Toxic Effect of Acute Cadmium and Lead Exposure in Rat Blood, Liver, and Kidney

Delay in puberty indices of Wistar rats caused by Cadmium. Focus on the redox system in reproductive organs

Puberty is a transitional period from juvenile stage to adulthood, followed by the functional maturation of gonads and reproductive organs. This period is sensitive to environmental pollutants like cadmium (Cd), a heavy metal that represents a serious health risk. Cd is an endocrine disruptor that interferes with reproduction by causing oxidative stress in the reproductive organs, affecting the sexual function and decreasing testosterone (T) levels. However, little research has been done on the effects of Cd on puberty markers and antioxidant systems. In this study, we evaluated the effects of Cd on puberty markers: preputial separation, testes descent and T levels, and the antioxidant activity (SOD, CAT, GSH/GSSG and TAC) in the seminal vesicles, testis and epididymis. Male Wistar pups were treated with 1 mg/kg Cd or saline solution by i.p. injection from day 1 to 35; the other treatment was administrated for 49 days. At the end of treatment, the animals were sacrificed, and the tissues of interest dissected, weighed and prepared for the respective assays. Cd treated rats from birth to puberty showed a delay onset in the puberty markers and a low weight in reproductive organs. Also, Cd induced differential effects on the redox system in reproductive organs and decreased T levels, these effects played a pivotal role in the delay of puberty markers onset (testes descent and preputial separation), affecting the development and sexual maturity of the male rats.

Mitochondrial redox-driven mitofusin 2 S-glutathionylation promotes neuronal necroptosis via disrupting ER-mitochondria crosstalk in cadmium-induced neurotoxicity

Reactive oxygen species (ROS)-mediated endoplasmic reticulum (ER) stress and mitochondrial dysfunction are known to affect the structural and functional damage in the neural system. Cadmium (Cd) is an environmental contaminant that is widely found in numerous environmental matrices and exhibits potential neurotoxic risk. However, it remains unclear how mitochondrial redox status induces, and whether Cd destabilizes, the ER-mitochondria crosstalk to have a toxic effect on the nervous system. Herein, in our present study, bioinformatics analysis revealed an important role of protein interaction and mitochondrial machinery in brain samples from Alzheimer's disease (AD) patients. Furthermore, we established a neurotoxicity model in vivo and in vitro induced by cadmium chloride (CdCl₂). We demonstrated that CdCl₂ exposure disrupts the balance in mitochondrial redox represented by enhanced mitochondrial ROS (mitoROS) levels, which enhance mitofusin 2 (Mfn2) S-glutathionylation and interrupt the mitochondria-associated ER membranes (MAMs) for crosstalk between the ER and mitochondria to induce neuronal necroptosis. Mechanistically, it was shown that CdCl₂ exposure significantly enhances the mitochondria-associated degradation (MAD) of Mfn2 via S-glutathionylation, which inhibits Mfn2 localization to the MAMs and subsequently leads to the formation of the RIPK1-RIPK3-p-MLKL complex (a key component of the necrosome) at MAMs, to promote neuronal necroptosis. Furthermore, the glutaredoxin 1 (Grx1) catalyzed and Mfn2 overexpression restored S-glu-Mfn2, MAMs perturbation, necrosome formation, and necroptosis in neurons induced by CdCl₂ exposure in vitro. Moreover, the intervention with antioxidants to reduce mitochondrial redox, such as N-acetyl-l-cysteine (NAC) and mitochondria-targeted antioxidant Mito-TEMPO, reduced the S-glutathionylation of Mfn2 involved in the antagonism of CdCl₂-induced necroptosis and neurotoxicity in vivo and in vitro. Taken together, our results are the first time to demonstrate that S-glutathionylation of Mfn2 promotes neuronal necroptosis via disruption of ER-mitochondria crosstalk in CdCl₂-induced neurotoxicity, providing the novel mechanistic insight into how hazardous chemical-induced adverse effects in various organs and tissues could be interpreted by intraorganellar pathways under the control of MAMs components in neurons.

Potentiation of the apoptotic signaling pathway in both the striatum and hippocampus and neurobehavioral impairment in rats exposed chronically to a low-dose of cadmium

Cadmium (Cd) is a highly toxic heavy metal. It accumulates in biological tissues, especially in fish which constitutes a first rank food for humans, particularly in the coastal areas. This study investigates the effect of long-term exposure to low Cd concentration (17 μg/kg/day) in rat striatum and hippocampus. In this study, the neurobehavioral ability changes were assessed by applying cognitive standard testing at the end of the rats' exposure period. In addition, the examination of mitochondrial swelling was performed at the same time of evaluation of its redox status in the brain regions studied through stress parameters (GSH, MDA, GST, and CAT). This study examined also whether this long-term exposure can modify the apoptotic signaling pathway via assessment of apoptotic markers (caspase-8 and 9, Bax, Bcl-2, and Cyt-c) in cell lysates. The results of this study showed changes in neurobehavioral abilities of animals and a stronger mitochondrial swelling associated with a significant decrease in antioxidant systems (GSH, GST, and CAT) and conversely an increase in the lipoperoxidation end product (MDA) in both the striatal and hippocampal mitochondria. In addition, the results revealed a significant increase in pro-apoptotic intracellular components such as caspase-9, Cyt-c, and Bax, and showed also an evident decrease in Bcl-2 levels. In conclusion, our results reported that chronic exposure to Cd produces behavioral and cognitive perturbations, enhances oxidative stress associated with mitochondrial edema and Cyt-c leakage, and, ultimately, potentiates apoptosis signaling pathway in both brain regions in rats.

Relief of Cadmium-Induced Intestinal Motility Disorder in Mice by Lactobacillus plantarum CCFM8610

Cadmium (Cd) is a toxic metal inducing a range of adverse effects on organs including liver and kidneys. However, the underlying molecular mechanisms of Cd-induced intestinal toxicity through dietary intake is poorly studied. This study evaluated the toxic effects of Cd on intestinal physiology and confirmed the effectiveness of the protective mechanism of the probiotic Lactobacillus plantarum CCFM8610 against chronic Cd toxicity. After treatment with Cd, the HT-29 cell line was subjected to iTRAQ analysis, which revealed that changes in the proteomic profiles after Cd exposure were related to pathways involved in the stress response and carbohydrate metabolism. The results of an animal trial also indicated that 10 weeks of Cd exposure decreased the fecal water content and contractile response of colonic muscle strips in mice, and delayed the excretion time of the first black feces. L. plantarum CCFM8610 treatment provided protective effects against these Cd-induced intestinal motility dysfunctions by recovering the levels of neurotransmitters, including substance P, acetyl cholinesterase, vasoactive intestinal peptide, 5-hydroxytryptamine, calcitonin gene-related peptide, and nitric oxide, and suppressing the cellular stress response in mice (e.g., the inhibition of mitogen-activated protein kinase pathways). The administration of this probiotic was also observed to reduce Cd levels in the tissues and blood of the mice. Our results suggest a newly identified protective mechanism of probiotics against Cd toxicity that involves the recovery of intestinal motility and increase in fecal cadmium excretion.

Correlation between blood levels of cadmium and lead and the expression of microRNA-21 in Egyptian bladder cancer patients

Objective

To investigate the relationship between blood levels of cadmium (Cd) and lead (Pb) and the expression of miRNA-21 among bladder cancer (BC) patients.

Material and methods

The blood concentrations of Cd and Pb in 268 BC patients and 132 controls were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The blood concentrations of Cd and Pb were interpreted according to the type and stage of the carcinoma. The expression of miRNA-21 was assessed by quantitative reverse transcription polymerase chain reaction in cancerous and adjacent non-cancerous bladder tissues among the patient groups.

Results

The blood concentrations of Cd and Pb were statistically elevated in BC patients compared to those of the controls. This elevation is more prevalent in groups with muscle-invasive bladder cancer (MIBC) than those with non-muscle invasive bladder cancer (NMIBC). Among the BC group, miRNA-21 was upregulated in cancerous tissues relative to adjacent non-cancerous tissues. Moreover, the expression was significantly higher in patients with MIBC compared to those with NMIBC. The expression of miRNA-21 in cancerous tissues was significantly associated with blood concentration of Cd and Pb among BC patients.

Conclusion

There is a relationship between Cd and Pb body burden and the tissue expression of miRNA-21 among BC patients. This indicates the role of miRNA-21 in Cd and Pb induced BC.

Long-term continuous and real-time in situ monitoring of Pb(II) toxic contaminants in wastewater using solid-state ion selective membrane (S-ISM) Pb and pH auto-correction assembly

Lead (Pb) contaminants in wastewater have inhibited microbial activities and thus exerted high energy consumption in wastewater treatment plants (WWTPs). Current Pb monitoring has been conducted ex situ and off line, unable to affect real-time proactive control and operation. This study targets the crucial challenge of better and faster Pb monitoring by developing novel mm-sized screen-printed solid-state ion-selective membrane (S-ISM) Pb sensors with low-cost, high accuracy and long-term durability and that enable real-time in situ monitoring of Pb(II) ion contamination down to low concentrations (15 ppb-960 ppb) in wastewater. An innovative pH auto-correction data-driven model was built to overcome the inextricable pH inferences on Pb(II) ISM sensors in wastewater. Electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) analysis showed (3,4-ethylenedioxythiophene, EDOT) deposited onto the mm-sized screen-printed carbon electrodes using electropolymerization effectively alleviated the interferences from dissolved oxygen and improved long-term stability in wastewater. Monte Carlo simulation of the nitrification process predicted that real-time, and high accurate in situ monitoring of Pb(II) in wastewater and swift feedback control could save ∼53 % of energy consumption by alleviating the errors from pH and DO impacts in WWTPs.

Metal mixtures and kidney function: An application of machine learning to NHANES data

BACKGROUND

Exposure to heavy metals may increase risk of kidney disease, but most studies have examined individual metals or two-way interactions. There is increasing recognition of the importance of studying exposure to metal mixtures and health outcomes.

OBJECTIVES

We used Bayesian kernel machine regression (BKMR) to examine associations between a mixture of four heavy metals and indicators of kidney function.

METHODS

We used NHANES 2015-16 data on 1435 adults aged 40 and over to study cross-sectional associations between blood levels of four heavy metals (Co, Cr, Hg and Pb) and kidney function. Kidney function was assessed by estimated glomerular filtration rate (eGFR) and by albumin to creatinine ratio (ACR), measured continuously and dichotomized into indicators of chronic kidney disease (CKD) and albuminuria, respectively. BKMR tested for non-linearity in the exposure-specific responses to evaluate dose-response relationships between mixtures and outcomes and possible interaction effects among exposures. Interactions among continuous outcomes were identified using the NLinteraction package in R.

RESULTS

A higher metals mixture was significantly associated with all four measures of kidney function in dose-response patterns. Pb had the strongest association with eGFR, albuminuria and ACR, and the second strongest association with CKD. We also observed an interaction between Pb and Co for eGFR and an interaction between Pb and Cd for ACR.

CONCLUSIONS

Exposure to a co-occurring heavy metals mixture was associated with indicators of poor kidney function. Within this mixture, Pb, Co and Cd considered singly and jointly made the greatest contributions to the observed effects. Future prospective study is needed to confirm the association between metal mixtures and kidney function.

Effects of acute oral lead exposure on the levels of essential elements of mice: a metallomics and dose-dependent study

BACKGROUND AND OBJECTIVES

Lead (Pb) has been reported to disturb the metabolism of essential elements, such as calcium (Ca), magnesium (Mg), iron (Fe) and zinc (Zn) in vivo. This study focused on the relationship between various dose of Pb and the essential elements.

METHODS

50 healthy male C57BL/6 mice underwent oral administration of 0.2 mL lead acetate trihydrate solution (0, 20, 100, 500, and 1000 mg Pb/day/kg body weight) for 3 days. The concentrations of Pb and four essential elements (Ca, Zn, Fe and Mg) in the blood, kidney, liver, bone and brain were quantified with inductively coupled plasma mass spectrometry.

RESULTS

Various doses of Pb led to significant increases in the contents of Ca, Fe and Zn in the liver, and decreased contents of Mg and Fe in the blood in a dose-dependent pattern. The Pb dose of 20 mg/kg reduced the concentration of bone Ca, which did not continue to show an obvious decline with continued increases in the oral Pb dose. Pb also caused alterations in the Mg distribution pattern, and decreased the correlation of Mg, Ca and Zn in the brain, both findings were dose-dependent. In addition to the changes in metallomics, the related oxidative stress was exacerbated, but no significant changes were detected in hepatic and renal histopathological lesions after a short period of Pb exposure.

CONCLUSIONS

This study contributes to a thorough analysis of the Pb-poisoning mechanism, and indicates that the concentrations of essential elements could be used as sensitive toxicological indicators of Pb exposure.

Exopolysaccharide-peptide complex from oyster mushroom (Pleurotus ostreatus) protects against hepatotoxicity in rats

Liver damage involves oxidative stress and a progression from chronic hepatitis to hepatocellular carcinoma (HCC). The increased incidence of liver disease in Egypt and other countries in the last decade, coupled with poor prognosis, justify the critical need to introduce alternative chemopreventive agents that may protect against liver damage. The aim of this study was to evaluate the efficacy of exopolysaccharide-peptide (PSP) complex extracted from Pleurotus ostreatus as a hepatoprotective agent against diethylnitrosamine (DEN)/carbon tetrachloride (CCL₄)-induced hepatocellular damage in rats. The levels of liver injury markers (ALT, AST and ALP) were substantially increased following DEN/CCl₄ treatment. DEN/CCl₄ - induced oxidative stress was confirmed by elevated levels of lipid peroxidation and decreased levels of superoxide dismutase, glutathione-S-transferase, and reduced glutathione. PSP reversed these alterations in the liver and serum, and provided protection evidenced by reversal of histopathological changes in the liver. The present study demonstrated that PSP extract from P. ostreatus exhibited hepatoprotective and antioxidant effects against DEN/CCl₄-induced hepatocellular damage in rats. Given the high prevalence of HCV-related liver damage in Egypt, our results suggest further clinical evaluation of P. ostreatus extracts and their potential hepatoprotective effects in patients with liver disease.

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Polysaccharo-peptide complex from Pleurotus ostreatus in Egypt is cytotoxic in the liver cancer cell line HepG2

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Polysaccharo-peptide complex protects against chemically induced liver damage in rats

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Polysaccharo-peptide complex activates the antioxidant system in the liver

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Polysaccharo-peptide complex reverses the chemically induced hematotoxicity

Effects of Cadmium and/or Lead on Autophagy and Liver Injury in Rats

Exposure to cadmium (Cd) and lead (Pb) can induce liver damage. However, the effects of the combined exposure to Cd and Pb on liver function have not been fully clarified. In the present study, we investigated the liver function in rats co-exposed to Cd and Pb. A total of 24 female SD rats were divided into 4 groups as follows: control group (DDW), Cd group (50 mg/l Cd), Pb group (300 mg/l Pb), Pb + Cd group (300 mg/l + 50 mg/l Cd). Following 12 weeks of continuous exposure, the results showed a large accumulation of Cd and Pb in the liver. The Liver weight and Liver coefficient were decreased, as well as liver structure and function was destroyed. In addition, Pb + Cd group exhibited additional pathological alterations. Moreover, the indices of oxidative stress and related trace elements were detected following treatment. The results showed that the single treatment of Pb or Cd and the combined Cd and Pb treatment could upregulate the contents of antioxidant enzymes and related trace elements. We further examined the expression levels of autophagy-related proteins and mRNAs, and we found that the single treatment of Pb or Cd and the combined Cd and Pb treatment could upregulate the expression of levels of autophagy-related proteins and mRNAs (Atg5, Atg7, Beclin-1, p62, and LC3). Transmission electron microscopy revealed the presence of autophagosomes in the exposed groups. All the results indicated that Cd and Pb may affect the level of oxidative stress and autophagy in hepatocytes, whereas the combination of Cd and Pb showed a tendency of escalation compared with the single treatment group.

Evaluation of long-term dermal exposure to soil contaminated with spent engine oil in male Wistar rats: An experimental approach

Continuous occupational exposure to spent engine oil (SEO) poses physiological risks to humans, especially to automobile mechanics. This study investigated the physiological effects of SEO-contaminated soil in a male Wistar rat model. Animals were dermally exposed to soil contaminated with SEO for 120 consecutive days and compared with rats exposed to uncontaminated soil (negative control). Heavy metal (lead (Pb), nickel (Ni), zinc, and cadmium (Cd)) accumulations, hematology, biochemical (aspartate aminotransferase (AST), alanine aminotransferase, alkaline phosphatase (ALP), urea, and creatinine) parameters, sperm morphology, and histopathology (liver, kidney, lungs, brain, skin, and testis) were evaluated as end points. Results revealed that the heavy metals in SEO-contaminated soil are far greater than the World Health Organisation permissible limits, with significant (p < 0.05) increases of Pb and Ni present in the brain, and Pb and Cd in the serum compared with the uncontaminated soil for the negative control. Only significant (p < 0.05) values were observed in the lymphocytes, activities of AST and ALP, and sperm abnormalities of the exposed rats compared with those used for the negative control. Histopathological changes were not evident in the brain but lesions were observed in the liver, kidney, lungs, skin, and testis of the exposed rats. Results herein suggest that the constituents of SEO may elicit harmful physiological changes to humans who are directly exposed to them.

Inducible and conditional activation of ERK5 MAP kinase rescues mice from cadmium-induced olfactory memory deficits

Cadmium (Cd) is a heavy metal that is one of the most toxic environmental pollutants throughout the world. We previously reported that Cd exposure impairs olfactory memory in mice. However, the underlying mechanisms for its neurotoxicity for olfactory function are not well understood. Since adult Subventricular zone (SVZ) and Olfactory Bulb (OB) neurogenesis contributes to olfaction, olfactory memory defects caused by Cd may be due to inhibition of neurogenesis. In this study, using bromodeoxyuridine (BrdU) labeling and immunohistochemistry, we found that 0.6 mg/L Cd exposure through drinking water impaired adult SVZ/OB neurogenesis in C57BL/6 mice. To determine if the inhibition of olfactory memory by Cd can be reversed by stimulating adult neurogenesis, we utilized the transgenic caMEK5 mouse strain to conditional stimulate of adult neurogenesis by activating the endogenous ERK5 MAP kinase signaling pathway. This was accomplished by conditionally induced expression of active MEK5 (caMEK5) in adult neural stem/progenitor cells. The caMEK5 mice were exposed to 0.6 mg/L Cd for 38 weeks, and tamoxifen was administered to induce caMEK5 expression and stimulate adult SVZ/OB neurogenesis during Cd exposure. Short-term olfactory memory test and sand-digging based, odor-cued olfactory learning and memory test were conducted after Cd and tamoxifen treatments to examine their effects on olfaction. Here we report that Cd exposure impaired short-term olfactory memory and odor-cued associative learning and memory in mice. Furthermore, the Cd-impaired olfactory memory deficits were rescued by the tamoxifen-induction of caMEK5 expression. This suggests that Cd exposure impairs olfactory function by affecting adult SVZ/OB neurogenesis in mice.

Redox and essential metal status in the brain of Wistar rats acutely exposed to a cadmium and lead mixture

Most Pb and Cd neurotoxicity studies investigate exposure to either of the toxic metals alone, while data on co-exposure are scarce. The aim of our study was to fill that gap by investigating acute combined effects of Pb and Cd on redox and essential metal status in the brain of Wistar rats. Animals were randomised in four groups of six to eight rats, which received 15 or 30 mg/kg of Cd, 150 mg/kg of Pb, or 150 mg/kg of Pb + 15 mg/kg of Cd by gavage. The fifth, control, group received distilled water only. Co-treatment with Pb and Cd induced significant increase in malondialdehyde (MDA) and thiobarbituric acid-reactive substances (TBARS) compared to control and groups receiving either metal alone. This is of special importance, as MDA presence in the brain has been implicated in many neurodegenerative disorders. The groups did not significantly differ in Zn, Cu, Mn, and Fe brain levels. Our findings highlight the importance of metal mixture studies. Neurotoxicity assessments of single chemicals do not provide a real insight into exposure to mixtures in real life. Further research should look into interactions between these metals to reveal complex molecular mechanisms of their neurotoxicity.

The Effect of Low Dose of Cadmium on Growth, Reproduction and Chicken Viability

Cadmium (Cd) is considered to be a highly polluting heavy metal with toxic effects on health and reproduction. In this study, the effects of low dose cadmium on growth, reproductive properties, and egg properties were studied. Cadmium as cadmium chloride (CdCl2) at a dose of 3 mg Cd.kg−1 was added as a feed supplement. The following parameters were evaluated: body weight, egg production, fertility, hatching, embryo and chick mortality, and egg quality characteristics. After 2 months of exposure to low doses of cadmium, the body weight increased in the cocks and did not change in the laying hens. Egg production was not affected, while fertility increased. The values of egg weight and hardness, thickness and shell weight were significantly higher (P < 0.05). The embryo mortality in the experimental group was lower (6.5 % vs. 12.8 %) compared to the control group. The hatching was significantly higher (P < 0.05) and the loss in 7 day old chickens was similar to that in the control group. Although the toxic effects of cadmium on reproduction and accumulation in poultry bodies have been generally described, low-doses of cadmium given to adult hens and cocks has improved the reproductive parameters and qualitative properties of laying hen eggs. The results related to the reproduction and quality of eggs obtained in this study have the characteristics of the hormetic effects of low cadmium uptake.

Hesperidin ameliorates hepatic dysfunction and dyslipidemia in male Wistar rats exposed to cadmium chloride

The ever-increasing human population with attendant industrialization poses serious global health challenge. Cadmium (Cd) with other heavy metals contribute greatly to environmental pollutions and humans are daily exposed to them, leading to diverse ailments. We explored whether Hesperidin (HSP) could protect against hepatic damage and dyslipidemia in Wistar rats exposed to Cd. Forty wistar rats were randomly assigned into five groups (n = 8). Group 1 received 2 mL/kg body weight of normal saline; Group 2 received 100 mg/kg body weight of HSP while Group 3 received 5 mg/kg body weight of Cadmium Chloride (CdCl2) for 28 days. Group 4 received 100 mg/kg body weight of HSP and after 90 min, CdCl2 (5 mg/kg) body weight was administered for 28 days. Group 5 received 50 mg/kg body weight of HSP and after 90 min, CdCl2 (5 mg/kg) body weight was administered for 28 days. The serum lipid profiles, hepatic dysfunction and oxidative stress markers were determined using standard methods. Cd toxicity in rats prominently elevated serum activities of AST, ALT, ALP and levels of total bilirubin, direct bilirubin, cholesterol, LDL-C and malondialdehyde with decreased levels of HDL-C, triglycerides, superoxide dismutase, catalase, glutathione and body weights. The pre-treatment of HSP before Cd intoxication prevented the dysregulated activities of liver enzymes and levels of lipid profiles, enzymatic and non-enzymatic antioxidants and other biomarkers investigated, thus suggesting anti-hyperlipidemic and hepato-protective potentials. HSP may have great potentials for development of therapeutics that could enhance the management of dyslipidemia and liver disorders associated with heavy metal exposure.

Lead and cadmium exposure induces male reproductive dysfunction by modulating the expression profiles of apoptotic and survival signal proteins in tea-garden workers

The aim of this study was to evaluate the impact of Lead (Pb) and Cadmium (Cd) exposure at the molecular level on the reproductive status of tea garden workers in North-East India. Using semen samples, we experimentally determined sperm analysis as well as oxidative stress parameters in all samples and evaluated the expression levels of apoptotic and cell survival proteins [p53, phospho-Akt, nuclear factor-κB (NF-κB, p50 subunit) and B cell lymphoma 2 (Bcl2)]. Our data revealed significant differences in the average heavy metal concentrations and various semen analysis profile between the infertile and normal groups. Increasing Pb and Cd concentrations in semen samples of patients showed positive associations with increasing number of multiple defects in sperm and the level of seminal oxidative stress markers in the high Pb and Cd concentration groups. These groups also exhibited positive correlations between high metal concentrations and the average p53 expression levels, but negative correlations with the mean p-Akt cascade protein levels in sperm cells. In the low Pb and Cd concentrations groups, we also observed reverse mean range and correlation patterns. Therefore, our findings may suggest that graded levels of metal exposure significantly influence the relative fluctuation in the levels of p53 and Akt cascade proteins in the sperm cells of infertile subjects. Furthermore, this may be a regulating factor of sperm cell fate, in turn, determining the fertility outcome of the men working in the tea gardens.

Lead exposure induces metabolic reprogramming in rat models

Lead is a toxin of great public health concern affecting the young and aging population. Several factors such as age, gender, lifestyle, dose, and genetic makeup result in interindividual variations to lead toxicity mainly due to variations in metabolic consequences. Hence, the present study aimed to examine dose-dependent lead-induced systemic changes in metabolism using rat model by administering specific doses of lead such as 10 (low lead; L-Pb), 50 (moderate lead; M-Pb), and 100 mg/kg (high lead; H-Pb) body weight for a period of one month. Biochemical and haematological analysis revealed that H-Pb was associated with low body weight and feed efficiency, low total protein levels (p ≤ 0.05), high blood lead (Pb-B) levels (p ≤ 0.001), low ALAD (δ-aminolevulinate dehydratase) activity (p ≤ 0.0001), high creatinine (p ≤ 0.0001) and blood urea nitrogen (BUN) (p ≤ 0.01) levels, elevated RBC and WBC counts, reduced haemoglobin and blood cell indices compared to control. Spatial learning and memory test revealed that H-Pb exposed animals presented high latency to the target quadrant and escape platform compared to other groups indicating H-Pb alters cognition function in rats. Histopathological changes were observed in liver and kidney as they are the main target organs of lead toxicity. LC-MS analysis further revealed that Butyryl-L-carnitine (p ≤ 0.01) and Ganglioside GD2 (d18:0/20:0) (p ≤ 0.05) levels were significantly reduced in H-Pb group compared to all groups. Further, pathway enrichment analysis revealed abundance and significantly modulated metabolites associated with oxidative stress pathways. The present study is the first in vivo model of dose-dependent lead exposure for serum metabolite profiling.

Plasma heavy metals and their effect on oxidative stress parameters of buffaloes inhabiting Buddha Nallah area of Ludhiana district in Punjab

In the present study, plasma lead, cadmium, arsenic and nickel concentrations and oxidative stress parameters in buffaloes residing near Buddha Nallah region were evaluated. Blood samples of 59 buffaloes were collected for the study and plasma was separated and analyzed for heavy metal levels and for oxidative stress parameters like reduced glutathione,malonyldialdehyde and superoxide dismutase. Significant increase in plasma heavy metal concentrations was recorded in the buffaloes of the region and significant decrease in GSH and SOD and significant increase in MDA levels were also recorded in the buffaloes of the region. Samples with higher levels of heavy metals depicted oxidative damage in the animals residing near Buddha Nallah area of the Ludhiana city.

Co-exposure to non-toxic levels of cadmium and fluoride induces hepatotoxicity in rats via triggering mitochondrial oxidative damage, apoptosis, and NF-kB pathways

Fluoride (F) and cadmium (Cd) are two common water pollutants. There is low information about their co-exposure in low doses. So, in this study, we evaluated the combination effects of non-toxic doses of F and Cd and the possible mechanism of their combined interaction. Male rats were exposed to non-toxic doses of sodium fluoride (30 mg/l) and/or cadmium chloride (40 mg/l) in drinking water for 6 weeks. Then, liver tissues were separated and several factors including oxidative stress, mitochondrial toxicity, inflammation, apoptosis, and biochemical and histopathological changes were evaluated. Cd and F alone did not induce any significant changes in evaluated factors compared to control group, while significant elevation in liver enzymes as well as histopathological changes were observed in rats treated with F+Cd. Also, a remarkable increase in oxidative stress markers including reactive oxygen species, lipid peroxidation, and protein carbonyl and also decreasing glutathione and superoxide dismutase levels were detected following co-exposure to F and Cd. Furthermore, a combination of F and Cd resulted in mitochondrial dysfunction, swelling, as well as a reduction in mitochondrial membrane potential in isolated liver mitochondria. On the other hand, TNF-α, IL-1β, and NF-kB inflammatory genes were upregulated in the liver after combined exposure to F and Cd compared to individual treatments. Also, F+Cd treatment increased the Bax expression but decreased the expression of Bcl-2 significantly. These findings suggest that Cd and F can potentiate their individual toxic effects on the liver tissue through disruption of the cellular redox status, inflammation, and apoptosis pathway.

Carbon monoxide: An emerging therapy for acute kidney injury

Treating acute kidney injury (AKI) represents an important unmet medical need both in terms of the seriousness of this medical problem and the number of patients. There is also a large untapped market opportunity in treating AKI. Over the years, there has been much effort in search of therapeutics with minimal success. However, over the same time period, new understanding of the underlying pathobiology and molecular mechanisms of kidney injury have undoubtedly helped the search for new therapeutics. Along this line, carbon monoxide (CO) has emerged as a promising therapeutic agent because of its demonstrated cytoprotective, and immunomodulatory effects. CO has also been shown to sensitize cancer, but not normal cells, to chemotherapy. This is particularly important in treating cisplatin-induced AKI, a common clinical problem that develops in patients receiving cisplatin therapies for a number of different solid organ malignancies. This review will examine and make the case that CO be developed into a therapeutic agent against AKI.

Luteolin protects against testicular injury induced by lead acetate by activating the Nrf2/HO-1 pathway

Lead (Pb) is a toxic heavy metal that is harmful to humans, especially male reproductive organs. Luteolin (LUT) is a naturally occurring flavonoid with numerous biological activities. Our aim was to investigate the possible reproprotective effect of LUT against testicular deficits induced by Pb intoxication. In the present study, 28 rats were distributed into 4 groups: control, LUT (50 mg/kg), lead acetate (PbAc, 20 mg/kg), and LUT + PbAc groups, in which rats were pre-treated with LUT 3 hr before PbAc injection. All animals were treated for 7 days. Oxidative stress, inflammatory and apoptotic markers along with histopathological changes have been examined using spectrophotometric, ELISA, real-time PCR, and histopathological methods. PbAc injection elevated Pb concentration in testicular tissue and decreased levels of sex hormones. PbAc intoxication exacerbated lipoperoxidation and nitric oxide formation, depleted superoxide dismutase, and catalase activities along with glutathione and its originated enzymes (glutathione peroxidase and glutathione reductase). At the molecular level, PbAc deactivated nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 in the testicular tissue. In addition, PbAc toxicity induced inflammatory and apoptotic cascades in testicular tissue as evidenced by the increased tumor necrosis factor-alpha, interleukin-1 beta, inducible nitric oxide synthase, Bax, and caspase 3, while Bcl-2 was declined. Histopathological examination of testicular tissue also revealed that PbAc caused degeneration alterations in spermatogenic cells, the spermatogenic epithelial cells were disconnected from the basement membrane, and the seminiferous tubules were vacuolated. Remarkably, pre-treatment with LUT minimized significantly the testicular damage induced by PbAc. Therefore, we conclude that LUT may have a beneficial effect against PbAc-induced testicular injury through preventing oxidative challenge, inflammation, and finally apoptosis.

Curcumin-loaded cockle shell-derived calcium carbonate nanoparticles: A novel strategy for the treatment of lead-induced hepato-renal toxicity in rats

Lead (Pb) toxicity affects the hepatic and renal systems resulting to homeostasis imbalance. Curcumin is a strong antioxidant but has restrained clinical applications due to its poor bioavailability. Nanomedicine showed promising potentials in drug delivery and has brought forth the use of cockle shell-derived aragonite calcium carbonate nanoparticles (CSCaCO₃NP) to enhance the effectiveness and targeted delivery of curcumin (Cur). Thus, this study aimed at evaluating the therapeutic effect of curcumin-loaded CSCaCO₃NP (Cur- CSCaCO₃NP) on lead-induced hepato-renal toxicity in rats. Thirty-six male adults Sprague-Dawley rats were randomly assigned into five groups. All groups contained six rats each except for group A, which contained 12 rats. All rats apart from the rats in group A (control) were orally administered a flat dose of 50 mg/kg of lead for four weeks. Six rats from group A and B were euthanized after four weeks of lead induction. Oral administration of curcumin (100 mg/kg) for group C and Cur-CSCaCO₃NP (50 and 100 mg/kg) for groups D and E respectively, commenced immediately after 4 weeks of lead induction which lasted for 4 weeks. All rats were euthanized at the 8th week of the experiment. Further, biochemical, histological and hematological analysis were performed. The findings revealed a biochemical, hematological and histological changes in lead-induced rats. However, treatments with the Cur-CSCaCO₃NP and free curcumin reversed the aforementioned changes. Although, Cur-CSCaCO₃NP presented better therapeutic effects on lead-induced toxicity in rats when compared to free curcumin as there was significant improvements in hematological, biochemical and histological changes which is parallel with attenuation of oxidative stress. The findings of the current study hold great prospects for Cur-CSCaCO₃NP as a novel approach for effective oral treatment of lead-induced hepato-renal impairments.

Fumaric acid protect the cadmium-induced hepatotoxicity in rats: owing to its antioxidant, anti-inflammatory action and aid in recast the liver function

In the modern world, indiscriminate human activities impelled environmental toxicity through heavy metals such as cadmium (Cd) that poses significant health hazards to the flora and fauna. Multiple mechanisms such as oxidative stress, inflammation, apoptotic cell death, and chromosomal aberrations underlie the Cd-induced organ toxicity with the liver and kidneys bearing most of the brunt. Fumaric acid (FA) is an organic acid (C₄H₄O₄) omnipresent in nature and attributed with such properties (e.g., antioxidant, anti-inflammatory, analgesic, chemopreventive, anti-psoriatic, immunomodulatory, and neuroprotective) that may bestow relief in Cd-induced liver damage. Hence, in the present study, the protective effects of FA were determined in Cd-induced hepatotoxicity in rats. Wistar rats were chronically exposed to Cd (5 mg/kg, p.o.) to induce liver dysfunction. The rats were subjected to FA (1.25, 2.5, 5 mg/kg; p.o.) pre-treatment for 28 days to observe effects on liver and serum biomarkers of oxidative stress, enzymatic activities, and hepatic damage (liver histopathology). Body weights, feed/water intake, body mass index (BMI), and non-invasive parameters (FIB-4 score; AST/ALT ratio) were quantified. Cd-triggered hepatic injury in rats through oxidative stress, derangement of hepatic serum biomarkers (ALT, AST, ALP, LDH, bilirubin, cholesterol, triglycerides, uric acid, and platelet count), and pathogenic alteration in non-invasive parameters. FA pre-treatment significantly protected rat livers against Cd toxicity by decreasing oxidative stress and improving the hepatic serum biomarkers and non-invasive parameters. In a histopathological analysis, FA prevented Cd-accrued hepatocellular damage. Fumaric acid showed potential to avert hepatic injury against cadmium in rats. Graphical abstract.

Ameliorative and protective effects of fucoidan and sodium alginate against lead-induced oxidative stress in Sprague Dawley rats

The current study was performed to evaluate the possible protective effects of fucoidan (F) and sodium alginate (SA) against lead-induced oxidative damage in vivo, and to identify relevant underlying mechanisms. Health Sprague Dawley (SD) rats were divided into nine groups of ten rats each and treated orally with lead acetate (5 mg/kg, Pb2+) for 4 weeks, then gavaged with DMSA (Meso-2, 3-dimercaptosuccinic acid, 25 mg/kg), F (50, 100, 200 mg/kg) and SA (50, 100, 200 mg/kg) individually after successful modelling. We found that the administration of both F or SA resulted in a beneficial effect by significantly decreasing lead levels (p < 0.05) in the kidneys from 2.85 mg/kg to 0.79 mg/kg and improving antioxidant status (SOD, GSH, and CAT) thereby alleviating lead-induced damage and injury of the liver and kidneys (AST, BUN, and Cr). Both natural extracts exerted dose-dependent effects. Protective effects were further demonstrated by histopathology. Our results demonstrate that the F and SA are effective natural extracts for lead-eliminating, and that they can ameliorate oxidative damage induced by lead toxicity.

Development of an Adsorbing System Made of DMS-1 Mesh Modified by Amino Groups to Remove Pb(II) Ions from Water

Water pollution by heavy metals represents several health risks. Conventional technologies employed to eliminate lead ions from residual or drinking water are expensive, therefore an efficient and low-cost technique is required and adsorption processes are a good alternative. In this work, the goal was to determine the adsorption capacity of a Disordered Mesoporous Silica 1 material (DMS-1) functionalized with amino groups, for Pb(II) ions removal. DMS-1 was prepared by sol-gel method and the incorporation of amino groups was performed by ex-situ method. As the source of amine groups, (3-Aminopropyl) triethoxysilane (APTES) was used and three different xNH2/DMS-1 molar ratios (0.2, 0.3, 0.4) were evaluated. In order to evaluate the incorporation of the amino group into the mesopore channels, thermal and structural analysis were made through Thermogravimetric Analysis (TGA), nitrogen adsorption-desorption at 77 K by Specific Brunauer-Emmett-Teller (SBET) method, Fourier Transfer Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS). The higher Pb(II) ions removal was achieved with the 0.3 molar proportion of xNH2/DMS-1 reaching 99.44% efficiency. This result suggests that the functionalized material can be used as an efficient adsorbent for Pb(II) ions from aqueous solution.

Hepatoprotective Effect of Oleuropein-Rich Extract from Olive Leaves against Cadmium-Induced Toxicity in Mice

Cadmium (Cd) is a harmful pollutant which mainly affects the liver and kidney. In this work, we investigated the hepatoprotective effects of olive leaf extract based on oleuropein against hepatic cadmium toxicity in mice. Three groups of animals were used: the first one served as the control (C); the second one received intraperitoneal injection of cadmium 2 mg/kg b.w. (CD), administered five times during two weeks; and the third group received the same doses of Cd and simultaneously 16 mg/kg b.w. of oleuropein. Results showed that Cd induced a significant increase in liver injury biomarkers coupled with enhanced lipid peroxidation (MDA) and significant depletion of antioxidants (CAT and SOD). Histological and immunohistochemical analysis confirmed these findings. In fact, we observed a severe central lobular apoptosis and inflammation around central veins. Cotreatment with oleuropein significantly reduced the oxidative damage induced by cadmium. Our findings suggest that oleuropein could be used in the prevention of Cd hepatotoxicity.

Mitigation of lead neurotoxicity by the ethanolic extract of Laurus leaf in rats

The present study was conducted in order to assess the chemical composition of Laurus, its antioxidant activities, and benefit from the Laurus extract effect on neurotoxicity caused by lead acetate (Pb). Chemical profile was assayed by using liquid chromatography coupled with high-resolution mass spectrometry (LC-HR-MS). In this study, 40 male rats were divided into four groups (10 rats per each group): (1) control group, (2) Laurus group: rats treated with 250 mg/kg b. wt. of Laurus leaves extract, (3) Pb group: rats treated with 100 mg/kg b. wt. of lead acetate, (4) Pb + Laurus group: rats treated with 250 mg/kg b. wt. of Laurus leaves extract in addition to lead acetate for 30 days. At the end of experiment, some estimates were calculated from blood samples, brain tissue, and histological examination. The results showed that the extract is highly affluent in total flavonoids, total phenolic, and also has antioxidant activity. The LC-MS appeared a wide range of compounds in the extract. The oxidative stress resulted from exposure to lead acetate has been reported to cause reduction in body and brain weights, levels of RBCs, acetylcholinesterase (AChE), GSH, SOD, and CAT in addition to increase in levels of WBCs and MAD. Moreover, Laurus leaves extract notably lessened the biochemical changes caused by lead acetate in the blood, homogenate, and brain tissue (P < 0.05). The current study indicates the antioxidant activity of Laurus leaves extract and assumes that it has a defensive role against the oxidative damage caused by lead in a rat's brain.

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

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

Ameliorative effect of curcumin against lead acetate-induced hemato-biochemical alterations, hepatotoxicity, and testicular oxidative damage in rats

Lead, toxic heavy metal of global concern, induces toxicity in various organs via oxidative stress. Thereby, in this study, the protective role of curcumin against lead acetate-induced toxicity was evaluated. Thirty-two male albino rats were allocated equally into four groups and orally administered with corn oil as a vehicle (Cont.), curcumin (CUR) (400 mg/kg bw), lead acetate (LA) (100 mg/kg bw), and lead acetate plus curcumin (LA + CUR). All rats had received their treatments daily for 4 weeks. The results revealed that LA toxicity induced normocytic normochromic anemia with significant leukocytosis and lymphocytosis. Moreover, LA-intoxicated rats showed a marked elevation in the liver enzyme activities, serum cholesterol, and triglyceride levels. In contrast, sero-immunological parameters, total protein, albumin, globulin, and testosterone levels were significantly reduced compared to the control rats. Additionally, LA-induced hepatic and testicular oxidative damage revealed by marked increased in MDA level with prominent reduction in the antioxidant system. The gene expression of the hepatic pro-inflammatory markers and testicular steroidogenic biomarkers including LHR and aromatase were significantly upregulated; meanwhile, the expressions of testicular StAR, CYP17a, 3B-HDS, SR-B1, and P450SCC were significantly downregulated in the LA-intoxicated group. Curcumin treatment could partially improve the hematological, biochemical, and histopathological alterations induced by LA. Also, it was observed that curcumin significantly restored hepatic pro-inflammatory markers and testicular steroidogenic enzymes. In conclusion, curcumin has antioxidant, anti-inflammatory, and immunomodulatory effects and is able to minimize the LA-induced oxidative damage in rats.

Ameliorative effect of curcumin on lead-induced hematological and hepatorenal toxicity in a rat model

INTRODUCTION

Lead (Pb) is a ubiquitous toxic heavy metal that inflicts numerous clinical consequences on humans. Curcumin is the principal component of turmeric, which is reported to have antioxidative properties. This study aimed at evaluating the ameliorative effects of curcumin on Pb-induced hepatorenal toxicity in a rat model.

METHODS

Thirty-six male Sprague-Dawley rats were randomly assigned into five groups with 12 rats in the control (normal saline) and six rats each for the lead-treated group (LTG) (50 mg/kg lead acetate [Pb acetate] for 4 weeks), recovery group (50 mg/kg Pb acetate for 4 weeks and left with no treatment for another 4 weeks), treatment group 1 (Cur100) (50 mg/kg Pb acetate for 4 weeks, followed by 100 mg/kg curcumin for 4 weeks), and treatment group 2 (Cur200) (50 mg/kg Pb acetate for 4 weeks, followed by 200 mg/kg curcumin for 4 weeks). All the experimental groups received oral treatments via orogastric-tube on alternate days. Pb concentration in the liver and kidney of the rats were evaluated using inductive-coupled plasma mass spectrometry techniques.

RESULTS

Pb-administered rats revealed significant alteration in oxidative status and increased Pb concentration in their liver and kidney with obvious reduction of hemogram and increased in leukogram as well as aberration in histological architecture of the liver and kidney. However, treatment with curcumin reduces the tissue Pb concentrations and ameliorates the above mention alterations.

CONCLUSIONS

The results in this study suggested that curcumin attenuates Pb-induced hepatorenal toxicity via chelating activity and inhibition of oxidative stress.

Plasma metals and serum bilirubin levels in workers from manganese-exposed workers healthy cohort (MEWHC)

Few studies specifically address the possible associations between multiple-metal exposures and liver damage among the occupational population. This study aimed to explore the cross-sectional relationships of plasma metals with liver function parameters. For 571 on-the-spot workers in the manganese-exposed workers healthy cohort (MEWHC), we determined liver function parameters: total bilirubin (TBILI), direct bilirubin (DBILI), indirect bilirubin (IBILI), alanine transaminase (ALT) and aspartate transaminase (AST). Total concentrations of 22 plasma metals were measured by ICP-MS. The LASSO (least absolute shrinkage and selection operator) penalized regression model was applied for selecting plasma metals independently associated with liver function parameters. Multiple linear regression analyses and restricted cubic spline (RCS) were utilized for identifying the exposure-response relationship of plasma metals with liver function parameters. After adjusting for covariates and selected metals, a 1-SD increase in log-10 transformed levels of iron was associated with increases in the levels of TBILI, DBILI and IBILI by 20.3%, 12.1% and 23.7%, respectively; similar increases in molybdenum for decreases in levels of TBILI, DBILI and IBILI by 6.1%, 2.6% and 8.3%, respectively. The effect of a 1-SD increase in plasma copper corresponded decreases of 3.2%, 3.4% and 5.0% in TBILI, AST and ALT levels, respectively. The spline analyses further clarified the non-linear relationships between plasma iron and bilirubin whilst negative linear relationships for plasma molybdenum and bilirubin. Plasma iron was positively whilst plasma molybdenum was negatively associated with increased serum bilirubin levels. Further studies are needed to validate these associations and uncover the underlying mechanisms.

Senna alexandrina extract supplementation reverses hepatic oxidative, inflammatory, and apoptotic effects of cadmium chloride administration in rats

Senna alexandrina is traditionally used for its antioxidant and anti-inflammatory properties, but little information is available concerning its potential protective effects against cadmium, which is a widespread environmental toxicant that causes hepatotoxicity. Here, we explored the effects of S. alexandrina extract (SAE) on cadmium chloride (CdCl₂)-induced liver toxicity over 4 weeks in rats. Rats were allocated into four groups: control, SAE (100 mg/kg), CdCl₂ (0.6 mg/kg), and SAE + CdCl₂, respectively. Cadmium level in hepatic tissue, blood transaminases, and total bilirubin as indicators of liver function were assessed. Oxidative stress indices [malondialdehyde (MDA), nitrate/nitrite (NO), and glutathione (GSH)], antioxidant molecules [superoxide dismutase (SOD, catalase (CAT), glutathione-derived enzymes, and nuclear factor erythroid 2-related factor 2 (Nrf2)], pro-inflammatory mediators [interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α)], apoptosis proteins (Bcl-2, Bax, and caspase-3), and histological alterations to the liver were examined. SAE administration before CdCl₂ exposure decreased cadmium deposition in liver tissue and the blood liver function indicators. SAE pre-treatment prevented oxidative, inflammatory, and apoptotic reactions and decreased histological alterations to the liver caused by CdCl₂ exposure. SAE can be used as a promising protective agent against CdCl₂-induced hepatotoxicity by increasing Nrf2 expression. Graphical abstract.

Rat liver and kidney post-mitochondrial dysfunction by addition of chronic mixed metal intoxication and hepatorenal wellness mediated by phenolic components from Croton zambiscus leaves

Chronic exposure of mixed-metal intoxication has been associated with prolonged oxidative stress and severe hepatorenal damage. This present study demonstrates the hepatoprotective and renoprotective activity of Croton zambesicus (C-ZAMB) leaves, naturally occurring phenolic compounds against chronic mixed-metal (EOMABRSL) induced toxicity. 0.5 ml of EOMABRSL via oral route induced chronic hepatoxicity and nephrotoxicity on exposure for 98 days (non-withdrawal) and 70 days (withdrawal) by abnormal alteration in the levels of endogenous antioxidants. Moreover, EOMABRSL induced hepatorenal damage by increasing the markers of liver toxicity (ALT, AST, ALP, GGT and bilirubin) and kidney failure (creatinine, urea, uric acid, and renal electrolytes-Na⁺ and K⁺). Both non-withdrawal and withdrawal approaches of EOMABRSL-exposed animals exhibited hepatorenal dysfunctions by increasing the activity of eco-5¹-nucleotidase (5¹ENT) followed by the decreased in the activity of lactate dehydrogenase (LDH)-index of cellular ATP. These results were further supported by the histopathological examination of nephritic cells, hepatocytes and splenocytes, manifested by hepatocellular necrosis, swelling or degeneration of tubular kidney epithelial cells as well as coalescing splenic periarteriolar lymphoid sheaths (PALSs) and lymphoid haemosiderin. The chronic EOMABRSL intoxication was ameliorated by administration of phenolic antioxidants from C-ZAMB leaves. Therefore, our study supports the view that phenolic C-ZAMB leaves may mediate hepatorenal wellness on chronic exposure to mixed-metal intoxication.

Toxic Effects of the Mixture of Phthalates and Bisphenol A-Subacute Oral Toxicity Study in Wistar Rats

Phthalates and bisphenol A, classified as endocrine disruptors, have weak estrogenic, anti-androgenic properties, and affect thyroid hormone regulation. The aim of this study on male rats was to compare the subacute toxic effects of low doses of single compounds (bis (2 -ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and bisphenol A (BPA)) with the effects of their mixture through different biochemical, hormonal, and hematological parameters. Rats were divided into five experimental groups: Control (corn oil), DEHP (50 mg/kg b.w./day), DBP (50 mg/kg b.w./day), BPA (25 mg/kg b.w./day), and MIX (50 mg/kg b.w./day DEHP + 50 mg/kg b.w/day DBP + 25 mg/kg b.w./day BPA). Animals were sacrificed after 28 days of oral treatment and blood was collected for further analysis. The results demonstrated that the mixture produced significant changes in lipid profile, liver-related biochemical parameters, and glucose level. Furthermore, the opposite effects of single substances on the thyroxine level have been shown in comparison with the mixture, as well as a more pronounced effect of the mixture on testosterone level. This study contributes to the body of knowledge on the toxicology of mixtures and gives one more evidence of the paramount importance of mixture toxicity studies, especially in assessing the endocrine disruptive effects of chemicals.

The influence of smoking habits on cadmium and lead blood levels in the Serbian adult people

According to the World Health Organization, in 2015, the Serbian population ranked among the highest ones in Europe in terms of smoking habit: 44.3% males and 36.2% females aged 18-64 smoked tobacco. In the last 7 years, 25% of total mortality in men and 9% in women from Serbia were associated with smoking. Tobacco smoking is one of the most important sources of exposure to many toxic substances in general population. Our study confirmed higher blood levels of two toxic metals, cadmium and lead, in the blood of smokers (3.5 and 1.5 times higher than in non-smokers, respectively). Furthermore, smoking habits, such as number of smoked cigarettes per day, smoking period and cigarette type, along with age, were shown to influence these metals' blood concentration. Higher blood levels of Cd and Pb were found in smokers consuming more than 10 cigarettes per day for more than 10 years. The present study also highlighted the importance of the controlled tobacco production, since it was shown that consumption of illicit tobacco could manifold the exposure to toxic metals that can subsequently increase the frequency of related diseases as well.

Cadmium Induces Acute Liver Injury by Inhibiting Nrf2 and the Role of NF-κB, NLRP3, and MAPKs Signaling Pathway

Acute Cadmium (Cd) exposure usually induces hepatotoxicity. It is well known that oxidative stress and inflammation causes Cd-induced liver injury. However, the effect of nuclear factor erythroid 2-related factor 2 (Nrf2) in Cd-induced liver injury is not completely understood. In this study, we observed Cd-induced liver damage and the potential contribution of Nrf2, nuclear factor-κB (NF-κB), Nod-like receptor 3 (NLRP3), and mitogen-activated protein kinases (MAPKs) signaling pathways. Changes in serum transaminases and proinflammatory cytokines expression showed that Cd could induce acute hepatotoxicity. Moreover, Nrf2 and its downstream heme oxygenase 1 (HO-1) were inhibited by Cd exposure, and Kelch-like ECH-associated protein 1 (Keap1), the inhibitory protein of Nrf2, was increased. Furthermore, NF-κB, NLRP3, and MAPKs signaling pathways were all activated by Cd intoxication. In conclusion, the inhibition of Nrf2, HO-1, and the activation of NF-κB, NLRP3, and MAPKs all contribute to Cd-induced liver injury.

Subchronic Exposure to Cadmium Causes Persistent Changes in the Reproductive System in Female Wistar Rats

Cadmium (Cd) is an environmental toxicant and endocrine disruptor in humans and animals, and recent studies have illustrated that the uterus is exceedingly sensitive to Cd toxicity. The aim of the study was to investigate the influence of subchronic (90 days) oral Cd exposure in daily doses of 0.09-4.5 mg/kg b.w. on the balance of sex hormones by estimating estradiol (E₂) and progesterone (P) concentrations in the uterus and plasma in comparison with the effects of 17β-E₂. Additionally, the uterine weight, histopathological changes in the uterus and ovaries, the regularity of the estrous cycle, Cd bioaccumulation in uterine tissue, and selected biochemical parameters of oxidative stress were determined. A long period of observation (three and six months following the administration period) was used to assess whether the existing effects are reversible. The lowest dose of Cd caused effects similar to 17β-E₂: an increase of E₂ concentration in the uterus, endometrial epithelium thickness, and disturbed estrous cycle with estrus phase prolongation. The obtained results suggest that Cd causes nonlinear response. Higher doses of Cd caused a significant decrease in E₂ concentration in the uterus and plasma, estrous cycle disturbances, endometrium atrophy, and structural damage in the ovaries. This dose additionally induces lipid peroxidation in the uterine tissues. It is noteworthy that a prolonged time of observation after terminating the exposure showed persistent changes in the concentration of E₂ in uterine tissue, as well as alterations in estrous cycle phases, and an increase in lipid peroxidation in the uterus. Moreover, significant positive correlations between the plasma E₂ concentration and endometrial epithelium thickness in all studied groups were found. In summary, subchronic oral Cd exposure of female rats may result in impaired fertility processes.

Carbon monoxide: An emerging therapy for acute kidney injury

Treating acute kidney injury (AKI) represents an important unmet medical need both in terms of the seriousness of this medical problem and the number of patients. There is also a large untapped market opportunity in treating AKI. Over the years, there has been much effort in search of therapeutics with minimal success. However, over the same time period, new understanding of the underlying pathobiology and molecular mechanisms of kidney injury have undoubtedly helped the search for new therapeutics. Along this line, carbon monoxide (CO) has emerged as a promising therapeutic agent because of its demonstrated cytoprotective, and immunomodulatory effects. CO has also been shown to sensitize cancer, but not normal cells, to chemotherapy. This is particularly important in treating cisplatin-induced AKI, a common clinical problem that develops in patients receiving cisplatin therapies for a number of different solid organ malignancies. This review will examine and make the case that CO be developed into a therapeutic agent against AKI.

Hepatorenal protective effect of flaxseed protein isolate incorporated in lemon juice against lead toxicity in rats

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Flaxseed protein isolate (FPI) is a good source of protein with potent antioxidant activity.

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Solubility and scavenging radical activity of FPI increased in the acidic medium.

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Lead intoxication elevated lipid peroxidation of kidney, urinary protein and creatinine as well as kidney and liver functions.

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lemon juice and FPI are considered protective sources of kidney and liver against lead toxicity.

Finding renal and hepatoprotective agents preferably with antioxidant activities against environmental pollutants especially lead which can adversely affect liver and kidney is a great demand. In the current study, flaxseed protein isolate (FPI) was extracted from defatted flaxseed meal. Amino acids profile, antioxidant capacity and solubility of the extracted FPI were determined. The solubility of FPI in the acidic media was exploited in preparation of lemon juice with FPI. Twenty four male rats were assigned to four groups; normal control, lead intoxicated (oral daily dose of 60 mg/kg b.w. in distilled water for four weeks), lead intoxicated and orally administrated with daily dose equal 1 ml of lemon juice as well as lead intoxicated and orally administered with FPI (daily dose equal 100 mg/kg) in 1 ml of lemon juice. The oral administration of FPI incorporated in lemon juice suppressed the elevation in kidney functions, lipid peroxidation of kidney tissues, urinary protein and creatinine as well as liver functions caused by lead intoxication. Additionally, lemon juice with FPI combated the reduction of GSH of kidney tissues. It was revealed also that lemon juice without FPI suppressed the elevation in kidney and liver functions caused by lead. It can be concluded that flaxseed protein isolate is a good source of protein with potent antioxidant activity. Additionally, lemon juice and FPI are considered protective sources of kidney and liver against lead toxicity.

Further verification of some postulates of the combined toxicity theory: New animal experimental data on separate and joint adverse effects of lead and cadmium

Outbred male rats were repeatedly injected intraperitoneally two-level sub-lethal doses of lead acetate and/or cadmium chloride solutions 3 times a week during 6 weeks. The animals developed explicit, even if moderate, subchronic intoxication characterized by a large number of indices, both common to both metals (including increased DNA fragmentation coefficient) and lead-specific. Special attention was paid to hemodynamic and electrocardiographic effects. The combined action of lead and cadmium was modeled with the help of the Response Surface Methodology to obtain additional support for the previously substantiated postulates of combined toxicity's typological ambiguity. This is dependent on which particular effect comes under consideration, on its level, and on the acting dose ratio. For one and the same toxic combination, the type of combined toxic action can vary from synergistic to contra-directional. In particular, the actions of lead and cadmium on blood pressure were found to be opposite in direction. Furthermore, it is shown once again that the systemic toxic effects of a metal combination, its in vivo genotoxicity included, can be more or less attenuated by background administration of a theoretically justified composition of biologically active agents.

The impacts of individual and combined exposure to cadmium and lead on intraocular pressure, electroretinography, and residual changes in the rabbit eyes

The human eye is very vulnerable to various environmental pollutants. Cadmium (Cd) and lead (Pb) are widely spread heavy metals. The goal of the existing study is to explore the impact of single or joint exposure to Cd and Pb on the eye indicators. In this study, male New Zealand white rabbits were treated orally for 30 days with Cd (5 mg Cd Cl₂/kg bw) associated or not with Pb (12.5 mg lead acetate/kg bw). Fundus and slit lamp examinations, electroretinography (ERG), intraocular pressure (IOP), Cd and Pb residues, and the histopathological picture of the eye were studied. The results revealed that the oral dosing of Cd or Pb evoked a significant (p < 0.05) decline in a- and b-wave amplitudes, under scotopic conditions, and IOP values. Single Pb or Cd treatment showed a significant (p < 0.001) increase in their residues in the whole eye tissue of the Pb- or Cd-treated group. Eye structures of Cd- or Pb-intoxicated rabbit showed mild degenerated changes of cornea and sclera tissues with the presence of irregular variably sized eosinophilic droplets in the lens. Notably, the simultaneous exposure to Cd and Pb leads to an antagonistic outcome in all of the estimated parameters. These findings concluded that oral exposure to Cd or Pb could significantly disturb the vision but their joint exposure caused an opposing effect on nearly all of these disturbances.

Metal-induced nephrotoxicity to diabetic and non-diabetic Wistar rats

The present study was conducted to examine the nephrotoxic effects of heavy metals including lead (Pb), manganese (Mn), arsenic (As), and cadmium (Cd) in diabetic and non-diabetic Wistar rats. Animals were exposed to heavy metals for 30 days, Pb was injected as lead acetate (C₄H₆O₄Pb), Mn was injected as manganese chloride (MnCl₂), Cd was injected as cadmium chloride (CdCl₂), and As was administered orally to rats in the form of sodium arsenite (AsO₂Na). Results showed that metal deposition trends in tissues were Pb > As > Cd > Mn and the urinary metal levels were Pb > Cd > As > Mn. Diabetic metal alone, as well as metal mixture-treated groups, showed decreased urinary metal levels as compared with non-diabetic metal alone and metal mixture-treated groups. Both diabetic- and non-diabetic metal mixture-treated groups revealed an increasing trend of blood urea nitrogen (BUN) and serum creatinine. In addition, heavy metal treatments resulted in elevated malondialdehyde (MDA) levels in the kidney tissue while decreased levels of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione (GHS) were observed in the kidney tissue in comparison with the control group. The histological analysis of the kidney tissues showed tubular degeneration, fibrosis, and vacuolation as a result of heavy metal exposure. The present study revealed that co-exposure of heavy metals (Pb, Cd, Mn, As) induced more nephrotoxicity as compared with the metal alone treatment. Moreover, diabetic Wistar rats are more prone to kidney damage as a result of heavy metal exposure.

A Review on Coordination Properties of Thiol-Containing Chelating Agents Towards Mercury, Cadmium, and Lead

The present article reviews the clinical use of thiol-based metal chelators in intoxications and overexposure with mercury (Hg), cadmium (Cd), and lead (Pb). Currently, very few commercially available pharmaceuticals can successfully reduce or prevent the toxicity of these metals. The metal chelator meso-2,3-dimercaptosuccinic acid (DMSA) is considerably less toxic than the classical agent British anti-Lewisite (BAL, 2,3-dimercaptopropanol) and is the recommended agent in poisonings with Pb and organic Hg. Its toxicity is also lower than that of DMPS (dimercaptopropane sulfonate), although DMPS is the recommended agent in acute poisonings with Hg salts. It is suggested that intracellular Cd deposits and cerebral deposits of inorganic Hg, to some extent, can be mobilized by a combination of antidotes, but clinical experience with such combinations are lacking. Alpha-lipoic acid (α-LA) has been suggested for toxic metal detoxification but is not considered a drug of choice in clinical practice. The molecular mechanisms and chemical equilibria of complex formation of the chelators with the metal ions Hg2+, Cd2+, and Pb2+ are reviewed since insight into these reactions can provide a basis for further development of therapeutics.

Curcumin Attenuates Lead-Induced Cerebellar Toxicity in Rats via Chelating Activity and Inhibition of Oxidative Stress

Lead (Pb) is a toxic, environmental heavy metal that induces serious clinical defects in all organs, with the nervous system being its primary target. Curcumin is the main active constituent of turmeric rhizome (Curcuma longa) with strong antioxidant and anti-inflammatory properties. This study is aimed at evaluating the therapeutic potentials of curcumin on Pb-induced neurotoxicity. Thirty-six male Sprague Dawley rats were randomly assigned into five groups with 12 rats in the control (normal saline) and 6 rats in each of groups, i.e., the lead-treated group (LTG) (50 mg/kg lead acetate for four weeks), recovery group (RC) (50 mg/kg lead acetate for four weeks), treatment group 1 (Cur100) (50 mg/kg lead acetate for four weeks, followed by 100 mg/kg curcumin for four weeks) and treatment group 2 (Cur200) (50 mg/kg lead acetate for four weeks, followed by 200 mg/kg curcumin for four weeks). All experimental groups received oral treatment via orogastric tube on alternate days. Motor function was assessed using a horizontal bar method. The cerebellar concentration of Pb was evaluated using ICP-MS technique. Pb-administered rats showed a significant decrease in motor scores and Superoxide Dismutase (SOD) activity with increased Malondialdehyde (MDA) levels. In addition, a marked increase in cerebellar Pb concentration and alterations in the histological architecture of the cerebellar cortex layers were recorded. However, treatment with curcumin improved the motor score, reduced Pb concentration in the cerebellum, and ameliorated the markers of oxidative stress, as well as restored the histological architecture of the cerebellum. The results of this study suggest that curcumin attenuates Pb-induced neurotoxicity via inhibition of oxidative stress and chelating activity.

Bone mineral health is sensitively related to environmental cadmium exposure- experimental and human data

Exposure to cadmium (Cd) is recognised as one of the risk factors for osteoporosis, although critical exposure levels and exact mechanisms are still unknown. Here, we first confirmed that in male Wistar rats challenged orally with 6 different levels of Cd (0.3-10 mg/kg b.w.), over 28 days, there was a direct dose relationship to bone Cd concentration. Moreover, bone mineral content was significantly diminished by ∼15% (p < 0.0001) plateauing already at the lowest exposure level. For the other essential bone elements zinc (Zn) loss was most marked. Having established the sensitive metrics (measures of Cd exposure), we then applied them to 20 randomly selected human femoral head bone samples from 16 independent subjects. Bone Cd concentration was inversely proportional to trabecular bone mineral density and mineral (calcium) content and Zn content of bone, but not the donor's age. Our findings, through direct bone analyses, support the emerging epidemiological view that bone health, adjudged by mineral density, is extremely sensitive to even background levels of environmental Cd. Importantly, however, our data also suggest that Cd may play an even greater role in compromised bone health than prior indirect estimates of exposure could reveal. Environmental Cd may be a substantially determining factor in osteoporosis and large cohort studies with direct bone analyses are now merited.

The remedial effect of Thymus vulgaris extract against lead toxicity-induced oxidative stress, hepatorenal damage, immunosuppression, and hematological disorders in rats

The Thymus vulgaris (T. vulgaris) has been used in foods for the flavor, aroma, and preservation and in folk medicines. The objective of the present work was to determine the antioxidant and protective effects of T. vulgaris extract against lead (Pb)-intoxicated rats. A thirty-two male Sprague-Dawley were randomly assigned into 4 equal groups and treated for six weeks as follows: group I (GP-I), served as negative control; GP-II, -III, and -IV received either Pb acetate in drinking water (500 mg/L), T. vulgaris extract (500 mg/kg/day) by oral gavage or Pb acetate with T. vulgaris extract, respectively. Blood samples were collected at the end of the study week 6 to measure the hepatic and renal biochemical markers, complete blood count alongside the serum levels of interleukin (IL)-1β, IL-6, IL-10, tumor necrosis (TNF)-α, and interferon (IFN)-γ. Additionally, liver and kidney tissue specimens were collected for histopathology as well as to measure the antioxidant-reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) alongside the lipid peroxidation marker, malonaldehyde (MDA). The results indicated that Pb toxicity increased the serum levels of IL-1β, IL-6, and TNF-α, whereas IL-10 and IFN-γ were reduced. The results showed disturbed liver and renal functions; increased serum levels of ALT, AST, ALP, total bilirubin, creatinine, and urea; and decreased total protein, albumin, and calcium. The GSH, Gpx, and CAT levels were significantly decreased in the Pb-administrated group, while MDA was increased. However, regarding the hepatorenal markers, those animals treated with T. vulgaris alone did not induce any significant changes. Moreover, the combined treatment with T. vulgaris extract together with Pb showed significant improvement in Pb-induced toxicity in all the tested parameters compared to the negative control group. We investigated the potential protective effects of the medicinal plant T. vulgaris in vivo, since there are no publications that address the potential protective effect of this leaf extract against Pb-induced hepatorenal toxicity. Our studies concluded that the T. vulgaris extract reduces Pb overload in hepatorenal tissues, and that this has a potential immunomodulatory role, antioxidant activity, and a protective effect against Pb toxicity.