Search results for "Clastogen"
showing 10 items of 10 documents
Protective Effects of Fruits and Vegetables against In Vivo Clastogenicity of Cyclophosphamide or Benzo[a]pyrene in Mice
1998
Seven fruits and 10 vegetables commonly consumed in Germany were investigated for their anticlastogenic potencies against cyclophosphamide (CP) and benzo[a]pyrene (BaP) in the in vivo mouse bone marrow micronucleus assay. We detected protective effects in 76.5% and 70.6% of the samples, respectively, and more or less distinct quantitative differences between the various plant materials and the two clastogens investigated. With respect to CP, moderate activities were exerted by sweet cherries, strawberries, cucumber, radish and tomatoes, average activities by bananas, oranges, peaches, asparagus and red beets and strong activities by yellow red peppers and especially spinach. Apples (cultiva…
Use of HepG2 cell line for direct or indirect mutagens screening: comparative investigation between comet and micronucleus assays.
2003
International audience; In the present study, DNA-damage and clastogenic or aneugenic effects of genotoxic compounds were examined in a metabolically competent human cell line (HepG2 cells) using the micronucleus and the comet assays. Compounds with various action mechanisms were tested: direct mutagens such as 4-nitroquinoline-N-oxide (4-NQO) and methyl methanesulfonate (MMS) and indirect mutagens requiring biotransformation to be active such as N-nitrosodimethylamine (NDMA), benzo[a]pyrene (B[a]P) and 2-acetylaminofluorene (2-AAF). The compounds were first tested for cytotoxicity by measuring their effects on RNA synthesis inhibition in HepG2 cells. 4-NQO, B[a]P and 2-AAF were the most po…
Importance of the toxicological tests in the application and safety of ozone therapy
2018
Until today, there is not any official registry of the different routes of systemic ozone therapy. With the aim to prove the safety of this therapy, several ways of ozone (O3) applications were evaluated, such as rectal insufflation (RI), major autohemotherapy (M-AHT) and intraperitoneal application (IP). For RI, some toxicological tests were performed such as: acute, sub-chronic, mutagenic (bone marrow chromosomic aberrations and micronucleus), teratogenic and irritation studies (at 40 mg/L and 10 mL during 15 days). For M-AHT, acute toxicological (in rats with 21, 47 and 64 mg/L and a volume of 2 mL with daily evaluation up to 15 days) and mutagenic (chromosomal aberration analysis, micr…
Inhibition of clastogenicity of benzo[a]pyrene and of its trans-7,8-dihydrodiol in mice in vivo by fruits, vegetables, and flavonoids.
2003
In the in vivo mouse bone marrow micronucleus assay, homogenates of spinach, artichoke, peaches, and blue grapes as well as commercial concentrates of these vegetables and fruits reduced induction of micronuclei by benzo[a]pyrene (BaP) by 43-50%. Concentrates of strawberries (31% reduction) and of cauliflower (20% reduction) were less potent. Inhibition of genotoxicity by spinach and peaches was not caused by any delay in maturation of micronucleated erythrocytes as shown by experiments with sampling times of 24, 48, and 72 h after dosing of BaP. Pre-treatment of the mice with spinach 48, 24, and 12h before application of BaP resulted in a 44% reduction of micronuclei while peaches generate…
Re-definition and supporting evidence toward Fanconi Anemia as a mitochondrial disease: Prospects for new design in clinical management
2021
Fanconi anemia (FA) has been investigated since early studies based on two definitions, namely defective DNA repair and proinflammatory condition. The former definition has built up the grounds for FA diagnosis as excess sensitivity of patients' cells to xenobiotics as diepoxybutane and mitomycin C, resulting in typical chromosomal abnormalities. Another line of studies has related FA phenotype to a prooxidant state, as detected by both in vitro and ex vivo studies. The discovery that the FA group G (FANCG) protein is found in mitochondria (Mukhopadhyay et al., 2006) has been followed by an extensive line of studies providing evidence for multiple links between other FA gene products and mi…
Cytogenetic effects of promutagens in genetically engineered V79 Chinese hamster cells expressing cytochromes P450.
1993
Abstract V79 Chinese hamster cell lines genetically engineered to express rat CYP2B1, CYP1A1, CYP1A2, and their parental cell lines V79-MZ, without acetyltransferase, and V79-NH, with acetyltransferase, were studied for chromosome aberrations and sister chromatid exchange induced by aflatoxin B 1 , cyclophosphamide, benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene and dimethylnitrosamine. The parental V79 cell lines did not show clastogenic effects. Significant clastogenic effects were observed after an 18 h exposure to aflatoxin B 1 and cyclophosphamide in CYP2B1 expressing cells, to benzo[a]pyrene in CYP1A1 and CYP1A2 expressing cells, to 7,12-dimethylbenz[a]anthracene and dimethylnitrosami…
Evaluation of the osteoclastogenic process associated with RANK / RANK-L / OPG in odontogenic myxomas
2018
Background Odontogenic myxoma (OM) is a benign intraosseous neoplasm that exhibits local aggressiveness and high recurrence rates. Osteoclastogenesis is an important phenomenon in the tumor growth of maxillary neoplasms. RANK (Receptor Activator of Nuclear Factor κappa B) is the signaling receptor of RANK-L (Receptor activator of nuclear factor kappa-Β ligand) that activates the osteoclasts. OPG (osteoprotegerin) is a decoy receptor for RANK-L that inhibits pro-osteoclastogenesis. The RANK / RANKL / OPG system participates in the regulation of osteolytic activity under normal conditions, and its alteration has been associated with greater bone destruction, and also with tumor growth. Object…
Clastogenic and aneuploidizing effects of antiblastic busulphan revealed by kinetochore immunofluorescence in CHO cells.
1991
We utilized, in CHO cells, the cytoplasm preservation technique to evaluate the micronucleus frequency at different busulphan concentrations, and the indirect immunofluorescence technique, using sera obtained from patients with scleroderma (CREST variant), to analyze if busulphan-induced micronuclei have kinetochores. Results show that this alkylating agent is capable of causing a significant increase of micronuclei in vitro, a great part (40%) of them having CREST-positive kinetochores. These findings confirm the clastogenic effect of busulphan and reveal a considerable capability of this agent to induce aneuploidy. These results are examined taking into account the high incidence of secon…
Genotoxicity of selected pesticides in the mouse bone-marrow micronucleus test and in the sister-chromatid exchange test with human lymphocytes in vi…
1996
Selected pesticides (aldicarb, 1,3-dichloropropene, methidathion, parathion, triadimefon, vinclozolin) were tested for their clastogenic and aneugenic activities in the mouse bone-marrow micronucleus (MN) test in vivo and for their sister-chromatid exchange-inducing activities in human lymphocytes in vitro in the presence and absence of an exogenous metabolizing system from rat-liver S9. 1,3-Dichloropropene significantly increased the frequencies of micronucleated polychromatic erythrocytes (PCE) in bone-marrow cells of female mice from 3.3 MN/1000 PCE to 15.3 MN/1000 PCE (187 mg per kg body weight). 1,3-Dichloropropene (100 microM) induced 16.0 SCE/metaphase after 24 h of incubation as com…
The DNA topoisomerase II catalytic inhibitor merbarone is genotoxic and induces endoreduplication
2012
Abstract In the last years a number of reports have shown that the so-called topoisomerase II (topo II) catalytic inhibitors are able to induce DNA and chromosome damage, an unexpected result taking into account that they do not stabilize topo II-DNA cleavable complexes, a feature of topo II poisons such as etoposide and amsacrine. Merbarone inhibits the catalytic activity of topo II by blocking DNA cleavage by the enzyme. While it was first reported that merbarone does not induce genotoxic effects in mammalian cells, this has been challenged by reports showing that the topo II inhibitor induces efficiently chromosome and DNA damage, and the question as to a possible behavior as a topo II p…