Search results for "Genotoxicity"
showing 10 items of 104 documents
Genotoxic effects of zinc oxide nanoparticles
2015
The potential toxicity of nanoparticles has currently provoked public and scientific discussions, and attempts to develop generally accepted handling procedures for nanoparticles are under way. The investigation of the impact of nanoparticles on human health is overdue and reliable test systems accounting for the special properties of nanomaterials must be developed. Nanoparticular zinc oxide (ZnO) may be internalised through ambient air or the topical application of cosmetics, only to name a few, with unpredictable health effects. Therefore, we analysed the determinants of ZnO nanoparticle (NP) genotoxicity. ZnO NPs (15-18 nm in diameter) were investigated at concentrations of 0.1, 10 and …
Assessment in vitro of cytogenetic and genotoxic effects of propolis on human lymphocytes
2012
We evaluated the genetic damage by ethanolic extract of propolis (EEP) induced to human lymphocytes which were exposed to increasing concentrations (0–2000 μg ml−1). The results indicated that EEP reduced significantly the mitotic index (MI) and proliferation index (PI) when high concentrations of EEP were used. Sister chromatid exchange (SCE) rates indicated that EEP could have genotoxic effects at high concentrations. Exposure of the cells to the amount of ethanol used as solvent did not alter either the MI and cell proliferation kinetics (CPK), or the rate of SCE. The results showed: (a) statistical increase in the percentage the cells with CAs and in the frequency of SCE at the highest …
Radioprotective activity and cytogenetic effect of resveratrol in human lymphocytes: An in vitro evaluation
2012
Trans-resveratrol is a natural occurring polyphenol, obtained from grapes and other berries. This compound has shown antioxidant, anti-inflammatory, immunostimulant or anti-carcinogenic properties. Our aim was to evaluate the radioprotective efficacy, in vitro, of trans-resveratrol against radiation-induced chromosomal damage and to study the genotoxicity and cytotoxicity of this polyphenol in cell cultures without irradiation. The study was carried out by the pre-treatment of human lymphocytes at concentrations from 0 to 219μM of trans-resveratrol. The results showed that all concentrations tested reduced radiation-induced chromosomal damage compared with cells with any treatment. Maximum …
A Quantitative In Vitro Approach to Study the Intracellular Fate of Gold Nanoparticles: From Synthesis to Cytotoxicity
2009
Due to their physico-chemical characteristics, gold nanoparticles (AuNPs) seem to be suitable for biomedical and therapeutic applications even if conflicting data on their toxicological profiles are present in literature. In order to better understand if AuNPs could be safe we must consider different biological endpoints such as cytotoxicity, genotoxicity, inflammation and biopersistence. Starting from these considerations, one of the first issues to be assessed is to better understand if AuNPs can be internalized by cells. In this work, we propose a methodological approach to radioactivate AuNPs by neutron activation and the quantification of their internalization by two in vitro cell syst…
Cytotoxicity, Genotoxicity and Disturbance of Cell Cycle in HepG2 Cells Exposed to OTA and BEA: Single and Combined Actions
2019
Mycotoxins are produced by a number of fungal genera spp., for example, Aspergillus, Penicillium, Alternaria, Fusarium, and Claviceps. Beauvericin (BEA) and Ochratoxin A (OTA) are present in various cereal crops and processed grains. This goal of this study was to determine their combination effect in HepG2 cells, presented for the first time. In this study, the type of interaction among BEA and OTA through an isobologram method, cell cycle disturbance by flow cytometry, and genotoxic potential by in vitro micronucleus (MN) assay following the TG 487 (OECD, 2016) of BEA and OTA individually and combined in HepG2 cells are presented. Cytotoxic concentration ranges studied by the MTT assay ov…
Multiple activation pathways of benzene leading to products with varying genotoxic characteristics.
1989
Abstract Benzene and 13 potential metabolites were investigated for genotoxicity in Salmonella typhimurium and V79 Chinese hamster cells. In the presence of NADPH-fortified hepatic postmitochondrial fraction (S9 mix), benzene reverted his- S. typhimurium strains. The effect was strongest in strain TA1535. Among the potential metabolites, only the trans-1,2-dihydrodiol, in the presence of S9 mix, and the diol epoxides, in the presence and absence of S9 mix, proved mutagenic in this strain. The anti-diol epoxide was more potent than the syn-diastereomer. Both enantiomers of the anti-diastereomer showed similar activities. S9 mix did not appreciably affect the mutagenicity of the anti-diol epo…
The BIOSAFEPAPER project for in vitro toxicity assessments: preparation, detailed chemical characterisation and testing of extracts from paper and bo…
2008
International audience; Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.8-35.5 mg/dm2). According to GC-MS the main substances extracted into water were pulp-derived natural products such as fatty acids, resin acids, natural wood sterols and alkanols. Substances extracted into ethanol particularly, were diisopropylnaphthalenes, alkanes and phthalic acid esters. The non-foo…
Photocatalytic Degradation of Paraquat and Genotoxicity of its Intermediate Products
2007
Abstract The photocatalytic degradation of paraquat (1,1-dimethyl-4,4′-bipyridylium dichloride) aqueous solutions in the presence of polycrystalline TiO2 Degussa P25 irradiated by near-UV light was investigated. The substrate and total organic carbon concentrations were monitored by UV spectroscopy and TOC measurements, respectively: the complete photocatalytic mineralization of paraquat (20 ppm) was achieved after ca. 3 h of irradiation by using 0.4 g l−1 of catalyst amount at natural pH (ca 5.8). On the contrary no significant photodegradation of paraquat was observed in the absence of TiO2 under similar experimental conditions. To evaluate the genotoxicity of paraquat and its intermediat…
Toxicity of a dental adhesive compared with ionizing radiation and zoledronic acid
2015
Background: To determine the toxicity of aqueous dilutions of a universal self-priming dental adhesive (DA) and comparing these with those elicited by exposure to ionizing radiation (IR), Zoledronic acid (Z) treatment and the synergic effects of the combined treatment with IR+Z. Material and Methods: The genotoxic effect of DA was determined by the increase in the frequency of micronuclei in cytokinesis-blocked in cultured human lymphocytes before and after exposure to 2Gy of X-rays. The cytotoxic effect was studied by using the MTT cell viability test in normal prostate cell lines (PNT2) after exposure to different X-ray doses (0Gy-20Gy). The cell lines divided into different groups and tr…
Loss of ATM sensitizes against O6-methylguanine triggered apoptosis, SCEs and chromosomal aberrations.
2003
A critical pre-cytotoxic and -apoptotic DNA lesion induced by methylating carcinogens and chemotherapeutic drugs is O6-methylguanine (O6MeG). The mechanism by which O6MeG causes cell death via apoptosis is only partially understood. The current model ascribes a role to DNA replication and mismatch repair, which converts O6MeG into a critical distal lesion (presumably a DNA double-strand break) that is finally responsible for genotoxicity and apoptosis. Here we analysed whether the PI3-like kinase ATM is involved in this process. ATM is a major player in recognizing and signaling DNA breaks, but most reports are limited to ionizing radiation. Comparing mouse ATM knockout fibroblasts (ATM-/-)…