The toxic effects of nickel chloride on liver, erythropoiesis, and development in Wistar albino preimplanted rats can be reversed with selenium pretreatment

Low Dose of Nickel and Benzo [a] Anthracene in Rat-Diet, Induce Apoptosis, Fibrosis, and Initiate Carcinogenesis in Liver via NF-Ƙβ Pathway

Environmental contaminants such as polycyclic aromatic hydrocarbon (PAH) and heavy metals are major contaminants of food such as fish thus serving as source of exposure to human. This study was designed to evaluate the carcinogenic risk and other risks associated with long-term consumption of environmentally relevant dose of nickel and benzo [a] anthracene in rats. Thirty-six (36) male rats weighing between 80 and 100 g were assigned into 6 groups of 6 animals each; normal, nickel-, and benzo [a] anthracene-exposed groups for 12 and 24 weeks, respectively. Micronucleus and comet analyses were done in the blood, liver, and bone marrow. Liver function, redox, and inflammatory markers (AST, ALT, GGT, SOD, GSH, MDA, protein carbonyl, protein thiol, total protein, IL-10, 1L-1β, TNF-α, TGF-β NF-Ƙβ, and 8-oxodeoxyguansine) were analysed by standard methods. Immuno-histochemical quantification of Bax, Bcl2, and Erk 1/2 as well as mRNA expression of cyclin D1 was done in liver. From the results, weight gain was observed in varying degrees throughout the exposure period. The polychromatic erythrocytes/normochromatic erythrocytes ratio > 0.2 indicates no cytotoxic effects on the bone marrow. Percentage-MnPCE in blood significantly (p < 0.05) increased throughout exposure duration. Percentage tail DNA in blood was significantly (< 0.05) increased at weeks 20 and 24 in the exposed groups and in liver at weeks 12 (16.22 ± 0.47) and 24 (17.00 ± 0.36) of nickel-exposed rats. The aspartate amino transferase (AST):alanine amino transferase (ALT) ratio indicated fatty liver disease in the benzo [a] anthracene (0.90) and acute liver injury in the nickel (> 10 times greater than the upper limits of the reference group) exposed groups during the first 12 weeks. Observation from the histological and cytological data of the liver revealed the presence of inflammation, fibrosis, and high nuclear/cytoplasmic ratio, respectively, in the nickel and benzo [a] anthracene groups. Only benzo [a] anthracene induced liver oxidative stress with significant (p < 0.05) decrease in SOD (0.64 ± 0.02) activity and increase in protein carbonyl (7.60 ± 0.80 × 10-5) and MDA (57.10 ± 6.64) concentration after 24 weeks. Benzo [a] anthracene up-regulated the cyclin D1 expression and significantly (p < 0.05) increased the levels of the cytokines. Nickel and benzo [a] anthracene significantly (p < 0.05) increased the Bax (183.45 ± 6.50 and 199.76 ± 10.04) and Erk 1/2 (108.25 ± 6.41 and 136.74 ± 4.22) levels when compared with the control (37.43 ± 22.22 and 60.37 ± 17.86), respectively. Overall result showed that the toxic effects of nickel and benzo [a] anthracene might involve fibrosis, cirrhosis, apoptosis, and inflammation of the liver. As clearly demonstrated in this study, benzo [a] anthracene after the 24 weeks of exposure stimulates carcinogenic process by suppressing the liver antioxidant capacity, altering apoptotic, cell proliferation, and differentiation pathways.

Associations of Urinary Nickel with NAFLD and Liver Fibrosis in the USA: A Nationwide Cross‑Sectional Study

Despite the robust correlation between metabolic disorders and heavy metals, there has been limited research on the associations between nickel levels and non-alcoholic fatty liver disease (NAFLD) as well as liver fibrosis. This study aimed to examine the associations among urinary nickel, NAFLD, and liver fibrosis. The data utilized in this study were obtained from the National Health and Nutrition Examination Survey 2017-2020. A comprehensive screening process was conducted, resulting in the inclusion of a total of 3169 American adults in the analysis. The measurement of urinary nickel was conducted through inductively coupled-plasma mass spectrometry. Vibration-controlled transient elastography was employed to assess the controlled attenuation parameter and liver stiffness measurement as indicators for NAFLD and liver fibrosis, respectively. Multivariable logistic regression models were employed to evaluate the associations among urinary nickel, NAFLD, and liver fibrosis. Restricted cubic splines were employed to explored the nonlinear associations. After adjusting for all covariates, the correlation between the highest quartile of urinary nickel and NAFLD was found to be significant (OR = 1.65; 95% CI, 1.19-2.27). Subgroup analysis revealed that the correlation was significant only in men. A significant association occurred between the second quartile of urinary nickel and liver fibrosis (OR 1.88; 95% CI, 1.22-2.90). Restricted cubic spline showed that the relationship was linear between urinary nickel and NAFLD and non-monotonic, inverse U-shaped between urinary nickel and liver fibrosis. This cross-sectional study indicated that the risk of NAFLD is associated with urinary nickel, and this correlation was only present among males.

Ginger mitigated the health risks associated with arsenic-contamination of rats feed via inflammatory and apoptosis regulation

Millions of people around the world are inadvertently exposed to arsenic through drinking water and food. However, food spices possess antioxidants and anti-inflammatory potentials. Therefore, this study evaluated the protective potentials of Zingiber officinale (ginger) against the toxic effects of arsenic in male Wistar rats. Thirty-six Wistar rats were assigned into 6 groups (n = 6); group A1 and A2 (control), group B1 and B2 were fed with arsenic-contaminated feed (3.45x10-3 mg/kg), group C1 and C2 were feed with arsenic-contaminated feed (3.45x10-3 mg) supplemented with ginger respectively for 12 and 24 weeks. The blood, bone marrow, and liver of rats were harvested and prepared for various analyses. Micronucleus and Comet analysis were performed for the genotoxicity assessment every 4 weeks. Activities of AST, ALT, GGT, and SOD, and the concentration of GSH, MDA, protein carbonyl, protein thiol, and total protein, were measured by spectrophotometric methods. Quantification of IL-10, 1 L-1β, TNF-α, TGF-β NF-Ƙβ, and 8-oxodeoxyguanosine was done by ELISA method while Bax, Bcl2, and Erk 1/2 were quantified by immuno-histochemical staining. mRNA expression of cyclin D1 was quantified using qRT-PCR. Statistical analysis was performed with SPSS and statistical significance was accepted when p<0.05. Result showed significant (p<0.05) decrease in the haemoglobin concentration, red blood cell, lymphocyte counts, tail DNA and MnPCE of rats fed arsenic-contaminated feed compared with control. The supplementation with ginger significantly reduced serum activities of AST and GGT (p<0.05). Ginger supplementation also lowered the arsenic indued increases in liver MDA, protein carbonyl and 8-OXdG levels. Ginger restores to near normal the histological changes due to arsenic exposure. In the arsenic-exposed group, liver IL-10, IL-1β and TNF-α decreased significantly (p<0.05) at week 24 whereas, NF-Ƙβ and TGF-β increased significantly (p 0.05) at weeks 12 and 24 and TNF-α, Bcl2 at week 24. mRNA expression of cyclin D1 was significantly (p<0.05) downregulated in the arsenic and ginger-supplemented groups. This study showed that long-term consumption of arsenic resulted in immunosuppression, anaemia and activated anti-apoptotic process that was mitigated due to ginger supplementation.

Nickel induces hepatotoxicity by mitochondrial biogenesis, mitochondrial dynamics, and mitophagy dysfunction

Nickel (Ni) is an important and widely hazardous chemical industrial waste. Excessive Ni exposure could cause multi-organs toxicity in human and animals. Liver is the major target organ of Ni accumulation and toxicity, however, the precise mechanism is still unclear. In this study, nickel chloride (NiCl₂ )-treatment induced hepatic histopathological changes in the mice, and, transmission electron microscopy results showed mitochondrial swollen and deformed of hepatocyte. Next, the mitochondrial damages including mitochondrial biogenesis, mitochondrial dynamics, and mitophagy were measured after NiCl₂ administration. The results showed that NiCl₂ suppressed mitochondrial biogenesis by decreasing PGC-1α, TFAM, and NRF1 protein and mRNA expression levels. Meanwhile, the proteins involved in mitochondrial fusion were reduced by NiCl₂ , such as Mfn1 and Mfn2, however, mitochondrial fission proteins Drip1 and Fis1 were significantly increased. The up-regulation of mitochondrial p62 and LC3II expression indicated that NiCl₂ increased mitophagy in the liver. Moreover, the receptor-mediated mitophagy and ubiquitin (Ub)-dependent mitophagy were detected. NiCl₂ promoted PINK1 accumulation and Parkin recruitment on mitochondria. And, the receptor proteins of mitophagy Bnip3 and FUNDC1 were increased in the NiCl₂ -treated mice liver. Overall, these results show that NiCl₂ could induce mitochondria damage in the liver of mice, and, dysfunction of mitochondrial biogenesis, mitochondrial dynamics and mitophagy involved in the molecular mechanism of NiCl₂ -induced hepatotoxicity.

Attenuating effects of selenium and zinc against hexavalent chromium-induced oxidative stress, hormonal instability, and placenta damage in preimplanted rats

As a toxic metal, hexavalent chromium (CrVI) has effects on both the reproductive and endocrine systems. This study aimed to evaluate the protective effects of selenium (Se) and zinc (Zn) against the toxicity of chromium on the placenta in pregnant Wistar albino rats. Thirty pregnant Wistar rats were divided into control and four treated groups, receiving subcutaneously (s.c) on the 3rd day of pregnancy, K₂Cr₂O₇ (10 mg/kg body weight (bw)) alone, or in association with Se (0.3 mg/kg bw), ZnCl₂ (20 mg/kg bw), or both of them simultaneously. Plasma steroid hormones, placenta histoarchitecture, oxidative stress profile, and developmental parameters were investigated. These results showed that K₂Cr₂O₇ exposure induced a significant increase in the levels of both plasma estradiol (E₂) and placenta malondialdehyde (MDA), the number of fetal resorptions, and percent of post-implantation loss. On the other hand, K₂Cr₂O₇ significantly reduced developmental parameters, maternal body and placenta weight, and plasma progesterone (P) and chorionic gonadotropin hormone (β HCG) levels. However, K₂Cr₂O₇ significantly decreased the placenta activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH), and nonprotein sulfhydryl (NPSH). These changes have been reinforced by histopathological evaluation of the placenta. Se and/or ZnCl₂ supplementation provoked a significant improvement in most indices. These results suggest that the co-treatment with Se or ZnCl₂ strongly opposes the placenta cytotoxicity induced by K₂Cr₂O₇ through its antioxidant action.

Selenium nanoparticles improve nickel-induced testosterone synthesis disturbance by down-regulating miR-708-5p/p38 MAPK pathway in Leydig cells

The present study was designed to investigate the role of miR-708-5p/p38 mitogen-activated protein kinase (MAPK) pathway during the mechanism of selenium nanoparticles (Nano-Se) against nickel (Ni)-induced testosterone synthesis disorder in rat Leydig cells. We conducted all procedures based on in vitro culture of rat primary Leydig cells. After treating Leydig cells with Nano-Se and NiSO₄ alone or in combination for 24 h, we determined the cell viability, reactive oxygen species (ROS) levels, testosterone production, and the protein expression of key enzymes involved in testosterone biosynthesis: steroidogenic acute regulatory (StAR) and cytochrome P450 cholesterol side chain cleavage enzyme (CYP11A1). The results indicated that Nano-Se antagonized cytotoxicity and eliminated ROS generation induced by NiSO₄ , suppressed p38 MAPK protein phosphorylation and reduced miR-708-5p expression. Importantly, we found that Nano-Se upregulated the expression of testosterone synthase and increased testosterone production in Leydig cells. Furthermore, we investigated the effects of p38 MAPK and miR-708-5p using their specific inhibitor during Nano-Se against Ni-induced testosterone synthesis disorder. The results showed that Ni-inhibited testosterone secretion was alleviated by Nano-Se co-treatment with p38 MAPK specific inhibitor SB203580 and miR-708-5p inhibitor, respectively. In conclusion, these findings suggested Nano-Se could inhibit miR-708-5p/p38 MAPK pathway, and up-regulate the key enzymes protein expression for testosterone synthesis, thereby antagonizing Ni-induced disorder of testosterone synthesis in Leydig cells.

Low-dose and repeated exposure to nickel leads to bioaccumulation and cellular and metabolic alterations in quails

Nickel (Ni) is a widespread environmental pollutant commonly released into effluent due to industrial activities, the use of fuels, or wastewater disposal. Many studies confirm the toxic effects of this heavy metal. However, there is a lack of knowledge and data on bioaccumulation patterns in tissues as well as cellular and molecular responses following the exposure of living organisms to Ni. In this study, Japanese quails were exposed to low (10 μg/L) and high (2000 μg/L) Ni concentrations in the form of nickel(II) chloride via drinking water. Sub-chronic exposure lasted 30 days while nominal concentrations represented average Ni content in drinking water (low dose) and average Ni levels in highly polluted aquatic environments (high dose). It was revealed that a high dose of Ni was correlated with increased water intake and decreased body weight. Overall, Ni exposure induced the development of microcytic anemia and alterations in measured blood indices. Moreover, Ni exposure impaired immunological activation as seen through the increased number of the white blood cells, increased heterophile/lymphocyte (H/L) ratio, and pronounced thrombocytosis. Ni elicited changes in the albumin, glucose, cholesterol, and triglyceride serum levels in a concentration-dependent manner. Alterations of plasma protein fractions suggested liver functional impairment while high levels of urea and creatinine indicated potential kidney injury. Granulation of heterophiles and an increase in erythroblasts in the bone marrow showed that the hematopoietic tissue was also impacted by Ni toxicity. On average each quail bioaccumulated 5.87 μg of Ni per gram of tissue. Moreover, the distribution and bioaccumulation of Ni in terms of relative concentration were as follows: feathers > kidneys > heart > liver > pectoral muscles. Assessed bioaccumulation levels and associated cellular and metabolic alterations have revealed new multilayer toxicological data that will help in the extrapolation of Ni toxicity in other vertebrates, including humans.

Selenium Improves Bone Microenvironment-Related Hematopoiesis and Immunity in T-2 Toxin-Exposed Mice

The T-2 toxin is one of the most frequent contaminants in the environment and agricultural production globally. It exerts a wide range of toxic effects. Selenium (Se), as an antioxidant, has the potential to be widely used to antagonize mycotoxin toxicity. To investigate the protective effects of Se on bone microenvironment (BM)-related hematopoiesis and immunity after T-2 toxin exposure, 36 male mice were treated with the T-2 toxin (1 mg/kg) and/or Se (0.2 mg/kg) by intragastric administration for 28 days. The results showed that Se alleviated T-2 toxin-induced cytopenia and splenic extramedullary hematopoiesis. Se also significantly relieved T-2 toxin-induced immunosuppression, as assessed by immune factors and lymphocytes. Furthermore, Se also attenuated oxidative stress and apoptosis and improved the BM in T-2 toxin-exposed mice. Therefore, Se improves BM-related hematopoiesis and immunity after T-2 toxin exposure. This study provides references for identifying the toxic mechanism and screening potential therapeutic drugs of the T-2 toxin.

Decreased thioredoxin reductase 3 expression promotes nickel-induced damage to cardiac tissue via activating oxidative stress-induced apoptosis and inflammation

Thioredoxin reductase 3 (Txnrd3) plays a crucial role in antioxidant and anti-cancer activities, and sperm maturation. The damage of heavy metals, including Nickel (Ni), is the most prominent harm in social development, and hampering Txnrd3 might exacerbate Ni-induced cardiac damage. In this study, a total of 160 8-week-old C57BL/N male mice with 25-30 g weight of Txnrd3+/+ wild-type and Txnrd3-/- homozygote-type were randomly divided into eight groups. The mice in the control and Ni groups were gavaged with distilled water and a freshly prepared 10 mg/kg NiCl₂ solution. Melatonin (Mel) groups were administered at a concentration of 2 mg/kg for 21 days at the mice's 0.1 ml/10 g body weight. Ni exposure up-regulated the messenger RNA (mRNA) levels of mitochondrial apoptosis (caspase-3, caspase-9, cytochrome c, p53, and BAX), autophagy (LC3, ATG 1, ATG 7, and Beclin-1), and inflammation (TNF-α, COX 2, IL-1β, IL-2, IL-6, and IL-7)-related markers, but down-regulated the mRNA levels of BCL-2, p62 and mTOR (p < .05). Ni exposure decreased the expression of BCL-2 and p62 protein but increased the expression levels of caspase-3, caspase-9, cytochrome c, p53, BAX, ATG 7, Beclin-1, TNF-α, COX 2, IL-1β and IL-2 protein (p < .05). Ni increased the contents of glutathione disulfide (GSSG) and malondialdehyde (MDA) and decreased the activities of catalase (CAT) and total superoxide dismutase (T-SOD) (p < .05). Decreased Txnrd3 expression significantly exacerbated changes compared to the Ni exposure (p < .05). Mel significantly attenuated these changes, but the effect decreased when Txnrd3 was inhibited (p < .05). In conclusion, decreased Txnrd3 expression promoted Ni-induced mitochondrial apoptosis and inflammation via oxidative stress and aggravated heart damage in mice. Decreased Txnrd3 expression significantly reduced the protective effect of Mel to Ni exposure.

Conjunctional Relationship between Serum Uric Acid and Serum Nickel with Non-Alcoholic Fatty Liver Disease in Men: A Cross-Sectional Study

Serum uric acid (SUA) and heavy metals are closely related to non-alcoholic fatty liver disease (NAFLD). Yet, the conjunctional relationship between SUA and serum nickel (Ni) concentrations with the risk of NAFLD in men has not yet been investigated. Therefore, we designed this cross-sectional study to investigate the association of SUA or serum Ni with NAFLD in men. The cross-sectional study was based on data obtained from a prospective cohort study of common chronic non-communicable diseases in Central China, conducted in Xinxiang city, Central China's Henan Province, between April and June 2017. A total of 1709 male participants completed the physical examination. B-ultrasound was used to examine the liver and to diagnose NAFLD. Binary logistic regression models and restricted cubic splines were performed to estimate the association of the SUA and serum Ni with NAFLD. The prevalence of NAFLD among 1709 male participants was 46.6%. After adjusting for potential confounders, with the highest quartile compared to those with the lowest quartile, SUA (OR = 1.579, 95% CI: 1.140-2.189) and serum Ni (OR = 1.896, 95% CI: 1.372-2.625) were associated with NAFLD, respectively. At the same time, the associations for the second and third SUA quartiles were null. Restricted cubic splines showed a positive linear relationship between serum Ni (ln-transformed) and NAFLD risk. Intriguingly, high SUA and high Ni (OR = 2.370, 95% CI: 1.577-3.597) increased the risk of NAFLD, compared with those with low SUA and low Ni. Our findings demonstrate a positive linear trend between serum Ni concentrations and NAFLD risk. Men with elevated serum Ni had a higher risk of developing NAFLD when compared to those with high SUA. Furthermore, the conjunctional relationship of SUA and serum Ni with NAFLD risk was observed in men.

Protective Effects of Selenium and Zinc Against Nickel Chloride-Induced Hormonal Changes and Oxidative Damage in Thyroid of Pregnant Rats

Nickel chloride (NiCl₂) is a heavy metal that may affect the function of the thyroid. Selenium (Se) and zinc (Zn) are essential trace elements involved in thyroid hormone metabolism. However, little is reported about thyrotoxicity during gestation. The current study aimed to investigate the protective effects of selenium and zinc against NiCl₂-induced thyrotoxicity in pregnant Wistar rats. Female rats were treated subcutaneously (s.c.) on the 3rd day of pregnancy, with NaCl 0.9% and served as control, NiCl₂ (100 mg/kg body weight (BW)) alone, or in association with Se (0.3 mg/kg, s.c.), ZnCl₂ (20 mg/kg, s.c.), or both of them simultaneously. Oxidative stress parameters, thyroid biomarkers, and histopathological examination were evaluated. Results showed that NiCl₂ exposure caused a significant decrease in maternal body weight and an increase in absolute and relative thyroid weight compared to the controls. NiCl₂ administration also led to decreased plasma triiodothyronine (T3) and thyroxine (T4) with a concomitant significant increase in thyroid-stimulating hormone (TSH) levels when compared to that of control. In addition, an overall pro-oxidant effect was associated with a decrease in the reduced glutathione (GSH) and nonprotein thiol (NPSH) contents and the enzymatic activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD), and an increase in malondialdehyde (MDA). These biochemical disturbances were confirmed by histological changes. However, the co-treatment of Se and/or ZnCl₂ attenuates NiCl₂-induced changes. Our findings suggested that Se and ZnCl₂ ameliorated NiCl₂-induced thyrotoxicity in pregnant Wistar rats by exhibiting antioxidant effects.

Kinetic mechanisms by which nickel alters the calcium (Ca2+) transport in intact rat liver

In the present work, the multiple-indicator dilution (MID) technique was used to investigate the kinetic mechanisms by which nickel (Ni²⁺) affects the calcium (Ca²⁺) transport in intact rat liver. ⁴⁵Ca²⁺ and extra- and intracellular space indicators were injected in livers perfused with 1 mM Ni²⁺, and the outflow profiles were analyzed by a mathematical model. For comparative purposes, the effects of norepinephrine were measured. The influence of Ni²⁺ on the cytosolic Ca²⁺ concentration ([Ca²⁺]_c) in human hepatoma Huh7 cells and on liver glycogen catabolism, a biological response sensitive to cellular Ca²⁺, was also evaluated. The estimated transfer coefficients of ⁴⁵Ca²⁺ transport indicated two mechanisms by which Ni²⁺ increases the [Ca²⁺]_c in liver under steady-state conditions: (1) an increase in the net efflux of Ca²⁺ from intracellular Ca²⁺ stores due to a stimulus of Ca²⁺ efflux to the cytosolic space along with a diminution of Ca²⁺ re-entry into the cellular Ca²⁺ stores; (2) a decrease in Ca²⁺ efflux from the cytosolic space to vascular space, minimizing Ca²⁺ loss. Glycogen catabolism activated by Ni²⁺ was transient contrasting with the sustained activation induced by norepinephrine. Ni²⁺ caused a partial reduction in the norepinephrine-induced stimulation in the [Ca²⁺]_c in Huh7 cells. Our data revealed that the kinetic parameters of Ca²⁺ transport modified by Ni²⁺ in intact liver are similar to those modified by norepinephrine in its first minutes of action, but the membrane receptors or Ca²⁺ transporters affected by Ni²⁺ seem to be distinct from those known to be modulated by norepinephrine.

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

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

Protective effects of selenium and zinc against potassium dichromate-induced thyroid disruption, oxidative stress, and DNA damage in pregnant Wistar rats

Hexavalent chromium (CrVI) is an environmental pollutant and an endocrine-disrupting metal. Se and Zn are essential trace elements, known to play a crucial role in thyroid homeostasis. However, there is a lack of data reporting thyrotoxicity during gestation. In this study, we investigated the protective effects of selenium and zinc against potassium dichromate-induced thyrotoxicity in pregnant Wistar rats. Thirty pregnant Wistar rats were divided into control and four treated groups receiving subcutaneously (s.c) on the 3rd day of pregnancy, K2Cr2O7 (10 mg/kg, s.c) alone, or in association with Se (0.3 mg/kg, s.c), ZnCl2 (20 mg/kg, s.c), or both of them simultaneously. The hormonal profile, oxidative stress biomarkers, DNA damage, and histological modifications were evaluated. Our main findings showed that K2Cr2O7 promoted hypothyroidism, oxidative stress, genotoxicity, and histological alterations in the thyroid gland. The co-treatment with Se or ZnCl2 has mitigated K2Cr2O7-induced thyrotoxicity in pregnant Wistar rats by exhibiting antioxidant and genoprotective effects. However, the combined co-treatment of both of them was less thyroprotective, and therefore, further investigations on the synergetic interaction of Se and Zn against CrVI toxicity using different doses and exposure routes are required.

Multiple metal exposure and platelet counts during pregnancy: A repeated measure study

BACKGROUND

Evidence from animal and in vitro studies suggest that some metals interfere with normal platelet counts (PLT). However, limited human studies have investigated the association of metals and PLT, a marker of hematologic and hemostatic, particularly in susceptible populations such as pregnant women.

OBJECTIVES

Our purpose was to investigate the associations of repeated measures of 13 urinary metals with PLT during pregnancy.

METHODS

The present study involved 3911 pregnant women participating in a prospective cohort study in Wuhan, China, from 2013 to 2016. We measured 13 metals in urine and PLT in blood samples collected in the first, second, and third trimester (median = 13, 24, and 35 weeks of gestation, respectively). Mixed linear models and general linear models were applied to analyze the associations between multiple metals and PLT during pregnancy. The odds ratio (OR) for gestational thrombocytopenia was examined using generalized estimating equations.

RESULTS

After adjusting for other metals and covariates, the repeated measure analyses showed that decreased levels of PLT were associated with a 10-fold increase in urinary concentration of cadmium (Cd) [percent difference (%Δ) = -5.02, 95%CI = -9.53, -0.29], manganese (Mn) [percent difference (%Δ) = -4.63, 95%CI = -7.50, -1.67], and arsenic (As) [percent difference (%Δ) = -4.56, 95%CI = -8.11, -0.86]. Cross-sectional analyses by trimesters revealed that Cd was inversely associated with PLT through the three trimesters. In addition, Cd was associated with an increased OR of 1.80 (95%CI: 1.26, 2.56), 1.65 (95%CI: 1.05, 2.59), 1.54 (95%CI: 1.02, 2.33) for gestational thrombocytopenia in the first, second, and third trimester, respectively.

CONCLUSIONS

Our study suggested an association of Cd, Mn, and As with decreased PLT during pregnancy. Particularly, Cd may increase the risk of gestational thrombocytopenia.

Neurobehavioural and biochemical responses associated with exposure to binary waterborne mixtures of zinc and nickel in rats

Environmental and occupational exposure to metal mixtures due to various geogenic and anthropogenic activities poses a health threat to exposed organisms. The outcome of systemic interactions of metals is a topical area of research because it may cause either synergistic or antagonistic effect. The present study investigated the impact of co-exposure to environmentally relevant concentrations of waterborne nickel (75 and 150 μg NiCl ₂ L^-1) and zinc (100 and 200 μg ZnCl₂ L^-1) mixtures on neurobehavioural performance of rats. Locomotor, motor and exploratory activities were evaluated using video-tracking software during trial in a novel arena and thereafter, biochemical and histological analyses were performed using the cerebrum, cerebellum and liver. Results indicated that zinc significantly (p < 0.05) abated the nickel-induced locomotor and motor deficits as well as improved the exploratory activity of exposed rats as verified by track plots and heat map analyses. Moreover, zinc mitigated nickel-mediated decrease in acetylcholinesterase activity, elevation in biomarkers of liver damage, levels of reactive oxygen and nitrogen species as well as lipid peroxidation in the exposed rats when compared with control. Additionally, nickel mediated decrease in antioxidant enzyme activities as well as the increase in tumour necrosis factor alpha, interleukin-1 beta and caspase-3 activity were markedly abrogated in the cerebrum, cerebellum and liver of rats co-exposed to nickel and zinc. Histological and histomorphometrical analyses evinced that zinc abated nickel-mediated neurohepatic degeneration as well as quantitative reduction in the widest diameter of the Purkinje cells and the densities of viable granule cell layer of dentate gyrus, pyramidal neurones of cornu ammonis 3 and cortical neurons in the exposed rats. Taken together, zinc abrogated nickel-induced neurohepatic damage via suppression of oxido-inflammatory stress and caspase-3 activation in rats.

Outcomes and Toxicology of Herbal Drugs in Alcoholic Hepatitis - A Single Center Experience from India

Background and Aims: We aimed to study clinical outcomes and liver biopsy features of alcoholic hepatitis (AH) patients on complementary and alternative medicines (CAMs) and to analyze the retrieved drugs for chemical and toxic components linked to drug-induced liver injury. Methods: We retrospectively assessed clinical, biochemical and liver biopsy features of AH patients on CAM with drug-induced liver injury (AH-CAM, n = 27) and compared them to a control group (classical AH, n = 29) on standard of care. Patients without liver biopsy evaluation and other causes for liver disease were excluded. Samples of the CAMs (n = 42) from patients were retrieved and assessed for chemical and toxins. Results: All were males, and significantly worse clinical presentation, biochemical severity, and liver disease scores were notable in patients with AH-CAM. Traditional Ayurvedic-polyherbal formulations were the most commonly used CAM. On liver histology, varying grades of severe-necrosis, severe hepatocellular, canalicular, cholangiolar cholestasis with predominant lymphocytic-portal-inflammation and varying grades of interface-hepatitis were noted in AH-CAM. Analysis of CAMs revealed presence of heavy metals up to 100,000 times above detectable range and adulterants, such as antibiotics, chemotherapy agents, nonsteroidal anti-inflammatory drugs, alcohols, antidepressants, anxiolytics, and recreational drugs. On follow up, a significantly higher number of patients with AH on CAM died at end of 1, 3- and-6-months compared to controls (37% vs. 83%, 29% vs. 62%, 18% vs. 52% respectively; p < 0.001). Conclusions: Patients with AH and CAM-related drug-induced liver injury have extremely poor short-term survival in the absence of liver transplantation compared to those patients with AH on evidence-based management. Early transplant referral and educating on and curbing of CAM use in severe liver disease through strict monitoring of unregulated traditional health practices can help ease the burden of liver-related death.

Toxic Effects of Low-Level Long-Term Inhalation Exposures of Rats to Nickel Oxide Nanoparticles

Rats were exposed to nickel oxide nanoparticles (NiO-NP) inhalation at 0.23 ± 0.01 mg/m³ for 4 h a day 5 times a week for up to 10 months. The rat organism responded to this impact with changes in cytological and some biochemical characteristics of the bronchoalveolar lavage fluid along with a paradoxically little pronounced pulmonary pathology associated with a rather low chronic retention of nanoparticles in the lungs. There were various manifestations of systemic toxicity, including damage to the liver and kidneys; a likely allergic syndrome as indicated by some cytological signs; transient stimulation of erythropoiesis; and penetration of nickel into the brain from the nasal mucous membrane along the olfactory pathway. Against a picture of mild to moderate chronic toxicity of nickel, its in vivo genotoxic effect assessed by the degree of DNA fragmentation in nucleated blood cells (the RAPD test) was pronounced, tending to increasing with the length of the exposure period. When rats were given orally, in parallel with the toxic exposure, a set of innocuous substances with differing mechanisms of expected bioprotective action, the genotoxic effect of NiO-NPs was found to be substantially attenuated.

The Response of Neotropical Fish Species (Brazil) on the Water Pollution: Metal Bioaccumulation and Genotoxicity

The streams and rivers of the Upper Paraná River Basin have been seriously affected by impacts of high population density around the basin area. Fishes are widely used as models to assess the health of aquatic ecosystems, being considered as bioindicators of environmental pollution. In this context, our objective was to assess the potential genotoxic and mutagenic effects of the polluted water in three native fish species (Astyanax lacustris, Hypostomus ancistroides, and Rhamdia quelen) from Tarumã Microbasin, Upper Paraná River, Brazil. We also investigated the concentration of metals in water and in fish muscle to verify bioavailability and bioaccumulation of metals. For both less impacted sites (LI) and impacted sites (IMP) of the microbasin, the concentrations of metals were above the maximum limit allowed by Brazilian legislation (Resolution CONAMA 357/2005), except for Pb, total Cr, and Cu at LI sites and total Cr at IMP sites. A. lacustris showed a higher frequency of micronuclei (MN) at IMP sites compared with LI sites (p < 0.0001). We found no significant differences in MN frequency between site classes for H. ancistroides and R. quelen (p > 0.05). There were no significant differences between site classes regarding to nuclear abnormalities in erythrocytes frequencies (p > 0.05). A. lacustris from IMP sites had higher concentrations of Pb, Cu, Fe, Zn, and Ni in muscle tissue (p < 0.05), whereas H. ancistroides from IMP sites had higher concentration of Cr, Cu, and Ni (p < 0.0001) and R. quelen showed higher concentration of Cd, Fe, and Ni at these sites (p < 0.0001). So, the chosen biomarkers are able to identify the environmental risk of the water pollution.

Association between prenatal nickel exposure and preterm low birth weight: possible effect of selenium

There is a proposed link between prenatal nickel (Ni) exposure and preterm low birth weight (PLBW); however, this association remains unclear. Selenium (Se) may modify this relationship by protecting against Ni toxicity. Concentrations of Ni and Se were measured in urine samples collected from 408 pregnant women (102 PLBW cases and 306 matched controls) in China. Conditional logistic regression was utilized to explore the association between Ni levels and PLBW, as well as the effect modification by Se on this association. A significant association was observed between higher maternal urinary Ni levels and risk of PLBW [adjusted odds ratio (OR) = 2.80 (95% confidence interval (CI): 1.44, 5.44) for the highest tertile], and this association was more apparent among female infants than that among male infants. Further analyses showed that mothers with high urinary Ni and low urinary Se levels had a significantly increased risk for PLBW [adjusted OR = 2.87 (95% CI: 1.09, 7.56)] compared with the mothers with low urinary Ni and high urinary Se levels. Our study indicates that prenatal exposure to Ni was a risk factor for PLBW. Se might provide protection against the toxicity of Ni.

Response to metals treatment of Fra1, a member of the AP-1 transcription factor family, in P. lividus sea urchin embryos

Lithium (Li), Nickel (Ni), and Zinc (Zn) are metals normally present in the seawater, although they can have adverse effects on the marine ecosystem at high concentrations by interfering with many biological processes. These metals are toxic for sea urchin embryos, affecting their morphology and developmental pathways. In particular, they perturb differently the correct organization of the embryonic axes (animal-vegetal, dorso-ventral): Li is a vegetalizing agent and Ni disrupts the dorso-ventral axis, while Zn has an animalizing effect. To deeply address the response of Paracentrotus lividus embryos to these metals, we studied the expression profiling of Pl-Fra transcription factor (TF), relating it to Pl-jun, a potential partner for AP-1 complex formation, and to Pl-MT, known to be an AP-1 target and to have a protective role against heavy metals. The AP-1 TFs are found throughout the animal kingdom and are involved in many cellular events, i.e. cell proliferation and differentiation, immune and stress responses, cancer growth. Here, we isolated the complete Pl-Fra cDNA and showed that Pl-Fra transcript, already present in the unfertilized eggs, was newly synthesized from the blastula stage, while its spatial distribution was mainly observed in skeletogenic cells, similarly to Pl-jun. Interestingly, Pl-Fra expression was induced by the different metals and the induction kinetics revealed its persistent expression during treatments. Moreover, its temporal and spatial behavior in response to the three metals was comparable to that of Pl-jun and Pl-MT. The understanding of AP-1 functions in invertebrates may provide new knowledge about the mechanisms of response to metal injuries, as well as it might lead to acknowledge the TFs as new type of biomarkers for the evaluation of hazards in polluted environment.

Heavy metal contamination, microbiological spoilage and biogenic amine content in sushi available on the Polish market

BACKGROUND

The present study determined the heavy metal contamination (mercury, cadmium, lead, arsenic and nickel) of nori, restaurant-served sushi and ready-to-eat sushi meals available via retail chains. Moreover, both microbiological load and biogenic amine content in ready-to-eat sushi meals were analysed.

RESULTS

All of the nori samples contained high levels of Cd (2.122 mg kg^-1 ), Ni (0.715 mg kg^-1 ), As (34.56 mg kg^-1 ) and Pb (0.659 mg kg^-1 ). The studied sushi samples contained high levels of Ni and Pb, reaching 0.194 and 0.142 mg kg^-1 wet weight, respectively, being potentially hazardous to women during pregnancy and lactation and small children. None of the studied samples contained high levels of Hg. Overall, 37% of ready-to-eat sushi meals exceeded a microbiological load of 10⁶  cfu g^-1 . However, biogenic amine content in all of the samples was low, with a highest histamine content of 2.05 mg kg^-1 .

CONCLUSION

Sushi is not the source of high levels of biogenic amines even with high microbiological loads. Nevertheless, the high microbiological loads at the end of the shelf-life indicate that some processors might have problems with the distribution chain or implement a poor hygienic regime. Moreover as a result of possible risk associated with heavy metal contamination, the present study highlights the need to establish new regulations regarding the contamination of nori and sushi. © 2017 Society of Chemical Industry.

Chelating effects of carnosine in ameliorating nickel-induced nephrotoxicity in rats

The kidney is one of the main organs affected by nickel toxicity. We investigated the protective effects of carnosine on nickel-induced oxidative stress in kidney of rats. Animals received NiSO₄ (20 mg·kg^-1·day^-1 intragastrically) and (or) carnosine (10 mg·kg^-1·day^-1 intragastrically) for 21 days and then were evaluated for biochemical, molecular, and histopathological alterations. Nickel caused an increase in renal levels of malondialdehyde and a decrease in reduced glutathione, catalase, and superoxide dismutase levels and total antioxidant capacity. Carnosine prevented the prooxidant and antioxidant imbalance induced by nickel. Nickel-treated rats showed an increase in serum creatinine, urea, and uric acid with a concomitant decrease in albumin. Nickel markedly accumulated in kidney of exposed rats, but its concentration was effectively reduced by carnosine treatment. Carnosine corrected the biochemical abnormalities and the elevated renal TNF-α and IL-6 levels in the nickel-treated group. It also attenuated nickel-induced abnormalities in renal architecture. Although carnosine showed antioxidant and anti-inflammatory effects in renal tissue of nickel-exposed rats, we cannot clearly attribute the protective effect of carnosine to these effects. Instead, the beneficial effect of carnosine observed in the current study may be due to chelation between nickel and carnosine. Thus, carnosine may represent a therapeutic option to protect against nickel-induced nephrotoxicity that deserves further consideration and examination.

Physiological and biochemical effects of nickel on rainbow trout (Oncorhynchus mykiss) tissues: Assessment of nuclear factor kappa B activation, oxidative stress and histopathological changes

We investigated changes in nuclear factor kappa B (NFkB) activity, antioxidant responses and histopathological effects in the liver, gill and kidney tissues of rainbow trout exposed to nickel chloride (Ni). Two different concentrations (1 mg/L and 2 mg/L) were administrated to fish for 21 days. Tissues were taken from all fish for NFkB activity, histopathological examination and determination of superoxide dismutase (SOD), catalase (CAT) enzyme activity and of lipid peroxidation (LPO), and glutathione (GSH) levels. The findings of this study indicated that Ni exposure led to a significant increase in LPO indicating peroxidative damage and antioxidant enzymes SOD and CAT activity in tissues (p < 0.05), but 2 mg/Ni concentration caused a significant decrease in CAT activity in kidney tissues (p < 0.05). One of mechanism in the antioxidant defense system seems to be GSH, which increased in gill and kidney tissues of fish exposed to Ni (p < 0.05). NFkB immunopositivity was detected in all tissues. Ni exposure caused lamellar thickening, cellular infiltration in gill tissues, hydropic degeneration of hepatocytes in liver tissues, hyalinous accumulation within the glomeruli and tubular degeneration in kidney tissues. Our results suggested that Ni toxicity may disturb the biochemical and physiological functions of fish by causing changes in NFkB activity and oxidative and histopathological damage in the tissues of rainbow trout. This study can provide useful information for understanding of Ni-induced toxicity.

Neurotoxic effects of nickel chloride in the rainbow trout brain: Assessment of c-Fos activity, antioxidant responses, acetylcholinesterase activity, and histopathological changes

The aim of this study was to determine the biochemical, immunohistochemical, and histopathological effects of nickel chloride (Ni) in the rainbow trout brain. Fish were exposed to Ni concentrations (1 mg/L and 2 mg/L) for 21 days. At the end of the experimental period, brain tissues were taken from all fish for c-Fos activity and histopathological examination and determination of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT) enzyme activities, lipid peroxidation (LPO), and glutathione (GSH) levels. Our results showed that Ni treatment caused a significant increase in the brain SOD activity and in LPO and GSH levels (p < 0.05), but it significantly decreased AChE and CAT enzyme activities (p < 0.05). Strong induction in c-Fos was observed in some cerebral and cerebellar regions of fish exposed to Ni concentrations when compared with the control group. However, c-Fos activity was decreased in necrotic Purkinje cells. Brain tissues were characterized by demyelination and necrotic changes. These results suggested that Ni treatment causes oxidative stress, changes in c-Fos activity, and histopathological damage in the fish brain.

Effects of gestational administration of nickel on postnatal development in Swiss albino mice

Effects on postnatal development of Swiss albino mice exposed to nickel (Ni2+) ions as nickel chloride haxahydrate (NiCl2·6H2O) during the gestation periods were evaluated in this study. Administration of Ni to pregnant females by gavage (46.125, 92.25, and 184.5 mg Ni/kg body weight (b.w.)) at doses below median lethal dose during 0–5 (preimplantation period), 6–13 (organogenetic period), and 14–18 days (fetal period) postconception. The dams were allowed to deliver and raise their pups. Significant ( p < 0.05) decrease in litter size was observed after 184.5 mg Ni/kg b.w. during the three gestation periods particularly from preimplantation period as compared to organogenetic and fetal periods in comparison with the control group. Exposure to 184.5 mg Ni/kg b.w. during fetal period revealed higher mortality as compared to organogenetic period. Exposure to 184.5 mg Ni/kg b.w. increased the eye, limb, and tail anomalies during organogenetic period. Gestation index from preimplantation period was low at all the doses. Live birth index decreased during preimplantation and organogenetic periods after 184.5 mg Ni/kg b.w. The viability and weanling of pups decreased during all periods after 92.25 and 184.5 mg Ni/kg b.w. doses. A dose-dependent highly significant ( p < 0.01) decrease in the body weight of offspring from day 0 to 6 weeks of age at all the doses during different gestation periods were observed. Maximum body weight decrease was observed in offspring from organogenetic period. This study concludes that young ones are vulnerable during different gestational and lactation period which indicates that Ni ingested by mothers constitutes a great threat to the progeny.

Embryotoxic and teratogenic effects of nickel in Swiss albino mice during organogenetic period

The present study evaluates potential hazardous of nickel (Ni(+2) as NiCl2 ·6H2O) to Swiss albino mice fetus. Ni was administered orally on body weight base from days 6 to 13 of gestation period. Based on LD50, Ni doses (46.125, 92.25, and 184.5) mg Ni/kg b.wt. were used. On day 18 of gestation, uteri of the sacrificed dams were examined. A dose-dependent decrease (P < 0.01) in the body weight of the pregnant females and fetuses during the gestation period was observed. Number of implant sites and placental weight at all the three dose levels was lower compared with their respective control groups. Average number of live fetuses/dams reduced significantly (P < 0.01) at 184.5 mg Ni/kg b.wt. with concomitant increase in the percentage of postimplantation death and percentage of resorbed, macerated, and dead fetuses, respectively. Exposure increased the fetal malformations, namely, hydrocephaly, open eyelids, microphthalmia, exophthalmia, club foot, umbilical hernia, and skeletal anomalies. Reduced ossification of nasal, frontal, parietal, intraparietal, and supraoccipital bones, absence/gap between the ribs, reduced/fused sternebrae, vertebral centra, and caudal vertebrae, reduced pelvic elements, absence of carpals, metacarpals, tarsals, metatarsals, and phalanges were distinct. This indicates vulnerability of the mice fetus to nickel during prenatal exposure.

Oxidative stress level in the testes of mice and rats during nickel intoxication

The genotioxic and carcinogenic effect of nickel probably results from its capacity to produce reactive oxygen species (ROS) and disturb the redox balance. The aim of the study was to find out if rats lacking spermatic protamine 2 are less susceptible to Ni(II) than mice. Consequently, the levels of malondialdehyde + 4 hydroxynonenal (MDA+4HDA) − markers of lipid peroxidation, as well as the level of reduced glutathione (GSH) were measured within the rat and mouse testes. Our results showed that the levels of lipid peroxidation markers were elevated in testicular homogenates of intoxicated mice without any changes in rats. GSH level was lower in the group of intoxicated mice comparing to the control without statistically significant changes in rats' homogenates. Moreover, the level of GSH in the testes of intoxicated mice was lower than in rats. On the basis of our results, it appears that Ni(II) can initiate oxidative stress in the testes of mice but not of rats and can reduce GSH level. Consequently, the antioxidative defense of the testes is reduced. Ni(II) that causes oxidative stress in the testes may also contribute to infertility.