title: Cytotoxic and genotoxic potential of Cr(VI), Cr(III)-nitrate and Cr(III)-EDTA complex in human hepatoma (HepG2) cells.
abstract: Chromium (Cr) and ethylenediaminetetraacetate (EDTA) are common environmental pollutants and can be present in high concentrations in surface waters at the same time. Therefore, chelation of Cr with EDTA can occur and thereby stable Cr(III)-EDTA complex is formed. Since there are no literature data on Cr(III)-EDTA toxicity, the aim of our work was to evaluate and compare Cr(III)-EDTA cytotoxic and genotoxic activity with those of Cr(VI) and Cr(III)-nitrate in human hepatoma (HepG2) cell line. First the effect of Cr(VI), Cr(III)-nitrate and Cr(III)-EDTA on cell viability was studied in the concentration range from 0.04 μg mL(-1) to 25 μg mL(-1) after 24 h exposure. Further the influence of non-cytotoxic concentrations of Cr(VI), Cr(III)-nitrate and Cr(III)-EDTA on DNA damage and genomic stability was determined with the comet assay and cytokinesis block micronucleus cytome assay, respectively. Cell viability was decreased only by Cr(VI) at concentrations above 1.0 μg mL(-1). Cr(VI) at ≥0.2 μg mL(-1) and Cr(III) at ≥1.0 μg mL(-1) induced DNA damage, while after Cr(III)-EDTA exposure no formation DNA strand breaks was determined. Statistically significant formation of micronuclei was induced only by Cr(VI) at ≥0.2 μg mL(-1), while no influence on the frequency of nuclear buds nor nucleoplasmic bridges was observed at any exposure. This study provides the first evidence that Cr(III)-EDTA did not induce DNA damage and had no influence on the genomic stability of HepG2 cells.
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: Breda
authors.initials: B
authors.lastname: Novotnik
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: Janez
authors.initials: J
authors.lastname: Ščančar
authors.affiliation: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: Radmila
authors.initials: R
authors.lastname: Milačič
authors.affiliation: National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Večna pot 111, Ljubljana, Slovenia.
authors.forename: Metka
authors.initials: M
authors.lastname: Filipič
authors.affiliation: National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Večna pot 111, Ljubljana, Slovenia. Electronic address: bojana.zegura@nib.si.
authors.forename: Bojana
authors.initials: B
authors.lastname: Žegura
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D002470:Cell Survival / Q000187:drug effects; D002857:Chromium / Q000633:toxicity*; D020552:Comet Assay; D003603:Cytotoxins / Q000633:toxicity*; D004249:DNA Damage; D004492:Edetic Acid / Q000737:chemistry*; D004785:Environmental Pollutants / Q000737:chemistry / Q000633:toxicity*; D042822:Genomic Instability / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D015162:Micronucleus Tests; D009153:Mutagens / Q000633:toxicity*; D009566:Nitrates / Q000737:chemistry*
chemical_list: D003603:Cytotoxins; D004785:Environmental Pollutants; D009153:Mutagens; D009566:Nitrates; D002857:Chromium; C074702:chromium hexavalent ion; D004492:Edetic Acid
keywords: Comet assay; Cr(III); Cr(III)-EDTA; Cr(VI); Cytokinesis block micronucleus cytome assay; Genotoxicity