBD) against oxidative stress and inflammation induced by toxic metal exposure in Transformed Human Liver Epithelial-2 (THLE-2) cell lines representing healthy liver cells. The IC50 value was determined by exposing THLE-2 human liver healthy cell line to different molarities of lead (Pb) using the XTT kit. The protective efficacy of CBD was assessed by adding 5 μM CBD in addition to the Pb doses determined at IC50 levels to the Pb groups created in cell lines. The levels of GSH, MDA, MPO, CAT, TNF-α, IL-1β, and IL-6 in cell lines were determined using ELISA kits. The inhibition of toxic metal entry into the cells by CBD was assessed through ICP-MS analysis. The IC50 value for Pb was determined as 10 μM in 2D cell lines and 25 μM in 3D cell lines. It was observed that the application of 5 μM concentration of CBD, along with the determined IC50 doses for Pb, increased the cell proliferation rate. Furthermore, the decrease in GSH and CAT levels and the increase in MDA, MPO, TNF-α, IL-1β, and IL-6 levels observed in cell lines treated only with Pb were reversed with the application of CBD. The ICP-MS analysis revealed that CBD reduced the cellular uptake of Pb. The reversal of oxidative stress and inflammation induced by Pb, the increase in cell proliferation, and the reduction in the cellular uptake of toxic metals by CBD can be considered as strong evidence for the protective use of CBD in Pb exposures.

Heavy Metal Exposure and Cardiovascular Disease

Heavy metals are harmful environmental pollutants that have attracted widespread attention due to their health hazards to human cardiovascular disease. Heavy metals, including lead, cadmium, mercury, arsenic, and chromium, are found in various sources such as air, water, soil, food, and industrial products. Recent research strongly suggests a connection between cardiovascular disease and exposure to toxic heavy metals. Epidemiological, basic, and clinical studies have revealed that heavy metals can promote the production of reactive oxygen species, which can then exacerbate reactive oxygen species generation and induce inflammation, resulting in endothelial dysfunction, lipid metabolism distribution, disruption of ion homeostasis, and epigenetic changes. Over time, heavy metal exposure eventually results in an increased risk of hypertension, arrhythmia, and atherosclerosis. Strengthening public health prevention and the application of chelation or antioxidants, such as vitamins and beta-carotene, along with minerals, such as selenium and zinc, can diminish the burden of cardiovascular disease attributable to metal exposure.

In silico prediction aided preparation of antioxidant soybean peptides by enzymatic hydrolysis for ameliorating lead exposure-induced toxicity

Food derived bioactive peptides are prominent dietary supplements to protect against oxidative stress induced by lead (Pb) exposure. This study aimed to develop a new strategy for rapid preparation of highly active antioxidant soybean polypeptides (ASPs) against Pb toxicity. In silico enzymatic hydrolysis simulation and antioxidant activity prediction showed that pepsin, chymotrypsin and bromelain can produce peptides with the highest activity. The preparation process was then optimized, and the obtained ASP showed good antioxidant and metal-chelating activities in vitro. An in vivo study showed that ASP exerted prominent protective effects against Pb-induced cognitive impairment and tissue damage in mice by reducing Pb deposition and enhancing the antioxidant capacity in tissues and was superior to Vc, DMSA or their combination in some aspects. ASP composition analysis demonstrated that its prominent antioxidant activity might be attributed to the high proportion of amino acid residues E, L, P and V in the peptide sequence and L, V and A at the C- and N-termini. In conclusion, in silico prediction could facilitate the preparation of ASP. And the ASP prepared with the new strategy exerted prominent protective effects against Pb toxicity.

Phytochemicals Involved in Mitigating Silent Toxicity Induced by Heavy Metals

Heavy metals (HMs) are natural elements present in the Earth's crust, characterised by a high atomic mass and a density more than five times higher than water. Despite their origin from natural sources, extensive usage and processing of raw materials and their presence as silent poisons in our daily products and diets have drastically altered their biochemical balance, making them a threat to the environment and human health. Particularly, the food chain polluted with toxic metals represents a crucial route of human exposure. Therefore, the impact of HMs on human health has become a matter of concern because of the severe chronic effects induced by their excessive levels in the human body. Chelation therapy is an approved valid treatment for HM poisoning; however, despite the efficacy demonstrated by chelating agents, various dramatic side effects may occur. Numerous data demonstrate that dietary components and phytoantioxidants play a significant role in preventing or reducing the damage induced by HMs. This review summarises the role of various phytochemicals, plant and herbal extracts or probiotics in promoting human health by mitigating the toxic effects of different HMs.

Cadmium as a male reproductive toxicant and natural and non-natural ways to tackle it: a review

Cadmium (Cd) is a naturally occurring environmental pollutant, a toxic substance that causes oxidative stress. According to epidemiological studies, the data suggested that environmental and occupational Cd exposure may be related to several diseases and severe testicular damage. However, studies are going on to explore the mechanism of Cd-induced male reproductive toxicity and its treatment strategies. Currently, researchers are focusing on naturally occurring bioactive compounds, plant extracts, and biochemical, which have better efficacy, less toxicity, and high bioavailability. This review focuses on the mechanistic effect of Cd on testicular toxicity and different categories of compounds having a beneficial impact on Cd-induced male reproductive toxicity. Some potent bioactive antioxidants are quercetin, caffeic acid phenethyl ester, cyanidin-3-O-glucoside, curcumin, and silymarin. In comparison, plant extracts are Costus afer leaf methanol extract, methanol root extract of Carpolobia lutea, red carrot methanolic extract, Panax ginseng extract, and biochemicals including melatonin, progesterone, glutamine, L-carnitine, and selenium. Advanced and more detailed studies are needed on these compounds to explore their mechanism in attenuating Cd-induced testicular toxicity and can be potential therapeutics in the future.

Higher cadmium and zinc accumulation in parsley (Petroselinum crispum) roots activates its antioxidants defense system

Parsley (Petroselinum crispum) is herb with many biological and medicinal benefits for humans. However, growth on zinc (Zn) and cadmium (Cd) contaminated sites might get severely affected due to over accumulation of heavy metals (HM) in different plant tissues. Antioxidants play a crucial role in minimizing the negative effects of HM. The present study investigates the effects of Zn and Cd stress on P. crispum morphological parameters, enzymatic/non-enzymatic antioxidant profiling and metal accumulation in shoot/root. Plants were exposed to different concentrations of Zn (50, 100, 150 and 200 µM) and Cd (10, 20, 40 and 80 µM) along with control (no stress), in soil-less Hoagland's solution. The results showed that Zn and Cd substantially decrease the growth parameters with increased contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL). Non-enzymatic antioxidant activities, like total phenolic contents (TPC) and ferric reducing antioxidant power (FRAP), were induced high in leaves only upon Cd stress and contrarily decreased upon Zn stress. Total flavonoid contents (TFC) were decreased under Zn and Cd stress. Enzymatic antioxidant activities like superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were also strongly induced upon Cd stress. At the same time, SOD and guaiacol peroxidase (GPX) activity was induced significantly upon Zn stress. Cd uptake and accumulation was notably high in roots as compared to shoots, which suggests P. crispum have a reduced ability to translocate Cd towards aboveground parts (leaves). Additionally, strong induction of antioxidants by P. crispum under Cd stress might indicate the capacity to effectively re-modulate its physiological response. However, further investigations regarding other HMs and experiments at the molecular level are still needed.

Immobilization of Cd2+ in an aqueous environment using a two-step microbial-induced carbonate precipitation method

Previous researches indicate that the potent toxicity of cadmium hinders the efficacy of the microbial-induced carbonate precipitation (MICP) process for bioremediation of Cd2+ in aqueous environment. Increasing urea and calcium resource doses, introducing synergists, and utilizing urease-producing consortia can improve bio-immobilization performance of MICP. However, such measures may incur cost increases and/or secondary contamination. This study first verifies the substantial biotoxicity of Cd2+ for urease activity and then analyzes the practical limitation of traditional MICP using Bacillus pasteurii for bioremediation of Cd2+ in an aqueous environment containing 1-40 mM Cd2+ by a series tube tests and numerical simulation. Subsequently, a two-step MICP method, which separates urea hydrolysis and heavy metal precipitation, is introduced in this study to eliminate the inhibitory effect of heavy metal on urease activity. The concentrations of ammonium, Cd2+, and pH were monitored over time. The results indicate that the urease expression in B. pasteurii can be significantly inhibited by Cd2+ particularly at the concentration ranging from 10 to 40 mM, leading to pretty low efficacy of traditional MICP for bioremediation of Cd2+ (Cd2+ removal rate as low as 21.55-38.47% when the initial Cd2+ concentration = 40 mM). In contrast, when the two-step MICP method is applied, the Cd2+ can be almost completely immobilized, even though the concentration ratio of urea to Cd2+ is as low as 1.5:1.0, which is close to the theory minimum concentration ratio for the complete precipitation of carbonate to cadmium ions(1.0:1.0). Therefore, the cost-effective, environmentally sustainable, and straightforward two-step MICP method holds great potential for application in the bioremediation of Cd2+-contaminated solutions in high concentration.

Metabolic Carcinogenesis

Several types of environmental, chemical and metabolic carcinogens exist both exogenously and endogenously. Humans are daily exposed to aforementioned carcinogens through various sources such as through water, air and food or through metabolic and inflammatory products. This chapter will summarize the links between exogenous and endogenous carcinogen exposure and their metabolism with the cancer pathogenesis and associated risks. This chapter will also cover the carcinogens acquired through lifestyle factors like tobacco use and occupational exposures to different chemicals like asbestos, arsenic, chloroform, vinyl chloride, etc. Moreover, environmental carcinogens such as radiation, sunlight, diet, smoke, etc. will also be discussed in this chapter. Furthermore, there are certain carcinogens that require bio-activation and various human enzymes that play a vital role in the metabolic carcinogenesis will also be recapitulated. Necessary preventive measures against carcinogenic exposure from the exogenous environment are significant to be taken into account to reduce the risks associated with the carcinogens.

Liposomal silymarin anti-oxidative and anti-apoptotic features in lung cells: An implication in cadmium toxicity

BACKGROUND

Several metallic elements with high atomic weight and density are serious systemic toxicants, and their wide environmental distribution increase the risk of their exposure to human. Silymarin (SL), a polyphenol from milk thistle (Silybum marianum) plant has shown protective role against heavy metal toxicity. However, its low aqueous solubility and rapid metabolism limits its therapeutic potential in clinic.

METHODS

We compared the role of silymarin nanoliposomes (SL-L) against cadmium (Cd) toxicity in normal MRC-5 and A 549 cancer cells. MRC-5 and A 549 cells exposed to Cd at 25 and 0.25 µM respectively, were treated with various non-toxic SL-L concentrations (2.5, 5, 10 µM) and cells viability, reactive oxygen species (ROS) generation, apoptosis and levels of cleaved PARP and caspase-3 proteins were determined following incubation.

RESULTS

Results indicated that Cd exposure significantly increased apoptosis due to ROS generation, and showed greater toxicity on cancer cells compared to normal cells. While SL-L at higher concentrations (25 µM and higher) exhibits pro-apoptotic features, lower concentrations (10 and 2.5 µM for MRC-5 and A 549 cancer cells, respectively) played a protective and anti-oxidant role in Cd induced toxicity in both cells. Further, lower SL-L was required to protect cancer cells against Cd toxicity. In general, treatment with SL-L significantly improved cell survival by decreasing ROS levels, cleaved PARP and caspase-3 in both MRC-5 and A 549 cells compared to free silymarin.

CONCLUSION

Results demonstrated that SL-L potential in protecting against Cd-induced toxicity depends on concentration-dependent antioxidant and anti-apoptotic balance.

Protective effects of Emblica officinalis polysaccharide against lead induced liver injury in mice model

Heavy metal contamination especially lead (Pb) causes a serious threat to global public health. In the current study, we explored the protective and regulating effects of Emblica officinalis polysaccharide (EOP) in the liver against Pb-induced toxicity. According to our findings, EOP decreased the Pb-induced pathological lesions of liver and overall weight index in mice (p < 0.05). Following treatment with EOP, the levels of biological biomarkers for liver hepatic function (i.e., ALT and AST) were significantly decreased (p < 0.01) in a dose-dependent manner, consisted with histopathological changes. The key proteins involved in hepatic oxidative stress and apoptosis, including Nrf2, HO-1, Bcl-2, and Bax were quantified, which indicated EOP as an effective approach in protecting against the liver injury. Moreover, EOP treatment ameliorated the negative changes of liver metabolic profile (i.e., metabolites concentrations and metabolic patterns). In conclusion, EOP could protect the liver against oxidative stress and apoptosis induced by Pb poisoning, associated with the efficacy of ameliorating the negative changes in liver metabolic profile. Hence, the current findings recommend EOP as an efficient way for alleviating liver injury in lead poisoning.

Ecotoxicology applied to conservation: Potential negative metal and metalloid contamination effects on the homeostatic balance of the critically endangered Brazilian guitarfish, Pseudobatos horkelii (Elasmobranchii: Rhinobatidae)

Metal contamination poses a significant threat to elasmobranchs, underscoring the need for targeted conservation approaches. The critically endangered Brazilian guitarfish, Pseudobatos horkelii, confronts an array of challenges, notably overexploitation, putting its survival at risk. Our study investigated the potential toxicity arising from arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) contamination across various adult guitarfish tissues from southeastern Brazil. Serological stress indicators, nutritional metabolites, and creatinine, an organ function marker, were also assessed, and Selenium (Se) levels were also investigated for possible protective effects. Our investigation unveiled significant correlations between metal concentrations and the determined physiological markers, shedding light on potential adverse effects. Remarkably, six correlations were indicative of how Hg and Pb negatively impact hepatic metabolite assimilation, while As was shown to influence renal phosphorus dynamics, Cd to affect rectal gland phosphorus regulation, and Pb to influence creatinine production in muscle tissue. Furthermore, Se demonstrated protective properties against Cd, Hg, and Pb, suggesting a role in alleviating the toxicity of these elements. Despite probable protective Se influences, the detected elemental interactions still suggest potential for organ impairment. These findings gain heightened significance within the context of the cumulative stressors faced by the Brazilian guitarfish, with metal contamination exhibiting the capacity to erode this species resilience against both anthropogenic and environmental pressures, thereby disrupting systemic equilibrium and jeopardizing wild populations. By investigating the intricate balance between metal accumulation and physiological consequences, our study contributes with crucial insights into potential conservation strategy formulations towards pollution for this critically endangered elasmobranch species.

Toxic metal mixtures in private well water and increased risk for preterm birth in North Carolina

BACKGROUND

Prenatal exposure to metals in private well water may increase the risk of preterm birth (PTB) (delivery < 37 weeks' gestation). In this study, we estimated associations between arsenic, manganese, lead, cadmium, chromium, copper, and zinc concentrations in private well water and PTB incidence in North Carolina (NC).

METHODS

Birth certificates from 2003-2015 (n = 1,329,071) were obtained and pregnancies were assigned exposure using the mean concentration and the percentage of tests above the maximum contaminant level (MCL) for the census tract of each individuals' residence at the time of delivery using the NCWELL database (117,960 well water tests from 1998-2019). We evaluated associations between single metals and PTB using adjusted logistic regression models. Metals mixtures were assessed using quantile-based g-computation.

RESULTS

Compared with those in other census tracts, individuals residing in tracts where > 25% of tests exceeded the MCL for lead (aOR 1.10, 95%CI 1.02,1.18) or cadmium (aOR 1.11, 95% CI 1.00,1.23) had an increased odds of PTB. Conversely, those residing in areas with > 25% MCL for zinc (aOR 0.77 (95% CI: 0.56,1.02) and copper (aOR 0.53 (95% CI: 0.13,1.34)) had a reduced odds of PTB. A quartile increase in the concentrations of a mixture of lead, cadmium, and chromium was associated with a small increased odds for PTB (aOR 1.02, 95% CI 1.01, 1.03). This metal mixture effect was most pronounced among American Indian individuals (aOR per quartile increase in all metals: 1.19 (95% CI 1.06,1.34)).

CONCLUSIONS

In a large study population of over one million births, lead and cadmium were found to increase the risk of PTB individually and in a mixture, with additional mixtures-related impacts estimated from co-exposure with chromium. This study highlights critical racial and ethnic health disparities in relation to private well water thereby emphasizing the urgent need for improved private well water quality to protect vulnerable populations.

Responses of the gut microbiota to environmental heavy metal pollution in tree sparrow (Passer montanus) nestlings

Gut microbiota plays a critical role in regulating the health and adaptation of wildlife. However, our understanding of how exposure to environmental heavy metals influences the gut microbiota of wild birds, particularly during the vulnerable and sensitive nestling stage, remains limited. In order to investigate the relationship between heavy metals and the gut microbiota, we analyzed the characteristics of gut microbiota and heavy metals levels in tree sparrow nestlings at different ages (6, 9 and 12-day-old). The study was conducted in two distinct areas: Baiyin (BY), which is heavily contaminated with heavy metals, and Liujiaxia (LJX), a relatively unpolluted area. Our result reveled a decrease in gut microbiota diversity and increased inter-individual variation among nestlings in BY. However, we also observed an increase in the abundance of bacterial groups and an up-regulation of bacterial metabolic functions associated with resistance to heavy metals toxicity in BY. Furthermore, we identified a metal-associated shift in the relative abundance of microbial taxa in 12-day-old tree sparrow nestlings in BY, particularly involving Aeromonadaceae, Ruminococcaceae and Pseudomonadaceae. Moreover, a significant positive correlation was found between the body condition of tree sparrow nestlings and the abundance of Bifidobacteriaceae in BY. Collectively, our findings indicate that the gut microbiota of tree sparrow nestlings is susceptible to heavy metals during early development. However, the results also highlight the presence of adaptive responses that enable them to effectively cope with environmental heavy metal pollution.

Pomegranate peel extract, N-Acetylcysteine and their combination with Ornipural alleviate Cadmium-induced toxicity in rats

Cadmium is a major environmental pollutant and a highly toxic metal. It was aimed to determine the effects of pomegranate peel extract (PPE), N-acetylcysteine (NAC) alone and along with Ornipural on cadmium-induced toxicity. Forty-six Wistar Albino male rats were divided into 6 groups and the groups were formed into healthy control, Cadmium group (5 mg/kg/day, oral), Cadmium + Pomegranate peel extract (500 mg/kg, oral), Cadmium + N-acetylcysteine (100 mg/kg, oral), Cadmium + Pomegranate peel extract (500 mg/kg, oral) + Ornipural (1 mL/kg, subcutaneous) and Cadmium + N-acetylcysteine (100 mg/kg, oral) + Ornipural (1 mL/kg, subcutaneous). Cadmium accumulated heavily in both liver and kidney tissue. The administration of N-acetylcysteine and pomegranate peel extract alone reduced cadmium levels in both tissues. N-acetylcysteine treatment prevented the increase in ALT and MDA levels by cadmium damage. N-acetylcysteine + Ornipural treatment inhibited the increase in liver 8-OHdG level in the liver. N-acetylcysteine and N-acetylcysteine + Ornipural treatments prevented the reduced serum MMP2 level. N-acetylcysteine and Pomegranate peel extract + Ornipural treatments significantly reduced the increased liver iNOS level in the liver. In conclusion, NAC therapy may be a successful treatment option for cadmium toxicity. However, further research is needed on the effects of PPE and Ornipural combinations for the treatment of cadmium toxicity. In future studies, various doses of these treatment options (with chelators) should be investigated for cadmium toxicity.

Investigating the Effectiveness of Exopolysaccharide-Producing Lactic Acid Bacteria in Biosorbing Lead (II), Attaching to Caco-2 Cells, and Provoking Antiinflammatory Responses

Lead is a common toxic heavy metal with harmful effects on the human body and is widely used in several industries. It can contaminate the environment by air and water emissions and can enter the human body through the respiratory tract, ingestion, or skin contact. Lead is considered as a persistent environmental pollutant, with a half-life of 30 days in the blood, and exists in the skeletal system for decades and causes damage to other systems. Biosorption is receiving increasing attention. Due to its high efficiency and economic value in removing heavy metals from the environment, a variety of biosorption methods can be used for the removal of heavy metals. Lactic acid bacteria (LAB) strains were capable of attaching to both human skin stratum corneum HaCaT cells and human rectal cancer Caco-2 cells. NBM-04-10-001 and NBM-01-07-003 significantly reduced the secretion of IL-6 and IL-8 after coculture with HaCaT cells. In the immune response of RAW264.7 mouse macrophages, high bacterial counts reduced the concentrations of IL-6 and TNF-α in a dose-dependent manner. The results of animal experiments revealed that feeding lead solution exerted no effect on the animal's food intake, and feeding PURE LAC NBM11 powder could effectively remove lead content in the blood. The group fed with PURE LAC NBM11 powder showed significantly less damage and lesions to liver cells. The LAB powder developed in this study has the potential to bind metals, preventing them from entering the body and protecting the host. LAB can be an ideal strain for future bioadsorption chelators.

Aridity-driven changes in structural and physiological characteristics of Buffel grass (Cenchrus ciliaris L.) from different ecozones of Punjab Pakistan

Cenchrus ciliaris L. is a perennial grass that can grow in a diverse range of habitats including challenging deserts. The purpose of the study was to investigate the impact of aridity on morpho-anatomical and physiological traits in C. ciliaris populations collected from arid and semi-arid areas of Punjab, Pakistan. The populations growing in extremely arid conditions displayed a range of structural and physiological adaptations. Under extremely dry conditions, root epidermal thickness (90.29 µm), cortical cell area (7677.78 µm2), and metaxylem cell area (11,884.79 µm2) increased while root pith cell area (2681.96 µm2) decreased in tolerant populations. The populations under extremely aridity maximized leaf lamina (184.21 µm) and midrib thickness (316.46 µm). Additionally, highly tolerant populations were characterized by the accumulation of organic osmolytes such as glycinebetaine (132.60 µmol g-1 FW) was increased in QN poulations, proline (118.01 µmol g-1 F.W) was maximum in DF populations, and total amino acids (69.90 mg g-1 FW) under extreme water deficit conditions. In arid conditions, abaxial stomatal density (2630.21 µm) and stomatal area (8 per mm2) were also reduced in DF populations to check water loss through transpiration. These findings suggest that various parameters are crucial for the survival of C. ciliaris in arid environments. The main strategies used by C. ciliaris was intensive sclerification, effective retention of ions, and osmotic adjustment through proline and glycinebetaine under arid conditions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01351-3.

Endocytosis-Mediated Transport of Pb in Rat Blood Cells

Blood is an important reservoir for Pb storage in living organisms, and the storage of Pb in blood cells inhibits its discharge from blood. However, the mechanism and molecular targets of Pb entry and exit from blood cells have not been elucidated, which is the major barrier to reducing blood Pb levels in normal human beings. In this study, we explored the effect of Pb-binding proteins on blood Pb levels in rats at environmentally relevant concentrations (0.32 μg/g) by identifying the functions of Pb-binding proteins and validating them with inhibitors. The results showed that Pb-binding proteins in blood cells were mainly related to phagocytosis, while in plasma, they were mainly involved in the regulation of endopeptidase activity. Meanwhile, at the normal population Pb levels, endocytosis inhibitors, endopeptidase activity inhibitors, and coadministration of both can reduce the level of Pb in MEL (mouse erythroleukemia cells) cells by up to 50, 40, and 50%, respectively, while in rat blood, the reduction can reach up to 26, 13, and 32%, respectively. Collectively, these findings reveal that endocytosis increases blood Pb levels and provides a possible molecular target for Pb excretion at ambient concentrations.

Moringa oleifera Lam. Commercial Beverages: A Multifaceted Investigation of Consumer Perceptions, Sensory Analysis, and Bioactive Properties

This study employs a multidisciplinary approach to evaluate consumers' perceptions and acceptance of Moringa oleifera Lam. beverages, examining sensory attributes, chemical composition, and bioactivities. High-performance liquid chromatography with diode array detection (HPLC-DAD) analyses revealed significant chemovariation in phenolic compositions among commercial moringa beverages. A soluble moringa powder drink exhibited the greatest concentrations of phenolic and flavonoid compounds, along with powerful antioxidant capacity powers assessed with ABTS^•+, DPPH^•, FRAP assays, ^•NO, and H₂O₂ scavenging activities. However, this sample was the least preferred and presented high Cd levels, exceeding WHO-acceptable values of 0.3 mg/kg. Sensory testing indicated that sweet and floral flavors contributed to beverages being liked, while green, grass, herbal flavors, sour, bitter, and precipitate presence were considered unfavorable sensory attributes. Health claims positively influenced acceptance, particularly among women. Consumers associated feelings of health, wellness, relaxation, and leisure with moringa beverages. During purchase, the most observed information included the ingredient list, health benefits, and type/flavor. These findings emphasize the importance of consumer awareness in reading labels, verifying product origins, and ensuring the absence of contaminants. By understanding consumer preferences and the impact of health claims, producers can better tailor M. oleifera beverages to meet consumer expectations while maintaining safety and quality standards.

Benefits of fermented synbiotic soymilk containing Lactobacillus acidophilus, Bifidobacterium lactis, and inulin towards lead toxicity alleviation

This study aims to evaluate the effect of fermented synbiotic soy milk containing Lactobacillus acidophilus, Bifidobacterium lactis, and inulin on a series of hematological and oxidative stress parameters, as well as serum lead levels in rats. In this study, 56 male Sprague-Dawley rats were randomly assigned to assess probiotics (L. acidophilus or B. lactis), probiotics with prebiotics (i.e., inulin), and the corresponding controls. Several hematologic parameters (red blood cell (RBC)), hematocrit (HCT) and hemoglobin (Hgb)), serum lead levels, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) presence was measured to evaluate changes on day 42. Although a significant difference was observed in serum lead levels, there were no significant changes in hematological and oxidative stress parameters between the study groups. In conclusion, this study demonstrates that administering synbiotic fermented soy milk containing the probiotic Lactobacillus acidophilus and the prebiotic inulin may significantly improve serum lead levels in rats.

Periconceptional diet quality and its relation to blood heavy metal concentrations among pregnant women: The Japan environment and Children's study

BACKGROUND

Diets contain toxic chemical contaminants as well as essential nutrients, both of which influence the intrauterine environment for foetal growth. However, whether a high-quality diet that is nutritionally healthy also results in lower exposure to chemical contaminants is unknown.

OBJECTIVE

We examined associations between periconceptional maternal diet quality and circulating concentrations of heavy metals during pregnancy.

DESIGN

Dietary intake over the year prior to the first trimester of pregnancy was assessed using a validated, self-administered food frequency questionnaire among 81,104 pregnant Japanese women who participated in the Japan Environment and Children's Study. Overall diet quality was determined using the Balanced Diet Score (BDS) based on the Japanese Food Guide Spinning Top, the Healthy Eating Index-2015 (HEI-2015), the Dietary Approaches to Stop Hypertension (DASH) score and the Mediterranean diet score (MDS). We measured whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) during the second or third trimester of pregnancy.

RESULTS

After controlling for confounders, all diet quality scores were positively associated with blood Hg concentrations. By contrast, higher BDS, HEI-2015 and DASH scores were associated with lower concentrations of Pb and Cd. Although the MDS was positively associated with concentrations of Pb and Cd, when dairy products were classified as a beneficial (rather than detrimental) food component, these associations were attenuated.

CONCLUSION

A high-quality diet may reduce exposure to Pb and Cd but not Hg. Further studies are required to determine the optimal balance between mercury exposure risk and nutritional benefits of high-quality diets prior to pregnancy.

Evaluation of Cadmium or Lead Exposure with Nannochloropsis oculata Mitigation on Productive Performance, Biochemical, and Oxidative Stress Biomarkers in Barki Rams

This study was designed to determine the lead or cadmium exposure of Barki rams and the beneficial role of Nannochlorposis oculata (N. oculata) 4% as a feed supplement, as well as its mitigating role against these elements' impacts concerning performance, biochemical markers of liver enzymes and kidney function, thyroid hormone activity, and oxidative stress markers. Six groups of 36 Barki rams (33.63 ± 1.29 kg) were divided into G1: which served as control; G2: was given 4% dietary N. oculata; G3: was given oral 1 mg/kg cadmium chloride; G4: was given 5 mg/kg/day lead acetate; G5: was given oral 1 mg/kg cadmium chloride and 4% dietary N. oculata, and G6: was given oral 5 mg/kg/day lead acetate and 4% dietary N. oculata; and treatments were continued for 60 days. Cadmium and lead-exposed groups exhibited lower and weaker weight gain as well as feed conversion ratio, respectively, than the control and other groups. Additionally, levels of T3, T4, total proteins, albumin, and glutathione (GSH) were significantly reduced in both G3 and G4 compared to control. However, urea, creatinine, ALT, AST, total cholesterol, triglycerides, protein carbonyl content (PCC), and malondialdehyde (MDA) were significantly increased (P ≤ 0.05) in cadmium and lead-exposed groups. Dietary N. oculata (4%) improves serum proteins, creatinine, urea, T4, and oxidative stress indicators as compared to the control group. Finally, 4% dietary N. oculata greatly enhances the investigated parameters in terms of performance, thyroid hormones, serum biochemical, and antioxidant activity and may assist in reducing the endocrine disrupting effects of Pb and Cd.

Health risk assessment of some selected heavy metals in infant food sold in Wa, Ghana

Infants remain a high-risk group as far as exposure to toxic metals is concerned. The levels of lead (Pb), cadmium (Cd), nickel (Ni), chromium (Cr), antimony (Sb), mercury (Hg), and arsenic (As) in twenty-two (22) samples of baby foods and formulas were determined using inductively coupled plasma mass spectrometry. The concentrations in (mg/kg) of As, Cd, Cr, Hg, Mn, Ni, Pb, and Sb were in the ranges 0.006-0.057, 0.043-0.064, 0.113-0.33, 0.000-0.002, 1.720-3.568, 0.065-0.183, 0.061-0.368 and 0.017-0.1 respectively. Health risk assessment indices like the Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), Cancer Risk (CR) and Hazard Index (HI) were calculated. EDI values of Hg, Cr, and As were below their recommended tolerable daily intake, that of Ni and Mn were lower in 95% of samples, and Cd was also lower in 50% of the samples. THQ values for As, Cd, Cr, Hg, Mn, Ni, and Pb were 0.32-3.21, 0.75-1.10, 0.65-1.94, 0.00-0.37, 0.21-0.44, 0.08-0.12 and 0.26-1.13 respectively. The CR values were greater than 10^-6, making them unacceptable for human consumption. HI values were between 2.68 and 6.83 (greater than 1), which implied that these metals are likely to pose non-carcinogenic health risks to infants.

A novel mushroom (Auricularia polytricha) glycoprotein protects against lead-induced hepatoxicity, promotes lead adsorption, inhibits organ accumulation of lead, upregulates detoxifying proteins, and enhances immunoregulation in rats

Introduction

Lead is a ubiquitous environmental and industrial pollutant. Its nonbiodegradable toxicity induces a plethora of human diseases. A novel bioactive glycoprotein containing 1.15% carbohydrate, with the ability of adsorbing lead and effecting detoxification, has been purified from Auricularia polytricha and designated as APL. Besides, its mechanisms related to regulation of hepatic metabolic derangements at the proteome level were analyzed in this study.

Methods

Chromatographic techniques were utilized to purify APL in the current study. For investigating the protective effects of APL, Sprague-Dawley rats were given daily intraperitoneal injections of lead acetate for establishment of an animal model, and different dosages of APL were gastrically irrigated for study of protection from lead detoxification. Liver samples were prepared for proteomic analyses to explore the detoxification mechanisms.

Results and discussion

The detoxifying glycoprotein APL displayed unique molecular properties with molecular weight of 252-kDa, was isolated from fruiting bodies of the edible fungus A. polytricha. The serum concentrations of lead and the liver function biomarkers aspartate and alanine aminotransferases were significantly (p<0.05) improved after APL treatment, as well as following treatment with the positive control EDTA (300 mg/kg body weight). Likewise, results on lead residue showed that the clearance ratios of the liver and kidneys were respectively 44.5% and 18.1% at the dosage of APL 160 mg/kg, which was even better than the corresponding data for EDTA. Proteomics disclosed that 351 proteins were differentially expressed following lead exposure and the expression levels of 41 proteins enriched in pathways mainly involved in cell detoxification and immune regulation were normalized after treatment with APL-H. The results signify that APL ameliorates lead-induced hepatic injury by positive regulation of immune processing, and suggest that APL can be applied as a therapeutic intervention of lead poisoning in clinical practice. This report represents the first demonstration of the protective action of a novel mushroom protein on lead-elicited hepatic toxicity.

Disturbed Ratios between Essential and Toxic Trace Elements as Potential Biomarkers of Acute Ischemic Stroke

Background: Cadmium (Cd) and lead (Pb) are known to be two of the metal contaminants that pose the greatest potential threat to human health. The purpose of this research study was to compare the levels of toxic metals (Cd, Pb) in patients with acute ischemic stroke (AIS), with a control group in Podlaskie Voivodeship, Poland. The study also aimed to assess the correlations between toxic metals and clinical data in AIS patients, and to assess the potential effect of smoking. Materials and methods: The levels of mineral components in the collected blood samples were assessed by means of atomic absorption spectrometry (AAS). Results: The Cd blood concentration was significantly higher in AIS patients as compared to the control group. We found that the molar ratios of Cd/Zn and Cd/Pb were significantly higher (p < 0.001; p < 0.001, respectively), when the molar ratios of Se/Pb, Se/Cd, and Cu/Cd were significantly lower (p = 0.01; p < 0.001; p < 0.001, respectively), in AIS patients as compared to control subjects. However, there were no considerable fluctuations in relation to the blood Pb concentration or molar ratios of Zn/Pb and Cu/Pb between our AIS patients and the control group. We also found that patients with internal carotid artery (ICA) atherosclerosis, particularly those with 20–50% ICA stenosis, had higher concentrations of Cd and Cd/Zn, but lower Cu/Cd and Se/Cd molar ratios. In the course of our analysis, we observed that current smokers among AIS patients had significantly higher blood-Cd concentrations, Cd/Zn and Cd/Pb molar ratios, and hemoglobin levels, but significantly lower HDL-C concentrations, Se/Cd, and Cu/Cd molar ratios. Conclusions: Our research has shown that the disruption of the metal balance plays a crucial role in the pathogenesis of AIS. Furthermore, our results broaden those of previous studies on the exposure to Cd and Pb as risk factors for AIS. Further investigations are necessary to examine the probable mechanisms of Cd and Pb in the onset of ischemic stroke. The Cd/Zn molar ratio may be a useful biomarker of atherosclerosis in AIS patients. An accurate assessment of changes in the molar ratios of essential and toxic trace elements could serve as a valuable indicator of the nutritional status and levels of oxidative stress in AIS patients. It is critical to investigate the potential role of exposure to metal mixtures in AIS, due to its public health implications.

Phytohormones enhance heavy metal responses in Euglena gracilis: Evidence from uptake of Ni, Pb and Cd and linkages to hormonomic and metabolomic dynamics

Over the last decade, significant effort has been made to understand phytohormonal functions (e.g., cytokinins (CKs) and abscisic acid (ABA)) in metal stress responses of higher plants and algae. Despite the potential for these phytohormones to improve industrial remediation by Euglena gracilis (Euglenophyceae), no such roles have been elucidated for this highly adaptive species and its response to heavy metals. This study demonstrates that toxic metals (nickel, lead, cadmium) modify hormonal activity profiles (i.e., CK forms and their concentrations) in E. gracilis. Furthermore, exogenous ABA or CK (tZ) enabled higher metal uptake efficiency (i.e., 9.35% in lead and 9.2% in cadmium uptake with CK) and alleviated metal toxicity through the regulation of endogenous CKs (i.e., total CK, isoprenoid CK) and gibberellin (GAs, GA₁ and GA₃) levels. These responses suggest that E. gracilis regulates multiple phytohormone signals during metal stress acclimation. A deeper approach, using untargeted metabolomic analyses, gave more detailed insight into phytohormone-controlled pathways and associated modified metabolites, which were frequently related to metal accumulation and the physiological acclimation to metal presence. Significant changes in the levels of cellular metabolites, especially those involved in acclimation to metal stress, were under the influence of phytohormones in algal cells. When grown under metal stress conditions, the presence of exogenous ABA or CKs, caused changes in cellular metabolites which included those from: lipid pathways, riboflavin metabolism, the biosynthesis of cofactors/vitamins, and carbohydrate metabolism. Also, bioactive secondary metabolites (e.g., terpenoids, alkaloids, flavonoids, carotenoids) were modified in algal cells treated with phytohormones. Thus, the study gives a detailed view on the regulatory functions of ABA and CKs in algal metal bioremediation strategies, which are attributed to enhanced metal uptake and in the fine-tuning of plant hormone levels during metal stress response. The results can guide efforts to develop efficient, low-cost and environmentally friendly methods for bioremediation.

Periconceptional maternal diet quality influences blood heavy metal concentrations and their effect on low birth weight: the Japan Environment and Children's Study

BACKGROUND

Both poor maternal nutrition and toxic heavy metal exposure influence foetal growth and development. However, whether consumption of a variety of healthy foods modifies the association between prenatal heavy metal exposure and foetal growth is unknown.

OBJECTIVE

We examined whether long-term maternal diet quality in periconception modifies the associations between maternal circulating concentrations of heavy metals and foetal growth.

DESIGN

Data of 72,317 Japanese women who delivered singleton infants was extracted from the Japan Environment and Children's Study. Maternal diet over a 1-year before the first trimester of pregnancy was assessed using a validated food frequency questionnaire, and overall diet quality was determined using the balanced diet score based on the Japanese Food Guide Spinning Top. Maternal whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) were measured during the second/third trimester of pregnancy. Bayesian inference of multiple linear regression analysis was performed to evaluate the relationships between maternal diet quality and the blood concentrations of heavy metals; Bayesian logistic regression was used to analyse the risk of low birth weight (LBW; <2,500 g).

RESULTS

After controlling for confounders, a high maternal balanced diet score was associated with low concentrations of blood Pb and Cd and high Hg. While all heavy metals assessed were positively associated with LBW risk, a higher maternal balanced diet score was negatively associated with LBW risk. A high-quality maternal diet attenuated the effect of Pb on LBW, an effect that was more marked at high blood Pb concentrations.

CONCLUSION

A high-quality, 'well-balanced' diet prior to conception may reduce exposure to some heavy metals and mitigate the elevated risk of LBW associated with prenatal Pb exposure in Japanese mother-child pairs.

Determination of cadmium in Chinese pepper and its health implications based on bioaccessibility

The contamination of cadmium (Cd) in agro-products causes major concern because of its potential dietary risks. In this study, a total of 647 pepper samples from 21 provinces in China were randomly collected according to the distribution of pepper production. Cd pollution levels in Chinses pepper and its health risks were evaluated based on bioaccessibility, which was measured by the physiologically based extraction test (PBET). The results showed that Cd concentration in all pepper ranged from 0.002 to 1.470 mg/kg, with an average of 0.222 mg/kg and a median of 0.132 mg/kg. The highest daily intake of Cd was observed in the female child group (4.037 × 10^-5 mg/kg bw/day), which accounted for 4% of the maximum daily permissible dose - 0.001 mg/kg bw/day. The target hazard quotients of Cd were all lower than 1, indicating low potential non-carcinogenic health risks to residents via the consumption of pepper. Notably, carcinogenic risk values suggested potential adverse health effects to adults, while after considering the bioaccessibility of Cd in pepper (mean of 43.07%), those values had fallen under the acceptable level (1 × 10^-4). This may indicate that dietary risk assessment of heavy metals in crops could not be conducted just based on their content; the bioaccessibility of metals is also an important factor for consideration.

Gallic acid abates cadmium chloride toxicity via alteration of neurotransmitters and modulation of inflammatory markers in Wistar rats

Cadmium is a highly neurotoxic heavy metal that disrupts membranes and causes oxidative stress in the brain. The study aimed to investigate the neuroprotective effect of gallic acid on oxidative damage in the brains of Wistar rats exposed to cadmium chloride (CdCl₂). Male Wistar rats were divided into four groups of five rats each. Group 1 was administered distilled water only throughout the study. Throughout the study, Group 2 received CdCl₂ alone (5 mg/kg b.w./day), Group 3 received gallic acid (20 mg/kg b.w./day), and Group 4 received CdCl₂ + gallic acid (20 mg/kg). Treatments were oral with distilled water as a vehicle. The study lasted 21 days. In the brain, the activities of cholinesterase and antioxidant enzymes were evaluated, as well as the levels of reduced glutathione, malondialdehyde, neurotransmitters, Na+/K+ ATPase, myeloperoxidase activity, nitric oxide, and interleukin-6. CdCl₂-induced brain impairments in experimental animals and gallic acid prevents the following CdCl₂-induced activities: inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), elevated neurotransmitters (serotonin and dopamine), decreased antioxidant enzymes (superoxide dismutase, catalase), decreased glutathione, Na+/K+ ATPases, and increased MDA and neuroinflammatory markers (myeloperoxidase (MPO), nitric oxide, and interleukin-6 in the brain of experimental rats exposed to CdCl₂ (p < 0.05). Taken together, the neuroprotective effects of gallic acid on CdCl₂-induced toxicity in the brains of rats suggest its potent antioxidant and neurotherapeutic properties.

Lead detoxification of edible fungi Auricularia auricula and Pleurotus ostreatus: the purification of the chelation substances and their effects on rats

Lead is a global pollutant that causes widespread concern. When a lead enters the body, it is distributed throughout the body and accumulates in the brain, bone, and soft tissues such as the kidney, liver, and spleen. Chelators used for lead poisoning therapy all have side effects to some extent and other drawbacks including high cost. Exploration and utilization of natural antidotes become necessary. To date, few substances originating from edible fungi that are capable of adsorbing lead have been reported. In this study, we found that two commonly eaten mushrooms Auricularia auricula and Pleurotus ostreatus exhibited lead adsorption capacity. A. auricula active substance (AAAS) and P. ostreatus active substance (POAS) were purified by hot-water extraction, ethanol precipitation from its fruiting bodies followed by ion exchange chromatography, ultrafiltration, and gel filtration chromatography, respectively. AAAS was 3.6 kDa, while POAS was 4.9 kDa. They were both constituted of polysaccharides and peptides. The peptide sequences obtained by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) proved that they were rich in amino acids with side chain groups such as hydroxyl, carboxyl, carbonyl, sulfhydryl, and amidogen. Two rat models were established, but only a chronic lead-induced poisoning model was employed to determine the detoxification of AAAS/POAS and their fruiting body powder. For rats receiving continuous lead treatment, either AAAS or POAS could reduce the lead levels in the blood. They also promoted the elimination of the burden of lead in the spleen and kidney. The fruiting bodies were also proved to have lead detoxification effects. This is the first study to identify new functions of A. auricula and P. ostreatus in reducing lead toxicity and to provide dietary strategies for the treatment of lead toxicity.

Urine metabolomic characteristics of female patients with occupational chronic cadmium poisoning after 15 years of treatment

Occupational chronic cadmium poisoning (OCCP) can cause irreversible organ damage. Currently, no effective treatment is available for OCCP, and effective and sensitive biomarkers for treatment evaluation are still lacking. In this study, metabolomics techniques were used to analyze changes in endogenous metabolites in the urine of patients with OCCP after 15 years of treatment. Thirty urine samples from female patients with OCCP and healthy female controls (n = 15 per group) were assessed using gas chromatography-time-of-flight mass spectrometry and ultra-high-performance liquid chromatography-Q-Exactive mass spectrometry. The OCCP group had higher concentrations of blood urea nitrogen and urinary cadmium but near-normal urinary concentrations of β₂ -microglobulin and retinol-binding protein. Compared with the control group, the OCCP group had 66 significantly different metabolites with a variable importance in projection score >1 and p < 0.05. These differential metabolites were involved in various metabolic pathways, such as creatine metabolism, nicotinate and nicotinamide metabolism, the pentose phosphate pathway, d-glutamine and d-glutamate metabolism, and amino acid metabolism. Compared with the control group, the OCCP group had significantly higher urinary concentrations of creatine, glutamic acid, quinolinic acid and nicotinic acid. In a receiver operator characteristic analysis, the area under the curve of creatine was higher than those for glutamic acid, quinolinic acid and nicotinic acid, indicating that urinary concentrations of creatine could be used as a sensitive biomarker for the diagnosis and prognosis of OCCP and for monitoring its treatment.

Renal glucose transporters play a role in removal of cadmium from kidney cells mediated by GMDTC - A novel metal chelator

Cadmium (Cd) is a toxic heavy metal, exposure to which leads to adverse health effects including chronic kidney damage. Tremendous efforts have been explored in identifying safe chelating agents for removing accumulated Cd from kidney, but with limited success owing to their associated side effects and the ineffectiveness in eliminating Cd. A newly developed chelating agent, sodium (S)-2-(dithiocarboxylato((2S,3 R,4R,5 R)-2,3,4,5,6-pentahydroxyhexyl) amino)-4(methylthio)butanoate (GMDTC), has been shown to effectively mobilize Cd from kidney. However, the mechanism(s) of removal are unclear, while it has been hypothesized that renal glucose transporters potentially play key roles mainly because GMDTC contains an open chain glucose moiety. To test this hypothesis, we utilized the CRISPR/Cas9 technology and human kidney tubule HK-2 cells, and constructed sodium-dependent glucose transporter 2 (SGLT2) or glucose transporter 2 (GLUT2) gene knockout cell lines. Our data showed that GMDTC's ability in removing Cd from HK-2 cells was significantly reduced both in GLUT2^-/- or SGLT2^-/- cells, with a removal ratio reduced from 28.28% in the parental HK-2 cells to 7.37% in GLUT2^-/- cells and 14.6% in SGLT2^-/- cells. Similarly, knocking out the GLUT2 or SGLT2 led to a compromised protective effect of GMDTC in reducing cytotoxicity of HK-2 cells. This observation was further observed in animal studies, in which the inhibition of GLUT2 transporter by phloretin treatment resulted in reduced efficiency of GMDTC in removing Cd from the kidney. Altogether, our results show that GMDTC is safe and highly efficient in removing Cd from the cells, and this effect is mediated by renal glucose transporters.

Threonine Facilitates Cd Excretion by Increasing the Abundance of Gut Escherichia coli in Cd-Exposed Mice

Cadmium (Cd) can easily enter the body through the food chain and threaten health since Cd pollution is prevalent in the environment. Gut microbiota is necessary for the reduction of metal ions. To reduce Cd-induced harmful impacts and Cd accumulation in the body, we investigated the effect of amino acids on gut microbiota and Cd excretion in (fecal Cd) Cd-exposed mice. The screening of 20 amino acids showed that threonine (Thr) effectively increased fecal Cd, and reduced Cd-induced intestinal structural damage. The abundance of Escherichia-Shigella genus and KF843036_g significantly increased after the oral administration of Thr. As the type species of the Escherichia-Shigella genus, Escherichia coli exhibited high similarity to KF843036_g species and significantly decreased Cd-induced gut damage. Cd contents in the liver, kidney, and gut of Cd-exposed mice were also significantly (p < 0.05) decreased after E. coli treatment, while the contents in the feces were increased. The results demonstrated the potential roles that gut E. coli might play in Thr-mediated Cd excretion in Cd-exposed mice. The findings may provide important data for better understanding the molecular biological mechanism of Thr in reducing Cd accumulation in the body.

Cobalt exposure triggers impairments in cognitive and anxiety-like behaviors, brain oxidative stress and inflammation, and hippocampo-amygdala histomorphological alterations: Protective role of aqueous Prosopis africana seed extract

Objectives

Cobalt toxicity has become a health concern in recent years, due to overexposure resulting in neurological impairments. With a growing interest in the therapeutic roles of herbs, in toxicity research, it's worth looking into the curative effects of aqueous Prosopis africana seed extract, a plant rich in flavonoids on cobalt-induced neurotoxicity.

Materials and Methods

We treated rats with CoCl₂ or CoCl₂ in combination with aqueous PA seed extract (PAE) orally for 14 days. Control rats received distilled water for the same period. Following treatments, behavioral experiments, analysis for oxidative stress, inflammation, and histological and immunohistochemical analysis were performed.

Results

Results revealed that CoCl₂ reduced the exploration time, recognition index in the novel object recognition test, percentage spontaneous alternation in the Y-maze tests, and reduced open arm entry and duration in elevated plus-maze. However, treatment with PAE improved these parameters to levels comparable with those of the control group. Furthermore, PAE therapy reduced CoCl₂-induced surge in hydrogen peroxide, malondialdehyde, TNF-α and IL-1β levels in brain homogenate, while also increasing superoxide dismutase and reduced reduced-glutathione activities. CoCl₂ exposure resulted in obvious features of neurodegeneration like nuclear disintegration, nuclear shrinkage, and cytoplasmic vacuolations of the cells of the hippocampus and amygdala, with an increased expression of GFAP. The hippocampal and amygdala histology improved after PAE administration, while exacerbated GFAP expressions were attenuated.

Conclusion

These findings imply that PAE may be anxiolytic and can help reduce cognitive impairments and hippocampal damage caused by CoCl₂ neurotoxicity, via mechanisms that involve attenuation of oxidative stress and inflammation.

Pollution characteristics and health risk assessment of potentially toxic elements in soils around China's gold mines: a meta-analysis

Since toxic element pollution is widespread in soils near gold mines due to increasing mining activities, the adverse effects of potentially toxic elements (PTEs) in the soils on ecological systems and human health cannot be ignored. However, assessments of PTE pollution in soils and their ecological-health risks on a national scale are still limited. Here, the concentrations of eight PTEs in soils near gold mines throughout China were obtained from published articles. Based on these data, the pollution levels and ecological-health risks of the eight PTEs in soils were comprehensively estimated. The results showed that the average contents of As, Cr, Cd, Pb, Hg, Cu, Ni, and Zn were 81.62, 79.82, 1.04, 206.03, 2.05, 40.82, 71.82, and 130.42 mg kg^-1, respectively, which exceeded the corresponding background values for soils. Most of the examined soils were heavily polluted by Hg and Cd, and higher pollution levels were found in the Henan and Shaanxi Provinces than in other regions. The average potential ecological risk value of all PTEs was 2534.71, indicating the presence of very high risks. Contribution of Hg to the potential ecological risk was more than 80%. For adults, all hazard index (HI) values of noncarcinogenic risks were below the safe level of 1.00. For children, none of the HI values exceeded the safe level, with the exception of As (HI = 1.81); nevertheless, four PTEs (As, Cr, Cu, and Ni) presented unacceptable carcinogenic risks. This study provides scientific basis for controlling PTE contamination and reducing the health risks in soils near gold mines worldwide.

Relationship between Metal Exposures, Dietary Macronutrient Intake, and Blood Glucose Levels of Informal Electronic Waste Recyclers in Ghana

While metal exposures are generally high among informal electronic waste (e-waste) recyclers, the joint effect of metals and dietary macronutrients on their metabolic health is unknown. Therefore, we investigated the relationship between metal exposures, dietary macronutrients intake, and blood glucose levels of e-waste recyclers at Agbogbloshie using dietary information (48-h recall survey), blood metals (Pb & Cd), and HbA1C levels of 151 participants (100 e-waste recyclers and 51 controls from the Accra, Ghana) in March 2017. A linear regression model was used to estimate the joint relationship between metal exposures, dietary macronutrient intake, and blood glucose levels. Except for dietary proteins, both groups had macronutrient deficiencies. Diabetes prevalence was significantly higher among controls. Saturated fat, OMEGA-3, and cholesterol intake were associated with significant increases in blood glucose levels of recyclers. In a joint model, while 1 mg of cholesterol consumed was associated with a 0.7% increase in blood glucose, 1 g/L of Pb was found to significantly increase blood glucose levels by 0.9% among recyclers. Although the dietary consumption of cholesterol and fat was not high, it is still possible that exposure to Pb and Cd may still increase the risk of diabetes among both e-waste recyclers and the general population.

[Elucidation and Application of Novel Action of Therapeutic Agents for Diabetic Neuropathy]

Epalrestat is the only aldose reductase inhibitor that is currently available for diabetic peripheral neuropathy. Oxidative stress impairs endothelial cells, thereby leading to numerous pathological conditions. Increasing antioxidative ability is important to prevent cellular toxicity induced by reactive oxygen species. Epalrestat increases antioxidant defense factors such as glutathione and γ-glutamylcysteine ligase in vascular endothelial cells through activation of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2). This increases suppression of oxidative stress-induced cellular toxicity. Cadmium is an industrial and environmental pollutant that targets the vascular endothelium. The vascular system is critically affected by cadmium toxicity. Therapeutic treatment against cadmium toxicity is chelation therapy that promotes metal excretion; however, cadmium chelators can cause renal toxicity. Therefore, safe and efficient therapeutic agents are required. Epalrestat suppresses cadmium-induced cytotoxicity in vascular endothelial cells through activation of Nrf2. In addition, epalrestat affects the intracellular levels of cadmium, cadmium transporter Zrt-Irt-like protein 8 (ZIP8), and metallothionein (MT). The upregulation of ZIP8 and MT may be involved in the suppression of cadmium-induced cytotoxicity by epalrestat. Drug repurposing is a new strategy for drug discovery in which the pharmacological action of existing medicines whose safety and pharmacokinetics have already been confirmed clinically and whose use has been approved is examined comprehensively at the molecular level. The results can be applied to the development of existing drugs for use as medicines for the treatment of other diseases. This review provides useful findings for future expansion of indications as research leading to drug repurposing of epalrestat.

Potential benefits of joint hypothetical interventions on diet, lead, and cadmium on mortality in US adults

BACKGROUND

Previous studies reported associations between high blood lead levels (BLLs) and urinary cadmium (UCd) concentrations and all-cause and cause-specific mortality. It is hypothesized that these associations are mediated by inflammation; therefore, adherence to an anti-inflammatory diet may mitigate these effects. We sought to estimate the potential effects of joint hypothetical interventions on metals levels and adherence to an anti-inflammatory diet or fruits and vegetables (FV) intake on the expected mortality distributions.

METHODS

We used data on 14,311 adults aged ≥ 20 years enrolled in the NHANES-III between 1988 and 1994 and followed up through Dec 31, 2015. We estimated daily FV servings and adherence to the dietary inflammatory index at baseline using 24-hour dietary recalls. Mortality was determined from the National Death Index records. We used the parametric g-formula with pooled logistic regression models to estimate the absolute risk of all-cause, cardiovascular, and cancer mortality under different hypothetical interventions compared to the natural course (no intervention).

RESULTS

Overall, we observed a decreased mortality risk when intervening to lower metals levels or increasing adherence to an anti-inflammatory diet or the daily FV servings. The joint intervention to lower BLLs and UCd and increase the adherence to the anti-inflammatory diet had the strongest impact on cancer mortality risk (risk difference [RD] = -1.50% (-2.52% to -0.62%)) compared to the joint intervention only on metals levels RD= -0.97% (-1.89 to 0.70). The same pattern of associations was observed for the joint intervention to lower both metals and increased daily FV servings and cardiovascular diseases mortality risk.

CONCLUSION

Higher diet quality may constitute a complementary approach to the interventions to reduce exposures to cadmium and lead to further minimize their effects on mortality. A paradigm shift is required from a pollutant-focused only to a combination with a human-focused approach for primary prevention against these metals.

Mutagenic, Carcinogenic, and Teratogenic Effect of Heavy Metals

Heavy metal (HM)-induced toxicity and its associated complications have become a major issue in the medical world. HMs are not biodegradable, enter into the food chain, and gets accumulated in the living systems. Increased concentrations and accumulation of HMs can cause severely damaging effects and severe complications in living organisms and can even lead to the death of the organism. In Ayurvedic medicine, ingredients of natural origin, including whole plants or certain portions of the plant, animal sources, and minerals, are used for therapeutic purposes as medicine, both alone and in combination. HM such as cadmium, copper, zinc, lead, chromium, nickel, and arsenic cause hazardous effects on animals, human health, and the environment. This review focuses on mutagenic, carcinogenic, and teratogenic effects of HM , mechanism, organ toxicity, available remedies in the market, and their side effects. Also, emphasis is given to alternative systems of medicine to treat HM toxicity.

One-step synthesis of highly fluorescent carbon dots as fluorescence sensors for the parallel detection of cadmium and mercury ions

Cadmium (Cd2+) and mercury ions (Hg2+) are essential for the quality control of food samples because of their serious toxicity to human health, but the effective and simple strategy for their parallel detection remains challenging. In this paper, a rapid and simple parallel detection method for Cd2+ and Hg2+ was developed using carbon dots (CDs) as fluorescent sensors. A one-step hydrothermal method with a single precursor l-arginine as both the carbon and nitrogen sources was employed to prepare nitrogen-doped CDs (N-CDs). N-CDs exhibited a uniform particle size and excitation-independent fluorescence emission. The maximum emission wavelength of N-CDs was observed at 354 nm with the excitation wavelength at 295 nm. The quantum yield of N-CDs reached as high as 71.6% in water. By using sodium diphosphate and phytic acid as masking agents, the fluorescent sensor can be quenched by Cd2+ and Hg2+ in the linear range of 0–26.8 μM and 0–49.9 μM within 5 min. Other common ions in farm products showed no significant effect on the fluorescence intensity of the sensing system. The results demonstrated that the sensing system had good selectivity and sensitivity for Cd2+ and Hg2+. The detection limits for Cd2+ and Hg2+ were 0.20 and 0.188 μM, respectively. In addition, the fluorescent sensor had been successfully applied for the detection of Cd2+ and Hg2+ in fruits and vegetables, and the recoveries were 86.44–109.40% and 86.62–115.32%, respectively. The proposed fluorescent sensor provides a rapid, simple, and sensitive detection method for Cd2+ and Hg2+ in food samples and thus a novel quantitative detection method for heavy metal ions in foods.