Ameliorative effect of the anticancer agent salinomycin on cadmium-induced hepatotoxicity and renal dysfunction in mice

This study presents experimental data on the effects of the tetraethylammonium salt of salinomycinic acid (Sal) on Cd-induced hepatotoxicity and renal dysfunction in Cd-treated mice compared to those of meso-2,3-dimercaptosuccinic acid (DMSA). Forty 60-day-old male ICR mice were randomized into five groups: control group (untreated mice), Cd group (Cd(II) acetate 20 mg/kg body weight provided orally once per day for 14 days), Cd + DMSA group (exposed to Cd(II) acetate as the Cd-exposed group followed by DMSA 20 mg/kg body weight provided orally once per day for 14 days), and Cd + Sal group (exposed to Cd(II) acetate as the Cd-exposed group followed by Sal 20 mg/kg body weight once per day for 14 days). Cd intoxication of mice induced significant liver and kidney injury and a significant elevation of the concentration of Cd in both organs. Treatment of Cd-exposed mice with DMSA or Sal restored the levels of the renal and hepatic functional markers and significantly decreased the concentration of the toxic metal ion in both organs. Administration of Sal improved Cd-induced alterations of the endogenous levels of the essential metal ions. Histological studies revealed that the antibiotic more effectively ameliorated the Cd effect on the liver morphology compared to DMSA. Taken together, the results confirm that the anticancer agent salinomycin is a promising antidote to Cd poisoning.

Monensin ameliorates cadmium-induced hepatic injury in mice, subjected to subacute cadmium intoxication

This study was designed to evaluate the potential application of monensin as an oral drug for the treatment of cadmium-induced hepatic dysfunction. The study was performed using ICR mouse model. Twenty-seven adult ICR male mice were divided into three groups of nine animals each: control (received distilled water and food ad libitum for 28 days); Cd-intoxicated (treated orally with 20 mg/kg b.w. Cd(II) acetate from the 1st to the 14th day of the experimental protocol); and monensin treated group (intoxicated with Cd(II) acetate as described for the Cd-intoxicated group followed by an oral treatment with 16 mg/kg b.w. tetraethylammonium salt of monensic acid for two weeks). The obtained results demonstrated that the treatment of Cd-intoxicated animals with monensin restored the liver weight/body weight index to normal values, decreased the concentration of the toxic metal ion by 50% compared to the Cd-treated controls, and recovered the homeostasis of Cu and Zn. Monensin reduced the activity of aspartate aminotransferase, alanine aminotrasnferase and alkaline phosphatase in the plasma of Cd-treated animals to the normal control levels and ameliorated the Cd-induced inflammation in the liver. Taken together, these data demonstrated that monensin could be an effective chelating agent for the treatment of Cd-induced hepatotoxicity.

Cadmium toxicokinetics and bioaccumulation in turtles: trophic exposure of Trachemys scripta elegans

Ecotoxicological data in reptiles are mainly represented by field studies reporting the tissue burden of wild-captured individuals but much less is known regarding the processes of uptake, depuration, accumulation and the effects of inorganic contaminants in these species. In the present study, the accumulation, the path and the effects of exposure to cadmium (Cd) through diet intake were investigated in female red eared slider turtles, Trachemys scripta elegans. In the first phase of the experiment, turtles underwent an acclimatization period during which they were fed a control diet. In the second phase, the turtles were exposed to cadmium through a CdCl(2) supplemented-diet with increased environmentally relevant concentrations for a period of 13 weeks. Following this, the turtles went through a third phase, a recovery phase of 3 weeks, during which they were fed uncontaminated food. Blood and feces were collected during the three phases of the experiment. The turtles were euthanized at the end of the experiment and organ samples collected. The Cd-concentrations in blood remained stable over the course of the experiment while Cd-concentrations in feces increased with time and with the amount of Cd ingested. The proportional accumulation in liver and kidney together was comprised between 0.7 and 6.1% and they represented the main organs of accumulation. Cd accumulated in the organs in the following order of concentration: kidney > liver > pancreas > muscle. In terms of burden in organs, the Cd-burden was the highest in liver followed by kidney and pancreas. The proportional accumulation decreased as Cd ingestion increased, suggesting that at a higher dose of Cd, assimilation decreased. Mineral content of the liver and pancreas became modified according to Cd level; increasing dietary Cd exposure increased concentrations of zinc and iron in liver and copper in pancreas in a dose-dependent manner. Accumulation of Cd had no effect on survival, food consumption, growth, weight or length suggesting no effect of the treatment on female turtle body condition.

Effect of zinc supplementation on bone metabolism in male rats chronically exposed to cadmium

The aim of the present study is to investigate, based on the rat model of moderate and relatively high human exposure to cadmium (Cd), whether zinc (Zn) supplementation may prevent Cd-induced disorders in bone metabolism. For this purpose, male Wistar rats received Cd (5 and 50mg/l) or/and Zn (30 and 60mg/l) in drinking water for 6 and 12 months. Bone densitometry and biochemical markers of bone turnover were used to assess the effects of Cd or/and Zn. Bone mineral content (BMC) and density (BMD) were measured in the femur. Serum osteocalcin (OC) and alkaline phosphatase in trabecular (bT-ALP) and cortical (bC-ALP) bone were determined as bone formation markers, and carboxy-terminal cross-linking telopeptides of type I collagen (CTX) in serum were measured as bone resorption marker. Serum concentration of calcium (Ca) and its renal handling, as well as Zn and Cd concentrations in the serum/blood, urine and femur were evaluated as well. The exposure to 5 and 50mg Cd/l (0.340+/-0.026 and 2.498+/-0.093mg Cd/kg body wt/24h, respectively), in a dose and duration dependent manner, affected bone turnover (inhibited bone formation and stimulated its resorption) and disturbed bone mineralization (decreased BMC, BMD and Zn concentration). Zn supply at the concentration of 30 and 60mg/l (1.904+/-0.123 and 3.699+/-0.213mg/kg body wt/24h, respectively) during Cd exposure influenced the Cd-induced disorders in bone metabolism. Zn administration to the Cd-exposed rats enhanced the bone ALP activity and prevented Cd-induced bone resorption, but had no statistically significant effect on BMC and BMD; however, mean values of the densitometric parameters in the rats receiving both Cd and Zn were higher than in those treated with Cd alone. Moreover, Zn supplementation at both levels of Cd exposure was found to prevent Cd accumulation in the femur and the Cd-induced decrease in bone Zn concentration. The results of the present study allow the conclusion that Zn supplementation during Cd exposure may partly protect from disorders in bone metabolism. The influence of Zn may be accompanied by its ability to prevent Cd-induced Zn deficiency and to decrease Cd accumulation in bone tissue. The findings seem to indicate that enhanced dietary intake of Zn in subjects chronically exposed to moderate and relatively high Cd levels may have a protective influence on the skeleton.

The effects of cadmium in feed, and its amelioration with zinc, on element balances in sheep1

The effects of feeding Cd to sheep at a level that is typical of polluted regions were investigated, as well as possible amelioration by adding Zn to the diet. Welsh Mountain ewes (n = 24) were fed herb-age and concentrate in metabolism crates, with four supplement treatments in a two-factor factorial design: no supplement, Cd supplement only, Zn supplement only, and a combination of both the Cd and Zn supplement. Cadmium (286 microg/kg of feed DMI) and Zn (8.6 mg/kg feed DMI) were added as sulfates. Food and water intakes and element balances were recorded over 20 d after 7 d dietary adaptation, and element concentrations were determined in wool samples. Neither metal affected DMI or digestibility (P > 0.15), but water intake (P = 0.001) and urine output (P = 0.03) were decreased when only the Zn supplement was added. Water retention was increased by the Cd supplement (P = 0.04). In wool, the Cd supplement greatly increased the K concentration if no Zn supplement was fed (P = 0.02), and the Zn supplement decreased Mn concentration (P = 0.02). Cadmium in feed increased the Cd balance and produced several mineral disturbances, in particular a decrease in Na balance that is typical of renal tubular disorders. Adding Zn as well as Cd to feed returned the Cd balance to a level similar to that of sheep receiving neither Cd nor Zn, which suggests that Zn status is critical in determining whether Cd in feed increases the Cd balance in sheep. Feeding Cd also increased urinary K, Fe, Mo, Cr, B, and Ca concentrations, even when supplementary Zn was fed. It is concluded that low levels of Cd in sheep feed can increase the Cd balance if adequate Zn is not provided, which can lead to subclinical mineral disturbances and changes in the mineral concentrations in wool.