Insight into the oxidative stress induced by lead and/or cadmium in blood, liver and kidneys

Polyamide/silica/sodium alginate in-situ composite: Synthesis and application in electrochemical probing for Pb2+/Cd2

In this study, polyamide/silica/sodium alginate (SA) composite (PA-Si-SA) was successfully prepared in one-step benzoxazine-isocyanide chemistry (BIC)/sol-gel process at room temperature. The chemical structure and fundamental properties of PA-Si-SA were characterized by FT-IR, solid-state 13C NMR, XPS, XRD, SEM, BET and TG, etc. The presence of anionic SA and diverse N, O-containing functional segments (amide, tertiary amine, alkyl/phenol -OH, Si-O-Si, and COO-) in PA-Si-SA endows it synergistic complexation capability toward Pb2+ and Cd2+. PA-Si-SA/GCE (glassy carbon electrode) fabricated by using PA-Si-SA as active modifier was applied to realize the efficient electrochemical detection of Pb2+/Cd2+. Relevant detection ranges, detection limits, anti-interference and detection mechanisms were systematically investigated further. Detection limits of Pb2+ and Cd2+ by PA-Si-SA/GCE were up to ~2.4 × 10-8 mol/L and ~ 4.1 × 10-9 mol/L, with corresponding linear detection ranges of 0.5-140.0 μmol/L and 0.01-140.0 μmol/L, respectively.

Combined Effects of Cadmium and Lead on Growth Performance and Kidney Function in Broiler Chicken

Cadmium (Cd) and lead (Pb) are heavy metals prevalent in the environment and feed, and they reduce production performance of domestic animals, as well as they result in residue in animal tissues. The kidney is the target tissue for Cd and Pb. And the kidney is crucial for the reabsorption of calcium (Ca), which consequently influences bone strength. However, there are relatively few studies related to the effects of Cd and Pb exposure on performance, bone strength and kidney damage in livestock. The purpose of this experiment was to explore the combined effect of Cd and Pb on growth performance and renal impairment and the possible underlying mechanism. For this, 168 1-day-old Ross 308 broilers were randomly divided into four groups of six birds each, with seven replicates in each group: control group, 50 mg Cd/kg body weight group, 200 mg Pb/kg body weight group and 50 mg Cd/kg body weight + 200 mg Pb/kg body weight group. Feed intake was recorded daily and body weight was recorded weekly. The results show that at the end of the 3rd and 6th week, one broiler from each replicate was randomly selected for sampling. Boilers co-exposed to Cd and Pb for 3 weeks and 6 weeks had significantly decreased average daily feed intake (ADFI) and average daily body weight gain (ADG) than the control group, and the ratio of feed-to-weight gain (F/G) significantly increased after 6 weeks of co-exposure to Cd and Pb. Microscopic picture and ultrastructure analyses of the kidneys showed that Cd and Pb caused kidney damage to broiler chickens, and the damage was more serious in the Cd + Pb group, which was manifested by increased renal tubular epithelial degeneration and increased interstitial stasis points. Dietary exposure to Cd and Pb impaired production performance and induced renal oxidative damage in broilers. The combined effects of Cd and Pb on the kidneys are greater than their effects alone. The PERK-ATF4 pathway mediated endoplasmic reticulum stress participates the renal oxidative damage during chronic Cd and Pb exposure.

Apex carnivores coping with metal(loid) pollution and oxidative stress: Biological and environmental drivers of variation in kidney of European brown bear

Induction of oxidative stress and the associated lipid peroxidation is a prevalent mechanism through which certain metal(loid)s exert nephrotoxic effects in mammals. Research on the toxic impacts of metal(loid)s in free-ranging large mammals at high trophic positions is exceedingly rare, yet crucial for understanding environmental exposure scenarios relevant to both human and animal risk assessment. Renal cortex tissues (N = 457) of free-ranging brown bears (Ursus arctos) from the Dinara-Pindos population sampled in Croatia were analysed herein for toxic metal(loid)s and the underlying biological and environmental drivers of variation, with their time trend monitored during the 2009-2022 period. In 28 individuals from the 2021-2022 period, we additionally investigated associations between metal(loid)s and oxidative stress and damage biomarkers in renal cortex cells. The principal generalized linear models used to approximate variations in biomarkers of oxidative stress and damage included non-essential As, Cd, Pb, Tl and U, and essential Co, Cu, Fe and Zn. Age class and season of sampling had no impact on biomarker levels, except for lipid peroxidation, LP (April ↑). Age, sex (females ↑), body condition index (↓) and season of sampling significantly influenced metal(loid)s levels. Non-specific mammalian thresholds were crossed for Cd and Pb toxicity in 1-16% and 2% of population, respectively. Renal levels of metal(loid)s did not exhibit a clear trend over the 13-year period. The levels found in this study were higher than in sympatric carnivorous and herbivorous species, but in line with findings in ursids worldwide. Potential adverse health effects from environmental exposure in brown bears may arise from disruption of oxidative balance, as evidence clearly indicated associated changes in catalase activity (↑), glutathione content (↑), LP (↓), reactive oxygen species (↓), total antioxidant capacity (↑) in the renal cortex due to the presence of the most toxicologically relevant Cd and Pb.

Association of blood cadmium and physical activity with mortality: A prospective cohort study

Physical activity (PA) may be considered an alternative method to ameliorate the elevated mortality risks associated with cadmium exposure. In this prospective cohort study, a total of 20,253 participants (weighted mean age, 47.79 years), including 10,247 men (weighted prevalence: 50.1 %), aged 18 years or older, were selected from the National Health and Nutrition Examination Survey from 2007 to 2018. Multivariable Cox proportional hazards regression models were utilized to evaluate the associations between blood cadmium levels, PA, and the risks of mortality. Restricted cubic spline analyses were employed to investigate the nonlinear relationships between blood cadmium and PA levels and mortality risks. During a median follow-up of 7.6 years, a total of 2002 (9.89 %) all-cause deaths occurred, of which 581 (2.87 %) participants were due to cardiovascular disease (CVD) and 498 (2.46 %) died of cancer. J-shaped associations were observed for blood cadmium with risks of mortality (all Poverall < 0.001; all Pnonlinearity < 0.001). Blood cadmium and PA had multiplicative interactions on mortality risk (all Pinteraction < 0.05). Compared with the subgroup with the lowest quartile of blood cadmium and recommended PA, the combination of the highest quartile of blood cadmium and without recommended PA was associated with the highest risks of all-cause and cancer mortality, followed by those meeting recommended PA but in the highest quartile of blood cadmium (hazard ratios, 2.43; 95 % confidence interval, 1.95-3.02). Achieving recommended PA significantly attenuated the detrimental effects of blood cadmium on all-cause, CVD, and cancer mortality risks.

Protective Effect of Protocatechuic Acid on Oxidative Damage and Cognitive Impairment in Pb-Induced Rats

Protocatechuic acid (PCA), a class of water-soluble phenolic acid abundant in the human diet, has been shown to be of great nutritional interest and to have medicinal value. However, the protective effects against lead (Pb)-induced body injury have not been elucidated. In this study, we explored the protective effect of PCA on Pb-induced oxidative damage and cognitive impairment in rats. The results showed that PCA could reduce the Pb content in rat bodies (blood, bone, brain, liver, and kidney) after Pb exposure. Moreover, PCA may inhibit Pb-induced oxidative damage by increasing the activity of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreasing the level of malondialdehyde (MDA) in the brain, liver, and kidney. In addition, PCA may alleviate Pb-induced learning and memory impairment by upregulating neurotransmitter levels; maintaining the normal function of N-methyl-D-aspartate receptors (NMDARs); and promoting Ca2+ influx, thus activating signaling molecules, related protein kinases, and transcription factors in the cAMP-PKA-CREB pathway. In general, PCA could reduce oxidative stress and ameliorate the learning and memory deficits in Pb-treated rats, indicating that PCA may be an effective preventive agent and treatment or plumbism.

Linalool may have a therapeutic effect on cadmium-induced nephrotoxicity by regulating NF-κB/TNF and GRP78/CHOP signaling pathways

Cadmium (Cd) is an environmental pollutant heavy metal with nephrotoxic effect. One of the primary constituents of essential oils is Linalool (Lin), a monoterpene having a variety of pharmacological properties including antimicrobial, anti-inflammatory, and antioxidant effects. The purpose of this study was to ascertain how Lin affected endoplasmic reticulum stress (ERS) and pro-inflammatory mediators in Cd-induced nephrotoxicity. In the experiment, 28 male rats were randomly divided into four equal groups as control (no application), Cd (Cd at a dose of 3 mg/kg for the first 7 days), Cd+Lin (Cd at a dose of 3 mg/kg for the first 7 days and 100 mg/kg/day Lin) and Lin (100 mg/kg/day Lin) (n=7). The experiment was completed on the 15th day after all treatments were performed. Blood serum and kidney tissue samples were used for analyses. Cd-induced histopathological changes, inflammation, oxidative stress, and apoptosis were determined to increase in kidney tissue. However, it was observed that Cd-induced adverse effects in kidney tissue were mainly eliminated by Lin treatment. In conclusion, Lin demonstrated anti-inflammatory, anti-oxidant and anti-apoptotic effects in Cd-induced nephrotoxicity. Therefore, we believe that Lin may represent a high potential therapeutic strategy against renal tissue damage.

Unveiling the interaction and combined effects of multiple metals/metalloids exposure to TNF-α and kidney function in adults using bayesian kernel machine regression and quantile-based G-computation

BACKGROUND

Exposure to multiple metals may cause adverse effects, particularly in the kidneys. However, studies on the combined and interaction effects of metal mixtures on human health remain limited.

OBJECTIVE

The study aims to evaluate the interaction between metals and assess the combined effects of exposure to metal mixtures on tumor necrosis factor-alpha (TNF-α) levels and kidney function METHODS: Particular emphasis has been placed on the impact of various metals, including arsenic (As), cadmium (Cd), lead (Pb), as well as essential trace elements, such as cobalt (Co), copper (Cu), selenium (Se), and zinc (Zn), on human health and their potential collective influence on both TNF-α and kidney function. This cross-sectional study analyzed the data of 421 adults who underwent a health examination. Generalized linear model (GLM), Bayesian kernel machine regression (BKMR), and quantile-based G-computation (qgcomp) were used to evaluate the association and joint effects between the metals and TNF-α, as well as kidney function.

RESULTS

Increased concentrations of As (β = 0.11, 95 % CI = 0.05, 0.17) and Pb (β = 0.30, 95 % CI = 0.23, 0.37) in the blood were associated with elevated levels of TNF-α, while elevated Cu (β = -0.42, 95 % CI = -0.77, -0.07) levels were linked to a significant reduction in TNF-α. The overall effect of metals mixture showed a significant association with a decline in eGFR and an increase TNF-α in the BKMR model. Qgcomp analysis of the metals mixture (β = -0.06, 95 % CI = -0.07, -0.05) indicated that As, Pb, and Zn were the primary contributors to the reduction in eGFR, while As and Pb were the major contributors in metals mixture (β = 0.12, 95 % CI = 0.08, 0.15) to the elevation of TNF-α levels.

CONCLUSION

Exposure to multiple metals could have joint association with the TNF-α levels and kidney function. Furthermore, TNF-α could act as a mediator between metal mixtures and eGFR.

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

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

The Effectiveness of Levamisole and Broccoli in Lead Poisoning: Hematobiochemical Changes and Tissue Damage in the Liver, Kidney, and Spleen of Wistar Rats

Lead, a heavy metal, has emerged as one of the most significant pollutants, bearing irreversible consequences on human and animal health in conjunction with industrial development. Presently, the use of medicinal plants to alleviate the adverse effects of heavy metal toxicity has captured the attention of researchers. Hence, the objective of this study was to assess the impact of levamisole and broccoli extract on the electrophoretic pattern of serum proteins, hematological parameters, and histopathological alterations in the liver, kidney, and spleen tissues within a lead poisoning model of rats. This experimental investigation spanned 28 days, involving 42 male Wistar rats categorized into seven groups: a control group, a lead acetate (AL) group administered at 1000 ppm in drinking water, a broccoli (B) group at 300 mg/kg/day, a levamisole (LE) group at 2.5 mg/kg/day, and combination groups of lead and broccoli (AL + B), lead and levamisole (AL + LE), and lead, broccoli, and levamisole (AL + LE + B). Upon completion of the study, hematological and biochemical parameters were assessed, and serum protein concentrations were analyzed using electrophoresis. Liver, kidney, and spleen tissues were fixed and subjected to histopathological examination with H&E staining. The findings indicated a significant decrease in white blood cells (WBC), red blood cells (RBC), and hemoglobin (Hb) levels in the AL group compared to other groups (p < 0.01). Conversely, the B group exhibited a notable increase in RBC and WBC compared to the AL group (p < 0.05). The most pronounced lead-induced damage was observed in the liver, resulting in elevated levels of specific enzymes such as AST and ALT in the AL group, accompanied by a decline in albumin and total protein (p < 0.001). A reduction in globulin levels, including Beta-2 globulin, was noted in the AL + B and AL + LE groups compared to the AL group (p < 0.001,  p < 0.05). Histopathological findings also unveiled increased infiltration of inflammatory cells and hemorrhage in the liver tissue, followed by the spleen, significantly higher in the AL group compared to other experimental groups (p < 0.05). Additionally, congestion and inflammation were evident in the spleen tissue compared to other groups. These tissue damages were mitigated in other combination treatment groups. Based on the aforementioned results, the combination of broccoli and levamisole is deemed effective in ameliorating liver and spleen injuries caused by lead and enhancing biochemical parameters and serum proteins.

Bioaccessibility and bioavailability of Pb and Cd in rice is affected by propolis and its extracts and Fe intervention

Increasing the intake of dietary supplements containing antioxidant components can reduce the oral bioavailability of lead (Pb) and cadmium (Cd) and benefit human health. In this study, the effects of propolis and its extracts (kaempferol (KAE), quercetin (QR), and caffeic acid phenethyl ester (CAPE)) in conjunction with proanthocyanidins (PA) on Pb and Cd bioaccessibility (BAC) and the relative bioavailability (RBA) in brown and polished rice are investigated. The results of in vitro tests showed that propolis and its extracts were effective in reducing Pb BAC in both brown and polished rice. A medium dose of PA had a significant reduction effect on Cd BAC (76 %) and RBA in both brown and polished rice. Based on mouse bioassays, the supplementation of propolis and its extracts significantly (p < 0.05) reduced the Pb-RBA in brown rice, resulting in a decrease in Pb RBA from 25 % in the control group to 16.5-17.6 %. The results showed that the BAC and RBA of Pb in brown rice with dietary supplements decreased significantly, which may be related to the enhanced inhibitory effect of high Fe. It was also found that the Pb RBA was negatively correlated with the Fe content in mice kidneys. This result provided evidence that antioxidants better inhibit the bioavailability of heavy metals, highlighting that propolis and PA may be alternative dietary supplements for intervening in human Pb and Cd exposure.

DNA damage-inducing endogenous and exogenous factors and research progress

The substances that cause abnormal DNA structures are known as DNA damage-inducing factors, and their resulting DNA damage has been extensively studied and proven to be closely related to cancer, neurodegenerative diseases, and aging. Prolonged exposure to DNA damage-inducing factors can lead to a variety of difficult-to-treat diseases, yet these factors have not been well summarized. It is crucial to use a combination of environmental science and life science to gain a deep understanding of the environmental sources and biological consequences of DNA damage-inducing factors for mechanistic research and prevention of diseases such as cancer. This article selected 14 representative carcinogenic exogenous DNA damage-inducing factors and summarized them through a literature search, including both exogenous and endogenous DNA damage factors, and explored the types of DNA damage caused by the relevant damage factors.

Association between blood heavy metals and diabetic kidney disease among type 2 diabetic patients: a cross-sectional study

Studies on the correlation of exposure to metals with diabetic kidney disease (DKD) is scarce, especially concerning the impact of mixed metals on DKD. This study aimed to explore the association of blood heavy metals with DKD risk among type 2 diabetes mellitus (T2DM) patients. This cross-sectional study enrolled patients with T2DM in NHANES 2011-2020. ICP‒MS was applied to detect five metals, namely, Pb, Cd, Hg, Se and Mn, in blood. At the same time, the impacts of exposure to single and mixed metals on DKD were assessed using multivariable logistic regression, WQS, and BKMR models. The relationship was examined based on age, sex, BMI, hypertension, smoking status and PIR. Totally 2362 participants were enrolled for final analysis. Among them, 634 (26.84%) patients undergoing T2DM had DKD. Logistic regression indicated that, Pb (Q4: OR [95% CI]: 1.557 [1.175, 2.064]) was related to DKD when all covariates were adjusted. The WQS analysis, which was set in a positive directional mode, suggested that Pb was correlated positively with a higher incidence of DKD. In BKMR analysis, linear dose‒response curves were generated for Pb when fixing the other metals in the 50th percentile. In addition, exposure to mixed metals was significantly positively related to DKD. Subgroup analysis during logistic regression demonstrated that Pb was significantly and positively related to DKD in females, over 50 years, those with over 25 kg/m2, no hypertension, no smoking status and under PIR. Serum albumin (ALB) did not regulate the indirect impact of blood Pb on DKD risk. The results showed that the increased mixed metal concentration may lead to an increased DKD risk among patients with T2DM. Blood Pb is positively related to the DKD risk in diabetic patients, especially, in females, over 50 years, those with over 25 kg/m2, no hypertension, no smoking status and under PIR in T2DM patients. According to our observations, Pb absorption at least slightly influences DKD occurrence and progression. More studies are needed to validate the results in this work and illustrate the relevant biological mechanism.

Icariin reduces cadmium-induced renal injury in rats

Icariin (ICA), an active ingredient found in Epimedium, possesses antioxidant and anti-inflammatory properties and has garnered widespread attention in recent years. This study investigated the protective effects of ICA against cadmium (Cd)-induced kidney injury in rats. Healthy male specific pathogen-free Sprague-Dawley rats were randomly divided into a control group, Cd group, a low-dose ICA group, a middle-dose ICA group, and a high-dose ICA group using a random number table. Tissue and blood samples were analyzed for renal function markers, histopathology, and gene expression. We found that ICA intervention ameliorates Cd-induced nephrotoxicity by enhancing glomerular filtration, mitigating renal tubular epithelial cell damage, reducing cellular degeneration and edema, and decreasing oxidative stress. ICA demonstrated anti-apoptotic activity through the regulation of pro- and anti-apoptotic gene transcription and by inhibiting apoptosis, thus protecting the kidneys. ICA also exhibited anti-inflammatory effects by reducing the transcription of Cd-induced pro-inflammatory genes, inhibiting nucleotide oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasome formation, and preventing pyroptosis. ICA potentially regulated the Toll-like receptor 4/P2rx7/nuclear factor kappa B signaling pathway, which modulated the activation of the NLRP3 inflammasome and contributed to its anti-inflammatory action. ICA reduced Cd-induced renal injury in rats, likely through a mechanism involving antioxidant, anti-apoptotic, and anti-inflammatory effects.

The relationships between blood lead levels and nocturia prevalence in adults: A retrospective study

PURPOSE

The purpose of this study was to examine the association between blood lead levels and the prevalence of nocturia in American adults.

METHODS

We analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2020, focusing on individuals aged 20 years or older (n = 11,919). Blood lead levels were categorized into two groups (<2 µg/dL and ≥2 µg/dL), and the presence of nocturia was assessed based on questionnaire responses. We used multivariable logistic regression models to explore the association between blood lead levels and nocturia while adjusting for various covariates, including sex, ratio of family income to poverty (RIP), lipid profile, age, body mass index (BMI), race, citizenship, sleep trouble, diabetes, and hypertension. To verify whether certain covariates influence blood lead levels and the risk of nocturia, we conducted subgroup analyses.

RESULTS

Of the study participants, 31.70% reported experiencing nocturia. Individuals with higher blood lead levels (≥2 µg/dL) exhibited a higher likelihood of experiencing nocturia compared to those with lower levels (<2 µg/dL) in all three models (Model 1: OR 1.46, 95% CI 1.29-1.66, p < 0.0001; Model 2: OR 1.25, 95% CI 1.09-1.44, p = 0.002; Model 3: OR 1.22, 95%CI 1.06-1.41, p = 0.01). Subgroup analyses revealed that factors such as age, sex, sleep trouble, diabetes, hypertension, BMI, RIP, and race did not affect the association between blood lead levels and the risk of nocturia (P for interaction >0.05).

CONCLUSIONS

This study reported the correlation between blood lead levels and nocturia. We found that compared to blood lead levels below 2 µg/dL, when lead levels reached or exceeded 2 µg/dL, the risk of nocturia occurrence increased by 22%.

CLINICAL TRIAL REGISTRATION

This study is based on existing data from a public database and not from a specific clinical trial; hence, clinical registration information is not provided.

Revisiting cadmium-induced toxicity in the male reproductive system: an update

Heavy metals like cadmium (Cd) are one of the main environmental pollutants, with no biological role in the human body. Cd has been well-documented to have disastrous effects on both plants and animals. It is known to accumulate in kidneys, lungs, liver, and testes and is thought to affect these organs' function over time, which is linked to a very long biological half-life and a very poor rate of elimination. According to recent researches, the testes are extremely vulnerable to cadmium. The disruption of the blood-testis barrier, seminiferous tubules, Sertoli cells, and Leydig cells caused by cadmium leads to the loss of sperm through various mechanisms, such as oxidative stress, spermatogenic cell death, testicular swelling, dysfunction in androgen-producing cells, interference with gene regulation, disruption of ionic homeostasis, and damage to the vascular endothelium. Additionally, through epigenetic control, cadmium disrupts the function of germ cells and somatic cells, resulting in infertile or subfertile males. A full grasp of the mechanisms underlying testicular toxicity caused by Cd is very important to develop suitable strategies to ameliorate male fertility. Therefore, this review article outlines cadmium's impact on growth and functions of the testicles, reviews therapeutic approaches and protective mechanisms, considers recent research findings, and identifies future research directions.

Heavy metal pollution in commonly consumed fish species: seasonal variations and health risks

This study examined the concentrations of seven heavy metals (Pb, Cu, Zn, Cr, Cd, Ni, and Mn) in the muscle tissue of six commonly consumed fish species (Cyprinus carpio, Labeo rohita, Wallagu attu, Hypophthalmicthys molitrix, Channa punctuate, and Puntius sophore) from the River Indus in the Mianwali district Pakistan. Samples were collected during both pre-monsoon and post-monsoon seasons to assess the potential human health risks associated with these heavy metals. The levels of metals were measured using atomic absorption spectroscopic analysis. The results showed varying concentrations of heavy metals in the fish samples (mg/kg), ranging from 10.17-2.06 for Pb, 41.83-12.54 for Cu, 417.04-41.93 for Zn, 2.06-0.46 for Cr, 0.86-0.08 for Cd, 4.33-1.43 for Ni, and 50.16-8.74 for Mn. Notably, metal concentrations were generally higher during the pre-monsoon season, with Pb consistently exceeding standard limits in the muscle tissue of all fish species. ANOVA analysis revealed significant variations in heavy metal concentrations among different fish species. While the current consumption rate poses no significant health risks, ongoing monitoring of heavy metal concentrations in fish and their environmental sources is crucial to ensure consumer safety and sustainable aquatic ecosystems.

The role of miR-216a-mediated Nrf2 pathway in muscle oxidative stress of Siniperca chuatsi induced by cadmium

Cadmium (Cd) is a toxic heavy metal pollutant in the environment. Excessive Cd in water has toxic effects on fish, endangering their healthy growth and ultimately affecting the quality and safety of aquatic products. To evaluate the toxicity of excessive Cd to fish through potential oxidative damage, Siniperca chuatsi was exposed to Cd in water for 15 days. It was found that Cd exposure significantly decreased the survival rate of S. chuatsi and Cd was detected in their muscle. Meanwhile, Cd disrupts the redox balance by reducing antioxidant enzyme activities, increasing reactive oxygen species (ROS) and malondialdehyde (MDA) levels in muscle, and promoting oxidative damage. Histomorphology showed that enlargement of muscle fiber gaps, cell swelling and vacuolar degeneration after Cd exposure. In addition, Cd toxicity induced up-regulating the expression of miR-216a, while down-regulation of Nrf2 protein and its downstream antioxidant enzyme genes expression. Further analysis revealed that miR-216a was significantly negatively correlated with the expression of Nrf2, and injection of miR-216a antagomir significantly enhanced the expression of Nrf2 and antioxidant enzyme genes, as well as the activity of antioxidant enzymes, thereby reducing the damage of Cd to fish. These results suggested that miR-216a-mediated Nrf2 signaling pathway plays an important role in Cd-induced oxidative stress of S. chuatsi muscle.

Internal blood lead exposure levels in permanent residents of Jiangxi Province and its effects on routine hematological and biochemical indices

Background

Lead exposure levels are closely linked to human health and can cause damage to multiple organ systems, including the blood system and liver. However, due to insufficient evidence, the effects of lead exposure on hematological and biochemical indices have not been fully established.

Objective

This study aims to explore the blood lead levels of permanent residents in Jiangxi Province and analyze the factors affecting blood lead levels and the impact of blood lead levels on hematological and biochemical indices.

Methods

We conducted a cross-sectional study including questionnaires, health examinations, and blood sample examinations on 720 randomly selected permanent residents (3-79 years) in Jiangxi Province in 2018. The blood lead levels were measured using inductively coupled plasma mass spectrometry. Routine hematological and biochemical tests were determined by qualified medical institutions using automated hematology analyzers and biochemistry analyzers.

Results

The geometric mean of blood lead concentration in permanent residents of Jiangxi Province was 20.45 μg/L. Gender, age, annual household income, smoking, and hypertension were the influencing factors for blood lead levels. For each 1 μg/L increase in blood lead, the risks of elevated red blood cell count (from low to high), platelet volume distribution width, alkaline phosphatase (from low to high), and cholesterol increased by 2.4, 1.6, 3.6, and 2.3%, respectively, whereas the risks of elevation of direct bilirubin and total bilirubin both decreased by 1.7%.

Conclusion

The blood lead level in permanent residents of Jiangxi Province is higher than the national average. Higher blood lead levels were found in men than in women; blood lead levels were positively correlated with age but negatively correlated with annual household income; smoking and hypertension are risk factors for elevated blood lead; and blood lead levels affect routine hematological and biochemical markers such as red blood cell count, platelet volume distribution width, direct bilirubin, total bilirubin, alkaline phosphatase, and cholesterol.

Cadmium-induced pancreatic toxicity in rats: comparing vitamin C and Nigella sativa as protective agents: a histomorphometric and ultrastructural study

The study aimed to assess the toxic effect of cadmium (Cd) on the exocrine and endocrine functions of pancreas, the changes in pancreatic tissue after Cd withdrawal, and the protective effects of vitamin C (VC) and Nigella sativa (NS) against Cd-induced damage. Rats were assigned to: control, Cd-treated (0.5 mg/kg/d intraperitoneal [IP] injection), VC and Cd-treated (receiving 100 mg/kg/d VC orally and Cd concomitantly), NS and Cd-treated (receiving 20 mg/kg/d NS and Cd, simultaneously), and Cd withdrawal (receiving Cd for 30 d then living free for recovery for other 30 d). Blood samples were collected and post-sacrifice pancreatic specimens were processed for light and electron microscope study. Quantitative analyses of pancreatic collagen area%, pancreatic islet parameters, β cell density, and insulin immunoexpression were done. Fasting blood glucose was significantly increased in Cd-treated and Cd-withdrawal groups, while co-treatment with VC and NS caused significant reductions (p < 0.05). Cd-induced extensive degenerative changes in pancreatic acini and islets at light and ultrastructure levels. Obvious fibrosis and congestion of blood vessels were noticed. Significant reductions in pancreatic islet number, volume, and surface area and diminished beta cell count and insulin immunoexpression were observed. After withdrawal of Cd, the whole pancreatic tissue still showed a serious impact. Concomitant treatment with VC or NS obviously reduced these degenerative changes and significantly improved pancreatic islet parameters and insulin immunoexpression. VC showed a better amendment than NS, but this difference was statistically insignificant. Therefore, VC and NS could be used as prophylactic agents that lessen Cd consequences on the pancreas.

Evaluation of the Potential Cytoprotective Effect of Melatonin in Comparison with Vitamin E and Trolox against Cd2+-Induced Toxicity in SH-SY5Y, HCT 116, and HepG2 Cell Lines

Cadmium (Cd) toxicity poses a significant threat to cellular health, leading to oxidative stress and cell damage. Antioxidant agents, particularly those of natural origin, have been studied as a potential alternative for mitigating heavy metal toxicity. This study aimed to evaluate the cytoprotective effects of the antioxidant melatonin (MLT) in comparison with Vitamin E (VitE) and Trolox against Cd2+-induced cellular toxicity. The MTT assay was employed to assess cell viability in neuronal SH-SY5Y, colorectal HCT 116, and hepatic HepG2 cell lines. The results showed that all three antioxidants offered some level of protection against Cd toxicity, with Vitamin E proving to be the most effective. MLT also demonstrated a substantial cytoprotective effect, especially at the highest Cd concentration of 30 µM. These findings suggest that MLT, alongside Vit E and Trolox, could be valuable in mitigating the detrimental effects of Cd exposure by reducing the oxidative stress in these cellular models.

Is the milk we drink safe from elevated concentrations of prioritised heavy metals/metalloids? - A global systematic review and meta-analysis followed by a cursory risk assessment reporting

Milk has been globally recognised as a comprehensive and vital food source for centuries. However, the presence of heavy metals and metalloids (metal(loid)s) in milk is a global problem. As metal(loid)s are present in the soil due to natural geogenic and various anthropogenic activities, these metal(loid)s are bio-transferred into animal feed, which further results in the presence of metal(loid)s in milk due to bio transfer/accumulation. This systematic review collated information from published literature between 2000 and 2021. It focused on the global issue of metal(loid)s in milk, posing potential health risks. These contaminants enter the food chain through the bio-transfer/accumulation process from soil to animal feed to milk. The key metal(loid)s examined are arsenic (As), mercury (Hg), lead (Pb), and cadmium (Cd). A meta-analysis of 66 selected papers revealed the widespread presence of these contaminants in milk samples globally, with Pb being the most studied (43 %). This research estimated metal(loid)s levels or concentrations as 12.71 (95 % Confidence Interval (CI) = 0.16-25.26), 16.09 (95 % CI = 4.31-27.70), 197.04 (95 % CI = 75.28-318.18), 31.67 (95 % CI = 20.14-43.20) μg/kg (ppb) for As, Hg, Pb, and Cd, respectively using Stata™. The metal(loid) concentrations in milk were within the threshold limits other than Pb and Cd. Some studies in America, Africa, and Asia reported elevated Pb and Cd concentrations, raising health concerns. The simulated Risk Quotients (RQ) and Integrated Risk Quotient (IRQ) values generally remain above one, indicating potential human health risks. Notably, the IRQ value increases with more metal(loid)s consideration. Subgroup analysis indicates low-fat milk contains higher metal(loid)s concentrations. While metal(loid)s concentrations in milk largely comply with safety limits, some regions exhibit concerning concentrations. Therefore, continued surveillance to address potential health risks associated with metal(loid)s in milk is necessary to ensure dairy products' safety.

Lead induced cerebellar toxicology of developmental Japanese quail (Coturnix japonica) via oxidative stress-based Nrf2/Keap1 pathway inhibition and glutathione-mediated apoptosis signaling activation

Lead (Pb) is a heavy metal that has been recognized as a neurotoxin, meaning it can cause harmful effects on the nervous system. However, the neurotoxicology of Pb to birds still needs further study. In this study, we examined the neurotoxic effects of Pb exposure on avian cerebellum by using an animal model-Japanese quail (Coturnix japonica). The one-week old male chicks were exposed to 50, 200 and 500 mg/kg Pb of environmental relevance in the feed for five weeks. The results showed Pb caused cerebellar microstructural damages charactered by deformation of neuroglia cells, granule cells and Purkinje cells with Nissl body changes. Moreover, cerebellar neurotransmission was disturbed by Pb with increasing acetylcholine (ACh) and decreasing acetylcholinesterase (AChE), dopamine (DA), γ-Aminobutyric Acid (GABA) and Na+/K+ ATPase. Meanwhile, cerebellar oxidative stress was caused by Pb exposure represented by increasing reactive oxygen species (ROS) and malondialdehyde (MDA) as well as decreasing catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH) and superoxide dismutase (SOD). Moreover, RNA-Seq analysis showed that molecular signaling pathways in the cerebellum were disrupted by Pb exposure. In particular, the disruption of nuclear factor erythroid-2-related factor 2 (Nfr2)/kelch-like ECH-associated protein 1 (Keap1) pathway and glutathione metabolism pathway indicated increasing cell apoptosis and functional disorder in the cerebellum. The present study revealed that Pb induced cerebellar toxicology through structural injury, oxidative stress, neurotransmission interference and abnormal apoptosis.

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.

Therapeutic potential of silver nanoparticles from Helianthemum lippii extract for mitigating cadmium-induced hepatotoxicity: liver function parameters, oxidative stress, and histopathology in wistar rats

Introduction: This study explores the therapeutic potential of silver nanoparticles (Ag NPs) synthesized using a Helianthemum lippii extract in mitigating cadmium-induced hepatotoxicity in Wistar rats. Given the increasing environmental and health concerns associated with cadmium exposure, novel and eco-friendly therapeutic strategies are essential. Methods: Ag NPs were characterized using X-ray diffraction, UV-Vis spectrometry, and energy-dispersive X-ray spectroscopy with scanning electron microscopy, confirming their formation with a cubic crystal structure and particle sizes ranging from 4.81 to 12.84 nm. A sub-acute toxicity study of Ag NPs (2 mg/kg and 10 mg/kg) was conducted, showing no significant difference compared to untreated control rats (n = 3 animals/group). Subsequently, adult Wistar rats (n = 5/group) were divided into a control group and three experimental groups: Ag NPs alone, exposure to 50 mg/kg CdCl2 in drinking water for 35 days, and CdCl2 exposure followed by 0.1 mg/kg/day Ag NPs intraperitoneally for 15 days. Results: In the CdCl2-exposed group, there was a significant decrease in body weight and increases in alanine and aspartate transaminase levels (p < 0.05 vs. control), indicating hepatotoxicity. Additionally, antioxidant defenses were decreased, and malondialdehyde levels were elevated. Liver histology revealed portal fibrosis, inflammation, necrosis, sinusoid and hepatic vein dilation, and cytoplasmic vacuolations. Treatment with Ag NPs post-CdCl2 exposure mitigated several adverse effects on liver function and architecture and improved body weight. Discussion: This study demonstrates the efficacy of Ag NPs synthesized via a green method in reducing cadmium-induced liver damage. These findings support the potential of Ag NPs in therapeutic applications and highlight the importance of sustainable and eco-friendly nanoparticle synthesis methods. By addressing both toxicity concerns and therapeutic efficacy, this research aligns with the growing emphasis on environmentally conscious practices in scientific research and healthcare.

Integrative investigation of hematotoxic effects induced by low doses of lead, cadmium, mercury and arsenic mixture: In vivo and in silico approach

The effect of the lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) mixture (MIX) on hematotoxicity development was investigated trough combined approach. In vivo subacute study (28 days) was performed on rats (5 per group): a control group and five groups orally exposed to increasing metal(loid) mixture doses, MIX 1- MIX 5 (mg/kg bw./day) (Pb: 0.003, 0.01, 0.1, 0.3, 1; Cd: 0.01, 0.03, 0.3, 0.9, 3; Hg: 0.0002, 0.0006, 0.006, 0.018, 0.06; As: 0.002, 0.006, 0.06, 0.18, 0.6). Blood was taken for analysis of hematological parameters and serum iron (Fe) analysis. MIX treatment increased thrombocyte/platelet count and MCHC and decreased Hb, HCT, MCV and MCH values compared to control, indicating the development of anemia and thrombocytosis. BMDIs with the narrowest width were identified for MCH [pg] (6.030E-03 - 1.287E-01 mg Pb/kg bw./day; 2.010E-02 - 4.290E-01 mg Cd/kg bw./day; 4.020E-04 - 8.580E-03 mg Hg/kg bw./day; 4.020E-03 - 8.580E-02 mg As/kg bw./day). In silico analysis showed target genes connected with MIX and the development of: anemia - ACHE, GSR, PARP1, TNF; thrombocytosis - JAK2, CALR, MPL, THPO; hematological diseases - FAS and ALAD. The main extracted pathways for anemia were related to apoptosis and oxidative stress; for thrombocytosis were signaling pathways of Jak-STAT and TPO. Changes in miRNAs and transcription factors enabled the mode of action (MoA) development based on the obtained results, contributing to mechanistic understanding and hematological risk related to MIX exposure.

Assessment of the effect of sodium tetraborate on oxidative stress, inflammation, and apoptosis in lead-induced nephrotoxicity

Exposure to Pb, a toxic heavy metal, is a risk factor for renal damage. Borax, an essential trace element in cellular metabolism, is a naturally occurring compound found in many foods. This study investigated the effects of sodium tetraborate (ST), a source of borax, on renal oxidative stress and inflammation in rats exposed to Pb. Wistar Albino rats (n = 24) were divided into four groups: Control (0.5 mL, i.p. isotonic), Pb (50 mg/kg/day/i.p.), ST (4.0 mg/kg/day/oral), and Pb + ST groups. At the end of the five-day experimental period, kidney tissue samples were obtained and analyzed. Histopathologically, the Pb-induced damage observed in the Pb group improved in the Pb + ST group. Immunohistochemically, Pb administration increased the expression of inducible nitric oxide synthase, cyclooxygenase-2, and caspase-3. When evaluated biochemically, Pb application inhibited catalase and glutathione peroxidase (GSH-Px) enzyme activities and activated superoxide dismutase enzyme activity. An increase in malondialdehyde levels was considered an indicator of damage. ST application increases glutathione peroxidase enzyme activity and decreased malondialdehyde levels. These results indicate that ST might play a protective role against Pb-induced renal damage via the upregulation of renal tissue antioxidants and cyclooxygenase-2, inducible nitric oxide synthase, and caspase-3 immunoexpression.

Rutin Nanoparticles Alleviate Cadmium-Induced Oxidative and Immune Damage in Broilers' Bursa of Fabricius via Modulating Hsp70/TLR4/NF-κB Signaling Pathway

Cadmium (Cd) is a serious environmental pollutant affecting various tissues/organs in broilers and compromising their immunological function and productivity. Therefore, the current study aimed to investigate Cd-induced immunotoxicity and potential immunoprotective effect of rutin nanoparticles (RNPs) in the bursal tissue of broilers. A total number of 150 chicks from the Hubbard breed were randomly divided into 5 groups. Group I was fed on standard basal diet (SD) with normal drinking water (DW), Group II received SD containing RNPs (50 mg/kg feed) with DW, Group III fed on SD and DW containing Cd (150 mg/L), Group IV co-treated with rutin-enforced SD (50 mg/kg diet) and DW containing Cd (150 mg/L), and finally, Group V co-supplemented with RNP-enhanced SD (50 mg/kg diet) DW containing Cd (150 mg/L). Productive performance, economic efficiency, oxidative biomarkers, histopathological changes, and the expression level of TLR-4, HSP-70, caspase 3, NF-κB, Bcl-2, and Bax were assessed in the BF tissue. Cd led to severe production and economic losses in exposed birds with a marked surge of oxidative biomarkers, pro-inflammatory cytokines, and histopathological changes in the bursal tissue which could be explained through upregulation of the Hsp70/TLR4/NF-κB molecular pathway in the BF tissue. Meanwhile, RNPs could alleviate most of these changes and prevail optimistic immunomodulatory properties which subsequently could enhance broilers' productivity when incorporated in their diets.

Environmental cadmium exposure perturbs systemic iron homeostasis via hemolysis and inflammation, leading to hepatic ferroptosis in common carp (Cyprinus carpio L.)

Cadmium (Cd) pollution is considered a pressing challenge to eco-environment and public health worldwide. Although it has been well-documented that Cd exhibits various adverse effects on aquatic animals, it is still largely unknown whether and how Cd at environmentally relevant concentrations affects iron metabolism. Here, we studied the effects of environmental Cd exposure (5 and 50 μg/L) on iron homeostasis and possible mechanisms in common carp. The data revealed that Cd elevated serum iron, transferrin saturation and iron deposition in livers and spleens, leading to the disruption of systemic iron homeostasis. Mechanistic investigations substantiated that Cd drove hemolysis by compromising the osmotic fragility and inducing defective morphology of erythrocytes. Cd concurrently exacerbated hepatic inflammatory responses, resulting in the activation of IL6-Stat3 signaling and subsequent hepcidin transcription. Notably, Cd elicited ferroptosis through increased iron burden and oxidative stress in livers. Taken together, our findings provide evidence and mechanistic insight that environmental Cd exposure could undermine iron homeostasis via erythrotoxicity and hepatotoxicity. Further investigation and ecological risk assessment of Cd and other pollutants on metabolism-related effects is warranted, especially under the realistic exposure scenarios.

Rat Hepatocytes Protect against Lead-Cadmium-Triggered Apoptosis Based on Autophagy Activation

Lead and cadmium are foodborne contaminants that threaten human and animal health. It is well known that lead and cadmium produce hepatotoxicity; however, defense mechanisms against the co-toxic effects of lead and cadmium remain unknown. We investigated the mechanism of autophagy (defense mechanism) against the co-induced toxicity of lead and cadmium in rat hepatocytes (BRL-3A cells). Cultured rat liver BRL-3A cell lines were co-cultured with 10, 20, 40 μM lead and 2.5, 5, 10 μM cadmium alone and in co-culture for 12 h and exposed to 5 mM 3-Methyladenine (3-MA), 10 μM rapamycin (Rapa), and 50 nM Beclin1 siRNA to induce cellular autophagy. Our results show that treatment of BRL-3A cells with lead and cadmium significantly decreased the cell viability, increased intracellular reactive oxygen species levels, decreased mitochondrial membrane potential levels, and induced apoptosis, which are factors leading to liver injury, and cell damage was exacerbated by co-exposure to lead-cadmium. In addition, the results showed that lead and cadmium co-treatment induced autophagy. We further observed that the suppression of autophagy with 3-MA or Beclin1 siRNA promoted lead-cadmium-induced apoptosis, whereas enhancement of autophagy with Rapa suppressed lead-cadmium-induced apoptosis. These results demonstrated that co-treatment with lead and cadmium induces apoptosis in BRL-3A cells. Interestingly, the activation of autophagy provides cells with a self-protective mechanism against induced apoptosis. This study provides insights into the role of autophagy in lead-cadmium-induced apoptosis, which may be beneficial for the treatment of lead-cadmium-induced liver injury.

Lead induced genotoxicity and hepatotoxicity in zebrafish (Danio rerio) at environmentally relevant concentration: Nrf2-Keap1 regulated stress response and expression of biomarker genes

Genotoxic and hepatotoxic potentials of Pb at an environmentally relevant concentration (5 ppm) in zebrafish were investigated in the present study. Erythrocytic nuclear abnormality tests revealed the increased frequencies of abnormal erythrocytes after Pb exposure, indicating a strong genotoxic potential of Pb. Multiple stress-related parameters were further evaluated in liver, the major detoxifying organ. Pb caused increased production of ROS, which in turn caused severe oxidative stress. As a result, lipid peroxidation was increased, whereas reduced glutathione level and catalase activity was decreased. Alterations in liver histoarchitecture also served as evidence of Pb-induced hepatotoxicity. Pb-induced ROS stress triggered upregulation of Nrf2, Nqo1, Ho1; downregulation of Keap1, and altered mRNA expressions of Mn-sod, Cu/Zn-sod, gpx1, cyp1a, ucp2 suggesting involvement of Nrf2-Keap1-ARE signaling in cellular defence. Nrf2-keap1 is a sensitive biomarker of Pb-induced ROS stress. Overexpression of Hsp70 and other genes in hepatocytes might help cell survival under oxidative stress generation.

Cerqueira F, Menezes-Filho JA. A Cross-Sectional Analysis Investigating Pregnant Women's Renal Function and Its Association with Lead and Cadmium Exposures-The DSAN Birth Cohort Study in Recôncavo Baiano, Brazil

Kidney dysfunction is increasing worldwide and is exacerbated by exposure to toxic metals. Also, pregnancy poses an overload on kidney function. We investigated how blood lead (PbB) and cadmium (CdB) levels were associated with kidney function in pregnant women from Recôncavo Baiano, Brazil, during their second trimester. In this cross-sectional study, the estimated glomerular filtration rate (eGFR) was calculated from serum creatinine and whole blood metal levels were measured by graphite furnace atomic absorption spectrophotometry in 136 volunteers. Sociodemographic data were collected using semi-structured questionnaires. The medians (IQR) of PbB, CdB, and eGFR were 0.85 µg/dL (0.45-1.75), 0.55 µg/L (0.08-0.91), and 121.8 mL/min/1.73 m2 (106.0-127.9), respectively. PbB medians were significantly higher in the eGFR < 90 group at 2.00 µg/dL (0.83, 3.10). After age-adjusted logistic regression, pregnant women with elevated PbB levels had decreased eGFR (OR = 1.82; 95%-CI, 1.14-3.14). However, the participants with elevated PbB levels who reported consuming alcohol during pregnancy or had CdB in the highest tertile had higher odds of reduced eGFR (OR = 2.44; 95%-CI, 1.30-5.47) and (OR = 11.22; 95% CI, 2.53-103.51), respectively. These results suggest that low Pb exposure may affect kidney function in pregnant women and calls for further investigation into toxic metal co-exposures on kidney function during pregnancy in at-risk communities.

Changes in Endogenous Essential Metal Homeostasis in the Liver and Kidneys during a Six-Month Follow-Up Period after Subchronic Cadmium Exposure

Cadmium (Cd) is one of the most dangerous environmental pollutants. Its mechanism of action is multidirectional; among other things, it disrupts the balance of key essential elements. The aim of this study was to assess how cumulative exposure to Cd influences its interaction with selected essential elements (Cu, Zn, Ca, and Mg) in the kidney and liver during long-term observation (90 and 180 days) after subchronic exposure of rats (90 days) to Cd at common environmental (0.09 and 0.9 mg Cd/kg b.w.) and higher (1.8 and 4.5 mg Cd/kg b.w.) doses. Cd and essential elements were analyzed using the F-AAS and GF-AAS techniques. It was shown that the highest bioaccumulation of Cd in the kidney occurred six months after the end of exposure, and importantly, the highest accumulation was found after the lowest Cd dose (i.e., environmental exposure). Organ bioaccumulation of Cd (>21 μgCd/g w.w. in the kidney and >6 μgCd/g w.w. in the liver) was accompanied by changes in the other studied essential elements, particularly Cu in both the kidney and liver and Zn in the liver; these persisted for as long as six months after the end of the exposure. The results suggest that the critical concentration in human kidneys (40 μgCd/g w.w.), currently considered safe, may be too high and should be reviewed, as the observed long-term imbalance of Cu/Zn in the kidneys may lead to renal dysfunction.

Tetramethylpyrazine Antagonizes the Subchronic Cadmium Exposure-Induced Oxidative Damage in Mouse Livers via the Nrf2/HO-1 Pathway

Hepatic oxidative stress is an important mechanism of Cd-induced hepatotoxicity, and it is ameliorated by TMP. However, this underlying mechanism remains to be elucidated. To investigate the mechanism of the protective effect of TMP on liver injuries in mice induced by subchronic cadmium exposure, 60 healthy male ICR mice were randomly divided into five groups of 12 mice each, namely, control (CON), Cd (2 mg/kg of CdCl2), Cd + 100 mg/kg of TMP, Cd + 150 mg/kg of TMP, and Cd + 200 mg/kg of TMP, and were acclimatized and fed for 7 d. The five groups of mice were gavaged for 28 consecutive days with a maximum dose of 0.2 mL/10 g/day. Except for the control group, all groups were given fluoride (35 mg/kg) by an intraperitoneal injection on the last day of the experiment. The results of this study show that compared with the Cd group, TMP attenuated CdCl2-induced pathological changes in the liver and improved the ultrastructure of liver cells, and TMP significantly decreased the MDA level (p < 0.05) and increased the levels of T-AOC, T-SOD, and GSH (p < 0.05). The results of mRNA detection show that TMP significantly increased the levels of Nrf2 in the liver compared with the Cd group as well as the HO-1 and mRNA expression levels in the liver (p < 0.05). In conclusion, TMP could inhibit oxidative stress and attenuate Cd group-induced liver injuries by activating the Nrf2 pathway.

Associations between patterns of blood heavy metal exposure and health outcomes: insights from NHANES 2011-2016

BACKGROUND

Extensive research has explored the association between heavy metal exposure and various health outcomes, including malignant neoplasms, hypertension, diabetes, and heart diseases. This study aimed to investigate the relationship between patterns of exposure to a mixture of seven heavy metals and these health outcomes.

METHODS

Blood samples from 7,236 adults in the NHANES 2011-2016 studies were analyzed for levels of cadmium, manganese, lead, mercury, selenium, copper, and zinc. Cluster analysis and logistic regression identified three distinct patterns of mixed heavy metal exposure, and their associations with health outcomes were evaluated.

RESULTS

Pattern 1 exhibited higher odds ratios (ORs) for malignancy during NHANES 2011-2012 (OR = 1.33) and 2015-2016 (OR = 1.29) compared to pattern 2. Pattern 3 showed a lower OR for malignancy during NHANES 2013-2014 (OR = 0.62). For hypertension, pattern 1 displayed higher ORs than pattern 2 for NHANES 2011-2012 (OR = 1.26), 2013-2014 (OR = 1.31), and 2015-2016 (OR = 1.41). Pattern 3 had lower ORs for hypertension during NHANES 2013-2014 (OR = 0.72) and 2015-2016 (OR = 0.67). In terms of heart diseases, pattern 1 exhibited higher ORs than pattern 2 for NHANES 2011-2012 (OR = 1.34), 2013-2014 (OR = 1.76), and 2015-2016 (OR = 1.68). Pattern 3 had lower ORs for heart diseases during NHANES 2013-2014 (OR = 0.59) and 2015-2016 (OR = 0.52). However, no significant trend was observed for diabetes. All three patterns showed the strongest association with hypertension among the health outcomes studied.

CONCLUSIONS

The identified patterns of seven-metal mixtures in NHANES 2011-2016 were robust. Pattern 1 exhibited higher correlations with hypertension, heart disease, and malignancy compared to pattern 2, suggesting an interaction between these metals. Particularly, the identified patterns could offer valuable insights into the management of hypertension in healthy populations.

Study on the combined toxicity of DEHP and lead on the blood system of rats

Di(2-ethylhexyl) phthalate (DEHP) is a commonly used phthalate ester compound, while lead is a persistent and bioaccumulative heavy metal. Both can be exposed to the body through a variety of ways, which may have an impact on the blood system. In this study, we examined the impact of co-exposure to DEHP (0, 10, 100 mg/kg) and Pb (0, 5, 50 mg/kg) on the blood system of male SD rats. The study revealed that continuous exposure to DEHP and Pb for 20 days resulted in a decrease in leukocytes and lymphocytes, while an increase in neutrophils and monocytes. Co-exposure led to a significant decrease in the spleen coefficients. Furthermore, the combined exposure could increase the ratio of bone marrow cells in G1 phase, and decrease the ratio of cells in S phase and G2 phase. Cytokine testing showed that combined exposure affects the secretion of hematopoietic factors and may cause bone marrow cell apoptosis. Single or combined exposure to DEHP and Pb can cause oxidative stress in serum and bone marrow. Overall, these results indicate that the co-exposure of DEHP and Pb adversely affected the blood system of rats, mainly due to the induction of oxidative stress and ultimately affects the secretion of cytokines. The combined effect of the two substances is primarily antagonistic. These results have important implications for the risk assessment of combined pollution and provide valuable theoretical guidance.

Chemical modification of Aloe vera leaf hydrogel for efficient cadmium-removal from spiked high-hardness groundwater

Herein, the hydrogel from the leaf of the Aloe vera plant (ALH) was succinylated (SALH) and saponified (NaSALH). The FTIR, solid-state CP/MAS 13C NMR, and SEM-EDX spectroscopic analyses witnessed the formation of SALH and NaSALH from ALH. The pHZPC for NaSALH was found to be 4.90, indicating the presence of -ve charge on its surface. The Cd2+ sorption efficiency of NaSALH was found to be dependent on pH, NaALH dose, Cd2+ concentration, contact time, and temperature. The maximum Cd2+ removal from DW and HGW was found to be 227.27 and 212.77 mg g-1 according to the Langmuir isothermal model (>0.99) at pH of 6, NaSALH dose of 40 mg g-1, Cd2+ concentration of 90 mg L-1, contact time of 30 min, and temperature of 298 K. The kinetic analysis of Cd2+ sorption data witnessed that the Cd2+ removal by chemisorption mechanism and followed pseudo-second-order kinetics (>0.99). The -ve values of ΔG° and ΔH° assessed the spontaneous and exothermic nature of sorption of Cd2+ by NaSALH. The regeneration and sorption/desorption studies indicated that the sorbent NaSALH is regenerable.

Protective effect of chitosan-modified rice porous starch loaded catechin on HT-29 cells exposed to lead ion

To explore how chitosan-modified rice porous starch-loaded catechin (CT@RPS/CS) protects HT-29 cells exposed to lead ions.

METHOD

The HT-29 cells were treated differently based on their grouping. The effect of CT@RPS/CS on lead-induced toxicity was evaluated using cell proliferation, apoptosis, oxidative stress index, and cytokine tests.

RESULTS

CT@RPS/CS did not affect the activity, cell apoptosis, oxidative stress level, and related cytokines of HT-29 cells. After exposure to lead, CT@RPS/CS has the potential to enhance cellular activity, minimize apoptosis, and decrease the level of oxidative stress.

DISCUSSION

CT@RPS/CS not only has no toxicity to cells but also adsorbs lead ions, which protects cells.

Hepato-renal toxicity of low dose metal(oid)s mixture in real-life risk simulation in rats: Effects on Nrf2/HO-1 signalling and redox status

The understanding that humans are exposed to a low level of toxic metals and metalloids in their lifetime has resulted in a shift in scientific and regulatory perspectives from the traditional evaluation of single metal toxicity to complex mixtures, relevant to real-life exposure. Therefore, the aim of this study was to examine the impact of real-life, 90-days exposure to mixture of toxic metal(oid)s, Cd, Pb, Ni, Cr, As and Hg, on the nuclear factor erythroid 2-related factor 2 and hemoxygenase-1 (Nrf2/HO-1) signalling and redox status by assessing total sulfhydryl groups (SH), glutathione (GSH), superoxide dismutase activity (SOD), malondialdehyde (MDA), and ischemia modified albumin (IMA) in the liver and kidney of Wistar rats. Animals (20 males and 20 females) were randomized in 2 control and 6 treated groups that received by oral gavage mixture of metal(oid)s solutions in doses that reflect blood metal(oid) levels determined in previous human biomonitoring study as benchmark dose (F/M _BMD), median (F/M _MED), and 95th percentile (F/M _95). Our results have shown that metal(oid)s mixture impaired the activation of the Nrf2/HO-1 pathway in the kidney and liver of male rats and kidney of female rats, followed by depletion of GSH levels in males. Additionally, in males elevated levels of IMA in the liver were observed, while in both genders increased MDA levels were observed in the kidney. Interestingly, the effects were more pronounced in male than in female rats. This study is among the first that examined hepato-renal toxic mechanisms of real-life metal mixture exposure, while our results might be of immense importance for assessing the risk of exposure to mixtures of toxic substances.

Modulating SIRT1, Nrf2, and NF-κB signaling pathways by bergenin ameliorates the cadmium-induced nephrotoxicity in rats

In light of the current industrial evolution, exposure to cadmium has become a significant public health concern. Cadmium accumulates in the renal tubular cells and causes nephrotoxicity largely through disruption of the redox homeostasis, induction of inflammation, and suppression of the histone deacetylase SIRT1 expression. The current work aimed at exploring the protective capability of bergenin, a naturally-occurring methyl gallic acid derivative, against the cadmium-evoked nephrotoxicity. Male Wistar rats were treated either with cadmium alone or with cadmium and bergenin for a 7-day experimental period followed by collection of kidney and blood specimens that were subjected to biochemical, molecular, and histological investigations. The results revealed the ability of bergenin to improve the renal functions in the cadmium-intoxicated rats as evidenced by increased glomerular filtration rate, and decreased serum creatinine and blood urea nitrogen. Equally important, bergenin reduced the renal tissue injury and enhanced its redox homeostasis as indicated by decreased protein expression of the kidney injury marker KIM-1, reduced lipid peroxidation, and improved antioxidant potential and histopathological picture of the renal tissues. Mechanistically, bergenin reduced the renal tissue cadmium content, markedly up-regulated protein expression of SIRT1 that regulates inflammation and the redox status of the renal tissues. Additionally, it improved the expression of the major antioxidant transcription factor Nrf2 and its responsive gene products heoxygenase-1 and NAD(P)H quinone dehydrogenase 1 in the cadmium-intoxicated rats. In the same context, bergenin down-regulated the acetylation and the nuclear translocation of the inflammatory transcription factor NF-κB and reduced levels of its responsive gene products TNF-α and IL-1β, as well as the activity of the inflammatory cell infiltration biomarker myeloperoxidase. Collectively, the current study underscores the ameliorating activity of bergenin against the cadmium-evoked nephrotoxicity and highlights modulation of SIRT1, Nrf2, and NF-κB signaling as potential underlining molecular mechanisms.

Associations of blood cadmium and lead concentrations with all-cause mortality in US adults with chronic obstructive pulmonary disease

BACKGROUND

Some literature indicates an association between exposure to cadmium and lead and the presence of emphysema and chronic bronchitis, which are the two primary components of COPD. Understanding whether there is a potential association between cadmium and lead exposure and higher mortality rates in individuals with COPD could provide profound insights into the long-term effects of these two metal exposures on human health.

METHODS

This study included 2024 patients with COPD in the US from the NHANES from 1999 through 2016 who were followed up to 2019. Multivariable Cox regression models were used to calculate HRs and 95 % CIs for all-cause mortality in relation to blood cadmium and lead concentrations. Plotting Kaplan-Meier curves and Restricted cubic spline curves to visualize results. Furthermore, stratified and sensitivity analyses were conducted.

RESULTS

After multivariate adjustment, blood cadmium and blood lead concentrations were independently associated with an increased risk of all-cause mortality. Compared with the first tertile, the HRs of all-cause mortality associated with the blood cadmium concentration were 1.74 (95 % CI, 1.22-2.49) in the second tertile and 1.89 (95 % CI, 1.31-2.72) in the third tertile. The HRs of all-cause mortality associated with the blood lead concentration were 1.13 (95 % CI, 0.84-1.51) in the second tertile and 1.43 (95 % CI, 1.05-1.93) in the third tertile.

CONCLUSION

This study found that increased blood cadmium and blood lead concentrations were associated with increased all-cause mortality in COPD patients. Reducing cadmium and lead exposure could potentially mitigate mortality risk in these individuals. More prospective studies are needed in the future to demonstrate our findings.

Blood Homocysteine Levels Mediate the Association Between Blood Lead Levels and Cardiovascular Mortality

Lead is a heavy, toxic metal and its exposure to humans can lead to increased risk of cardiovascular disease development and mortality. Lead exposure has been shown to induce hyperhomocysteinemia (HHCy) which may be a major pathogenic risk for the risk of CVDs. The aim of this study was to investigate whether homocysteine (Hcy) mediates the effect of lead on cardiovascular mortality. A total of 17,915 adults aged ≥ 20 who participated in the National Health and Nutrition Examination Survey (1999 to 2006). Information on mortality was ascertained via probabilistic matching to the death certificates from the National Death Index recorded up to December 31, 2015. Cox proportional hazards regression was performed to assess the association between blood lead levels and mortality. Mediation via Hcy was examined using a logit model. During a mean follow-up of 11.6 years, the incidences of CVD mortality were 0.73, 2.18, 3.03 and 4.94 per 1000 person-years across quarterlies of blood lead levels from low to high. Following multivariable adjustment, blood lead levels were strongly associated with CVD mortality in all mortality models (p-trend < 0.001). This association remained statistically significant after further adjusting for quartiles of homocysteine (model 3; HR 1.38 (95% CI 1.01-1.89) p-trend < 0.001). Furthermore, blood lead levels increased the odds of CVD mortality via homocysteine (indirect effect) (OR 1.42 (95% CI 1.30-1.55)), demonstrating the mediatory effect of homocysteine. This the first study that demonstrates that increased homocysteine mediates nearly half of CVD mortality related to blood lead levels.

Recent advances in the antioxidant activity of metal-curcumin complexes: a combined computational and experimental review

Curcumin, an extensively studied phytochemical compound, has gained attention for its potential therapeutic applications across a spectrum of diseases. Its notable attributes include its relatively high tolerability within the human body and its perceived absence of adverse side effects. This review article presents a comprehensive overview of the antioxidant effects exhibited by complexes formed by curcumin and curcumin derived ligands with metals like Mn, Cu, Fe, Zn, Ga and In, which leads to toxic effects beyond a certain limit, based on both experimental and theoretical findings. Additionally, the discussion delves into metal-curcumin complexes characterized by stoichiometries of 1:1 and 1:2, exploring their geometric arrangements and corresponding antioxidant activity, as highlighted in recent studies. These complexes hold the promise of improving curcumin's solubility, stability, and bioavailability, potentially augmenting its overall therapeutic potential and expanding its scope for medical applications.

Moderate selenium mitigates hand grip strength impairment associated with elevated blood cadmium and lead levels in middle-aged and elderly individuals: insights from NHANES 2011-2014

Background: Selenium (Se) has been reported to have an antagonistic effect on heavy metals in animals. Nevertheless, there is a lack of epidemiological research examining whether Se can mitigate the adverse effects of cadmium (Cd) and lead (Pb) on hand grip strength (HGS) in middle-aged and elderly individuals. Methods: This study used data from the 2011-2014 National Health and Nutrition Examination Survey (NHANES). HGS measurements were conducted by trained examiners with a dynamometer. Concentrations of Se, Cd, and Pb in blood were determined via inductively coupled plasma mass spectrometry. We employed linear regression, restricted cubic splines, and quantile g-computation (qgcomp) to assess individual and combined associations between heavy metals and HGS. The study also explored the potential influence of Se on these associations. Results: In both individual metal and multi-metal models adjusted for confounders, general linear regression showed Se's positive association with HGS, while Cd and Pb inversely related to it. At varying Se-Cd and Se-Pb concentrations, high Se relative to low Se can attenuate Cd and Pb's HGS impact. An inverted U-shaped correlation exists between Se and both maximum and combined HGS, with Se's benefit plateauing beyond approximately 200 μg/L. Stratified analysis by Se quartiles reveals Cd and Pb's adverse HGS effects diminishing as Se levels increase. Qgcomp regression analysis detected Se alleviating HGS damage from combined Cd and Pb exposure. Subsequent subgroup analyses identified the sensitivity of women, the elderly, and those at risk of diabetes to HGS impairment caused by heavy metals, with moderate Se supplementation beneficial in mitigating this effect. In the population at risk for diabetes, the protective role of Se against heavy metal toxicity-induced HGS reduction is inhibited, suggesting that diabetic individuals should particularly avoid heavy metal-induced handgrip impairment. Conclusion: Blood Cd and Pb levels are negatively correlated with HGS. Se can mitigate this negative impact, but its effectiveness plateaus beyond 200 μg/L. Women, the elderly, and those at risk of diabetes are more vulnerable to HGS damage from heavy metals. While Se supplementation can help, its protective effect is limited in high diabetes risk groups.

Caffeine Administration Mitigates Chronic Stress-Induced Behavioral Deficits, Neurochemical Alterations, and Glial Disruptions in Rats

Prolonged exposure to stress has detrimental effects on health, and the consumption of caffeine, mostly contained in energy drinks, has become a widely adopted stress coping strategy. Currently, there is limited information regarding the effects of caffeine intake on chronic stress exposure. Thus, this study investigated the effects of caffeine administration on chronic stress-induced behavioral deficits, neurochemical alterations, and glial disruptions in experimental rats. Thirty male Wistar rats were randomly assigned to five groups (n = 6): non-stress control, stress control, and caffeine groups of doses 12.5, 25, and 50 mg/kg. The stress control and caffeine groups were subjected to an unpredictable chronic mild stress (UCMS) protocol daily for 14 days. The rats were evaluated for phenotypic and neurobehavioral assessments. Thereafter, the rat brains were processed for biochemical and immunohistochemical assays. Caffeine administration was found to ameliorate behavioral dysfunctions in rats exposed to UCMS. The UCMS-induced changes in brain levels of monoamines, cholinesterases, and some oxidative stress biomarkers were reversed by caffeine. Caffeine administration also produced mild protective effects against UCMS-induced changes in GFAP and Iba-1 expression in stress-specific brain regions. These results showed that low and moderate doses of caffeine reversed most of the stress-induced changes, suggesting its ameliorative potential against chronic stress-induced alterations.

Saccharomyces cerevisiae additions normalized hemocyte differential genes expression and regulated crayfish (Procambarus clarkii) oxidative damage under cadmium stress

Because China produces the most crayfish in the world, safe solutions must be improved to mitigate the risks of ongoing heavy metal stressors accumulation. This study aimed to use Saccharomyces cerevisiae as a bioremediation agent to counteract the harmful effect of cadmium (Cd) on crayfish (Procambarus clarkia). Our study used three concentrations of S. cerevisiae on crayfish feed to assess their Cd toxicity remediation effect by measuring total antioxidant capacity (TAC) and the biomarkers related to oxidative stress like malondialdehyde (MDA), protein carbonyl derivates (PCO), and DNA-protein crosslink (DPC). A graphite furnace atomic absorption spectroscopy device was used to determine Cd contents in crayfish. Furthermore, the mRNA expression levels of lysozyme (LSZ), metallothionein (MT), and prophenoloxidase (proPO) were evaluated before and following the addition of S. cerevisiae. The results indicated that S. cerevisae at 5% supplemented in fundamental feed exhibited the best removal effect, and Cd removal rates at days 4th, 8th, 12th, and 21st were 12, 19, 29.7, and 66.45%, respectively, which were significantly higher than the basal diet of crayfish. The addition of S. cerevisiae increased TAC levels. On the other hand, it decreased MDA, PCO, and DPC, which had risen due to Cd exposure. Furthermore, it increased the expression of proPO, which was reduced by Cd exposure, and decreased the expression of LSZ and MT, acting in the opposite direction of Cd exposure alone. These findings demonstrated that feeding S. cerevisiae effectively reduces the Cd from crayfish and could be used to develop Cd-free crayfish-based foods.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

In vivo and in silico approach in revealing the influence of lead (Pb) on thyroid gland function

The purpose of this study was to examine the impact of low doses of lead (Pb) on levels of thyroid hormones (T3, T4, FT3, and FT4) and thyroid-related antibodies (anti-Tg and anti-TPO) in the rat model, as well as genes that are related to Pb and thyroid function, relationships between genes, biological processes, molecular processes, and pathways using an in silico approach. Male rats were randomized into seven groups (n = 42), one control group and six groups that received a range of Pb doses: 0.1, 0.5, 1, 3, 7, and 15 mg Pb/kg body weight (b.w.). Dose-response modelling was performed by PROAST software using model averaging method. The Comparative Toxicogenomics Database, GeneMANIA server, and ToppGene Suite portal were used as the main bioinformatic tools in this analysis. The results of our study have shown that low Pb doses induced elevation of thyroid hormones (T4, FT4, and TSH) in rats after subacute exposure, while had no impact on T3, FT3, anti-TPO, and anti-Tg, indicating hyperthyroidism. Dose-dependent effects were increases in T4 and FT4, with the lowest benchmark dose derived for FT4 levels. In silico toxicogenomic data analysis showed that the main molecular pathways/process related to Pb-induced hyperthyroidism are connected with 14 genes involved in antioxidant defense and Se-dependent processes. The results presented here may be useful in further investigation of the health impacts of low-level Pb exposure on thyroid function and endocrine disruption effects.

Similarity in human health risk assessment using models of soil-blood lead levels (IEUBK) and non-carcinogenic condition (US EPA 2002)

Soil lead (Pb) concentrations in Sydney estuary (Australia) catchment are substantially elevated and strongly associated with traffic networks. This study compared the health risk predictions of blood Pb levels (BLL) in children using the soil IEUBK model and an independent, non-carcinogenic human health risk (NCR) assessment using the soil US EPA 2002 model. The predictions by the two models were significantly correlated (p < 0.001) and showed similar spatial distributions, but the NCR model may be more stringent in protection of human health when exposed to soil Pb in relation to adverse health effect, as the warning soil Pb concentration from the BLL was 4.6-fold higher than that from the NCR. The empirical IEUBK model considers gastric phase adsorption only and of the three exposure pathways (ingestion, inhalation and dermal) assessed by the theoretical NCR model, ingestion was the major exposure route. The reason for the similarity in outcomes of the two models is unknown, however the close correlation may be due to broadly similar formulations and, or that neurological and non-carcinogenic risks may be related to the adverse effects of Pb on bodily function. Parallel studies of human health risk based on BLL and NCR models have not been attempted previously and this opportunity to compare results from the two health risk assessments employing the same soil metal data is therefore unique.

The Antioxidant Activity of Betanin protects MRC-5 cells Against Cadmium Induced Toxicity

Cadmium (Cd) can induce both acute and chronic effects in the lungs depending on the time and the exposure route. Betanin is a component derived from the roots of red beets and it is well-known for its antioxidant and anti-apoptosis effects. The current study aimed to survey the protective effects of betanin on cell toxicity induced by Cd. Different concentration of Cd alone and in combination with betanin was assessed in MRC-5 cells. The viability and oxidative stress were measured using resazurin and DCF-DA methods respectively. Apoptotic cells were assessed by PI staining of the fragmented DNA and western blot analysis detected the activation of caspase 3 and PARP proteins. Cd exposure for 24 h declined viability and increased ROS production in MRC-5 cells compared to the control group (p < 0.001). Also, Cd (35 μM) elevated DNA fragmentation (p < 0.05), and the level of caspase 3-cleaved and cleaved PARP proteins in MRC-5 cells (p < 0.001). Co-treatment of cells with betanin for 24 h significantly enhanced viability in concentrations of 1.25 and 2.5 μM (p < 0.001) and 5 μM (p < 0.05) and declined ROS generation (1.25 and 5 μM p < 0.001, and 2.5 μM p < 0.01). As well as, betanin reduced DNA fragmentation (p < 0.01), and the markers of apoptosis (p < 0.001) compared to the Cd-treated group. In conclusion, betanin protects lung cells against Cd-induced toxicity through antioxidant activity and inhibition of apoptosis.