Effects of vanadium(V) and/or chromium(III) on L-ascorbic acid and glutathione as well as iron, zinc, and copper levels in rat liver and kidney

Evaluation of immunotoxicity of sodium metavanadate following drinking water exposure in female B6C3F1/N mice in a 28-day study

Sodium metavanadate (NaVO3 ) is a pentavalent vanadium compound used in the metal industry and dietary supplements; human exposure occurs through inhalation of fumes and dust and ingestion of NaVO3 -containing products. The objective of this study was to assess the potential immunotoxicity of NaVO3 . Female B6C3F1/N mice were exposed to 0-500 ppm NaVO3 in drinking water for 28 days and evaluated for effects on immune cell populations and innate, cellular-mediated, and humoral-mediated immunity. There was a decreasing trend in body weight (BW) and BW gain in NaVO3 exposed mice, with a decrease (p ≤ 0.05) in BW gain at ≥250 ppm, relative to control. Conversely, increasing trends in spleen weights and an increase (p ≤ 0.05) in the spleen:BW ratio at ≥250 ppm NaVO3 were observed. NaVO3 exposure altered antibody production against sheep red blood cells (SRBC). Antibody forming cells (AFC)/106 spleen cells exhibited a decreasing trend, with a decrease (p ≤ 0.05) at 500 ppm NaVO3 , concurrent with an increase in percent B cells. NaVO3 had no effect on the serum anti-SRBC IgM antibody titers or anti-keyhole limpet hemocyanin antibody production. Exposure to NaVO3 decreased the percentage of natural killer cells at all dose levels (p ≤ 0.05), with no effect on the lytic activity. NaVO3 altered T-cell populations at 500 ppm but had no effect on T-cell proliferative responses or the lytic activity of cytotoxic T cells. Collectively, these data indicate that NaVO3 exposure can adversely affect the immune system by inducing alterations in humoral-mediated immunity, specifically the AFC response, with no effect on cell-mediated or innate immunity.

Response of Cytoprotective and Detoxifying Proteins to Vanadate and/or Magnesium in the Rat Liver: The Nrf2-Keap1 System

Oxidative stress (OS) is a mechanism underlying metal-induced toxicity. As a redox-active element, vanadium (V) can act as a strong prooxidant and generate OS at certain levels. It can also attenuate the antioxidant barrier and intensify lipid peroxidation (LPO). The prooxidant potential of V reflected in enhanced LPO, demonstrated by us previously in the rat liver, prompted us to analyze the response of the nuclear factor erythroid-derived 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2-Keap1) system involved in cellular regulation of OS to administration of sodium metavanadate (SMV, 0.125 mg V/mL) and/or magnesium sulfate (MS, 0.06 mg Mg/mL). The levels of some Nrf2-dependent cytoprotective and detoxifying proteins, i.e., glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), glutamate cysteine ligase catalytic subunit (GCLC), glutathione synthetase (GSS), NAD(P) H dehydrogenase quinone 1 (NQO1), UDP-glucumno-syltransferase 1 (UGT1), and heme oxygenase 1 (HO-1); glutathione (GSH); metallothionein (MT1); and glutamate-cysteine ligase (GCL) mRNA were measured. We also focused on the V-Mg interactive effects and trends toward interactive action as well as relationships between the examined indices. The elevated levels of Nrf2, GCL mRNA, and GCL catalytic subunit (GCLC) confirm OS in response to SMV and point to the capacity to synthesize GSH. The results also suggest a limitation of the second step in GSH synthesis reflected by the unchanged glutathione synthetase (GSS) and GSH levels. The positive correlations between certain cytoprotective/detoxifying proteins (which showed increasing trends during the SMV and/or MS administration, compared to the control) and between them and malondialdehyde (MDA), the hepatic V concentration/total content, and/or V dose (discussed by us previously) point to cooperation between the components of antioxidant defense in the conditions of the hepatic V accumulation and SMV-induced LPO intensification. The V-Mg interactive effect and trend are involved in changes in Nrf2 and UGT1, respectively. The p62 protein has to be determined in the context of potential inhibition of degradation of Keap1, which showed a visible upward trend, in comparison with the control. The impact of Mg on MT1 deserves further exploration.

Epigallocatechin-3-gallate Alleviates Vanadium-Induced Reduction of Antioxidant Capacity via Keap1-Nrf2-sMaf Pathway in the Liver, Kidney, and Ovary of Laying Hens

This study evaluated the effect of epigallocatechin-3-gallate (EGCG) alleviating the reduction of antioxidant capacity induced by dietary vanadium (V) in the liver, kidney, and ovary of laying hens. Furthermore, Kelch-like ECH-associated protein 1(Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2)-small Maf proteins (sMaf) pathway was explored to reveal the molecular mechanism. A total of 768 40-week-old Hyline-Brown laying hens were randomly allocated to 4 groups with 8 pens per group and 24 hens per pen. The experimental groups were as follows: control (basal diet); V15, control + 15 mg/kg V; EGCG150, control + 150 mg/kg EGCG; V15 + EGCG150, V15 + 150 mg/kg EGCG. Our results revealed that dietary EGCG supplementation completely alleviated the V-induced reductions of hen-day egg production, average egg weight, Haugh unit, albumen height, eggshell strength, and eggshell thickness. Dietary EGCG supplementation completely prevented the V-induced reductions of serum follicle-stimulating hormone and luteinizing hormone levels. Besides, dietary EGCG supplementation reversed the V-induced increments of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine (Cr), and uric acid (UA). In addition, dietary EGCG supplementation partially alleviated the V-induced reductions of the enzyme activities and gene expressions of superoxidative dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GSH-Px). Furthermore, dietary EGCG supplementation partially alleviated the V-induced reductions of Nrf2 and sMaf gene expressions, and the increments of Keap1 gene expression. In summary, EGCG partially alleviated V-induced reduction of antioxidant capacity through Keap1-Nrf2-sMaf pathway in the liver, kidney, and ovary of laying hens.

Vanadium: Risks and possible benefits in the light of a comprehensive overview of its pharmacotoxicological mechanisms and multi-applications with a summary of further research trends

BACKGROUND

Vanadium (V) is an element with a wide range of effects on the mammalian organism. The ability of this metal to form organometallic compounds has contributed to the increase in the number of studies on the multidirectional biological activity of its various organic complexes in view of their application in medicine.

OBJECTIVE

This review aims at summarizing the current state of knowledge of the pharmacological potential of V and the mechanisms underlying its anti-viral, anti-bacterial, anti-parasitic, anti-fungal, anti-cancer, anti-diabetic, anti-hypercholesterolemic, cardioprotective, and neuroprotective activity as well as the mechanisms of appetite regulation related to the possibility of using this element in the treatment of obesity. The toxicological potential of V and the mechanisms of its toxic action, which have not been sufficiently recognized yet, as well as key information about the essentiality of this metal, its physiological role, and metabolism with certain aspects on the timeline is collected as well. The report also aims to review the use of V in the implantology and industrial sectors emphasizing the human health hazard as well as collect data on the directions of further research on V and its interactions with Mg along with their character.

RESULTS AND CONCLUSIONS

Multidirectional studies on V have shown that further analyses are still required for this element to be used as a metallodrug in the fight against certain life-threatening diseases. Studies on interactions of V with Mg, which showed that both elements are able to modulate the response in an interactive manner are needed as well, as the results of such investigations may help not only in recognizing new markers of V toxicity and clarify the underlying interactive mechanism between them, thus improving the medical application of the metals against modern-age diseases, but also they may help in development of principles of effective protection of humans against environmental/occupational V exposure.

Associations between renal functions and exposure of arsenic and polycyclic aromatic hydrocarbon in adults living near a petrochemical complex

BACKGROUND

The understanding for the impact of petrochemical pollutants exposure on renal functions is limited.

OBJECTIVES

Our study examined the associations between renal functions and pollutants exposure in adult residents living in the vicinity of a petrochemical industry.

METHODS

We recruited 2069 adult residents near a big petrochemical complex in Taiwan in 2009-2012, and they were categorized into high exposure (HE) and low exposure (LE) groups based on their address to source by 10 km radius. Study subjects were measured the urinary levels of arsenic, cadmium, mercury, thallium, and 1-hydroxypyrene (1-OHP). The estimated glomerular filtration rate (eGFR) was calculated using the Taiwanese Chronic Kidney Disease Epidemiology Collaboration equation, and the chronic kidney disease (CKD) prevalence and risks were defined according to KDIGO 2012 guidelines. Adjusted generalized linear and logistic regression models were applied to evaluate the associations between petrochemical exposure and renal functions.

RESULTS

Subjects in the HE areas had significantly lower eGFR, higher CKD prevalence, and higher levels of urinary arsenic, cadmium, mercury, thallium and 1-OHP. The closer to complex and high exposure group of study subjects were significantly associated with the decrease in eGFR, higher ORs for CKD and high-intermediate risk of CKD. In addition, the study subjects who had two-fold urinary arsenic and 1-OHP levels were significantly with decreased 0.68 and 0.49 ml/min/1.73 m² of eGFR, respectively.

CONCLUSIONS

Residing closer and higher arsenic and polycyclic aromatic hydrocarbon exposure were associated with the renal impairment and risks of CKD among the residential population near the petrochemical industry.

The Combined Effects of Cr(III) Supplementation and Iron Deficiency on the Copper and Zinc Status in Wistar Rats

The aim of the study was to assess the combined effects of chromium(III) supplementation and iron deficiency on the copper (Cu) and zinc (Zn) status in female rats. The Cr, Fe, Cu and Zn dietary and tissular levels were measured by Atomic Absorption Spectrometry (AAS) method. The data show that chromium(III) supplementation compensated for the negative effects of Fe deficiency on the Cu content but it deepened the effect on Zn levels in the female rats. Detailed data on the status of trace elements and their interactions in healthy subjects and patients with metabolic disorders (e.g. anaemia, diabetes mellitus) are strongly required for effective nutritional and therapeutic strategies.

The combined effects of Cr(III) propionate complex supplementation and iron excess on copper and zinc status in rats

It is suggested that both iron overload and chromium(III) deficiency may be risk factors of diabetes. It seems that both Fe and Cr(III) metabolism as well as copper and zinc metabolism are interrelated. However, the direction of these changes may depend on mutual proportions of these elements in the diet and organism. The aim of the study was to evaluate the combined effects of Cr(III) supplementation with Fe excess on the Cu and Zn status in female rats. Thirty-six healthy rats were divided into 6 experimental groups with different Fe levels in the diet. Groups marked with C (control) contained Fe at the recommended level (45 mg kg^-1). The excess groups (E) contained Fe at 180 mg kg^-1. At the same time the animals were supplemented with Cr(III) of doses 1, 50 and 500 mg kg^-1 of diet. The Cr, Fe, Cu and Zn dietary and tissular contents were measured with the AAS method.The excess Fe in the diet significantly decreased the Cu content in the liver and kidneys, but it increased the spleen Cu level. The Cr(III) supplementary did not affect the tissular Cu levels, regardless of Fe supply with diet. The experimental factors did not have significant interactional effect on the Cu status parameters under study.The Fe excess in the diet reduced the renal and splenic Zn content, but increased the heart Zn content. The Cr(III) supplementation decreased the Zn content in the kidneys. The Zn content in the liver and spleen tended to decrease as the Cr(III) supply in the diet increased. There was no significant interactional effect of Cr(III) supplementation and the Fe excessive supply in diet on the parameters of Zn metabolism in Wistar rats. Iron oversupply disturbed the rat's Cu and Zn status. However, Cr(III) supplementation did not affect the tissular levels of these elements, except the kidney Zn content. Simultaneous supplementation with the Cr(III) propionate complex did not deepen changes in tissular Cu and Zn levels caused by the Fe excess in the diet.

Pathological and Clinical Pathological Changes Induced by Four-week, Repeated-dose, Oral Administration of the Wood Preservative Chromated Copper Arsenate in Wistar Rats

Chromated copper arsenate (CCA) is used as a wood preservative worldwide. Exposure to it may adversely affect human health. Some events have increased human exposure to CCA, including the Great East Japan Earthquake, which generated a large amount of lumber debris from CCA-treated woods. We elucidated the toxicity due to daily exposure to CCA over a 4-week period at doses of 0, 8, 40, and 80 mg/kg/day in Wistar Hannover rats. Chromium (Cr) and arsenic (As), but not copper, were detected in the plasma samples of rats treated with various doses of CCA. Males and females showed sedation, and males had poor body weight gain. The clinical pathologies observed in both sexes included hypochromic and microcytic anemia, hepatic and renal dysfunction, and changes in lipid and glucose levels. Histopathologically, males and females showed forestomach hyperkeratosis, mucosal epithelial hyperplasia in the small intestine, rectal goblet cell hypertrophy, and lipofuscin deposition in the proximal renal tubule. Females showed diffuse hepatocellular hypertrophy with increased 8-hydroxydeoxyguanosine levels. These results indicated that oral administration of CCA mainly affected hematopoietic, gastrointestinal, hepatic, and renal systems owing to the toxic effects of As and/or Cr. Major toxic effects were observed in both sexes receiving 40 and 80 mg/kg/day.

Vanadium (V) and magnesium (Mg) - In vivo interactions: A review

Vanadium (V) and magnesium (Mg) arouse interest of many research centres worldwide. Many aspects of their action have already been recognized but some of them have not been fully elucidated yet. Relatively little is known about the mechanisms of absorption, transport, and excretion of V. There is also a lack of sufficient data about the most sensitive biomarkers of V toxicity and the mechanisms of its toxic action, which have not been fully explained yet. There is also a lack of comprehensive research on the consequences, character, and mechanisms of mutual interactions of V (which has strong pro-oxidant properties) with elements with an antioxidant potential such as Mg, the recognition of which, besides the cognitive value, may have great practical importance. It should be highlighted that the question of interactions between elements is always up to date and it is still an important issue in toxicology. A comprehensive research on interactions of V with Mg can be particularly important in the studies of the usage of V (which has a narrow margin of safety) in the treatment of certain diseases in humans, especially diabetes, which is accompanied by changes in the level of Mg in the tissues and weakening of the antioxidant barrier and oxidative stress. Therefore, the aspect concerning the possible interaction of V (as a potent pro-oxidant) with Mg (as an antioxidant) was the subject of our special interest. In addition, the examination of the effects of the interactions between V and Mg is very important especially for extending the knowledge of the mechanism of the influence of V on the organism and a potential role of Mg (which is characterized by a wide therapeutic window) in prevention of V toxicity. This review summarizes the most important results obtained from our experiments in a rodent model referring to the interactions of V with Mg on the background of the in vivo experimental data published by other researchers of this issue. Our studies have shown that V and Mg supplied in combination are able to modulate the response in an interactive manner to produce a specific effect that is distinct from that observed during separate administration thereof. The present report also provides the most important information about the effects of the action of V and Mg with other metals.

Air pollution particles and iron homeostasis

BACKGROUND

The mechanism underlying biological effects, including pro-inflammatory outcomes, of particles deposited in the lung has not been defined.

MAJOR CONCLUSIONS

A disruption in iron homeostasis follows exposure of cells to all particulate matter including air pollution particles. Following endocytosis, functional groups at the surface of retained particle complex iron available in the cell. In response to a reduction in concentrations of requisite iron, a functional deficiency can result intracellularly. Superoxide production by the cell exposed to a particle increases ferrireduction which facilitates import of iron with the objective being the reversal of the metal deficiency. Failure to resolve the functional iron deficiency following cell exposure to particles activates kinases and transcription factors resulting in a release of inflammatory mediators and inflammation. Tissue injury is the end product of this disruption in iron homeostasis initiated by the particle exposure. Elevation of available iron to the cell precludes deficiency of the metal and either diminishes or eliminates biological effects.

GENERAL SIGNIFICANCE

Recognition of the pathway for biological effects after particle exposure to involve a functional deficiency of iron suggests novel therapies such as metal supplementation (e.g. inhaled and oral). In addition, the demonstration of a shared mechanism of biological effects allows understanding the common clinical, physiological, and pathological presentation following exposure to disparate particles. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu.

Hepatoprotective effect of Taraxacum officinale leaf extract on sodium dichromate-induced liver injury in rats

Taraxacum officinale (L.) Weber, commonly known as Dandelion, has been widely used as a folkloric medicine for the treatment of liver and kidney disorders and some women diseases such as breast and uterus cancers. The main objective of the present study was to assess the efficiency of T. officinale leaf extract (TOE) in treating sodium dichromate hazards; it is a major environmental pollutant known for its wide toxic manifestations witch induced liver injury. TOE at a dose of 500 mg/kg b.w was orally administered once per day for 30 days consecutively, followed by 10 mg/kg b.w sodium dichromate was injected (intraperitoneal) for 10 days. Our results using Wistar rats showed that sodium dichromate significantly increased serum biochemical parameters. In the liver, it was found to induce an oxidative stress, evidenced from increase in lipid peroxidation and changes in antioxidative activities. In addition, histopathological observation revealed that sodium dichromate causes acute liver damage, necrosis of hepatocytes, as well as DNA fragmentation. Interestingly, animals that were pretreated with TOE, prior to sodium dichromate administration, showed a significant hepatoprotection, revealed by a significant reduction of sodium dichromate-induced oxidative damage for all tested markers. These finding powerfully supports that TOE was effective in the protection against sodium dichromate-induced hepatotoxicity and genotoxicity and, therefore, suggest a potential therapeutic use of this plant as an alternative medicine for patients with acute liver diseases.

Ameliorative Effect of Tephrosia Purpurea in Arsenic-induced Nephrotoxicity in Rats

Objectives:

The present investigation was conducted to evaluate the nephroprotective activity of Tephrosia purpurea (TPE) against arsenic-induced toxicity.

Materials and Methods:

Twenty four number of wistar rats were equally divided into three groups. Sodium arsenite (10 mg/kg) was orally given to group I for 28 days, additionally group II was orally treated with TPE (500 mg/kg), while the control group was kept untreated with neither arsenic nor TPE. Serum biomarker levels, oxidative stress indices and arsenic concentration in kidney were estimated. Histopathology of kidney was also conducted.

Results:

Group II animals show significantly reduced blood urea nitrogen and plasma creatinine, and increased serum albumin level compared to group I. The higher lipid peroxidation with exhausted superoxide dismutase activity and reduced glutathione level were noticed in group I compared to group II. There was no significant difference in arsenic accumulation in kidneys between the two arsenic treated groups, but the histopathology of kidney of group II rats revealed reduced necrosis and intact tubular architecture as compared to group I.

Conclusions:

Tephrosia Purpurea extract has a significant role in protecting the animals from arsenic-induced nephrotoxicity.

The renal effects of vanadate exposure: potential biomarkers and oxidative stress as a mechanism of functional renal disorders--preliminary studies

The alterations in the levels/activities of selected biomarkers for detecting kidney toxicity and in the levels of some oxidative stress (OS) markers and elements were studied in male rats to evaluate biochemically the degree of kidney damage, investigate the role of OS in the mechanism of functional renal disorders, reveal potential biomarkers of renal function, and assess the renal mineral changes in the conditions of a 12-week sodium metavanadate (SMV, 0.125 mg V/mL) exposure. The results showed that OS is involved in the mechanism underlying the development of SMV-induced functional renal disturbances. They also suggest that the urinary cystatin C (CysCu) and kidney injury molecule-1 (KIM-1u) could be the most appropriate to evaluate renal function at the conditions of SMV intoxication when the fluid intake, excreted urinary volume (EUV), body weight (BW), and the urinary creatinine excretion (Creu) decreased. The use of such tests as the urinary lactate dehydrogenase, alkaline phosphatase, γ-glutamyltranspeptidase, and N-acetyl-β-D-glucosaminidase (LDHu, ALPu, GGTPu, and NAGu) seems not to be valid given their reduced activities. The use of only traditional biomarkers of renal function in these conditions may, in turn, be insufficient because their alterations are greatly influenced by the changes in the fluid intake and/or BW.

The influence of combined magnesium and vanadate administration on the level of some elements in selected rat organs: V–Mg interactions and the role of iron-essential protein (DMT-1) in the mechanism underlying altered tissues iron level

The levels of elements in rats' organs in the V–Mg interaction. A role of DMT-1 in tissue Fe homeostasis.

Alterations in kidney tissue following zinc supplementation to STZ-induced diabetic rats

Diabetes mellitus is a chronic disease characterized by anomalies forming in carbohydrate, lipid, protein metabolisms and the incidence of this disease varies widely throughout the world. Zinc is an important element which is essential for life and is present in nature. In this study, the animals were divided into four groups. These groups were named as untreated; zinc sulfate; streptozotocin (STZ); STZ and zinc sulfate. STZ (65 mg/kg) was dissolved in a freshly prepared 0.01 M pH 4.5 citrate buffer and given with intraperitoneal injection in a single dose. Zinc sulfate (100mg/kg) was dissolved in distilled water and given to the animals by gavage at a daily dose for 60 days. The rats were sacrificed under ether anesthesia. This study was aimed to investigate histological and biochemical changes of zinc supplementation on the kidney tissue in STZ-induced diabetic rats. In the current study, histological and histochemical observations showed that the occurred degenerative changes decreased after giving zinc in the kidney tissue of diabetic group. Kidney glutathione (GSH) levels decreased and lipid peroxidation (LPO), nonenzymatic glycosylation (NEG), urea and creatinine levels increased in diabetic rats. GSH levels increased, while LPO, NEG, urea and creatinine levels decreased in the kidney with administration of zinc to diabetic rats. As a result, we observed curative effects of zinc given to diabetic rats. We can say that zinc may be an important antioxidant for the treatment of secondary complications of diabetes in kidney tissue.

Evaluation of anti-diabetic potential of chromium(III) propionate complex in high-fat diet fed and STZ injected rats

The aim of this study was to examine the anti-diabetic potential of the chromium(III) propionate complex (CrProp) in a diabetic rat model. Male Wistar rats (n=28, 8-week old) were divided into 4 groups (with 7 rats each) and fed at libitum: the control diet (AIN-93M), and high-fat diets with or without supplementary CrProp (10 and 50mg Crkg(-1) diet; 1 and 5 mg kg(-1) body mass per day) for 5 weeks, and subsequently injected with STZ to induce diabetes. Rats were further fed the same diets for another week until the end of the experiment. Blood indices and the contents of minerals (Fe, Zn, Cu and Cr) in rat tissues were determined by atomic absorption spectrometry. Supplementary CrProp did not affect blood glucose level, but significantly improved insulin sensitivity (HOMA-IR index) and reduced serum levels of triacylglycerols, total and LDL cholesterols. Both supplementary dosages of CrProp (10 and 50mg Cr kg(-1) diet) normalized the increased liver Fe content, reduced hepatic and renal Cu levels and elevated renal Cr contents in diabetic rats. In conclusion, CrProp has a significant anti-diabetic (insulin-sensitizing and hypolipidemic) potential; thus it might be a candidate for a therapeutic agent in diabetes.

Exposure to multiple metals from groundwater-a global crisis: geology, climate change, health effects, testing, and mitigation

This paper presents an overview of the global extent of naturally occurring toxic metals in groundwater. Adverse health effects attributed to the toxic metals most commonly found in groundwater are reviewed, as well as chemical, biochemical, and physiological interactions between these metals. Synergistic and antagonistic effects that have been reported between the toxic metals found in groundwater and the dietary trace elements are highlighted, and common behavioural, cultural, and dietary practices that are likely to significantly modify health risks due to use of metal-contaminated groundwater are reviewed. Methods for analytical testing of samples containing multiple metals are discussed, with special attention to analytical interferences between metals and reagents. An overview is presented of approaches to providing safe water when groundwater contains multiple metallic toxins.

Chromium(III) propionate complex supplementation improves carbohydrate metabolism in insulin-resistance rat model

The purpose of this study was to evaluate the antidiabetic potential and safety of the chromium(III) propionate complex (CrProp) in insulin resistance induced by a high-fructose diet in rats. The experiment was carried out on 32 nine-week old male Wistar rats divided into 4 groups of 8 rats each. Animals were fed at libitum: the control diet (AIN-93M), and high-fructose diets (HF) containing various levels of Cr(III) given as CrProp (1 mg Cr kg(-1) diet (HF) and supplemented with 10 mg Cr kg(-1) diet (HFCr10), or 50 mg Cr kg(-1) diet (HFCr50), equal to approx. 0.1, 1 and 5 mg kg(-1) body mass per day) for 8 weeks. It was found that supplemental CrProp improved carbohydrate metabolism indices (decreasing serum insulin levels and insulin resistance indices HOMA-IR and HOMA-B, while increasing insulin sensitivity index QUICKI). Supplemental CrProp did not affect overall nutritional indices, blood morphology, most of the toxicity indices, blood glucose and lipids levels, while it increased kidney Cr level (HFCr50), normalized decreased liver Cu concentrations, and decreased kidney Fe and Cu levels (HFCr50). Supplemental CrProp administered at 10- and 50-fold doses of the basal dietary Cr level has a significant antidiabetic effect in insulin resistant rats. However, a prolonged treatment with this compound can affect Fe status.

Tissue trace and major element levels in organophosphate insecticide fenthion (Lebaycid) toxicity in rats: prophylactic and therapeutic effect of exogenous melatonin

Organophosphate compounds are very toxic chemicals and used in widespread applications. The present study was designed to examine the role of exogenous melatonin against organophosphate toxicity in tissues (brain, heart, jejunum, kidney, liver, lung, muscle and pancreas) trace and major element levels of rats. Trace and major element concentrations in the tissues were measured in the sham group, the control group, prophylaxis with the melatonin group and therapy with the melatonin group (TM) by inductively coupled plasma-optical emission spectroscopy. Statistically significant differences among the experimental groups were detected for some tissue trace and major element concentrations. In the brain tissue, the Al, Mn and Se concentrations in the sham group were significantly higher than those in the control group (p<0.05). In the heart tissue, the Cu, Mn and Se concentrations in the sham group were significantly increased than those in the control group (p<0.05). In the kidney tissue, trace and major element concentrations in the TM group were significantly lower than those in the sham group (Fe and Mn; p<0.05, Cu, Mo, Ni, Ti, V and Zn; p<0.01). In the liver, Mg, Al, Zn and Ca concentrations in the TM group were significantly higher than those in the fenthion-treated control group (p<0.01). In the muscle tissue, element concentrations in the TM group were significantly lower when compared with the sham groups (Ca and Si; p<0.01). The Al, Cr, Mo, Ni, Si and Zn element concentrations were markedly decreased in the control group as compared with the TM group in the pancreas tissue (p<0.01). In conclusion, according to the results of the present study the major findings are that the fenthion-treated rat's tissue element levels were effected and the melatonin may normalize the altered levels of some trace and major elements of the tissues in organophosphate toxicity.

Urinary arsenic species and CKD in a Taiwanese population: a case-control study

BACKGROUND

Inorganic arsenic has been linked to decreased kidney function through oxidative damage. Arsenic methylation is believed to be a pathway for arsenic metabolism. Lycopene is an antioxidant that reduces oxidative stress; however, the association between urinary arsenic species, plasma lycopene level, and chronic kidney disease (CKD) has seldom been evaluated.

STUDY DESIGN

Case-control study.

SETTING & PARTICIPANTS

125 patients with CKD and 229 controls were recruited from a hospital-based pool.

PREDICTOR

Urinary arsenic species and plasma lycopene level.

OUTCOMES & MEASUREMENTS

CKD was defined as estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m(2), calculated by using the Modification of Diet in Renal Disease Study equation. Plasma lycopene was measured by means of high-performance liquid chromatography. Urinary arsenic species, including arsenite, arsenate, monomethylarsonic acid, and dimethylarsinic acid, were determined by means of high-performance liquid chromatography and hydride generator-atomic absorption spectrometry.

RESULTS

Lycopene level was associated positively with eGFR, and participants with a high serum lycopene level had a significant, inverse association with CKD (odds ratio, 0.41; 95% confidence interval, 0.21 to 0.81). Total arsenic level was associated significantly with CKD in a dose-response relationship, especially in participants with a total arsenic level greater than 20.74 compared with 11.78 microg/g creatinine or less (odds ratio, 4.34; 95% confidence interval, 1.94 to 9.69). Furthermore, participants with a high urinary total arsenic level or participants with a low percentage of dimethylarsinic acid had a positive association with CKD when their plasma lycopene level was low.

LIMITATIONS

Because of the single spot evaluation of plasma antioxidants and urinary arsenic species and the small sample size, statistical significance should be interpreted with caution.

CONCLUSIONS

This study shows that high urinary total arsenic or low plasma lycopene level is associated positively with CKD. Results suggest that the capacity for arsenic methylation may be associated with CKD in individuals who ingest low arsenic levels in drinking water and also have a low plasma lycopene level.

Taurine plays a beneficial role against cadmium-induced oxidative renal dysfunction

The present study has been carried out to investigate the role of taurine (2-aminoethanesulfonic acid), a conditionally essential amino acid, in ameliorating cadmium-induced renal dysfunctions in mice. Cadmium chloride (CdCl(2)) has been selected as the source of cadmium. Intraperitoneal administration of CdCl(2 )(at a dose of 4 mg/kg body weight for 3 days) caused significant accumulation of cadmium in renal tissues and lessened kidney weight to body weight ratio. Cadmium administration reduced intracellular ferric reducing/antioxidant power (FRAP) of renal tissues. Levels of serum marker enzymes related to renal damage, creatinine and urea nitrogen (UN) have been elevated due to cadmium toxicity. Cadmium exposure diminished the activities of enzymatic antioxidants, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx) and glucose-6-phosphate dehydrogenase (G6PD) as well as non-enzymatic antioxidant, reduced glutathione (GSH) and total thiols. On the other hand, the levels of oxidized glutathione (GSSG), lipid peroxidation, protein carbonylation, DNA fragmentation, concentration of superoxide radicals and activities of cytochrome P450 enzymes (CYP P450s) have been found to increase due to cadmium intoxication. Treatment with taurine (at a dose of 100 mg/kg body weight for 5 days) before cadmium intoxication prevented the toxin-induced oxidative impairments in renal tissues. The beneficial role of taurine against cadmium-induced renal damage was supported from histological examination of renal segments. Vitamin C, a well-established antioxidant was used as the positive control in the study. Experimental evidence suggests that both taurine and vitamin C provide antioxidant defense against cadmium-induced renal oxidative injury. Combining all, results suggest that taurine protects murine kidneys against cadmium-induced oxidative impairments, probably via its antioxidative property.

Effect of different doses of hexavalent chromium on mandibular growth and tooth eruption in juvenile Wistar rats

Not only workers employed at industrial plants are exposed to intoxication with the element they manipulate, the population at large is also at risk of suffering health problems caused by contaminating wastes inadequately treated for their safe disposal. As a result certain toxic substances, such as hexavalent chromium,has reached the general population including children. The present study sought to evaluate the effect of intoxication with hexavalent chromium on body and mandibular growth and tooth eruption in suckling Wistar rats. Potassium dichromate was administered by gavage in a dose of 6.25 or 12.5mg/kg body weight (b.w.) to one of the two groups of 4-day-old Wistar rats during 10 days. Our results showed that the effects of chromium are dose-dependent. Morphometric studies of body growth showed lower body weight in both experimental groups and shorter tail length in animals receiving 12.5mg/kg b.w. dose of chromium, compared with controls. All parameters of mandibular growth were lower in the experimental group receiving 12.5mg/kg b.w. of chromium. Differences in tooth eruption were observed at the level of the first molar in animals receiving 12.5mg/kg and of the second molar in those receiving 6.25mg/kg b.w. of chromium. Chromium was found to affect all the studied parameters.

Tissue 65Zinc translocation in a rat model of chronic aldosteronism

Zinc, an essential micronutrient, is involved in wound healing. The hypozincemia seen with chronic aldosteronism is associated with enhanced fecal and urinary excretory Zn losses, and its tissue distribution is less certain. This study monitored tissue 65Zn distribution in uninephrectomized rats at weeks 1 and 4 of aldosterone/salt treatment (ALDOST). Plasma and tissue total radionucleotide uptake was determined by calculating its mean radioactivity at 1, 4, 8, 24, and 48 hours after intravenous 65Zn administration and where respective area under the concentration-time curves (AUC) were determined by the linear trapezoidal rule and expressed as a tissue:plasma AUC ratio. Examined tissues included: (1) injured heart and kidney in response to ALDOST and incised skin; (2) noninjured liver, skeletal muscle, and spleen sites of stress-linked Zn uptake; and (3) bone, a major storage and release site when Zn homeostasis is threatened. In comparison with age-matched and gender-matched controls, the following were found with week 1 and 4 ALDOST: (1) reduced plasma 65Zn; (2) an accumulation of 65Zn in heart and kidneys, where a well-known vasculopathy involves intramural vessels, and in incised skin at week 1; (3) an organ-specific increase in tissue 65Zn in liver, in keeping with upregulated metallothionein expression, skeletal muscle, and spleen; and (4) a fall in bone and healed skin Zn at week 4. Thus a wide-ranging disturbance in Zn homeostasis appears during ALDOST to include its translocation from plasma to injured heart, kidneys, and skin and noninjured liver, skeletal muscle, and spleen together with a resorption of stored Zn in bone at week 4. Zinc dyshomeostasis is an integral feature of chronic aldosteronism.

Arjunolic acid attenuates arsenic-induced nephrotoxicity

Arsenic is highly toxic naturally occurring element that affects numerous organ systems in humans. Present study was designed to investigate the preventive role of a triterpenoid saponin, arjunolic acid (AA) against arsenic-induced nephrotoxicity in mouse model. For this study, NaAsO(2) was chosen as the source of arsenic. Oral administration of NaAsO(2) at a dose of 10mg/kg body weight for 2 days caused significant accumulation of arsenic in renal tissues as well as altered the activities of serum markers, urea nitrogen (UN) and creatinine, antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx), level of cellular metabolites, reduced glutathione (GSH), oxidized glutathione (GSSG) and total thiols, level of lipid peroxidation end products and protein carbonyl content. Treatment with AA at a dose of 20mg/kg body weight for 4 days almost normalized above indices. Histological studies also indicated preventive role of AA against NaAsO(2)-induced nephrotoxicity. The radical scavenging activity and in vivo antioxidant power of AA were determined from its DPPH radical scavenging ability and ferric reducing/antioxidant power (FRAP), respectively. A well-known antioxidant, vitamin C was used as positive control throughout the study. Combining all, results suggest that arsenic could cause kidney damage by inducing oxidative stress in mice and that could be prevented by AA.

Protection of arsenic-induced testicular oxidative stress by arjunolic acid

Arsenic-induced tissue damage is a major concern to the human population. An impaired antioxidant defense mechanism followed by oxidative stress is the major cause of arsenic-induced toxicity, which can lead to reproductive failure. The present study was carried out to investigate the preventive role of arjunolic acid, a triterpenoid saponin isolated from the bark of Terminalia arjuna, against arsenic-induced testicular damage in mice. Administration of arsenic (in the form of sodium arsenite, NaAsO(2), at a dose of 10 mg/kg body weight) for 2 days significantly decreased the intracellular antioxidant power, the activities of the antioxidant enzymes, as well as the levels of cellular metabolites. In addition, arsenic intoxication enhanced testicular arsenic content, lipid peroxidation, protein carbonylation and the level of glutathione disulfide (GSSG). Exposure to arsenic also caused significant degeneration of the seminiferous tubules with necrosis and defoliation of spermatocytes. Pretreatment with arjunolic acid at a dose of 20 mg/kg body weight for 4 days could prevent the arsenic-induced testicular oxidative stress and injury to the histological structures of the testes. Arjunolic acid had free radical scavenging activity in a cell-free system and antioxidant power in vivo. In summary, the results suggest that the chemopreventive role of arjunolic acid against arsenic-induced testicular toxicity may be due to its intrinsic antioxidant property.