Protective role of selenium against renal toxicity induced by cadmium in rats

The Antagonistic Effect of Selenium on Cadmium-Induced Damage and mRNA Levels of Selenoprotein Genes and Inflammatory Factors in Chicken Kidney Tissue

Selenium (Se) is a necessary trace mineral in the diet of humans and animals. Cadmium (Cd) is a toxic heavy metal that can damage animal organs, especially the kidneys. Antagonistic interactions between Se and Cd have been reported in previous studies. However, little is known about the effects of Se against Cd toxicity and on the mRNA levels of 25 selenoprotein genes and inflammatory factors in chicken kidneys. In the current study, we fed chickens with a Se-treated, Cd-treated, or Se/Cd treated diet for 90 days. We then analyzed the mRNA expression of inflammatory factors (including prostaglandin E synthase (PTGES), nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2)) and 25 selenoprotein genes (Gpx1, Gpx2, Gpx3, Gpx4, Txnrd1, Txnrd2, Txnrd3, Dio1, Dio2, Dio3, SPS2, Sepp1, SelPb, Sep15, Selh, Seli, Selm, Selo, Sels, Sepx1, Selu, Selk, Selw, Seln, Selt). The results demonstrated that Cd exposure increased the Cd content in the chicken kidneys, renal tubular epithelial cells underwent denaturation and necrosis, and the tubules became narrow or disappeared. However, Se supplementation reduced the Cd content in chicken kidneys and induced normal development of renal tubular epithelial cells. In addition, we also observed that Se alleviated the Cd-induced increase in the mRNA levels of inflammatory factors and ameliorated the Cd-induced downtrend in the mRNA levels of 25 selenoprotein genes in chicken kidneys.

Protective Effects of Fragaria ananassa Extract Against Cadmium Chloride-Induced Acute Renal Toxicity in Rats

For experiments of cadmium toxicity in animal models, cadmium (II) chloride is often used due to its solubility in water and its ability to produce high concentrations of cadmium at the target site. The present study was designed to investigate the potential inhibitory effect of the Fragaria ananassa fruit extract on cadmium (II) chloride-induced renal toxicity in rats. Tested animals were pretreated with the extract of F. ananassa and injected with cadmium (II) chloride (6.5-mg/kg body weight) for 5 days. Cadmium (II) chloride significantly increased kidney cadmium concentration, kidney weight, lipid peroxidation, and nitric oxide production. Plasma uric acid, urea, and creatinine levels also increased significantly, indicative of kidney dysfunction. These effects were accompanied by significantly decreased levels of nonenzymatic and enzymatic antioxidant molecules (i.e., glutathione content and the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase). Moreover, messenger RNA (mRNA) expression of the antiapoptotic protein, Bcl-2, and the antioxidant proteins, superoxide dismutase 2 and glutathione reductase, were downregulated markedly, whereas mRNA expression of tumor necrosis factor-α was upregulated significantly in kidney tissues of cadmium-treated rats. Histology of kidney tissue demonstrated severe, adverse changes that reflected cadmium-induced tissue damage. Pretreatment of rats with the extract of F. ananassa ameliorated all aforementioned cadmium (II) chloride-induced changes. In conclusion, the present study showed acute renal toxicity in rats treated with cadmium (II) chloride. The study also revealed that pretreatment with the extract of F. ananassa could protect the kidney against cadmium (II) chloride-induced acute renal toxicity.

Hematological, biochemical, and histopathological impacts of barium chloride and barium carbonate accumulation in soft tissues of male Sprague-Dawley rats

The present study was designed to investigate the hematotoxicity, sero-biochemical and histological changes due to the accumulation of BaCl₂ and BaCO₃, the most important barium salts in our daily lives, in different soft tissues including the liver, kidney, heart, and spleen of adult rats after an oral exposure for 30 consecutive days, and to explain the different mechanisms by which this metal can exert these impacts. For this purpose, adult male rats were divided into three main groups of 15 animals each: group I, serving as controls, group II, receiving BaCl₂ orally in a dose of 179 mg barium/kg b.wt, and group III, receiving BaCO₃ orally in a dose of 418 mg barium/kg b.wt. for 30 consecutive days. Obviously, normocytic normochromic anemia was evident in both barium groups. Serum biochemical analysis revealed significant declines in glutathione peroxidase, catalase, superoxide dismutase, and urea with significant elevations in malondialdehyde, lactate dehydrogenase, and creatine kinase levels. Hyperphosphatemia, hypokalemia, hypocalcemia, and hypochloremia were also evident in both barium groups. Besides, residual analysis of both barium salts in different body organs revealed significantly abundant barium residues in the liver, spleen, heart, and kidney, respectively in both barium salts groups. Moreover, splenic tissue showed hemosiderosis, peritubular congestion, and necrotic glomeruli with intratubular hemorrhage. Sever subepicardial congestion with intramuscular edema was evident in the heart. In conclusion, BaCl₂ and BaCO₃ were able to deliver mortalities, antioxidant enzymes exhaustion, and a sort of normocytic normochromic anemia, as well as marked disturbances in cardiac, hepatic, and renal functions due to the accumulation of these two salts in the soft tissues. Therefore, these results demonstrate the unrecognized toxicity of those two barium salts due to their accumulation in various soft tissues of the body and so, this needs to reconsider about barium exposure.

Maternal exposure to selenium and cadmium, fetal growth, and placental expression of steroidogenic and apoptotic genes

BACKGROUND

Cadmium (Cd) and selenium (Se) antagonistically influence redox balance and apoptotic signaling, with Cd potentially promoting and Se inhibiting oxidative stress and apoptosis. Alterations to placental redox and apoptotic functions by maternal exposure to Cd and Se during pregnancy may explain some of the Cd and Se associations with fetal development.

OBJECTIVES

Investigate associations between Cd and Se concentrations in maternal toenails with placental expression patterns of tumor necrosis factor (TNF) and steroidogenic genes involved in redox reactions and test associations with fetal growth.

METHODS

In a sub-sample from the Rhode Island Child Health Study (n = 173), we investigated the relationships between: (1) maternal toenail Cd and Se concentrations and fetal growth using logistic regression, (2) Cd and Se interactions with factor scores from placental TNF and steroidogenic expression patterns (RNAseq) using linear models, and (3) TNF and steroidogenic expression factors with fetal growth via analysis of covariance.

RESULTS

Se was associated with decreased odds of intrauterine growth restriction (IUGR) (OR = 0.27, p-value = 0.045). Cd was associated with increased odds of IUGR (OR = 1.95, p-value = 0.13) and small for gestational age (SGA) births (OR = 1.46, p-value = 0.11), though not statistically significant. Cd and Se concentrations were antagonistically associated with placental TNF and steroidogenic expression patterns, which also differed by birth size.

CONCLUSIONS

Se may act as an antagonist to Cd and as a modifiable protective factor in fetal growth restriction, and these data suggest these effects may be due to associated variations in the regulation of genes involved in placental redox balance and/or apoptotic signaling.

Selenium protects against cadmium-induced kidney apoptosis in chickens by activating the PI3K/AKT/Bcl-2 signaling pathway

Cadmium (Cd) is a toxic heavy metal that can induce apoptosis. Selenium (Se) is a necessary trace element and can antagonize the toxicity of many heavy metals, including Cd. PI3K/AKT/Bcl-2 is a key survival signaling pathway that regulates cellular defense system against oxidative injury as well as cell proliferation, survival, and apoptosis. The antagonistic effects of Se on Cd-induced toxicity have been reported. However, little is known about the effect of Se on Cd-induced apoptosis in chicken kidneys via the PI3K/AKT/Bcl-2 signaling pathway. In the present study, we fed chickens with Se, Cd, or both Se and Cd supplements, and after 90 days of treatment, we detected the related index. The results showed that the activity of inducible nitric oxide synthase (iNOS) and concentration of nitric oxide (NO) were increased; activities of the mitochondrial respiratory chain complexes (complexes I, II, and V) and ATPases (the Na⁺-K⁺-ATPase, the Mg²⁺-ATPase, and the Ca²⁺-ATPase) were decreased; expression of PI3K, AKT, and Bcl-2 were decreased; and expression of Bax, Bak, P53, Caspase-3, Caspase-9, and cytochrome c (Cyt c) were increased. Additionally, the results of the TUNEL assay showed that the number of apoptotic cells was increased in the Cd group. By contrast, there was a significant improvement of the correlation indicators and occurrence of apoptosis in the Se + Cd group compared to the Cd group. In conclusion, our results confirmed that Se had a positive effect on ameliorating Cd-induced apoptosis in chicken kidney tissue by activating the PI3K/AKT/Bcl-2 signaling pathway.

Biological activities of ginger against cadmium-induced renal toxicity

Our aim was to evaluate the protective and antioxidant effects of ginger extract against cadmium-induced renal toxicity in animal models and to support the use of ginger as anti-renal failure natural remedy. Seventy rats were examined in a 4-week experiment to evaluate the effect of Ginger (Zingiber officinale) at doses of 100 and 200 mg/kg body weight on molecular DNA content, antioxidant status, and renal function in rats intoxicated with cadmium at dose of (5 mg/kg) using biochemical and histological analysis. Renal dysfunction, kidney tissue damage, and oxidative effect were evident in cadmium intoxicated rats as estimated by significant increase in (creatinine, urea), decrease in (creatinine clearance and reabsorption rate of urine albumin), increase in MDA, decrease in total antioxidant status (TAC), reduction in DNA content, and histopathological changes of kidneys' tissues compared to control rats. Treatment with ginger resulted in significant restoring of renal function biomarkers, TAC, molecular DNA, and histological improvements which occurs via free radical scavenging and regenerative mechanisms. The activity of ginger was supported by estimation of bioactive phenolic and falvinods constituents. Twenty-eight polyphenolic compounds were estimated in ginger extract; [6]-gingerol, [6]-shogaol, citral and pyrogallol were the highest amounts in ginger, and supposed to be responsible for its major antioxidant and free radical scavenging activity as shown by In vitro DPPH/β-carotene-linolic acid assay tests. Consequently, ginger extracts could have a potent protective effects against nephrotoxicity induced by various toxicants.

Toxicity of cadmium and its health risks from leafy vegetable consumption

Cadmium (Cd) is a highly toxic heavy metal and has spread widely in the environment in recent decades. This review summarizes current knowledge about Cd contamination of leafy vegetables, its toxicity, exposure, health risks, and approaches to reducing its toxicity in humans. Leafy vegetable consumption has been identified as a dominant exposure pathway of Cd in the human body. An overview of Cd pollution in leafy vegetables as well as the main sources of Cd is given. Notable estimated daily intakes and health risks of Cd exposure through vegetable consumption for humans are revealed in occupational exposure areas and even in some reference areas. Vegetable consumption is one of the most significant sources of exposure to Cd, particularly in occupational exposure regions. Therefore, numerous approaches have been developed to minimize the accumulation of Cd in leafy vegetables, among which the breeding of Cd pollution-safe cultivars is one of the most effective tools. Furthermore, dietary supplements from leafy vegetables perform positive roles in alleviating Cd toxicity in humans with regard to the effects of essential mineral elements, vitamins and phytochemicals taken into the human body via leafy vegetable consumption.

Ameliorative effect of vitamin E and selenium against oxidative stress induced by sodium azide in liver, kidney, testis and heart of male mice

The study purported to define the effects of daily administration of vitamin E (Vit E) and selenium (Se) on antioxidant enzyme activity in mice treated with high doses of sodium azide (SA). Male mice were randomly split into nine groups. Groups 1, 2 and 3 were injected daily with saline, Vit E, and Se, respectively, while groups 4, 5 and 6 administrated with different doses of SA (low, medium and high, respectively). The mice in groups 7, 8 and 9 received 100mg/kg Vit E, 17.5mg/kg Se, and a combination of Vit E and Se, respectively before the SA-treatment. Hepatic, renal, testis and heart, antioxidant enzymes as well as levels of lipid peroxidation and total antioxidant capacity levels were determined. Vit E alone affected on the antioxidant parameters of the examined tissues. Se had a preventive effect on the decrease of antioxidant parameters caused by SA and improved the diminished activities of all of them. The study demonstrates that a high dose of SA may alter the effects of normal level antioxidant/oxidative status of male mice and that Se is effective in reducing the SA-damage. Se acts as a synergistic agent with the effect of Vit E in various damaged caused by SA.

Caffeic acid phenethyl ester protects the brain against hexavalent chromium toxicity by enhancing endogenous antioxidants and modulating the JAK/STAT signaling pathway

Hexavalent chromium [Cr(VI)] is commonly used in industry, and is a proven toxin and carcinogen. However, the information regarding its neurotoxic mechanism is not completely understood. The present study was designed to scrutinize the possible protective effects of caffeic acid phenethyl ester (CAPE), a bioactive phenolic of propolis extract, on Cr(VI)-induced brain injury in rats, with an emphasis on the JAK/STAT signaling pathway. Rats received 2mg/kgK₂CrO₄ and concurrently treated with 20mg/kg CAPE for 30 days. Cr(VI)-induced rats showed a significant increase in cerebral lipid peroxidation, nitric oxide and pro-inflammatory cytokines, with concomitantly declined antioxidants and acetylcholinesterase. CAPE attenuated oxidative stress and inflammation and enhanced antioxidant defenses in the cerebrum of rats. Cr(VI) significantly up-regulated JAK2, STAT3 and SOCS3, an effect that was reversed by CAPE. In conclusion, CAPE protects the brain against Cr(VI) toxicity through abrogation of oxidative stress, inflammation and down-regulation of JAK2/STAT3 signaling in a SOCS3-independent mechanism.

Effect of various selenium doses on chromium(IV)-induced nephrotoxicity in a male chicken model

Our study aimed to explore whether Na₂SeO₃ (Se) can alleviate the nephrotoxicity induced by K₂Cr₂O₇ [Cr(VI)]. One hundred and five male chickens were randomly divided into seven groups with 15 chickens each group: The 6 experimental groups received K₂Cr₂O₇ alone or in combination with 0.31, 0.63, 1.25, 2.50, and 5.00 mg/kg for 42 days, respectively, while control group was treated with equivalent water. Exposure to Cr(VI) significantly increased MDA contents and organ coefficient, whereas decreased T-SOD activities, Ca²⁺-ATPase activities, mitochondrial membrane potential and GSH contents, and histological studies demonstrated renal damage. Above indicators were restored by Se supplement (0.31, 0.63, and 1.25 mg/kg), in which supplement with 0.63 mg/kg Se developed more effectively than the other two groups; on the contrary, in the groups of Se supplement with 2.50 and 5.00 mg/kg, the above indicators were not ameliorated and even exacerbated. This study demonstrated that Cr(VI) can result in kidney oxidative damage in male chickens, and Se of certain dose has the protective effects against Cr(VI)-induced nephrptoxicity.

Ameliorative Effects of Dietary Selenium Against Cadmium Toxicity Is Related to Changes in Trace Elements in Chicken Kidneys

The ameliorative effects of selenium (Se) against cadmium (Cd)-induced toxicity have been reported extensively. However, few studies have assessed the effects of multiple ions simultaneously on the variations of elements. In this study, the changes in Se, Cd, and 26 other element concentrations were investigated in chicken kidneys. One hundred and twenty-eight 31-week-old laying hens were fed a diet supplemented with either Se, Cd, or both Se and Cd for 90 days. The ion content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). We found that the Se, Cd, and combined Se and Cd treatments significantly affected the trace elements in the chicken kidneys. The Cd supplement caused ion profile disorders, including reduced concentrations of V, Cr, Mn, Mo, As, Ba, Hg, Ti, and Pb and increased Si, Cu, Li, Cd, and Sb. The Se supplement reduced the contents of Co, Mo, and Pb and increased the contents of Cr, Fe, and Se. Moreover, Se also increased the concentrations of Cr, Mn, Zn, and Se and decreased those of Li and Pb, which in contrast were induced by Cd. Complex interactions between elements were analyzed, and both positive and negative correlations among these elements are presented. The present study indicated that Se can help against the negative effects of Cd and may be related to the homeostasis of the trace elements in chicken kidneys.

Selenium supplementation can protect from enhanced risk of keel bone damage in laying hens exposed to cadmium

The aim of this study was to investigate whether selenium (Se) supplementation can provide protection from an enhanced risk of keel bone damage (KBD) in laying hens due to the cadmium (Cd) toxicity associated with sub-chronic exposure.

The Protective Effect of Selenium on Chronic Zearalenone-Induced Reproductive System Damage in Male Mice

This study aims to explore the protective effect of selenium (Se) on chronic zearalenone (ZEN)-induced reproductive system damage in male mice and the possible protective molecular mechanism against this. The chronic ZEN-induced injury mouse model was established with the continuous intragastric administration of 40 mg/kg body mass (B.M.) ZEN for 28 days. Then, interventions with different doses (0.1, 0.2, and 0.4 mg/kg B.M.) of Se were conducted on mice to analyse the changes in organ indexes of epididymis and testis, antioxidant capability of testis, serum level of testosterone, sperm concentration and motility parameters, and the expression levels of apoptosis-associated genes and blood testis barrier- (BTB) related genes. Our results showed that Se could greatly improve the ZEN-induced decrease of epididymis indexes and testis indexes. Results also showed that the decrease in sperm concentration, sperm normality rate, and sperm motility parameters, including percentage of motile sperm (motile), tropism percentage (progressive) and sperm average path velocity (VAP), caused by ZEN were elevated upon administration of the higher dose (0.4 mg/kg) and intermediate dose (0.2 mg/kg) of Se. Selenium also significantly reduced the content of malondialdehyde (MDA) but enhanced the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the testis tissue. Further research demonstrated that ZEN increased the level of mRNA expression of BCL2-associated X protein (Bax) and caspase 3 (Casp3), decreased the level of mRNA expression of B cell leukemia/lymphoma 2 (Bcl2), vimentin (Vim) and cadherin 2 (Cdh2), whereas the co-administration of Se reversed these gene expression levels. Our results indicated that high levels of Se could protect against reproductive system damage in male mice caused by ZEN and the mechanism might such be that Se improved mice antioxidant ability, inhibited reproductive cell apoptosis, and increased the decrease of BTB integrity-related genes caused by ZEN.

The Influence of Selenium Yeast on Hematological, Biochemical and Reproductive Hormone Level Changes in Kunming Mice Following Acute Exposure to Zearalenone

Healthy male Kunming mice received selenium yeast for 14 days prior to a single oral administration of zearalenone (ZEN). After 48 h, blood samples were collected for analysis and showed that mice in the ZEN-treated group has significantly decreased lymphocytes (P < 0.05) and platelets (P < 0.05) along with an increased white blood cell (WBC) count and other constituents (P < 0.05). The serum biochemistry analysis of the ZEN group indicated that glutamic pyruvic transaminase (ALT), glutamic oxaloacetic transaminase (AST), urea, and uric acid were significantly increased (P < 0.05), whilst total bilirubin (TB) and albumin (ALB) were decreased along with serum testosterone and estrogen (P < 0. 05). The level of malondialdehyde (MDA) in the serum of the ZEN group was significantly increased whilst glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) had significantly decreased (P < 0.05). Treatment with selenium yeast had a significant effect on response with most of the experimental parameters returning to levels similar to those observed in the untreated control mice. From these data, it can be concluded that ZEN is highly poisonous in Kunming mice with high levels of toxicity on the blood, liver, and kidneys. High levels of oxidative stress were observed in mice and pre-treatment with selenium yeast by oral gavage is effective in the ameliorated effects of ZEN-induced damage.

Cadmium Concentration in Mother's Blood, Milk, and Newborn's Blood and Its Correlation with Fatty Acids, Anthropometric Characteristics, and Mother's Smoking Status

The aim of this study was to determine cadmium concentration in mothers' blood, milk, and newborns' blood from Szczecin (Poland) as a result of environmental cadmium exposure and evaluate the correlation (1) between cadmium levels in analyzed matrices, (2) between cadmium and fatty acids in those matrices, and (3) between cadmium and some selected personal variables, such as anthropometric characteristics, mothers' smoking status, and fruit and fish consumption by mothers. The concentration of cadmium in whole blood and milk of mothers and in the umbilical cord blood of newborns was determined by atomic absorption spectrometry with graphite furnace atomization and Zeeman correction. The fatty acid concentrations were determined by gas chromatography in our previous study. The mean concentrations of cadmium in maternal blood, newborn's blood, and breast milk were 0.61 ± 0.62 μg/L, 0.05 ± 0.04 μg/L, and 0.11 ± 0.07 μg/L, respectively, and differed significantly between analyzed matrices. Cadmium concentrations in the umbilical cord blood were 15 % (range 0-83 %) of the concentration in maternal blood, whereas cadmium concentrations in breast milk constituted 35 % (range 3-142 %) of the concentration in mothers' blood. No correlation was found between cadmium levels in three analyzed matrices. The correlation analysis revealed significant low positive correlation between maternal blood cadmium concentrations and concentrations of elaidic, oleic, and cis-vaccenic acids in mothers' milk (correlation coefficients 0.30, 0.32, and 0.31, respectively). Mothers' blood cadmium correlated with mothers' age (r = -0.26, p = 0.03), maternal smoking before pregnancy (r = 0.55, p < 0.000), maternal smoking during pregnancy (r = 0.58, p < 0.000), and fruit consumption by mothers after delivery (r = -0.44, p = 0.003). Mothers' height was the only variable that correlated significantly with breast milk cadmium levels. Newborns' blood cadmium concentrations correlated significantly with mothers' height (r = 0.28, p = 0.02), newborns' birth weight (r = 0.26, p = 0.03), maternal smoking during pregnancy (r = 0.24, p = 0.048), and fish consumption by mothers after delivery (r = 0.37, p = 0.02). The concentrations of cadmium in Polish mother-newborn pairs are among the lowest in Europe and within the norms established by different institutions. The results of our study confirm the existence of effective partial barriers (such as the placenta and mammary gland) restricting cadmium passage from mother to newborn. The significant positive correlations between maternal blood Cd and concentrations of oleic, elaidic, and cis-vaccenic acids in breast milk might suggest the increased cadmium toxicity to infant, taking into consideration even low cadmium passage to milk. Maternal smoking during pregnancy increases both maternal and newborn's blood cadmium level. Promotion of nonsmoking among pregnant women could substantially reduce prenatal and neonatal exposure to cadmium. Moreover, the results of our study point to the need of establishing complex biomonitoring of cadmium in mother-infant pairs in order to better protect children from this toxic and carcinogenic metal exposure.

Effects of sub-chronic Cd exposure on levels of copper, selenium, zinc, iron and other essential metals in rat renal cortex

Cd (Cd) is a nephrotoxic environmental pollutant that causes generalized proximal tubule dysfunction. Even though the specific mechanisms by which Cd damages the kidney have yet to be fully elucidated, there is evidence to suggest that some of these nephrotoxic effects may result from the ability of Cd to alter the levels and function of metals such as Cu, Se, Zn and Fe within the kidney. In order to further explore this issue, we examined the effects of subchronic Cd exposure on tissue levels of a panel of metals (Ca, Cu, Fe, K, Mg, Na, Se and Zn) in the rat renal cortex. Adult male Sprague-Dawley rats were treated with CdCl₂ (0.6 mg Cd/kg body weight in isotonic saline by subcutaneous injection, 5 days per week for 6, 9 or 12 weeks). At each time point, 24 h urine samples were collected and assayed for levels of protein, creatinine, β₂ microglobulin and cystatin C. Samples of renal cortex were removed and assayed for levels of the metals of interest by inductively-coupled mass spectrometry at Michigan State University. Results showed that at 9 and 12 weeks, Cd caused significant increases in urine volume and urinary protein with no change in creatinine excretion. Increases in the excretion of the urinary biomarkers β₂ microglobulin and cystatin C were evident after 6 weeks of Cd exposure. Results of the metal analyses showed that Cd caused significant increases in tissue levels of Cu and Se at all of the time points examined. Tissue levels of Zn were transiently elevated at 6 weeks but declined to control levels at 9 and 12 weeks. Cd caused a significant decrease in levels of Fe at 9 and 12 weeks. Cd had no effects on any of the other metals. Tissue levels of Cd were 530 ± 52, 863 ± 23, 837 ± 23 ppm dry weight at 6, 9 and 12 weeks, respectively. These results indicate that the early stages of Cd nephrotoxicity are associated with alterations in renal tissue levels of Cu, Se, Zn and Fe. The fact that the changes in levels of the metals occurred during the early stages of Cd toxicity raises the possibility that the alterations in renal cortical metal content may play some role in the pathophysiology or Cd-induced injury.

Combined toxicity of Fe3O4 nanoparticles and cadmium chloride in mice

Nanomaterials have been widely used in diverse areas. Heavy metals are ubiquitous environmental pollutants. In spite of the real risk of humans' co-exposure to nanoparticles and heavy metals, their combined toxicity has received little attention. We have reported that silica nanoparticles and CdCl2 have a positive synergistic toxicity in mice. Here, we demonstrate that Fe3O4 nanoparticles (nano-Fe3O4) and CdCl2 have a negative synergistic toxicity in mice. Nano-Fe3O4 showed low toxicity in mice. In contrast, CdCl2 caused significant oxidative damage mainly in the liver as indicated by severe liver dysfunction and histopathological abnormalities. Co-exposure to nano-Fe3O4 and CdCl2 significantly attenuated CdCl2-induced damage in the liver through reduction of oxidative stress. Nano-Fe3O4 and CdCl2 had negative cooperative effects on the biodistributions of Fe and Cd in mice due to mutually competitive inhibition of Fe and Cd uptake. The reduction of Cd accumulation in tissues and the inhibition of Cd-induced deprivation of tissue Fe by nano-Fe3O4 played two key roles in the protective effect of nano-Fe3O4 on CdCl2-induced oxidative damage.

Selenium-binding protein 1: a sensitive urinary biomarker to detect heavy metal-induced nephrotoxicity

Identifying novel biomarkers to detect nephrotoxicity is clinically important. Here, we attempted to identify new biomarkers for mercury-induced nephrotoxicity and compared their sensitivity to that of traditional biomarkers in animal models. Comparative proteomics analysis was performed in kidney tissues of Sprague-Dawley rats after oral treatment with HgCl₂ (0.1, 1, or 5 mg/kg/day) for 21 days. Kidney cortex tissues were analyzed by two-dimensional gel electrophoresis/matrix-assisted laser desorption/ionization, and differentially expressed proteins were identified. The corresponding spots were quantitated by RT-PCR. Selenium-binding protein 1 (SBP1) was found to be the most markedly upregulated protein in the kidney cortex of rats after HgCl₂ administration. However, blood urea nitrogen, serum creatinine, and glucose levels increased significantly only in the 1 or 5 mg/kg HgCl₂-treated groups. A number of urinary excretion proteins, including kidney injury molecule-1, clusterin, monocyte chemoattractant protein-1, and β-microglobulin, increased dose-dependently. Histopathological examination revealed severe proximal tubular damage in high-dose (5 mg/kg) HgCl₂-exposed groups. In addition, urinary excretion of SBP1 significantly increased in a dose-dependent manner. To confirm the critical role of SBP1 as a biomarker for nephrotoxicity, normal kidney proximal tubular cells were treated with HgCl₂, CdCl₂, or cisplatin for 24 h. SBP1 levels significantly increased in conditioned media exposed to nephrotoxicants, but decreased in cell lysates. Our investigations suggest that SBP1 may play a critical role in the pathological processes underlying chemical-induced nephrotoxicity. Thus, urinary excretion of SBP1 might be a sensitive and specific biomarker to detect early stages of kidney injury.

Calcium, zinc and vitamin E ameliorate cadmium-induced renal oxidative damage in albino Wistar rats

This study was aimed to examine the protective effects of supplementation with calcium + zinc (Ca + Zn) or vitamin E (Vit-E) on Cd-induced renal oxidative damage. Young albino Wistar rats (180 ± 10 g) (n = 6) control rats, Cd, Cd + Ca + Zn, and Cd + Vit-E experimental groups and the experimental period was 30 days. Rats were exposed to Cd (20 mg/kg body weight) alone treated as Cd treated group and the absence or presence of Ca + Zn (2 mg/kg each) or Vit-E (20 mg/kg body weight) supplementation treated as two separate groups. The activities of the stress marker enzymes superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and lipid peroxidase (LPx) were determined in renal mitochondrial fractions of experimental rats. We observed quantitative changes in SOD isoenzymatic patterns by non-denaturing PAGE analysis, and quantified band densities. These results showed that Cd exposure leads to decreases in SOD, CAT, GR, and GPx activities and a concomitant increase in LPx and GST activities. Ca + Zn and Vit-E administration with Cd significantly reversed Cd-induced perturbations in oxidative stress marker enzymes. However, Vit-E showed more inhibitory activity against Cd than did Ca + Zn, and it protected against Cd-induced nephrotoxicity.

Barium chloride induces redox status unbalance, upregulates cytokine genes expression and confers hepatotoxicity in rats-alleviation by pomegranate peel

The present study was performed to establish the therapeutic efficacy of pomegranate peel against barium chloride induced liver injury. Adult rats were divided into four groups of six animals each: group I, serving as controls, received distilled water; group II received by their drinking water 67 ppm of BaCl2; group III received both 67 ppm of BaCl2 by the same way than group II and 5 % of pomegranate peel (PP) via diet; group IV received 5 % of PP. Analysis by HPLC/MS of PP showed its rich composition in flavonoids such as gallic acid, castalin, hyperin, quercitrin, syringic acid, and quercetin. The protective effects of pomegranate peel against hepatotoxicity induced by barium chloride were assessed using biochemical parameters and histological studies. Exposure of rats to barium caused oxidative stress in the liver as evidenced by an increase in malondialdehyde (MDA), lipid hydroperoxides (LOOHs), H2O2 and advanced oxidation protein product (AOPP) levels, and lactate dehydrogenase (LDH), gamma glutamyl transpeptidase (GGT), alanine aminotransferase (AST) and aspartate aminotransferase (ALT) activities, a decrease in catalase (CAT) and glutathione peroxidase (GPx) activities, glutathion (GSH), non-protein thiol (NPSH), vitamin C levels, and Mn-SOD gene expression. Liver total MT levels, MT-1, and MT-2 and pro-inflammatory cytokine genes expression like TNF-α, IL-1β and IL-6 were increased. Pomegranate peel, supplemented in the diet of barium-treated rats, showed an improvement of all the parameters indicated above.The present work provided ethnopharmacological relevance of pomegranate peel against the toxic effects of barium, suggesting its beneficial role as a potential antioxidant.

Effect of combined exposure to lead and decabromodiphenyl ether on neurodevelopment of zebrafish larvae

The effect of combined exposure to decabromodiphenyl ether (BDE-209) and lead (Pb) on neurodevelopment of zebrafish (Danio rerio) larvae was investigated. Zebrafish embryos were exposed to Pb (0, 5, 10, 20 µg/L) and BDE-209 (0, 50, 100, 200 µg/L), either alone or in combination (Mix1: 5 + 50 µg/L, Mix2: 10 + 100 µg/L, Mix3: 20 + 200 µg/L) for up to 144 h post-fertilization. Growth of secondary motoneuron axons and expression of genes related to central nervous system development was significantly inhibited in Mix3 co-exposure group. A significant increase in reactive oxygen species (ROS), lipid peroxidation, DNA damage, and perturbation of the antioxidant system was detected in the Mix3 group compared to single-toxicant treatments or control. Depressed locomotor activity was recorded in the Mix2 and Mix3 groups. Addition of N-acetyl cysteine to Mix3 eliminated excessive ROS, and protected against lipid peroxidation, DNA damage, and locomotor dysfunction. Pb uptake was increased in the presence of BDE-209, but BDE-209 bioconcentration and the ability to metabolize BDE-209 were decreased in the presence of Pb. These results suggest that BDE-209 and Pb have a synergistic disruptive effect on neurodevelopment in zebrafish larvae by enhanced generation of ROS, which is a major factor that contributes to developmental neurotoxicity.

Cadmium Protection Strategies--A Hidden Trade-Off?

Cadmium (Cd) is a non-essential transition metal which is introduced into the biosphere by various anthropogenic activities. Environmental pollution with Cd poses a major health risk and Cd toxicity has been extensively researched over the past decades. This review aims at changing the perspective by discussing protection mechanisms available to counteract a Cd insult. Antioxidants, induction of antioxidant enzymes, and complexation of Cd to glutathione (GSH) and metallothionein (MT) are the most potent protective measures to cope with Cd-induced oxidative stress. Furthermore, protection mechanisms include prevention of endoplasmic reticulum (ER) stress, mitophagy and metabolic stress, as well as expression of chaperones. Pre-exposure to Cd itself, or co-exposure to other metals or trace elements can improve viability under Cd exposure and cells have means to reduce Cd uptake and improve Cd removal. Finally, environmental factors have negative or positive effects on Cd toxicity. Most protection mechanisms aim at preventing cellular damage. However, this might not be possible without trade-offs like an increased risk of carcinogenesis.

Protective Roles of Selenium on Nitric Oxide and the Gene Expression of Inflammatory Cytokines Induced by Cadmium in Chicken Splenic Lymphocytes

Cadmium (Cd) is an environmental toxicant and an inflammation-related xenobiotic. Selenium (Se) is a well-known nutritional trace element and a potent chemopreventive agent. The present study aimed to investigate the effect of Se on the cytotoxicity of Cd in bird immunocytes in vitro. Chicken splenic lymphocytes exposed to CdCl2 (10(-6) mol/L), Na2SeO3 (10(-7) mol/L), or a mixture of the two (10(-7) mol/L Na2SeO3 and 10(-6) mol/L CdCI2) were incubated for 12, 24, 36, 48, or 60 h. Cd significantly increased (P < 0.05 or P < 0.01) the messenger RNA (mRNA) expression levels of nuclear factor kappaB (NF-κB), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF-α), and prostaglandin E2 (PGE2), and similar results were observed in the protein expression levels of NF-κB and COX-2. In addition, the nitric oxide (NO) content and the inducible iNOS activity were increased in the Cd-treated group compared to the control group. Furthermore, the protective effects of Se against Cd toxicity in chicken splenic lymphocytes were illustrated by the increase in select cytokines (NF-κB, iNOS, COX-2, TNF-α, and PGE2), NO content and iNOS activity. The biochemical parameters exhibited sensitivity to Se and Cd, suggesting that they may act as potential biomarkers for assessing the effects of Se and Cd risk on chicken splenic lymphocytes.

Effect of Sodium Selenite on Pathological Changes and Renal Functions in Broilers Fed a Diet Containing Aflatoxin B₁

To evaluate the renal toxicity of dietary aflatoxin B₁ (AFB₁) and ameliorating effects of added dietary sodium selenite in broiler, renal histopathological changes, ultrastructural changes, and renal function parameters were monitored at 7, 14, and 21 days of age. Two hundred one-day-old healthy male Avian broilers were divided into four groups, namely control group, AFB₁ group (0.3 mg/kg AFB₁), +Se group (0.4 mg/kg Se), and AFB₁+Se group (0.3 mg/kg AFB₁+0.4 mg/kg Se). Compared with that of the control group, the relative weight of kidney was increased in the AFB₁ group. There were no significant differences between the AFB₁+Se group and the control group. By histopathological observation, the renal epithelia were swelling and necrosis at 7 and 21 days of age. Ultrastructurally, the lipid droplets and expanded endoplasmic reticulum appeared in the plasma of epithelia cells in the AFB₁ group. Enlarged mitochondria with degenerated cristae were observed in the +Se group. Compared with the control group, the contents of serum creatinine and serum uric acid in the AFB₁ group were increased, while the activity of renal Na⁺-K⁺ ATPase was decreased. When 0.4 mg/kg selenium was added into the diet containing 0.3 mg/kg AFB₁, there were no obvious histological changes in the AFB₁+Se group, and the contents of the serum creatinine and serum uric acid contents and the activity of renal Na⁺-K⁺ ATPase were close to those in the control group. In conclusion, sodium selenite exhibited protective effects on AFB₁-induced kidney toxicity in broilers.

Protective effects of sodium selenite on lead nitrate-induced hepatotoxicity in diabetic and non-diabetic rats

In the present study, the effect of sodium selenite on lead induced toxicity was studied in Wistar rats. Sodium selenite and lead nitrate were administered orally for 28 days to streptozotocin induced diabetic and non-diabetic rats. Eight groups of rats were used in the study: control, sodium selenite, lead nitrate, lead nitrate+sodium selenite, streptozotocin-induced diabetic-control, diabetic-sodium selenite, diabetic-lead nitrate, diabetic-lead nitrate+sodium selenite groups. Serum biochemical parameters, lipid peroxidation, antioxidant enzymes and histopathological changes in liver tissues were investigated in all groups. There were statistically significant changes in liver function tests, antioxidant enzyme activities and lipid peroxidation levels in lead nitrate and sodium selenite+lead nitrate treated groups, also in diabetic and non-diabetic groups. Furthermore, histopathological alterations were demonstrated in same groups. In the present study we found that sodium selenite treatment did not show completely protective effect on diabetes mellitus caused damages, but diabetic rats are more susceptible to lead toxicity than non-diabetic rats.

Cadmium toxicity induces ER stress and apoptosis via impairing energy homoeostasis in cardiomyocytes

Cadmium, a highly toxic environmental pollutant, is reported to induce toxicity and apoptosis in multiple organs and cells. The present findings showed that cadmium toxicity induces cell stress and promotes apoptosis in cardiomyocytes in a metabolic manner, by either disrupting the glucose metabolism or inhibiting mitochondrial respiratory gene expressions through AKT/mTOR pathway.

Cadmium, a highly toxic environmental pollutant, is reported to induce toxicity and apoptosis in multiple organs and cells, all possibly contributing to apoptosis in certain pathophysiologic situations. Previous studies have described that cadmium toxicity induces biochemical and physiological changes in the heart and finally leads to cardiac dysfunctions, such as decreasing contractile tension, rate of tension development, heart rate, coronary flow rate and atrioventricular node conductivity. Although many progresses have been made, the mechanism responsible for cadmium-induced cellular alternations and cardiac toxicity is still not fully understood. In the present study, we demonstrated that cadmium toxicity induced dramatic endoplasmic reticulum (ER) stress and impaired energy homoeostasis in cultured cardiomyocytes. Moreover, cadmium toxicity may inhibit protein kinase B (AKT)/mTOR (mammalian target of rapamycin) pathway to reduce energy productions, by either disrupting the glucose metabolism or inhibiting mitochondrial respiratory gene expressions. Our work will help to reveal a novel mechanism to clarify the role of cadmium toxicity to cardiomyocytes and provide new possibilities for the treatment of cardiovascular diseases related to cadmium toxicity.

Protective effect of Irvingia gabonensis stem bark extract on cadmium-induced nephrotoxicity in rats

Cadmium has been considered a risk factor for humans as it accumulates in body tissues, such as the liver, lungs, kidneys, bones, and reproductive organs. The aim of the present study was to evaluate the effect of Irvingia gabonensis (IG) against cadmium (Cd)-induced nephrotoxicity. The study was performed on twenty (20) male rats divided into four groups: control group, cadmium group (4 mg/kg/day, intraperitoneally), cadmium + extract (200 mg/kg body weight by oral gavage) and cadmium + extract (400 mg/kg body weight by oral gavage). Changes in the kidney biochemical markers, namely glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), aminotransferase (ALT), aspartate aminotransferase (AST) activities and levels of malondialdehyde (MDA), urea, and creatinine were determined in serum. Histological examinations were monitored. Exposure to Cd lowered the activities of kidney antioxidants, while it increased LPO levels. Levels of all disrupted parameters were alleviated by co-administration of IG extract. The malondialdehyde concentration of the rats treated with 200 and 400 mg/kg body weight of the extract significantly decreased (p<0.05) compared with the untreated cadmium rats. Yet the creatinine concentration decreased significantly (p<0.05) when the cadmium animals treated with 200 and 400 mg/kg body weight of the extract were compared with the cadmium control. Furthermore, histological alterations in the kidney were observed in cadmium untreated rats and these were ameliorated in cadmium treated rats by co-administration of IG extract. IG showed apparent protective and curative effect on Cd-induced nephrotoxicity.

Cytotoxic effects and cellular oxidative mechanisms of metallic nanoparticles on renal tubular cells: impact of particle solubility

Many uncertainties remain regarding the potential toxic effect of nanoparticles.

Four endoplasmic reticulum resident selenoproteins may be related to the protection of selenium against cadmium toxicity in chicken lymphocytes

Cadmium could induce the damage of endoplasmic reticulum. In the present study, we investigated the effect of Cadmium on messenger RNA expressions of endoplasmic reticulum resident selenoproteins, selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T, in cultured chicken lymphocytes and the antagonistic effect of Selenium. Chicken splenic lymphocytes were treated with 10(-7) mol/L Selenium, 10(-6) mol/L Cadmium, and the mixture of 10(-6) mol/L Selenium and 10(-7) mol/L Cadmium in the culture medium for 12, 24, 36, and 48 h, respectively. Then, we detected the messenger RNA expressions of selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T by using real-time polymerase chain reaction method. The results indicated that Selenium significantly increased the expressions of selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T, which were reduced by Cadmium in chicken splenic lymphocytes. It indicated that endoplasmic reticulum was one target of Cadmium toxication, and Cadmium toxicity might be related to the reduced expressions of selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T in chicken lymphocytes. Selenium reserved the protective role by increasing the expressions of selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T. The present study provided a useful clue to investigate the possible pathogenesis of Cadmium toxicity.

Cadmium-induced injury and the ameliorative effects of selenium on chicken splenic lymphocytes: mechanisms of oxidative stress and apoptosis

Cadmium (Cd) is an important environmental pollutant present in soil, water, air, and food. Selenium (Se) can antagonize some metal element toxicity including Cd. To investigate the cytotoxicity of Cd and the protective effects of Se on bird immunocytes in vitro, chicken splenic lymphocytes with CdCl2 (10(-6) mol/L), Na2SeO3 (10(-7) mol/L), and the mixture (10(-7) mol/L Na2SeO3 and 10(-6) mol/L CdCI2) were incubated for 12, 24, 36, and 48 h, respectively. A high level of malondialdehyde (MDA) and reactive oxygen species (ROS) productions were observed in Cd treatment group; the activities of catalase (CAT), glutathione peroxidise (GSH-Px), superoxide dismutase (SOD), and the mitochondrial inner transmembrane potential (ΔΨm) were significantly lower in Cd treatment group than those in controls (P < 0.05 or P < 0.01). In contrast, Se significantly improved the activities of antioxidant enzymes and reduced MDA and ROS levels compared to Cd treatment alone group, although not restored to the levels of control group. The population of apoptosis cells demonstrated that Cd induces the apoptosis of chicken splenic lymphocytes; in addition, increased mRNA level of Bak, p53, caspase-3, caspase-9, and cytochrome c (Cyt c) and decreased Bcl-2, Bcl-xl, and CaM were observed in Cd treatment group. Se ameliorated ΔΨm and [Ca(2+)]i for mitochondria function restoring, and Se was able to modulate the expression of relative genes. In conclusion, concurrent treatment with Se reduced the Cd-induced morphological changes and oxidative stress, ion disorder, and apoptosis, suggesting that the toxic effects of Cd on the chicken splenic lymphocytes were partly meliorated by Se.

Prophylactic Effects of Ethanolic Extract of Irvingia gabonensis Stem Bark against Cadmium-Induced Toxicity in Albino Rats

The prophylactic effect of ethanolic extract of Irvingia gabonensis stem bark on cadmium-induced oxidative damage in male albino rats’ liver was investigated. Male Wistar rats were divided into control, cadmium, and treatment groups. In the prophylactic experiment, Irvingia gabonensis (200 and 400 mg/kg body weight) was administered by oral gavage for 21 days before exposure to cadmium. Antioxidant marker enzymes such as reduced glutathione (GSH) levels, catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), and lipid peroxidation (LPO) were determined in the liver and heart alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were monitored and histological examination was carried out. Results indicate that cadmium-induced rats had significantly increased relative weight of liver and heart when compared to controls. Treatment with Irvingia gabonensis at 200 and 400 mg/kg caused a significant decrease in relative weight of the organs. In cadmium-induced rats, serum ALT and AST activities and levels of LPO were increased whereas hepatic and cardiac marker enzymes significantly decreased. Furthermore, histological alteration in liver and aorta was observed in cadmium untreated rats and was ameliorated in cadmium rats treated with Irvingia gabonensis. In conclusion, the extract indicates antioxidant and hepatoprotective properties that eliminate the deleterious effects of toxic metabolites of cadmium.

Effect of Cadmium on Lipid Peroxidation and on Some Antioxidants in the Liver, Kidneys and Testes of Rats Given Diet Containing Cadmium-polluted Radish Bulbs

The aim of this study was to examine the effects of cadmium (Cd), incorporated in radish bulbs, on malondialdehyde and glutathione levels and on superoxide dismutase activity in the liver, kidneys and testes of male rats. The control animals were given diet containing ordinary radish bulbs for 4, 8 and 12 weeks, while contaminated animals were given diet containing Cd-polluted radish bulbs (1.1 mg Cd/g of diet) for the same periods as in the controls. At each time point, rats were euthanized and the liver, kidneys and testes were removed. The results indicated that the body weight gain of contaminated rats was identical to that of the control rats. Cd concentrations in the liver, kidneys and testes increased significantly and gradually from the 4th to 12th week of treatment. Malondialdehyde concentrations decreased significantly in the liver and increased significantly in the kidneys and testes after 12 weeks of treatment, while glutathione levels increased significantly in the liver, and decreased significantly in the kidneys and testes at the same time. No changes were observed in SOD activity in the liver, while in the kidneys and testes, this activity was increased after 12 weeks of treatment as compared with the control rats.

Determination of optimal toxic concentration and accumulation of cadmium in broiler chicks

Cadmium is considered one of the most toxic, non biodegradable heavy metal for the human and animals. The purpose of the present study was to investigate the changes in biochemical parameters of blood and accumulation of cadmium in various tissue caused by various levels of dietary cadmium chloride (CdCl₂) in broiler chicks. CdCl₂ was administered through drinking water to broiler chicks. In spectral analysis, CdCl₂ treatment caused a significant increase in Glutamate pyruvate transaminase (GPT), creatinine and uric acid levels in all treated groups. Intriguingly, the GPT, creatinine, and uric acid levels were significantly higher at 75 mg/kg as compared to the groups treated with high doses (100, 125 and 150 mg/kg) of CdCl₂. Atomic Absorption Spectrophotometer (AAS) was used for the determination of Cd accumulation in kidney, liver and Breast muscles. AAS analysis revealed that Cd accumulation is increased in breast muscles as compared to liver and kidney at higher doses of Cd than 75 mg/kg.

Cadmium induced hepatotoxicity in chickens (Gallus domesticus) and ameliorative effect by selenium

Cadmium (Cd) is one of the most toxic metal compounds released into the environment. It was well known that Cd induced hepatotoxicity in animal models. However, little is known about the negative effects of Cd toxicity in the liver of birds. To investigate the Cd hepatotoxicity in birds and the protective effects of selenium (Se) against subchronic exposure to dietary Cd, 100-day-old cocks received either Se (as 10mg Na2SeO3 per kg of diet), Cd (as 150mg CdCl2 per kg of diet) or Cd+Se in their diets for 60 days. Histological and ultrastructural changes in the liver, the concentrations of Cd and Se, the lipid peroxidation (LPO) and nitric oxide (NO) production, the activities of the antioxidants superoxide dismutase (SOD) and glutathione peroxidase (GPx), nitric oxide synthase (NOS) activities and apoptosis were determined. Exposure to Cd significantly reduced SOD and GPx activity, Se content in the liver tissue. It increased the LPO and NO production, the numbers of apoptotic cells and Cd concentration and caused obvious histopathological changes in the liver. Concurrent treatment with Se reduced the Cd-induced liver histopathological changes, oxidative stress, overexpression of NO and apoptosis, suggesting that the toxic effects of Cd on the liver is partly ameliorated by inorganic Se. Se supplementation also modified the distribution of Cd in the liver.

Catechin prevents the calcium oxalate monohydrate induced renal calcium crystallization in NRK-52E cells and the ethylene glycol induced renal stone formation in rat

BACKGROUND

Reactive oxygen species play important roles in renal calcium crystallization. In this study, we examined the effects of catechin, which have been shown to have antioxidant properties on the renal calcium crystallization.

METHODS

In the vitro experiment, the changes of the mitochondrial membrane potential, expression of superoxide dismutase (SOD), 4-hydroxynonenal (4-HNE), cytochrome c, and cleaved caspase 3 were measured to show the effects of catechin treatment on the NRK-52E cells induced by calcium oxalate monohydrate (COM). In the vivo study, Sprague-Dawley rats were administered 1% ethylene glycol (EG) to generate a rat kidney stone model and then treated with catechin (2.5 and 10 mg/kg/day) for 14 days. The urine and serum variables were dected on 7 and 14 days after EG administration. The expression of cytochrome c, cleaved caspase 3, SOD, osteopontin (OPN), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG) in kidney were measured. Furthermore, the mitochondrial microstructure in the kidney was also examined by transmission electron microscopy.

RESULTS

Catechin treatment could prevent the changes in mitochondrial membrane potential and expression of SOD, 4-HNE, cytochrome c, and cleaved caspase 3 in NRK-52E cells induced by the COM. For the in vivo experiments, the EG administration induced renal calcium crystallization was also prevented by the catechin. The expression of SOD, OPN, MDA, OPN and 8-OHdG, were increased after EG administration and this increase was diminished by catechin. Moreover, catechin also prevented EG induced mitochondrial collapse in rat.

CONCLUSIONS

Catechin has preventive effects on renal calcium crystallization both in vivo and in vitro, and provide a potential therapeutic treatment for this disease.

Nanotoxicological evaluation of oxidative responses in rat nephrocytes induced by cadmium

The aim of this study was to investigate the interaction of cadmium chloride with mineral elements in rat nephrocytes in terms of the biosynthesis of nanocomplexes. The results show that selenium supplementation enhanced cadmium accumulation in kidneys. Analysis of the fluorescence revealed an increase in red fluorescence in the kidneys of rats co-exposed to cadmium and selenium. Interestingly, X-ray diffraction measurements carried out on kidney fractions of co-exposed rats point to the biosynthesis of cadmium selenide and/or sulfide nanoparticles (about 62 nm in size). Oxidative stress assays showed the ability of selenium to reduce lipid peroxidation and to restore glutathione peroxidase and superoxide dismutase activity in kidneys. Hence, cadmium complexation with selenium and sulfur at a nanoscale level could reduce oxidative stress induced by cadmium in kidneys.

Effects of cobalt on membrane ATPases, oxidant, and antioxidant values in the cerebrum and cerebellum of suckling rats

Chronic overexposure to cobalt (Co) may result in neurotoxic effects, but the mechanism of Co-induced neurotoxicity is not yet well established. Our study was conducted to determine whether Co is associated to the induction of central nervous system damage in pregnant rats and their progeny. Twelve pregnant female rats were randomly divided into 2 groups: group I served as controls and group II received Co (350 mg/L, orally). Treatments started from the 14th day of pregnancy until day 14 after delivery. Co concentration in plasma was higher in the treated groups than in the controls. Exposure to Co also increased the levels of MDA, PCO, H2O2, and AOPP, while Na(+)K(+)-ATPase and Mg(2+)-ATPase, AChE, and BuChE activities decreased in the cerebrum and cerebellum of suckling pups. A smear without ladder formation on agarose gel was also shown in the cerebrum and cerebellum, indicating random DNA degradation. A reduction in GPx, SOD, CAT, GSH, NPSH, and vitamin C values was observed. The changes were confirmed by histological results. In conclusion, these data showed that the exposure of pregnant and lactating rats to Co resulted in the development of oxidative stress and the impairment of defense systems in the cerebrum and cerebellum of their suckling pups.

Thiol/disulfide redox states in signaling and sensing

Rapid advances in redox systems biology are creating new opportunities to understand complexities of human disease and contributions of environmental exposures. New understanding of thiol-disulfide systems have occurred during the past decade as a consequence of the discoveries that thiol and disulfide systems are maintained in kinetically controlled steady states displaced from thermodynamic equilibrium, that a widely distributed family of NADPH oxidases produces oxidants that function in cell signaling and that a family of peroxiredoxins utilize thioredoxin as a reductant to complement the well-studied glutathione antioxidant system for peroxide elimination and redox regulation. This review focuses on thiol/disulfide redox state in biologic systems and the knowledge base available to support development of integrated redox systems biology models to better understand the function and dysfunction of thiol-disulfide redox systems. In particular, central principles have emerged concerning redox compartmentalization and utility of thiol/disulfide redox measures as indicators of physiologic function. Advances in redox proteomics show that, in addition to functioning in protein active sites and cell signaling, cysteine residues also serve as redox sensors to integrate biologic functions. These advances provide a framework for translation of redox systems biology concepts to practical use in understanding and treating human disease. Biological responses to cadmium, a widespread environmental agent, are used to illustrate the utility of these advances to the understanding of complex pleiotropic toxicities.

Toxic effects of chromium (VI) by maternal ingestion on liver function of female rats and their suckling pups

Potassium dichromate (K(2)Cr(2)O(7)) is an environmental contaminant widely recognized as a carcinogen, mutagen, and teratogen toward humans and animals. This study investigated the effects of K(2)Cr(2)O(7) on the hepatic function of pregnant and lactating rats and their suckling pups. Experiments were carried out on female Wistar rats given 700 ppm of K(2)Cr(2)O(7) in their drinking water from the 14th day of pregnancy until day 14 after delivery. Hepatotoxicity was objectified by the significant increase in liver malondialdehyde content and a significant accumulation of chromium in this soft tissue. Moreover, exposure to K(2)Cr(2)O(7) induced a decrease of glutathione, nonprotein thiols, and vitamin C in the liver of mothers and their suckling pups. Alteration of the antioxidant system in the treated group was confirmed by the significant decline of antioxidant enzyme activities such as catalase, glutathione peroxidase, while liver superoxide dismutase activity increased in mothers and decreased in their offspring. It was found that K(2)Cr(2)O(7) induced liver damages as evidenced by the elevation of plasma aminotransferases, lactate dehydrogenase activities, and bilirubin levels. Impairment of the hepatic function corresponded histologically. Our investigation revealed hemorrhage, leukocytes infiltration cells, and necrosis, which were more pronounced in the hepatocytes of mothers than in those of their suckling pups.