Comparative evaluation of the toxicity and genotoxicity of cadmium in amphibian larvae (Xenopus laevis andPleurodeles waltl) using the comet assay and the micronucleus test (original) (raw)
Related papers
Environmental Toxicology and Pharmacology, 2010
The present investigation was undertaken to study the induction of DNA damage by CdCl 2 in freshwater climbing perch Anabas testudineus (Bloch) using alkaline single cell gel electrophoresis (comet assay). The DNA damage was measured in the tissue of gill, kidney and liver as the percentage of DNA in comet tails and comet heads in the tissue of the fish specimens exposed to 0.1, 1.0, 2.0 mg L −1 concentrations of CdCl 2 . It was found that at all the concentrations of CdCl 2 , the liver tissue exhibited significantly (p < 0.01) higher DNA damage, followed by kidney and gill tissue. The DNA damage was found to be concentration dependent, with the highest DNA damage at 2 mg L −1 concentration, followed by 1.0 and 0.1 mg L −1 . At the concentration of 2 mg L −1 of CdCl 2 , the tail and head DNA of liver tissue were 38.81% and 59.49%, in kidney tissue the values were 32.37% and 64.66% whereas in gill tissue the values were 31.30% and 66.40% respectively. This study conclude that comet assay can be used for in vivo laboratory experiment using fish as model for screening the genotoxic potential of cadmium.
Cadmium accumulation and biochemical responses in Sparus aurata following sub-lethal Cd exposure
Ecotoxicology and Environmental Safety, 2009
Cadmium (Cd), a heavy metal with limited biological function, is widely distributed in the aquatic environment as a result of natural and anthropogenic activities. The effect of 4 and 11 days exposure of gilthead sea bream Sparus aurata to sub-lethal concentrations of Cd was evaluated as levels of Cd content and Cd-metallothionein (MT) presence in different organs. The possible genotoxic effect was also evaluated in erythrocytes by using the ''comet assay'', a promising tool for estimating DNA damage at the single-cell level. The results obtained show that in the controls, Cd content was significantly higher in gills compared to in liver, but the treatment of fish with 0.1 mg/l Cd induced a stronger accumulation of metal in liver depending on the length of the exposure period. Cd traces were found in plasma, muscle and kidney. Cd forms complexes in the cytosol with MT only in the liver but Cd-MT content significantly increased after 11 days of exposure to the metal, while after 4 days of treatment the protein level was similar to the control. The ''comet assay'' performed on S. aurata eryhtrocytes isolated from fish treated for 4 and 11 days with 0.1 mg/l Cd, showed that there was no DNA damage at both exposure periods.
Aquatic Toxicology, 2016
The aim of this study was to verify if the freshwater safety values established from the European Community (1998) and the Italian Ministry of Health (2001) for cadmium (44.5 nM/L in drinking water and 178 nM/L in sewage waters) were safe for amphibians, since at these same concentrations cadmium induced endocrine disruption in the newt Triturus carnifex. Adult male specimens of T. carnifex were exposed daily to cadmium (44.5 nM/L and 178 nM/L as CdCl 2 , nominal concentrations), respectively, during 3-and 9-months; at the same time, control newts were exposed to tap water only. The accumulation of cadmium in the skin, liver and kidney, the levels of metallothioneins in the skin and the liver, the expression of metallothionein mRNA in the liver, as well as the presence of histological alterations and of apoptosis in the target organs were evaluated. The 9-months exposure induced cadmium accumulation in all the tissues examined; moreover, histological changes were observed in all the tissues examined, irrespective of the dose or the time of exposure. Apoptosis was only detected in the kidney, whereas metallothioneins and metallothionein mRNA did not increase. This study demonstrates that the existing chronic water quality criterion established for cadmium induces in the newt T. carnifex cadmium accumulation and histological alterations in the target organs examined. Together with our previous results, showing that, at these same concentrations, cadmium induced endocrine disruption, the present results suggest that the existing chronic water quality criterion for cadmium appears to be not protective of amphibians.
Environmental Toxicology, 2013
This paper presents an evaluation of the genotoxic effects of cadmium chloride (CdCl 2) on marine gastropod, Nerita chamaeleon following the technique of comet assay and the DNA alkaline unwinding assay (DAUA). In this study the extent of DNA damage in gill cells of N. chamaeleon were measured after in vivo exposure to four different concentrations (10; 25; 50 and 75 µg/L) of CdCl 2. In vitro exposure of H 2 O 2 (1; 10; 25 and 50 µM) of the gill cells showed a significant increase in the % tail DNA, Olive tail moment (OTM) and tail length (TL). Significant changes in % tail DNA by CdCl 2 exposure were observed in all exposed groups of snails with respect to those in control. Exposure to 75 µg/L of CdCl 2 produced significant decrease in DNA integrity as measured by DAUA at all duration with respect to control. In vivo exposure to different concentrations of CdCl 2 (10; 25; 50 and 75 µg/L) to N. chamaeleon showed considerable increase in DNA damage as observed by both alkaline comet assay and the DAUA. The extent of DNA damage in marine gastropods determined by the application of alkaline comet assay and DAUA clearly indicated the genotoxic responses of marine gastropod, N. chamaeleon to a wide range of cadmium concentration in the marine environment.
2018
Amphibians are increasingly being used as bio-indicator of contamination in ecosystems due to their sensitivity to xenobiotics in the environment. Cadmium and lead compounds, ubiquitous mutagens and carcinogens, are capable of eliciting genome instability in adult toads which may enhance amphibian decline. Micronucleus cytome (MN-cyt) assay, a comprehensive cytogenetic test for the assessment of genome instability induced by xenobiotics in organisms, was utilized in the differential cytogenotoxic evaluation of Cd and Pb in adult Amietophrynus regularis. A. regularis was exposed to six concentrations (8 - 512 mg/L) of the metal solutions to determine 96 h acute toxicity. Four toads per group were exposed to five sub-lethal concentrations (5 - 75 %) of the 96 h LC50 of the metals for 14 days. At post exposure, bone marrow and peripheral erythrocytes were collected for MN-cyt analysis. The metals induced differential concentration and time-dependent increase in mortality with 96 h LC50...
Effects of cadmium exposure on bioaccumulation and larval growth in the frog Rana ridibunda
Environmental Pollution, 1999
The bioaccumulation of cadmium and the eect on growth of larvae of the frog Rana ridibunda after exposure to Cd for 15 and 30 days was investigated. The 96-h LC 50 value was 71.8 ppm. The water content of all the tadpoles exposed to all cadmium concentrations was higher than that of controls. There was a tendency for the animals exposed to Cd to retard their growth. Mortality rates at 15 days exposure increased with increasing cadmium concentration and remained constant in all the cadmium concentrations at 30 days exposure. Cadmium accumulation was higher in the 15 days exposed tadpoles, compared to that of 30 days exposure. Growth retardation may be a factor contributing to the declining of amphibian populations, since they, because of their smaller size, spend more time in more vulnerable stages, becoming thus more susceptible to predators.
TURKISH JOURNAL OF BIOLOGY, 2016
The worldwide decline in amphibian populations has made heavy metal pollution a subject of interest. The aim of this work was to analyze the effect of sublethal doses of cadmium (Cd) on the liver, kidney, and blood of Rhinella arenarum specimens. Serum markers indicative of hepatic injury (gamma glutamyltransferase, alkaline phosphatase, pseudo cholinesterase, and total cholesterol) and markers of renal dysfunction (blood urea nitrogen, serum creatinine, calcium, and glucose) showed variation in animals treated with a 0.5 mg/kg dose compared to controls. Histopathological images revealed alterations in the liver (hepatocyte ballooning and hyperplasia of Kupffer cells) and kidney (renal tubular lumen dilation with tubular necrosis) of animals with abnormal serum markers. The above-mentioned lesions were more evident with the 5 mg/kg dose. With the 0.5 mg/kg dose, hematological values remained normal with the exception of the leukocyte formula. Animals treated with 5 mg/kg showed a significant decrease in both white and red blood cell counts and hematocrit and hemoglobin values. Differential leukocyte counts showed neutrophilia, monocytosis, and lymphopenia. Morphological aberrations were found in white and red blood cells. Results indicated that the evaluation of morphological and functional parameters in kidney, liver, and blood is required in order to monitor amphibian populations exposed to chemical contaminants.
Cadmium pollution and amphibians – Studies in tadpoles of Rana limnocharis
Chemosphere, 2016
h i g h l i g h t s • Cadmium caused concentration and time dependent mortality in Rana limnocharis tadpoles. • Cadmium reduced the time to metamorphosis in R. limnocharis. • The body weight at metamorphosis decreased while body length increased following cadmium exposure in R. limnocharis. • Cadmium caused chromosome and DNA damage in R. limnocharis.
Ecotoxicity and genotoxicity of cadmium in different marine trophic levels
Environmental pollution (Barking, Essex : 1987), 2016
Cadmium ecotoxicity and genotoxicity was assessed in three representative species of different trophic levels of marine ecosystems - the calanoid copepod Acartia tonsa, the decapod shrimp, Palaemon varians and the pleuronectiform fish Solea senegalensis. Ecotoxicity endpoints assessed in this study were adult survival, hatching success and larval development ratio (LDR) for A. tonsa, survival of the first larval stage (zoea I) and post-larvae of P. varians, egg and larvae survival, as well as the presence of malformations in the larval stage of S. senegalensis. In vivo genotoxicity was assessed on adult A. tonsa, the larval and postlarval stage of P. varians and newly hatched larvae of S. senegalensis using the comet assay. Results showed that the highest sensitivity to cadmium is displayed by A. tonsa, with the most sensitive endpoint being the LDR of nauplii to copepodites. Sole eggs displayed the highest tolerance to cadmium compared to the other endpoints evaluated for all teste...
This paper presents an evaluation of the genotoxic effects of cadmium chloride (CdCl 2 ) on marine gastropod, Nerita chamaeleon following the technique of comet assay and the DNA alkaline unwinding assay (DAUA). In this study, the extent of DNA damage in gill cells of N. chamaeleon was measured after in vivo exposure to four different concentrations (10, 25, 50, and 75 mg/L) of CdCl 2 . In vitro exposure of hydrogen peroxide (H 2 O 2 ; 1, 10, 25, and 50 mM) of the gill cells showed a significant increase in the percentage tail DNA, Olive tail moment, and tail length (TL). Significant changes in percentage tail DNA by CdCl 2 exposure were observed in all exposed groups of snails with respect to those in control. Exposure to 75 mg/L of CdCl 2 produced significant decrease in DNA integrity as measured by DAUA at all duration with respect to control. In vivo exposure to different concentrations of CdCl 2 (10, 25, 50, and 75 mg/L) to N. chamaeleon showed considerable increase in DNA damage as observed by both alkaline comet assay and the DAUA. The extent of DNA damage in marine gastropods determined by the application of alkaline comet assay and DAUA clearly indicated the genotoxic responses of marine gastropod, N. chamaeleon to a wide range of cadmium concentration in the marine environment. V C 2013 Wiley Periodicals, Inc. Environ Toxicol 00: 000-000, 2013.