This dissertation investigated locational risks to ecosystem health associated with proximity to industrial complexes. The study was performed at the behest of ranchers and citizens living and working down-prevailing wind from the Formosa Plastics, Inc. and ALCOA facilities located in Calhoun County, Texas. Concerns expressed were for potential genotoxicity resulting from exposure to complex chemical mixtures released by the facilities. Exposure assessment of the marine environment was performed with sediments and oysters from Lavaca Bay being analyzed. Numerous chemicals were found to be present at concentrations considered likely to result in adverse responses in exposed populations. Bayesian geostatistical analysis was performed to determine if the concentrations were affected by a spatial process. Mercury and polycyclic aromatic hydrocarbons were the most notable of the chemicals found to be present at elevated concentrations and affected by a spatial process. Evaluation of maps generated from spatial modeling revealed that proximity to ALCOA resulted in elevated risks for exposure to harmful concentrations of pollutants. Genotoxicity was measured in two sentinel species. Oysters (Crassostrea virginica) were utilized for evaluation of the marine environment and cattle (Bos taurus and Bos taurus crossbred cattle) were chosen for evaluation of the terrestrial environment. Chromosomal aberration analysis was performed on oyster hematocytes. Analysis of the results failed to demonstrate the presence of an important generalized spatial process but some specific locations close to the ALCOA plant had elevations in this measure of genotoxicity. Stress as measured by the lysosomal destabilization assay was also performed on oyster hematocytes. These results were found to be affected by a significant spatial process with the highest degree of destabilization occurring in close proximity to ALCOA. Genotoxicity in cattle was evaluated with the single cell gel electrophoresis assay and chromosomal aberration analysis. Bayesian geostatistical analyis revealed the presence of important spatial processes. DNA-protein cross-linkage was the most notable with a strong indication of increased damage down-prevailing wind from the industrial complexes. Results indicated that proximity to industrial facilities increased the risk for harmful exposures, genotoxicity, and lysosomal destabilization.

Complex chemical mixtures may be released into the environment from a variety of sources including hazardous waste sites. Components of chemical mixtures and their metabolites may be genotoxic leading to cancer and heritable gene mutations. Chemical analysis alone does not always provide the most accurate information from which to estimate the risk of adverse effects associated with exposure to mixtures. Current methods to estimate the human health risk for complex mixtures assume additive effects of the components. Although it is assumed that this approach is protective of human and ecological health, it is also recognized that chemical mixtures may induce a variety of interactions including potentiation, synergism, and antagonism. A combined testing protocol, using chemical analysis coupled with a battery of in vitro, in vivo, and in situ bioassays, provides the most accurate information from which to estimate risk. Such a combined testing protocol provides information to describe the major organic and inorganic constituents, as well as the pharmacokinetics and potential interactions of chemical mixtures. This research was conducted to investigate the potential genotoxic effects of complex chemical mixtures of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated aromatics (PCA) using microbial bioassays (Salmonella/microsome assay and the E. coli prophage induction assay), the 32P-postlabeling assay in mice, and in situ measurements of genotoxicity using flow cytometry. Samples of environmental media and wildlife tissues were collected from four National Priority List Superfund sites within the United States. In general, chemical analysis was not always predictive of mixture toxicity. Although biodegradation reduced the concentration of total and carcinogenic PAHs in soils and groundwater, the genotoxicity of extracts from environmental media did not display a corresponding reduction. Mixtures of polychlorinated biphenyls (PCBs) extracted from sediments were found to inhibit the genotoxicity of PAH mixtures when administered dermally to rodents. This inhibition exhibited a dose-response relationship, with the adduct frequency reduced at increasing doses of sediment extract. Finally, PAH concentrations in environmental media and tissues were found to correlate with DNA damage in wildlife receptors. An integrated approach, combining in vitro and in vivo methods to characterize genotoxicity provides more accurate information from which to estimate uptake and risk associated with exposure to complex mixtures and should be considered in both the human and ecological risk assessment process.

This dissertation investigated locational risks to ecosystem health associated with proximity to industrial complexes. The study was performed at the behest of ranchers and citizens living and working down-prevailing wind from the Formosa Plastics, Inc. and ALCOA facilities located in Calhoun County, Texas. Concerns expressed were for potential genotoxicity resulting from exposure to complex chemical mixtures released by the facilities. Exposure assessment of the marine environment was performed with sediments and oysters from Lavaca Bay being analyzed. Numerous chemicals were found to be present at concentrations considered likely to result in adverse responses in exposed populations. Bayesian geostatistical analysis was performed to determine if the concentrations were affected by a spatial process. Mercury and polycyclic aromatic hydrocarbons were the most notable of the chemicals found to be present at elevated concentrations and affected by a spatial process. Evaluation of maps generated from spatial modeling revealed that proximity to ALCOA resulted in elevated risks for exposure to harmful concentrations of pollutants. Genotoxicity was measured in two sentinel species. Oysters (Crassostrea virginica) were utilized for evaluation of the marine environment and cattle (Bos taurus and Bos taurus crossbred cattle) were chosen for evaluation of the terrestrial environment. Chromosomal aberration analysis was performed on oyster hematocytes. Analysis of the results failed to demonstrate the presence of an important generalized spatial process but some specific locations close to the ALCOA plant had elevations in this measure of genotoxicity. Stress as measured by the lysosomal destabilization assay was also performed on oyster hematocytes. These results were found to be affected by a significant spatial process with the highest degree of destabilization occurring in close proximity to ALCOA. Genotoxicity in cattle was evaluated with the single cell gel electrophoresis assay and chromosomal aberration analysis. Bayesian geostatistical analyis revealed the presence of important spatial processes. DNA-protein cross-linkage was the most notable with a strong indication of increased damage down-prevailing wind from the industrial complexes. Results indicated that proximity to industrial facilities increased the risk for harmful exposures, genotoxicity, and lysosomal destabilization.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / A radiação ultravioleta (UV) induz diversos efeitos nocivos nos organismos e a quantidade desta radiação que atinge a biosfera é afetada pela concentração de ozônio, latitude, altitude, clima e reflexão especular. As respostas de briófitas em relação aos efeitos da radiação UV e a presença de compostos que absorvem esta radiação têm sido estudadas. Sanionia uncinata, Holomitriopsis laevifolia e Leucobryum laevifolium são espécies de musgos encontrados em locais expostos a alta incidência de radiação UV e com habitats distintos. Considerando que as respostas de musgos contra os efeitos da radiação UV e seus mecanismos de proteção ainda são pouco caracterizados, o objetivo deste estudo foi investigar o potencial fotoprotetor e possíveis riscos toxicológicos associados aos extratos dos musgos S. uncinata, proveniente da Antártica e H. laevifolia e L. laevifolium, proveniente do Amazonas. Seus extratos metanólico (EM), aquoso (EA), hidroalcoólico (EH) e etanólico (EE) foram estudados com a caracterização química por absorção ao UV e visível e pela cromatografia líquida de alta eficiência; quantificação do índice total de compostos fenólicos; determinação da capacidade captadora do radical 2,2-difenil-1-picril-hidrazila a fim de avaliar as atividades antioxidantes; avaliação do potencial de fotoproteção cutânea pela determinação do fator de proteção solar; avaliações do potencial mutagênico e citototóxico, através do ensaio de Salmonella/microssoma, utilizando as cepas TA97, TA98, TA100, TA102 e TA104; do potencial fotomutagênico através do ensaio de fotomutagenicidade, usando as cepas TA102 e TA104; e investigação dos efeitos genotóxicos e fotogenotóxicos, pelo ensaio de micronúcleo e fotomicronúcleo, respectivamente, usando diferentes linhagens celulares estabelecidas. Foram encontradas atividades fotoprotetoras e antioxidantes e observou-se que os extratos se apresentaram singulares devido a sua composição química. Os resultados fotoprotetores, além dos mutagênicos/fotomutagênicos, genotóxicos/fotogenotóxicos e suas respectivas avaliações citotóxicas também permitiram selecionar extratos e suas concentrações, como promissores candidatos em fotoproteção Assim, os EA e EH de H. laevifolia e L. laevifolium apresentam, no geral, os resultados mais significativos, tornando-se potenciais para avaliações refinadas em fotoproteção e na separação de componentes que possam levar a futuras aplicações como antioxidantes e protetores solares ou como adjuvantes. / The ultraviolet radiation (UV) induces many harmful effects in all living organisms and the amount of this radiation that reaching the ground is affected by many factors including ozone concentration, latitude, altitude, climate and specular reflection. The responses of bryophytes against the effects of UV radiation and the presence of compounds that absorb the UV region have been studied. Mosses Sanionia uncinata, Holomitriopsis laevifolia and Leucobryum laevifolium are found in locations exposed to UV at high levels of radiation and in different habitats. Whereas that the responses of mosses against the effects of UV radiation and their protection systems are poorly characterized yet, the aim of this study was to investigate photoprotective potential and possible toxicological risks associated with extracts of mosses S. uncinata (from Antarctica) and H. laevifolia and L. laevifolium (from Amazônia). Methanol (ME), aqueous (AE), hydroalcoholic (HE) and ethanolic (EE) were studied by: chemical characterization by UV/visible spectrophotometry and by High performance liquid chromatography; phenolic content estimation; 2,2-diphenyl-1-picrylhydrazyl scavenging activity; potential of skin photoprotection by in vitro determination of sun protection factor; the mutagenic potential, and cytotoxic by Salmonella/microsome assay, using the TA97, TA98, TA100, TA102 and TA104 strains; photomutagenic potential by photomutagenicity test, using TA102 and TA104 strains and; investigation of genotoxic and photogenotoxic effects by micronucleus test and photo-micronucleous assay, respectively, using different established cell lines. Photoprotective and antioxidant activities were found and it was observed that the extracts showed strong uniqueness due to its chemical composition. From the photoprotective, mutagenic/photomutagenic and genotoxic/photogenotoxic results and their cytotoxic evaluations it was possible to select extracts and their concentrations as promising candidates for photoprotection. Thus, the EA and EH of H. laevifolia and L. laevifolium demonstrated the most significant results, becoming potential for refined evaluations in photoprotection and separating components that can lead to future applications such as sunscreens and antioxidants or as adjuvants.

Phenolic antioxidants reduce the effect of oxidative stress within cells. They are found in a various fruits, vegetables and as food additives to reduce spoilage. Consumption of antioxidants by humans has been linked with increased lifespan and reduced incidence of cancer and cardiovascular disorders (Cabrera et al. 2006; Kuriyama 2008). In cultured mammalian cells however, some of these phenolic antioxidants have been reported to generate reactive oxygen species (ROS), leading to chromosomal breakage (Long et al. 2007; Long & Halliwell 2001). It is clear then, that amongst this group of compounds, in vitro toxicological study is not a reliable prediction of human hazard. It is for this reason that the work described in this thesis was undertaken: the principal aim was to gain a better understanding of the reasons underlying this contradiction. It has been suggested that excessive ROS generated in vitro might be a result of the higher levels of oxygen (~20%) compared to (1-7%) in vivo: (Yusa et al. 1984; Turrens et al. 1982). With clearer understanding, new experimental approaches might be taken to highlight or reduce positive in vitro genotoxicity test results that might be considered misleading. A diverse set of test compounds was first chosen. It included polyphenolic (PPA), monophenolic (MPA) and non-phenolic antioxidants (NPA), in addition to mechanistically characterised oxidants, genotoxins and cytotoxic, non-genotoxins as controls. Genotoxicity was assessed in vitro using the GADD45a, GFP reporter assay and in silico using Derek Nexus™. Amongst the 19 antioxidants assessed, the 11 of 12 of PPAs, 0 of 4 MPAs and 1 of 3 NPAs (ethoxyquin) produced positive results in vitro and 8 of 12 PPAs generated alerts of at least plausible genotoxicity in silico. To discover whether these results were the result of cellular hyperoxia-promoted generation of physiologically irrelevant ROS in cells, genotoxicity was reassessed in the presence of 1 and 5% oxygen. This reduced oxygen exposure had no effect upon the qualitative result for any of the assessed compounds and a negligible effect upon the dose at which any positive result was produced. An assessment of the ability of antioxidants to generate potentially genotoxic ROS within cells was carried out using the intracellular fluorescent dye, dichlorofluorescin diacetate (DCFH-DA). 10 of 12 PPAs, 0 of 4 MPAs and 1 of 3 NPAs (ethoxyquin) were shown to increase the level of ROS within TK6 human lymphoblastoid cells within 4 hours of compound exposure. Within this same timeframe, the mitochondrial membranes in cells treated with 10 of 12 PPAs, 2 of 4 MPAs and 1 of 3 NPAs (ethoxyquin) were shown to become depolarised using JC-1 dye. It was unclear however, whether mitochondrial membrane depolarisation was a cause or a consequence of ROS generation within the cells. In order to assess whether the increase in intracellular ROS led to an increase in oxidised DNA within treated cells, 8-oxoguanine (8-OG) was quantified using a FITC conjugated anti8-OG antibody. This assessment revealed that levels of the oxidised base were only increased in cells exposed to two of the 12 PPAs (quercetin and resorcinol). The level of 8OG detected was lower than the vehicle control for cells treated with 10 of the 15 antioxidants. One interpretation of this is that these agents induce the repair pathway for oxidative damage, which leads to a lower level of oxidised DNA bases in the genome. The results showed that while a large proportion of PPAs produce genotoxic results in vitro and lead to increased levels of ROS, the amount of oxidised DNA is not higher in treated cells. This would suggest the presence of a different mechanism for the observed genotoxicity.

Orientador: Carlos Henrique Ribeiro Camargo / Banca: Cácio de Moura Netto / Banca: Marcia Carneiro Valera / Resumo: Objetivo deste estudo foi avaliar a citotoxicidade e a genotoxidade de quatro cimentos endodônticos: AH Plus (Dentsply De Trey, Alemanha); Endo Rez (Ultradent, USA); RoekoSeal (Coltene Whaledent, Alemanha) e o Cimento experimental à base de óleo-resina de Copaiba (Brasil). A avaliação foi realizada em três diferentes tempos após manipulação: 0h, 12h e 24h. Os espécimes foram preparados, deixados por 12 e 24h em estufa (37 °C a 100% umidade a 5% de CO2) e colocados em contato com meio de cultura (82,4 mm2 superfície/ml) por 24 h. Células V79 foram expostas à diferentes diluições dos cimentos por 24 h e a viabilidade celular foi mensurada pelo teste de MTT em espectrofotômetro. Para o teste de genotoxicidade os extratos que apresentaram concentrações de citototoxicidade média foram selecionados para o teste cometa após 24 h de exposição. A viabilidade celular e o dano ao DNA foram comparados aos grupos controles e analisados pelos testes de Kruskal-Wallis e Dunn (p<0,05). No teste de citotoxicidade, todos os cimentos apresentaram diferença significativa em relação ao controle, com exceção do RoekoSeal. A viabilidade celular de acordo com cimento utliizado pode ser classificada da maior toxicidade para a menor seguindo: EndoREZ > AH Plus > Copaíba > RoekoSeal. O dano ao DNA verificado no teste cometa pode ser classificado do maior para o menor em: EndoREZ > RoekoSeal > AH Plus > Copaíba. Conclui-se que o cimento EndoREZ é citotóxico e genotóxico nos tempos e diluições estudadas / Abstract: The aim of this study was to evaluate cytotoxicity and the genotoxicity of four different root canal sealers, AH Plus (Dentsply De Trey, Germany); Endo REZ (Ultradent, USA); RoekoSeal (Coltene Whaledent, Germany) and the experimental root canal sealer based on Copaiba oil-resin sealer (Brazil). The evaluation of the materials was performed after three different times of manipulation: 0h, 12h and 24h. The specimens were prepared, incubated in a humidified incubator (37°C with 5% CO2 in air for 12h and 24h) and them put in contact with the culture medium (82,4 mm2surface/ml) during 24h. V79 cells were exposed at different dilutions of the sealers during 24h and the cell's viability was measured by the MTT test in a spectrophotometer. For the genotoxicity tests, the extracts from the concentrations with medium citotoxicity were selected for the comet assay after 24h of exposure. The cellular viability and the DNA damage were compared with the control groups and analyzed by the tests of Kruskal-Wallis and Dunn (p<0,05). The citotoxicity test showed that all root canal sealers showed a statistically significant difference when compared with the control group, with the exception of the RoekoSeal. The ranking of cell's viability according with sealer utilized from the most to the least toxicic material was: EndoRez > AH Plus > Copaíba > RoekoSeal. The ranking of DNA damage verified at the comet assay, from the most to the least was: EndoREZ > RoekoSeal > AH Plus > Copaíba. It was conclude that, at the times and dilutions studied, the EndoREZ sealer is genotoxic and citotoxic / Mestre

Orientador: Carmem Silvia Fontanetti Christofoletti / Banca: Patricia Pasquali Parise Maltempi / Banca: José Augusto de Oliveira David / Banca: Maria Aparecida Marin-Morales / Banca: Elaine Cristina Mathias da Silva Zacarin / Resumo: O sistema de biorremediação denominado landfarming tem sido utilizado por refinarias de petróleo para dispor e tratar, em grandes áreas de solo, localizadas na própria indústria, o resíduo sólido final gerado, que é composto por uma emulsão formada por água, diversas frações de hidrocarbonetos e metais. Contudo, em landfarmings, a biodegradação de algumas classes de hidrocarbonetos pode levar tempo, meses ou anos. Desse modo, tratamentos complementares podem ser utilizados, visando estimular o metabolismo microbiano, tais como a adição de agentes descompactantes e nutrientes no solo. O progresso da biorremediação pode ser acompanhado por meio de medidas da concentração dos contaminantes de interesse, pela análise do metabolismo microbiano e por meio de ensaios biológicos que mensuram as atividades tóxica, genotóxica e mutagênica das amostras avaliadas. O objetivo do presente trabalho foi investigar os efeitos da adição de dois resíduos agroindustriais, casca de arroz e vinhaça, na biorremediação, na genotoxicidade e na mutagenicidade de um solo de landfarming proveniente de uma refinaria de petróleo, por meio de análises químicas, taxa de CO2 liberado por microrganismos e por meio do teste de anormalidades mitóticas e cromossômicas na espécie vegetal Allium cepa. Também foi objetivo desse trabalho avaliar o potencial bioindicador do invertebrado terrestre Rhinocricus padbergi após exposição a amostras do landfarming desativado. Análises histológicas e histoquímicas no intestino médio e no corpo gorduroso perivisceral do diplópodo foram realizadas. Os resultados do presente trabalho mostraram que a casca de arroz, empregada como agente descompactante do solo, constitui uma alternativa economicamente viável para a biorremediação de resíduos derivados da indústria do petróleo. A adição desse material promoveu um aumento da quantidade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The bioremediation system called landfarming has been used by petroleum refineries to dispose and treat, in large areas of soil, located in the own industry, the final solid residue generated, which is composed by an emulsion formed by water, several fractions of hydrocarbons and metals. However, in landfarmings, the biodegradation of some classes of hydrocarbons can take time, months or years. Thus, complementary treatments can be used in order to stimulate the microbial metabolism, such as addition of uncompressing agents and nutrients in the soil. The bioremediation progress can be monitored by measuring the concentrations of contaminants of interest, by the analysis of the microbial metabolism and by biological assays that measure toxic, genotoxic and mutagenic activities of the assessed samples. The aim of this study was to investigate the effects of adding two agroindustrial residues, rice hull and vinasse, in the bioremediation, genotoxicity and mutagenicity of a soil of landfarming from a petroleum refinery by chemical analyses, rate of CO2 released by microorganisms and by the mitotic and chromosomal abnormalities test in the plant species Allium cepa. It was also objective of this study assess the bioindicator potential of the terrestrial invertebrate Rhinocricus padbergi after exposure to deactivated landfarming samples. Histological and histochemical analyses of the midgut and fat body of this invertebrate were also carried out. The results of this study showed that rice hull, used as an uncompressing agent of the soil, constitutes an economically viable alternative for the bioremediation of residues derived from petroleum industry. The addition of this material promoted an increase in the quantity of CO2 released, decreased the concentration of total petroleum hydrocarbons (TPHs) of the landfarming soil and reduced its genotoxicity. On the contrary, vinasse... (Complete abstract click electronic access below) / Doutor

Conselho Nacional de Desenvolvimento Científico e Tecnológico / A radiação ultravioleta (UV) induz diversos efeitos nocivos nos organismos e a quantidade desta radiação que atinge a biosfera é afetada pela concentração de ozônio, latitude, altitude, clima e reflexão especular. As respostas de briófitas em relação aos efeitos da radiação UV e a presença de compostos que absorvem esta radiação têm sido estudadas. Sanionia uncinata, Holomitriopsis laevifolia e Leucobryum laevifolium são espécies de musgos encontrados em locais expostos a alta incidência de radiação UV e com habitats distintos. Considerando que as respostas de musgos contra os efeitos da radiação UV e seus mecanismos de proteção ainda são pouco caracterizados, o objetivo deste estudo foi investigar o potencial fotoprotetor e possíveis riscos toxicológicos associados aos extratos dos musgos S. uncinata, proveniente da Antártica e H. laevifolia e L. laevifolium, proveniente do Amazonas. Seus extratos metanólico (EM), aquoso (EA), hidroalcoólico (EH) e etanólico (EE) foram estudados com a caracterização química por absorção ao UV e visível e pela cromatografia líquida de alta eficiência; quantificação do índice total de compostos fenólicos; determinação da capacidade captadora do radical 2,2-difenil-1-picril-hidrazila a fim de avaliar as atividades antioxidantes; avaliação do potencial de fotoproteção cutânea pela determinação do fator de proteção solar; avaliações do potencial mutagênico e citototóxico, através do ensaio de Salmonella/microssoma, utilizando as cepas TA97, TA98, TA100, TA102 e TA104; do potencial fotomutagênico através do ensaio de fotomutagenicidade, usando as cepas TA102 e TA104; e investigação dos efeitos genotóxicos e fotogenotóxicos, pelo ensaio de micronúcleo e fotomicronúcleo, respectivamente, usando diferentes linhagens celulares estabelecidas. Foram encontradas atividades fotoprotetoras e antioxidantes e observou-se que os extratos se apresentaram singulares devido a sua composição química. Os resultados fotoprotetores, além dos mutagênicos/fotomutagênicos, genotóxicos/fotogenotóxicos e suas respectivas avaliações citotóxicas também permitiram selecionar extratos e suas concentrações, como promissores candidatos em fotoproteção Assim, os EA e EH de H. laevifolia e L. laevifolium apresentam, no geral, os resultados mais significativos, tornando-se potenciais para avaliações refinadas em fotoproteção e na separação de componentes que possam levar a futuras aplicações como antioxidantes e protetores solares ou como adjuvantes. / The ultraviolet radiation (UV) induces many harmful effects in all living organisms and the amount of this radiation that reaching the ground is affected by many factors including ozone concentration, latitude, altitude, climate and specular reflection. The responses of bryophytes against the effects of UV radiation and the presence of compounds that absorb the UV region have been studied. Mosses Sanionia uncinata, Holomitriopsis laevifolia and Leucobryum laevifolium are found in locations exposed to UV at high levels of radiation and in different habitats. Whereas that the responses of mosses against the effects of UV radiation and their protection systems are poorly characterized yet, the aim of this study was to investigate photoprotective potential and possible toxicological risks associated with extracts of mosses S. uncinata (from Antarctica) and H. laevifolia and L. laevifolium (from Amazônia). Methanol (ME), aqueous (AE), hydroalcoholic (HE) and ethanolic (EE) were studied by: chemical characterization by UV/visible spectrophotometry and by High performance liquid chromatography; phenolic content estimation; 2,2-diphenyl-1-picrylhydrazyl scavenging activity; potential of skin photoprotection by in vitro determination of sun protection factor; the mutagenic potential, and cytotoxic by Salmonella/microsome assay, using the TA97, TA98, TA100, TA102 and TA104 strains; photomutagenic potential by photomutagenicity test, using TA102 and TA104 strains and; investigation of genotoxic and photogenotoxic effects by micronucleus test and photo-micronucleous assay, respectively, using different established cell lines. Photoprotective and antioxidant activities were found and it was observed that the extracts showed strong uniqueness due to its chemical composition. From the photoprotective, mutagenic/photomutagenic and genotoxic/photogenotoxic results and their cytotoxic evaluations it was possible to select extracts and their concentrations as promising candidates for photoprotection. Thus, the EA and EH of H. laevifolia and L. laevifolium demonstrated the most significant results, becoming potential for refined evaluations in photoprotection and separating components that can lead to future applications such as sunscreens and antioxidants or as adjuvants.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-08-02T18:27:23Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação ÉRIMA.pdf: 1439027 bytes, checksum: fdf84cb299bbcf04b46e42fe907f5130 (MD5) / Made available in DSpace on 2016-08-02T18:27:23Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação ÉRIMA.pdf: 1439027 bytes, checksum: fdf84cb299bbcf04b46e42fe907f5130 (MD5) Previous issue date: 2016-02-23 / Capes / Liquens, organismos simbiontes notáveis, produzem metabólitos secundários amplamente citados por suas atividades biológicas. Entretanto, pouco se sabe a respeito do potencial tóxico ao DNA destes fenóis. Este trabalho avaliou o perfil mutagênico e genotóxico dos ácidos úsnico e divaricático, através do teste de Mutação e Recombinação Somática (SMART) e ensaio Cometa, utilizando Drosophila melanogaster como modelo experimental. Organismos descendentes dos cruzamentos entre as linhagens de D. melanogaster mwh e flr3, foram submetidos a diferentes concentrações do ácido úsnico (0,63, 1,26, 2,53, 5,05 e 10,11 mg/mL) e do ácido divaricático (0,32, 0,63, 1,26, 2,53, 5,05 e 10,11 mg/mL). Os resultados foram comparados com o controle positivo, mitomicina a 1,0 mg/mL e negativo, solventes de diluição. Os ensaios cometa foram realizados em hemócitos de D. melanogaster, linhagem Oregon-R. As células foram expostas às doses 0,63, 1,26, 2,53, 5,05 e 10,11 mg/mL do ácido úsnico e 0,32, 0,63, 1,26, 2,53 mg/mL do ácido divaricático. Os resultados foram comparados aos controles positivo de ciclofosfamida à 1mg/mL e negativo, mistura dos solventes. No ensaio de antigenotóxicidade foram utilizadas as mesmas concentrações de ácido úsnico acrescidas de mitomicina a 1mg/mL. Os resultados mostraram que as larvadas submetidas o ácido úsnico no teste SMART apresentaram uma sobrevivência superior a 70% dos indivíduos demonstrando, com níveis não significativos de genotoxicidade. Resultado semelhante ao ensaio Cometa. O ácido úsnico apresentou redução da mutagenicidade, em todas as concentrações quando associado à mitomicina, caracterizando efeito antigenotóxico. O ácido divaricático, no teste SMART, apresentou efeito tóxico nas concentrações 5,05 e 10,11 mg/mL e efeito genotóxico no ensaio cometa nas doses 0,32, 0,63, 1,26, 2,53. / Lichens are notable symbiontic organisms. They can produce phenolic compounds widely described because its biological properties. However a little bit is known about the mutagenic and genotoxic potential of these molecules. This study evaluated the mutagenic and genotoxic profile of the usnic and divaricatic acids through the Somatic Mutation and Recombination test (SMART) and the comet assay using the Drosophila melanogaster as experimental model. Organisms descendants of the crossing between strains of D. melanogaster mwh and flr3 were submitted to different concentrations of usnic (0,63, 1,26, 2,53, 5,05 and 10,11 mg/mL) and divaricatic acid (0,32, 0,63, 1,26, 2,53, 5,05 and 10,11 mg/mL). The results were obtained by comparation with the positive and negative standards, mitomicine (1,0 mg/mL) and the dilution solvent respectively. The comet assay were realized using hemocites of D. melanogaster from the Oregon – R strain. The cells were exposed to the different concentrations of the usnic and divaricatic acids. The results were obtained byu comparation with the positive and negative standards, cyclophosphamide (1,0 mg/mL) and the dilution solvent. The antigenotoxicity assay used the same concentrations of the usnic acid with the addition of the mitomicyn (1,0 mg/mL). The results demonstrated that the larvae submitted to usnic acid exhibit a higher survival rate of 70%, with no significant levels of genotoxicity. The same result was observed to the comet assay. The usnic acid showed a significant reduction of the mutagenicity in all the tested concentrations with the addition of mitomicyn characterizing an antigenotoxic effect. The divaricatic acid in the SMART test showed a toxic effect at the concentrations of 5,05 and 10,11 mg/mL and a genotoxic effect ant the concentrations of 0,32, 0,63, 1,26, 2,53 mg/mL.

Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-04-06T19:44:29Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 2012-Dissertação-KleisonMerlo.pdf: 1387071 bytes, checksum: 3ebe03b22eb3efc7773006a1a48f6b26 (MD5) / Made available in DSpace on 2017-04-06T19:44:29Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 2012-Dissertação-KleisonMerlo.pdf: 1387071 bytes, checksum: 3ebe03b22eb3efc7773006a1a48f6b26 (MD5) Previous issue date: 2012 / O formocresol, principal droga utilizada em pulpotomias, tem um longo e bem sucedido histórico de uso clínico. Contudo, sua segurança tem sido questionada devido a possíveis efeitos genotóxicos, mutagênicos e carcinogênicos, relacionados à presença do formaldeído em sua composição. Resultados de estudos sobre a genotoxicidade do formocresol são bastante inconsistentes, logo, uma avaliação mais aprofundada sobre seu potencial genotóxico se faz relevante, uma vez que é uma droga mundialmente utilizada. Nesse trabalho foram investigados os potenciais efeitos genotóxicos do formocresol através de ensaios citogenéticos in vitro e in vivo (teste de metáfase). Nos ensaios in vitro, as preparações cromossômicas foram obtidas de cultura de linfócitos, onde após 24 horas de incubação, 50 µl das diluições do formocresol (1:50, 1:100, 1:200, 1:500, 1:1000) foram adicionados, sendo as preparações citológicas realizadas após 48 e 72 horas. Para o controle negativo foram realizadas culturas sem adição de qualquer droga. Nos ensaios in vivo, camundongos Swiss webster foram inoculados com as mesmas diluições na proporção de 0,1 ml/10 g, sendo utilizado como controle positivo a ciclofosfamida (25 mg/kg) e como negativo a glicerina/água (1:1). Para análise estatística foi aplicado o teste do qui-quadrado ao nível de 5%. Em culturas de 48 e 72 horas, comparando-se as dosagens de 1:50 e 1:100 com o controle negativo foi constatado haver diferença significativa, o que não observou-se para as outras diluições. Ao comparar-se a diluição de 1:50 em machos e a diluição de 1:200 em fêmeas com o controle negativo houve diferença significativa, o que não foi observado para as outras diluições. Sob as condições experimentais empregadas nesse estudo, o formocresol revelou-se genotóxico nas diluições mais concentradas, contrariando alguns trabalhos que apontam para sua não genotoxicidade. Entretanto, a dose final de formaldeído presente nessas diluições parece ser superior àquela geralmente empregada em pulpotomias. Isso demonstra que o uso displicente do formocresol parece ser o principal responsável pelos efeitos genotóxicos relatados na literatura. / Formocresol, the main substance used in pulpotomies, has a long and successful historical of clinical use. Although, its safety has been questioned because of possible genotoxic, mutagenic and carcinogenic effects, related to the presence of formaldehyde on its composition. Results from studies about formocresol genotoxicity are quite inconsistent, so a deep evaluation about its genotoxic potential is important, once this medicament is widely used. The potential genotoxic effects of formocresol were investigated employing in vitro and in vivo cytogenetic assays (chromosomal aberration test). On in vitro assays chromosomal preparations were provided from lymphocyte cultures, where after 24 hours of incubation, 50 µl from formocresol dilutions (1:50, 1:100, 1:200, 1:500, 1:1000) were added, with the cytological preparations done after 48 and 72 hours. The negative control cultures were done without adding any drug. On in vivo assays Swiss webster mice were inoculated with the same dilutions using the proportion of 0,1 ml/10 g body weight, and for positive control was used cyclophosphamide (25 mg/kg) and as negative control glycerine/water (1:1). The statistical analysis was performed using chi-square test at 5% level. On 48 and 72 hours culture comparing the 1:50 and 1:100 dosages with the negative control was observed significant difference, the same was not observed with the other dilutions. Comparing 1:50 dilution of male and 1:200 dilution of female with the negative control any significant difference was observed, the same did not happen with the other dilutions. Under the experimental conditions employed in this study, formocresol revealed its genotoxicity in the more concentrated dilutions, confronting some studies that point to its non-genotoxicity. However, the final dosage of formaldehyde present in these dilutions seems to be higher than those generally used in pulpotomies. It shows that the incorrect use of formocresol is the main responsible for the genotoxic effects reported in the literature.