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Cytotoxicity and genotoxicity of bovine pericardium preserved in glycerol

RODAS, Andrea C. D.; MAIZATO, Marina J. S.; LEIRNER, Adolfo A.; PITOMBO, Ronaldo N. M.; POLAKIEWICZ, Bronislaw; BEPPU, Marisa M.; HIGA, Olga Z.
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.13%
Bovine pericardium is a widely utilized biomaterial. Usually, after harvesting, it is advantageous that the pericardium be immersed in glycerol to improve its shelf life. This can induce some degree of toxicity in the material. The studies were performed in compliance with the rules of ISO 10993 and OECD 487, in the biological evaluation of medical devices. The material was prepared without previous washing. After sterilization by gamma radiation the pericardium was immersed in RPMI 1640 culture medium to fulfill the extraction condition. The same extract was employed in the cytotoxic and genotoxic tests. The procedures were carried out with Chinese hamster ovary cell line and to determine the cytotoxicity, a colorimetric method with the tetrazolium compound MTS was used. For the genotoxicity, following the in vitro micronucleus assay, the test was developed with and without metabolic activation. The Cytotoxicity Index was graphically estimated at the extract concentration of 78%. In the genotoxicity test, the average value of cell proliferation index was found to be 1.62 +/- 0.02 with S9 metabolic activator and 1.91 +/- 0.01 without S9 metabolic activator. Both values are similar to the negative control value in the micronucleus assay. We observed that although the pericardium preserved in glycerol shows a certain level of cytotoxicity...

Genotoxicity and composition of particulate matter from biomass burning in the eastern Brazilian Amazon region

ALVES, Nilmara de Oliveira; Loureiro, Ana Lucia Matos; Santos, Fernando Cavalcante dos; Nascimento, Kátia Halter; DALLACORT, Rivanildo; Vasconcellos, Perola de Castro; HACON, Sandra de Souza; Artaxo Netto, Paulo Eduardo; MEDEIROS, Silvia Regina Batistuzz
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.13%
In the present study Tradescantia pallida micronucleus (Trad-MCN) bioassay was used to assess the genotoxicity of particulate matter with a mass median aerodynamic diameter less than 10 pm (PM(10)) in Tangara da Serra (MT), a Brazilian Amazon region that suffers the impact of biomass burning. The levels of PM (coarse and fine size fractions) and black carbon (BC) collected were also measured. Furthermore, the alkanes and polycyclic aromatic hydrocarbons (PAHs) were identified and quantified in the samples taken during the burning period by gas chromatography with flame ionization detection (GC-FID). The PM and BC results for both fractions indicate a strong correlation (p < 0.001). The analysis of alkanes indicates an anthropic influence. Retene was the most abundant PAH found, an indicator of biomass burning, and 12 other PAHs considered to be potentially mutagenic and/or carcinogenic were identified in this sample. The Trad-MCN bioassay showed a significant increase in micronucleus frequency during the period of most intense burning, possibly related to the mutagenic PAHs that were found in such extracts. This study demonstrated that Trad-MCN was sensitive and efficient in evaluating the genotoxicity of organic compounds from biomass burning. It further emphasizes the importance of performing chemical analysis...

Assessment of trophic transfer of benzo(a)pyrene genotoxicity from the post-larval pink shrimp F. brasiliensis to the juvenile Florida pompano T. carolinus

Rocha, Arthur Jose da Silva; Santos, Thaís da Cruz Alves dos; Gomes, Vicente; Bicego, Marcia Caruso; Barbosa, Ana Cecilia Rizzatti de Albergaria; Passos, Maria Jose de Arruda Campos Rocha; Hasue, Fabio Matsu; Ngan, Phan Van
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.03%
In the present study, the polycyclic aromatic hydrocarbon (PAH) genotoxicity was investigated in a one-step predator-prey relationship with the trophic-related marine species. Florida pompanos were fed for 5 and 10 days with pink shrimp post larvae previously exposed to benzo(a)pyrene (BaP) concentrations. Parent BaP body burden was measured in samples of Farfantepenaeus brasiliensis. BaP metabolites were determined in bile samples of Trachinotus carolinus and DNA damage was assessed through the comet and erythrocyte nuclear abnormalities (ENAs) assays in fish erythrocytes. BaP body burden increased significantly with the PAH concentration in pink shrimp PLs as well as the fish bile BaP metabolites. Both, comet and ENAs assays indicated significant increase on erythrocyte DNA damage of Florida pompanos fed with BaP-exposed pink shrimp on both feeding periods. The trophic route of BaP genotoxicity is discussed as well as the PAH biotransformation as the inducing mechanism for the DNA damages observed.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2006/03925-1, 2007/01012-1]

Protective effect of bixin on cisplatin-induced genotoxicity in PC12 cells

dos Santos, Graciela Cristina; Mendonca, Leonardo Meneghin; Antonucci, Gilmara Ausech; dos Santos, Antonio Cardozo; Greggi Antunes, Lusania Maria; Pires Bianchi, Maria de Lourdes
Fonte: PERGAMON-ELSEVIER SCIENCE LTD; OXFORD Publicador: PERGAMON-ELSEVIER SCIENCE LTD; OXFORD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.03%
Bixin is the main carotenoid found in annatto seeds (Bixa orellana L.) and is responsible for their reddish-orange color. The antioxidant properties of this compound are associated with its ability to scavenge free radicals, which may reduce damage and protect tissues against toxicity caused by anticancer drugs such as cisplatin. In this study, the genotoxicity and antigenotoxicity of bixin on cisplatin-induced toxicity in PC12 cells was assessed. Cytotoxicity was evaluated using the mu assay, mutagenicity, genotoxicity, and protective effect of bixin were evaluated using the micronucleus test and comet assay. PC12 cells were treated with bixin (0.05, 0.08, and 0.10 mu g/mL), cisplatin (0.1 mu g/mL) or a combination of both bixin and cisplatin. Bixin was neither cytotoxic nor genotoxic compared to the controls. In the combined treatment bixin significantly reduced the percentage of DNA in tail and the frequency of micronuclei induced by cisplatin. This result suggests that bixin can function as a protective agent, reducing cisplatin-induced DNA damage in PC12 cells, and it is possible that this protection could also extend to neuronal cells. Further studies are being conducted to better understand the mechanisms involved in the activity of this protective agent prior to using it therapeutically. (C) 2011 Elsevier Ltd. All rights reserved.; CNPq [470214/2008-2]; CNPq

Biomonitoring genotoxicity and cytotoxicity of Microcystis aeruginosa (Chroococcales, Cyanobacteria) using the Allium cepa test

Laughinghouse, Haywood Dail; Pra, Daniel; Silva-Stenico, Maria Estela; Rieger, Alexandre; Frescura, Viviane Dal-Souto; Fiore, Marli de Fatima; Tedesco, Solange Bosio
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.13%
Water pollution caused by toxic cyanobacteria is a problem worldwide, increasing with eutrophication. Due to its biological significance, genotoxicity should be a focus for biomonitoring pollution owing to the increasing complexity of the toxicological environment in which organisms are exposed. Cyanobacteria produce a large number of bioactive compounds, most of which lack toxicological data. Microcystins comprise a class of potent cyclic heptapeptide toxins produced mainly by Microcystis aeruginosa. Other natural products can also be synthesized by cyanobacteria, such as the protease inhibitor, aeruginosin. The hepatotoxicity of microcystins has been well documented, but information on the genotoxic effects of aeruginosins is relatively scarce. In this study, the genotoxicity and ecotoxicity of methanolic extracts from two strains of M. aeruginosa NPLJ-4, containing high levels of microcystin, and M. aeruginosa NPCD-1, with high levels of aeruginosin, were evaluated. Four endpoints, using plant assays in Allium cepa were applied: rootlet growth inhibition, chromosomal aberrations, mitotic divisions, and micronucleus assays. The microcystin content of M. aeruginosa NPLJ-4 was confirmed through ELISA, while M. aeruginosa NPCD-1 did not produce microcystins. The extracts of M. aeruginosa NPLJ-4 were diluted at 0.01...

In vitro metabolism effect on genotoxicity and antigenotoxicity of Agaricus blazei organics and aqueous extracts by the comet assay

Bellini, Marilanda Ferreira; Terezan, Ana Paula; Ribeiro, Lúcia Regina; Mantovani, Mário Sérgio
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 205-211
ENG
Relevância na Pesquisa
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There is high interest in the natural products properties due to their use in popular medicine. Agaricus blazei Murrill ss. Heinem. (Ab) is native to Brazil and has been widely disseminated because its medicinal properties. In the present study, the genotoxic and antigenotoxic potential of Ab extracts were investigated using the comet assay. The cells utilized were the non drug-metabolizing line CHO-k1 (Chinese hamster ovary) and the drug-metabolizing line HTC (rat hepatoma). Cells were treated for 3 h in the absence of fetal bovain serum (FBS) with methanolic, hexanic and n-butanolic extracts at 50 μg/ml and 0.75% aqueous extract to test for genotoxicity. Antigenotoxic effects of extracts were determined in cells exposed to the DNA damage inducing agent ethyl methanesulfonate under simultaneous or simultaneous with 1 h pre-incubation conditions. The extracts did not show genotoxicity in HTC, while they were genotoxic in CHO-k1. No antigenotoxic effect was observed with any extract under any condition. These results demonstrate that the metabolism in presence or in absence has a direct influence on the genotoxicity of these extracts. © 2006 The Japan Mendel Society.

A Comparative Genotoxicity Study of a Supraphysiological Dose of Triiodothyronine (T3) in Obese Rats Subjected to Either Calorie-Restricted Diet or Hyperthyroidism

de Sibio, Maria Teresa; Luvizotto, Renata Azevedo Melo; Olimpio, Regiane Marques Castro; Corrêa, Camila Renata; Marino, Juliana; de Oliveira, Miriane; Conde, Sandro José; Ferreira, Ana Lúcia dos Anjos; Padovani, Carlos Roberto; Nogueira, Célia Regina
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.29%
This study was designed to determine the genotoxicity of a supraphysiological dose of triiodothyronine (T3) in both obese and calorie-restricted obese animals. Fifty male Wistar rats were randomly assigned to one of the two following groups: control (C; n = 10) and obese (OB; n = 40). The C group received standard food, whereas the OB group was fed a hypercaloric diet for 20 weeks. After this period, half of the OB animals (n = 20) were subjected to a 25%-calorie restriction of standard diet for 8 weeks forming thus a new group (OR), whereas the remaining OB animals were kept on the initial hypercaloric diet. During the following two weeks, 10 OR animals continued on the calorie restriction diet, whereas the remaining 10 rats of this group formed a new group (ORS) given a supraphysiological dose of T3 (25 μg/100 g body weight) along with the calorie restriction diet. Similarly, the remaining OB animals were divided into two groups, one that continued on the hypercaloric diet (OB, n = 10), and one that received the supraphysiological dose of T3 (25 μg/100 g body weight) along with the hypercaloric diet (OS, n = 10) for two weeks. The OB group showed weight gain, increased adiposity, insulin resistance, increased leptin levels and genotoxicity; T3 administration in OS animals led to an increase in genotoxicity and oxidative stress when compared with the OB group. The OR group showed weight loss and normalized levels of adiposity...

Cytotoxicity and genotoxicity of bovine pericardium preserved in glycerol

RODAS, Andrea C. D.; MAIZATO, Marina J. S.; LEIRNER, Adolfo A.; PITOMBO, Ronaldo N. M.; POLAKIEWICZ, Bronislaw; BEPPU, Marisa M.; HIGA, Olga Z.
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.13%
Bovine pericardium is a widely utilized biomaterial. Usually, after harvesting, it is advantageous that the pericardium be immersed in glycerol to improve its shelf life. This can induce some degree of toxicity in the material. The studies were performed in compliance with the rules of ISO 10993 and OECD 487, in the biological evaluation of medical devices. The material was prepared without previous washing. After sterilization by gamma radiation the pericardium was immersed in RPMI 1640 culture medium to fulfill the extraction condition. The same extract was employed in the cytotoxic and genotoxic tests. The procedures were carried out with Chinese hamster ovary cell line and to determine the cytotoxicity, a colorimetric method with the tetrazolium compound MTS was used. For the genotoxicity, following the in vitro micronucleus assay, the test was developed with and without metabolic activation. The Cytotoxicity Index was graphically estimated at the extract concentration of 78%. In the genotoxicity test, the average value of cell proliferation index was found to be 1.62 +/- 0.02 with S9 metabolic activator and 1.91 +/- 0.01 without S9 metabolic activator. Both values are similar to the negative control value in the micronucleus assay. We observed that although the pericardium preserved in glycerol shows a certain level of cytotoxicity...

BC nanofibres : in vitro study of genotoxicity and cell proliferation

Moreira, Susana Margarida Gomes; Silva, Naisandra Bezerra; Almeida-Lima, Jailma; Rocha, Hugo Alexandre Oliveira; Medeiros, Silvia Regina Batistuzzo; Alves Junior, Clodomiro; Gama, F. M.
Fonte: Elsevier Ireland Publicador: Elsevier Ireland
Tipo: Artigo de Revista Científica
Publicado em /09/2009 ENG
Relevância na Pesquisa
37.13%
Nanomaterials have unusual properties not found in the bulk materials, which can be exploited in numerous applications such as biosensing, electronics, scaffolds for tissue engineering, diagnostics and drug delivery. However, research in the past few years has turned up a range of potential health hazards, which has given birth to the new discipline of nanotoxicology. Bacterial cellulose (BC) is a promising material for biomedical applications, namely due its biocompatibility. Although BC has been shown not to be cytotoxic or genotoxic, the properties of isolated BC nanofibres (NFs) on cells and tissues has never been analysed. Considering the toxicity associated to other fibre-shaped nanoparticles, it seems crucial to evaluate the toxicity associated to the BC-NFs. In thiswork, nanofibreswere produced frombacterial cellulose by a combination of acid and ultrasonic treatment. The genotoxicity of nanofibres from bacterial cellulosewas analysed in vitro, using techniques previously demonstrated to detect the genotoxicity of fibrous nanoparticles. The results from single cell gel electrophoresis (also known as comet assay) and the Salmonella reversion assays showed that NFs are not genotoxicity under the conditions tested. A proliferation assay using fibroblasts and CHO cells reveals a slight reduction in the proliferation rate...

Studies of genotoxicity and mutagenicity of nitroimidazoles: demystifying this critical relationship with the nitro group

Boechat,Núbia; Carvalho,Alcione S; Salomão,Kelly; Castro,Solange L de; Araujo-Lima,Carlos F; Mello,Francisco VC; Felzenszwalb,Israel; Aiub,Claudia AF; Conde,Taline Ramos; Zamith,Helena PS; Skupin,Rolf; Haufe,Günter
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
Relevância na Pesquisa
37.13%
Nitroimidazoles exhibit high microbicidal activity, but mutagenic, genotoxic and cytotoxic properties have been attributed to the presence of the nitro group. However, we synthesised nitroimidazoles with activity against the trypomastigotes of Trypanosoma cruzi, but that were not genotoxic. Herein, nitroimidazoles (11-19) bearing different substituent groups were investigated for their potential induction of genotoxicity (comet assay) and mutagenicity (Salmonella/Microsome assay) and the correlations of these effects with their trypanocidal effect and with megazol were investigated. The compounds were designed to analyse the role played by the position of the nitro group in the imidazole nucleus (C-4 or C-5) and the presence of oxidisable groups at N-1 as an anion receptor group and the role of a methyl group at C-2. Nitroimidazoles bearing NO2 at C-4 and CH3 at C-2 were not genotoxic compared to those bearing NO2 at C-5. However, when there was a CH3 at C-2, the position of the NO2 group had no influence on the genotoxic activity. Fluorinated compounds exhibited higher genotoxicity regardless of the presence of CH3 at C-2 or NO2 at C-4 or C-5. However, in compounds 11 (2-CH3; 4-NO2; N-CH2OHCH2Cl) and 12 (2-CH3; 4-NO2; N-CH2OHCH2F)...

Animal model for age- and sex-related genotoxicity of diethylstilbestrol

Fučić,A.; Stojkovic,R.; Katić,J.; Markovic,D.; Ferencic,Z.; Koršić,M.; Jazbec,A.M.; Gamulin,M.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2009 EN
Relevância na Pesquisa
37.13%
Environmental xenoestrogens pose a significant health risk for all living organisms. There is growing evidence concerning the different susceptibility to xenoestrogens of developing and adult organisms, but little is known about their genotoxicity in pre-pubertal mammals. In the present study, we developed an animal model to test the sex- and age-specific genotoxicity of the synthetic estrogen diethylstilbestrol (DES) on the reticulocytes of 3-week-old pre-pubertal and 12-week-old adult BALB/CJ mice using the in vivo micronucleus (MN) assay. DES was administered intraperitoneally at doses of 0.05, 0.5, and 5 µg/kg for 3 days and animals were sampled 48, 72 and 96 h, and 2 weeks after exposure. Five animals were analyzed for each dose, sex, and age group. After the DES dose of 0.05 µg/kg, pre-pubertal mice showed a significant increase in MN frequency (P < 0.001), while adults continued to show reference values (5.3 vs 1.0 MN/1000 reticulocytes). At doses of 0.5 and 5 µg/kg, MN frequency significantly increased in both age groups. In pre-pubertal male animals, MN frequency remained above reference values for 2 weeks after exposure. Our animal model for pre-pubertal genotoxicity assessment using the in vivo MN assay proved to be sensitive enough to distinguish age and sex differences in genome damage caused by DES. This synthetic estrogen was found to be more genotoxic in pre-pubertal mice...

Evaluation of genotoxicity using the micronucleus assay and nuclear abnormalities in the tropical sea fish Bathygobius soporator (Valenciennes, 1837) (Teleostei, Gobiidae)

Galindo,Toni P.; Moreira,Lília M.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
Relevância na Pesquisa
37.13%
The micronucleus and nuclear abnormalities assays have been used increasingly to evaluate genotoxicity of many compounds in polluted aquatic ecossystems. The aim of this study is to verify the efficiency of the micronucleus assay and nuclear abnormality assay in field and laboratory work, when using erythrocytes of the tropical marine fish Bathygobius soporator as genotoxicity biomarkers. Gill peripheral blood samples were obtained from specimens of Bathygobius soporator. In order to investigate the frequencies of micronuclei and to assess the sensitivity of species, the results were compared with samples taken at the reference site and maintained in the laboratory, and fish treated with cyclophosphamide. The micronucleus assay was efficient in demonstrating field pollution and reproducing results in the labotatory. There were significant higher frequencies of micronuclei in two sites subject to discharge of urban and industrial effluents. The nuclear abnormality assay did not appear to be an efficient tool for genotoxicity evaluation when compared with field samples taken at a reference site in laboratory, with a positive control.

Genotoxicity and mutagenicity of Echinodorus macrophyllus (chapéu-de-couro) extracts

Vidal,Leonardo S.; Alves,Adriana M.; Kuster,Ricardo M.; Lage,Claudia; Leitão,Alvaro C.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
37.13%
Echinodorus macrophyllus, commonly known as chapéu-de-couro, is a medicinal plant used in folk medicine to treat inflammation and rheumatic diseases. In this work, we used short-term bacterial assays based on the induction of SOS functions to examine the genotoxicity and mutagenicity of an aqueous extract of E. macrophyllus leaves. Whole extract and an ethyl acetate fraction showed similar genotoxicity and caused an ~70-fold increase in lysogenic induction. The extract also gave a positive result in the SOS chromotest with an increase of 12-fold in β-Galactosidase enzymatic units. There was a strong trend towards base substitutions and frameshifts at purine sites in the mutations induced by the extract in Escherichia coli (CC103 and CC104 strains) and Salmonella typhimurium test strains (22-fold increase in histidine revertants in TA98 strain). Since reactive oxygen species may be implicated in aging process and in degenerative diseases, we used antioxidant compounds as catalase, thiourea and dipyridyl in the lysogenic induction test. All this compounds were able to reduce the induction factor observed in the treatment with chapéu-de-couro, thus suggesting that the genotoxicity and mutagenicity were attributable to the production of reactive oxygen species that targeted DNA purines.

The influence of organic solvents on estimates of genotoxicity and antigenotoxicity in the SOS chromotest

Quintero,Nathalia; Stashenko,Elena E.; Fuentes,Jorge Luis
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
Relevância na Pesquisa
37.2%
In this work, the toxicity and genotoxicity of organic solvents (acetone, carbon tetrachloride, dichloromethane, dimethylsulfoxide, ethanol, ether and methanol) were studied using the SOS chromotest. The influence of these solvents on the direct genotoxicity induced by the mutagens mitomycin C (MMC) and 4-nitroquinoline-1-oxide (4-NQO) were also investigated. None of the solvents were genotoxic in Escherichia coli PQ37. However, based on the inhibition of protein synthesis assessed by constitutive alkaline phosphatase activity, some solvents (carbon tetrachloride, dimethylsulfoxide, ethanol and ether) were toxic and incompatible with the SOS chromotest. Solvents that were neither toxic nor genotoxic to E. coli (acetone, dichloromethane and methanol) significantly reduced the genotoxicity of MMC and 4-NQO. When these solvents were used to dissolve vitamin E they increased the antigenotoxic activity of this compound, possibly through additive or synergistic effects. The relevance of these results is discussed in relation to antigenotoxic studies. These data indicate the need for careful selection of an appropriate diluent for the SOS chromotest since some solvents can modulate genotoxicity and antigenotoxicity.

Comparison of the in vivo and in vitro genotoxicity of glyphosate isopropylamine salt in three different organisms

Alvarez-Moya,Carlos; Reynoso Silva,Mónica; Valdez Ramírez,Carlos; Gómez Gallardo,David; León Sánchez,Rafael; Canales Aguirre,Alejandro; Feria Velasco,Alfredo
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
Relevância na Pesquisa
37.13%
There is considerable controversy with regard to the genotoxicity of glyphosate, with some reports stating that this compound is non-toxic for fish, birds and mammals. In this work, we used the comet assay to examine the genotoxicity of glyphosate isopropylamine (0.7, 7, 70 and 700 µM) in human lymphocytes, erythrocytes of Oreochromis niloticus and staminal nuclei of Tradescantia (4430) in vitro and in vivo. Cells, nuclei and fish that had and had not been exposed to 5 mM N-nitrosodiethylamine (NDEA) were used as positive and negative controls, respectively. Significant (p < 0.01) genetic damage was observed in vivo and in vitro in all cell types and organisms tested. Human lymphocytes and Tradescantia hairs showed lower genetic damage in vivo compared to in vitro, possibly because of efficient metabolization of the herbicide. In O. niloticus erythrocytes, significant (p < 0.001) genotoxicity was observed at > 7 µM, whereas in vitro, glyphosphate was genotoxic in human lymphocytes and Tradescantia hairs at > 0.7 µM. These results indicate that glyphosate is genotoxic in the cells and organisms studied at concentrations of 0.7-7 µM.

Citotoxicidade e genotoxicidade do percarbonato de s??dio: compara????o com agentes clareadores comumente utilizados no tratamento de dentes despolpados; Cytotoxicity and genotoxicity of sodium percarbonate: a comparison with bleaching agents commonly used in discolored pulpless teeth

MOR??NIGO, Maria Raquel Fern??ndez
Fonte: Universidade Federal de Pelotas; Odontologia; Programa de P??s-Gradua????o em Odontologia; UFPel; BR Publicador: Universidade Federal de Pelotas; Odontologia; Programa de P??s-Gradua????o em Odontologia; UFPel; BR
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
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Aim: To evaluate the cytotoxicity and genotoxicity of sodium percarbonate in comparison with bleaching agents used in discolored pulpless teeth from a mouse fibroblast cell culture. Methodology: The bleaching agents cytotoxicity and genotoxity were evaluated both in their pure form of products as well as in concentration commonly used in clinical practice. Hydrogen peroxide (HP), carbamide peroxide (CP), sodium perborate (SP) and sodium percarbonate (SPC) were diluted in DMEM in series. To evaluate the cytotoxicity, the survival of 3T3 mouse fibroblasts were measured photometrically by using MTT assay after a 24h exposure period. Genotoxicity was indicated by the micronuclei (MN) formation and the modification of the normal cell was analyzed by light microscopy (400x). The statistical analysis was performed by one-way ANOVA, followed by a multiplecomparison Tukey post hoc test (p < 0.05). Results: All tested groups exhibited a dose-dependent cytotoxicity. However, CP has showed a similar cytotoxic effect when compared with DMEM untreated control (UC) group. PH and SPC were significantly more cytotoxic than SP. Genotoxicity test has showed that SPC and SP have presented an intermediate rate of MN frequency over the UC group. The mean rate of MN frequency to HP was higher and statistically more significant than other groups tested. No difference was observed when CP and UC groups were compared. Conclusions: The results suggest that the cytotoxicity of SPC was similar to HP and significantly more cytotoxic than SP and CP. On the other hand...

Genotoxicity investigation of organic n-chloramines.

Laingam, Somprasong
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010
Relevância na Pesquisa
37.38%
Organic N-chloramines have long been recognised as disinfection by-products (DBPs) found in both chlorinated and chloraminated water, but have gained little attention from water authorities in the past. However, in recent years studies have shown that organic N-chloramines are molecules involved in inflammation and several chronic diseases including cancers. A recent study (Bull et al., 2006) has suggested that organic N-chloramines can be potential health risks but due to a lack of available toxicological information toxicity studies of compounds in this group have been recommended as a priority in DBPs research. The aim of this study was to investigate genotoxicity of individual organic N-chloramines utilising a mammalian cell-based genotoxicity assay to help determine which compound(s) should be subject to further in vivo studies. The flow cytometry-based micronucleus (FCMN) assay was optimised and validated for use as a rapid screening for genotoxicity of organic N-chloramine candidates. A number of assay validations were conducted on two mammalian cell lines (WIL2-NS and L5178Y) using model genotoxicants with various modes of action. Comparative studies on these two cell lines showed that WIL2-NS cells were suitable for the FCMN assay and therefore selected for use in all studies described in this thesis. For the genotoxicity investigation of organic N-chloramines...

Acute effects of a prooxidant herbicide on the microalga Chlamydomonas reinhardtii: Screening cytotoxicity and genotoxicity endpoints

Esperanza, Marta; Cid Blanco, Ángeles; Herrero López, Concepción; Rioboo Blanco, Carmen
Fonte: Elsevier Publicador: Elsevier
Tipo: info:eu-repo/semantics/acceptedVersion
ENG
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37.25%
Since recent evidence has demonstrated that many types of chemicals exhibit oxidative and/or genotoxic potential on living organisms, reactive oxygen species (ROS) formation and DNA damage are currently the best accepted paradigms to assess the potential hazardous biological effects of a wide range of contaminants. The goal of this study was to evaluate the sensitivity of different cytotoxicity and genotoxicity responses on the model microalga Chlamydomonas reinhardtii exposed to the prooxidant herbicide paraquat. In addition to the growth endpoint, cell viability, mitochondrial membrane potential and presence of reactive oxygen species (ROS) were assayed as potential markers of cytotoxicity using flow cytometry (FCM). To study the effects of paraquat on C. reinhardtii DNA, several genotoxicity approaches were implemented for the first time in an ecotoxicological study on microalgae. Oxidative DNA base damage was analysed by measuring the oxidative DNA lesion 8-OHdG by FCM. DNA fragmentation was analysed by different methods: comet assay, and cell cycle analysis by FCM, with a particular focus on the presence of subG1-nuclei. Finally, effects on morphology of nuclei were monitored through DAPI staining. The evaluation of these endpoints showed that several physiological and biochemical parameters reacted to oxidative stress disturbances with greater sensitivity than integrative parameters such as growth rates or cell viability. The experiments revealed concentration-dependent cytotoxicity (ROS formation...

Studies of genotoxicity and mutagenicity of nitroimidazoles: demystifying this critical relationship with the nitro group

Boechat,Núbia; Carvalho,Alcione S; Salomão,Kelly; Castro,Solange L de; Araujo-Lima,Carlos F; Mello,Francisco VC; Felzenszwalb,Israel; Aiub,Claudia AF; Conde,Taline Ramos; Zamith,Helena PS; Skupin,Rolf; Haufe,Günter
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
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37.13%
Nitroimidazoles exhibit high microbicidal activity, but mutagenic, genotoxic and cytotoxic properties have been attributed to the presence of the nitro group. However, we synthesised nitroimidazoles with activity against the trypomastigotes of Trypanosoma cruzi, but that were not genotoxic. Herein, nitroimidazoles (11-19) bearing different substituent groups were investigated for their potential induction of genotoxicity (comet assay) and mutagenicity (Salmonella/Microsome assay) and the correlations of these effects with their trypanocidal effect and with megazol were investigated. The compounds were designed to analyse the role played by the position of the nitro group in the imidazole nucleus (C-4 or C-5) and the presence of oxidisable groups at N-1 as an anion receptor group and the role of a methyl group at C-2. Nitroimidazoles bearing NO2 at C-4 and CH3 at C-2 were not genotoxic compared to those bearing NO2 at C-5. However, when there was a CH3 at C-2, the position of the NO2 group had no influence on the genotoxic activity. Fluorinated compounds exhibited higher genotoxicity regardless of the presence of CH3 at C-2 or NO2 at C-4 or C-5. However, in compounds 11 (2-CH3; 4-NO2; N-CH2OHCH2Cl) and 12 (2-CH3; 4-NO2; N-CH2OHCH2F)...

Characterization of cytotoxicity and genotoxicity of sediments from a potentially contaminated estuary

Pinto, Miguel
Fonte: Instituto Nacional de Saúde Doutor Ricardo Jorge Publicador: Instituto Nacional de Saúde Doutor Ricardo Jorge
Tipo: Dissertação de Mestrado
Publicado em //2011 ENG
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Dissertação de mestrado apresentada à Faculdade de Ciências da Universidade de Lisboa, 2011; The Sado Estuary (W Portugal) is affected by various sources of pollution, associated with the existence of an urban center, heavy-industry, mining activities and agriculture. It also remains a privileged site for fishing activities that are responsible for the supplying of consumable resources either locally or externally. Previous studies revealed sizable amounts of contaminants in the estuary sediments, namely metals, pesticides and polycyclic aromatic hydrocarbons. These compounds can be absorbed and accumulated in the edible parts of estuarine species and in local agricultural products, thus entering the human food chain and posing a public health problem. This study aims to assess the cytotoxic and genotoxic effects of sediments from the Sado Estuary in a human cell line, in order to contribute to hazard identification. Sediments were collected in 4 distinct fishing sites (P, E, A, C) of the Sado Estuary; a reference (Mf) and a potentially contaminated sample (M) from a different estuary (Mira Estuary, W Portugal) were also included. Total organic and inorganic contaminants were extracted with a mixture of methanol:dicholomethane and recovered in DMSO. HepG2 cells were exposed for 48h to several concentrations of each extract. Cytotoxicity was measured by the neutral red assay and genotoxicity by the comet assay. A dose-related decrease in cell viability was observed for extracts P...