In utero and lactational exposure to fenvalerate disrupts reproductive function in female rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genotoxic, mutagenic and cytotoxic effects of the commercial dye CI Disperse Blue 291 in the human hepatic cell line HepG2

Textile dyes are discarded into the aquatic ecosystem via industrial effluents and potentially expose humans and local biota to adverse effects. The commercial dye CI Disperse Blue 291 which contains the aminoazobenzene 2-[(2-bromo-4,6-dinitrophenyl)azo]-5(diethylamino)-4-methoxyacetanilide (CAS registry no. 56548-64-2), was tested for genotoxicity and cytotoxicity in the human hepatoma cell line HepG2, using the comet assay, micronucleus (MN) test and a cell viability test. Five different concentrations of the test compound were examined: 200 mu g/ml, 400 mu g/ml, 600 mu g/ml, 800 mu g/ml and 1000 mu g/ml. An increase in comet tail length and in the frequency of MN was detected with exposure of cells to concentrations of the commercial dye from 400 pg/ml. Furthermore, the dye was found to decrease cell viability. The results of this study demonstrate for the first time the genotoxic and mutagenic effects of the dye CI Disperse Blue 291 in mammalian cells, thus stressing the need to develop non-mutagenic dyes and to invest in improving the treatment of effluents. These measures will help to prevent harmful effects that these compounds can have on humans and aquatic organisms that come in contact with them. (C) 2007 Elsevier Ltd. All rights reserved.

Evaluation of the antigenotoxicity of polysaccharides and beta-glucans from Agaricus blazei, a model study with the single cell gel electrophoresis/Hep G2 assay

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Allium cepa test in environmental monitoring: A review on its application

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Protective effects of beta-glucan extracted from barley against benzo[a]pyrene-induced DNA damage in hepatic cell HepG2

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

BTEX biodegradation by bacteria from effluents of petroleum refinery

Groundwater contamination with benzene, toluene, ethylbenzene and xylene (BTEX) has been increasing, thus requiring an urgent development of methodologies that are able to remove or minimize the damages these compounds can cause to the environment. The biodegradation process using microorganisms has been regarded as an efficient technology to treat places contaminated with hydrocarbons, since they are able to biotransform and/or biodegrade target pollutants. To prove the efficiency of this process, besides chemical analysis, the use of biological assessments has been indicated. This work identified and selected BTEX-biodegrading microorganisms present in effluents from petroleum refinery, and evaluated the efficiency of microorganism biodegradation process for reducing genotoxic and mutagenic BTEX damage through two test-systems: Allium cepa and hepatoma tissue culture (HTC) cells. Five different non-biodegraded BTEX concentrations were evaluated in relation to biodegraded concentrations. The biodegradation process was performed in a BOO Trak Apparatus (HACH) for 20 days, using microorganisms pre-selected through enrichment. Although the biodegradation usually occurs by a consortium of different microorganisms, the consortium in this study was composed exclusively of five bacteria species and the bacteria Pseudomonas putida was held responsible for the BTEX biodegradation. The chemical analyses showed that BTEX was reduced in the biodegraded concentrations. The results obtained with genotoxicity assays, carried out with both A. cepa and HTC cells, showed that the biodegradation process was able to decrease the genotoxic damages of BTEX. By mutagenic tests, we observed a decrease in damage only to the A. cepa organism. Although no decrease in mutagenicity was observed for HTC cells, no increase of this effect after the biodegradation process was observed either. The application of pre-selected bacteria in biodegradation processes can represent a reliable and effective tool in the treatment of water contaminated with BTEX mixture. Therefore, the raw petroleum refinery effluent might be a source of hydrocarbon-biodegrading microorganisms. (c) 2010 Elsevier B.A. All rights reserved.

The Allium cepa bioassay to evaluate landfarming soil, before and after the addition of rice hulls to accelerate organic pollutants biodegradation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chlorination treatment of aqueous samples reduces, but does not eliminate, the mutagenic effect of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do potencial genotóxico do extrato bruto de Pyrostegia venusta (Ker Gawl.) Miers, Bignoneaceae, em medula óssea de camundongos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos tardios dos praguicidas organoclorados no homem

Procurou-se relacionar as informações disponíveis sobre os organoclorados e os efeitos crônicos provocados pela exposição. Os compostos organoclorados são os praguicidas mais persistentes já fabricados. Embora sejam geralmente eficientes no controle das pragas, são importantes poluentes ambientais e potenciais causas de problemas de saúde para o homem, tendo sido proibidos ou controlados na maioria dos países. Com poucas exceções, os efeitos tardios desses compostos sobre a saúde humana são difíceis de detectar, em função de dificuldades metodológicas e da extrapolação dos resultados. A genotoxicidade está entre os mais sérios dos possíveis danos causados por esses compostos e merece atenção especial, devido à natureza irreversível do processo. Outro ponto a ser considerado é o aumento na incidência de alterações no desenvolvimento do trato reprodutivo e na fertilidade masculina observada nas últimas décadas provavelmente decorrente do aumento da exposição intra-uterina a compostos estrogênicos e anti-androgênicos, como os organoclorados.

Dehydromonocrotaline inhibits mitochondrial complex 1. A potential mechanism accounting for hepatotoxicity of monocrotaline

Monocrotaline is a pyrrolizidine alkaloid present in plants of the Crotalaria species, which causes cytotoxicity and genotoxicity, including hepatotoxicity in animals and humans. It is metabolized by cytochrome P-450 in the liver to the alkylating agent dehydromonocrotaline. We evaluated the effects of monocrotaline and its metabolite on respiration, membrane potential and ATP levels in isolated rat liver mitochondria, and on respiratory chain complex I NADH oxidase activity in submitochondrial particles. Dehydromonocrotaline, but not the parent compound, showed a concentration-dependent inhibition of glutamate/malate-supported state 3 respiration (respiratory chain complex 1), but did not affect succinate-supported respiration (complex II). Only dehydromonocrotaline dissipated mitochondrial membrane potential, depleted ATP, and inhibited complex I NADH oxidase activity (IC50 = 62.06 mu M) through a non-competitive type of inhibition (K-I = 8.1 mu M). Therefore, dehydromonocrotaline is an inhibitor of the activity of respiratory chain complex I NADH oxidase, an action potentially accounting for the well-documented monocrotaline's hepatotoxicity to animals and humans. The mechanism probably involves change of the complex I conformation resulting from modification of cysteine thiol groups by the metabolite. (c) 2007 Elsevier Ltd. All rights reserved.

Early cytotoxic and genotoxic effects of atrazine on Wistar rat liver: A morphological, immunohistochemical, biochemical, and molecular study

Risk assessments suggest that intermediate and long-term exposure to triazine herbicides and its metabolites through water can cause severe damage to human health. The objective of this study was to investigate the possible effects of atrazine on Wistar rats submitted to subacute treatment. For this purpose, the activity of catalase and alanine aminotransferase was quantified, and the effect of the herbicide on cell membranes was examined based on the measurement of lipid peroxidation and consequent formation of malondialdehyde and on the mRNA expression of antioxidant enzymes (Mn-superoxide dismutase [SOD] and GSTM1) and connexins. In addition, we evaluated histopathological alterations in the liver, cellular expression of SOD and glutathione (GST), activation of heat shock proteins (HSPs) by immunohistochemistry, and the induction of apoptosis. The genotoxic potential of the herbicide was investigated by the micronucleus test in bone marrow smears. Adult male Wistar rats were treated with an aqueous solution of atrazine at a concentration of 400 mg/kg/day, by gavage, for 14 consecutive days. Control groups were also included. The results showed an increase of catalase levels and maintenance of the expression of antioxidant enzymes (SOD and GST). In addition, lipid peroxidation, hepatic tissue degeneration, activation of HSP90, increased levels of connexin mRNA, and genotoxicity were observed. In conclusion, atrazine induced early hepatic oxidative stress that triggered defense mechanisms to maintain the morphophysiological integrity of the liver. Further studies are needed to better understand the effects of this herbicide on human health. (C) 2011 Elsevier B.V. All rights reserved.

Dehydromonocrotaline induces cyclosporine A-insensitive mitochondrial permeability transition/cytochrome c release

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of monocrotaline on energy metabolism in the rat liver

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mutagenic and genotoxic effects of the Atrazine herbicide in Oreochromis niloticus (Perciformes, Cichlidae) detected by the micronuclei test and the comet assay

Atrazine is the triazinic herbicide most found in the rural aquatic environments due to its extensive use and its stability in such places. The mutagenicity and the genotoxicity of different concentrations of the Atrazine herbicide were determinated by the micronucleus test and the comet assay, using Oreochromis niloticus as test-system. The tested concentrations of Atrazine herbicide were 6.25, 12.5 and 25 mu g/L, both for the micronuclei test and for the comet assay. The results showed a significant rate of micronuclei and nuclear abnormalities for all the tested concentrations of Atrazine herbicide. For the comet assay, we also observed results significantly different from the control in 6.25, 12.5 and 25 mu g/L concentrations. Due to these results, we could infer that such herbicide may be dangerous to the lives of those organisms exposed to it. (c) 2007 Elsevier B.V. All rights reserved.