Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a phytoestrogenic component of Rheum plant extracts which has been used for medical treatment since ancient times. It has been shown to have anti-inflammatory and anti-cancer effects. In our research, we aimed to study the biological effects of emodin on MCF-7 and MDA-231 cell lines. Cytotoxicity assays showed that emodin treatment for 48hours caused a concentration dependent decrease in viable cell numbers of both cell lines. As determined by cell counting with tryphan blue, IC50 values were 8.40 and 12.17 &micro / g/ml for MCF-7 and MDA-231 cells, respectively. Apoptotic effects of emodin was investigated by measuring the changes in apoptotic and antiapoptotic gene expressions by qRT-PCR. In MCF-7 cells, Bax expression increased with increasing emodin concentrations, while Bcl-2 expression was downregulated. Bax/Bcl-2 ratio was calculated as 9.2 fold at 10&micro / g emodin/ml treatment for 48 hours, indicating stimulation of apoptosis. However, Bax/Bcl-2 ratio was found 1.6 fold for MDA-231 cells. These results were in accordance with the results obtained from microarray analysis of related gene expressions. MCF-7 cells were more apoptotic in comparison to MDA-231 cells. DNA fragmentation was observed in MCF-7 cells by TUNEL method. GST enzyme activity that was measured using CDNB as substrate, was increased 100% with respect to control up to 5&micro / g emodin/ml treatment of MCF-7 cells for 48 hours. However, effect of emodin on GST activity in MDA-231 cells was found insignificant. According to microarray analysis results, emodin affected the gene expressions of GST isozymes in MCF-7 cells much more than in MDA-231 cells.

Defining the mechanics and consequences of protein adduction is crucial to understanding the toxicity of reactive electrophiles. Application of tandem mass spectrometry and data analysis algorithms enables detection and mapping of chemical adducts at the level of amino acid sequence. Nevertheless, detection of adducts does not indicate relative reactivity of different sites. In this dissertation I describe a method to measure the kinetics of competing adduction reactions at different sites on the same protein using quantitative mass spectrometry. Adducts are formed by electrophiles at Cys-14 and Cys-47 on the metabolic enzyme glutathione-S-transferase P1-1 and accompanied by a loss of enzymatic activity. Relative quantitation of protein adducts was done by tagging N-termini of peptide digests with isotopically labeled phenyl isocyanate and tracking the ratio of light-tagged peptide adducts to heavy-tagged reference samples. This method was used to measure rate constants for adduction at both positions with two different model electrophiles, IAB and BMCC. The results indicate that Cys-47 was approximately 2-3-fold more reactive toward both electrophiles than was Cys-14. This result was consistent with the relative reactivity of these electrophiles in a complex proteome system. Quantitative analyses of protein modifications provide a means of determining the reactivity and selectivity of damaging protein modifications in chemical toxicity.Another area of study explored in this dissertation is looking at the effects of protein alkylation on activating cellular signaling pathways, specifically the JNK signaling pathway. Protein adduction has been shown to be selective between different alkylating agents. It would then be reasonable to think this selectivity of adduction translates to selectivity of downstream consequences or cellular events directly tied to specific adductions. My work will show how treatment of HEK293 cells with either IAB or BMCC leads to differences in activation of JNK signaling. In addition, I've been able to show a difference in selectivity of a number of adducted targets by each alkylating agent, which are directly involved in regulation of the JNK signaling pathway. These studies illustrate not only the significance of protein adduction, but the importance for continual research to better understand their behavior in living systems.

This thesis describes the results obtained from the phytochemical analysis of Matricaria chamomilla, and the microbial transformation of oxymatrine (85) and harmine (87), as summarized below. 1. Chemical investigation of the crude methanolic extract of Matricaria chamomilla resulted in the isolation of a new natural product, matriisobenzofuran (72), along with four known compounds: apigenin (73), apigenin-7-O-β-glucopyranoside (74), scopoletin (75), and fraxidin (76). The structures of compounds 72-76 were elucidated with the aid of extensive NMR and mass spectroscopic studies. All of the aforementioned compounds showed moderate to good inhibitory activities against glutathione S-transferase, an enzyme which has been implicated in the resistance of cancer cells to chemotherapeutic agents. These compounds were also evaluated for antioxidant activity and displayed moderate to good free radical scavenging activity. Additionally, compounds 72-76 were screened for anti-leishmanial activity. Compounds 75 and 76 were significantly active in this assay, while the remaining compounds were weakly active. In the antibacterial and antifungal assays, compounds 72-76 were not active. 2. The second part of this thesis deals with the biotransformation studies on oxymatrine (85) and harmine (87). Oxymatrine (85) was metabolized to the deoxy analogue, matrine (84) by Penicillum chrysogeneum (ATCC 9480), Cunninghamella bainieri (ATCC 9244), Cunninghamella blakesleena (ATCC 9245 and 8688A), Curvularia lunata (ATCC 12017), and Fusarium sp. In the time-based analysis of this transformation, the metabolism of oxymatrine (85) could be detected after 48 hours of incubation. Additionally, incubation of harmine (87) with Mucor plumbeus (ATCC 4740) resulted in the isolation of harmine-N-oxide (94). The biotransformed products (84 and 94) were identified using IR, UV, NMR, and mass spectroscopic techniques. Compound 94 was evaluated for its ability to inhibit the enzyme acetylcholinestrase, whose overexpression has been linked to Alzheimer’s disease, and was found to possess weaker activity than harmine (87).

This thesis describes the results obtained from the phytochemical analysis of Matricaria chamomilla, and the microbial transformation of oxymatrine (85) and harmine (87), as summarized below. 1. Chemical investigation of the crude methanolic extract of Matricaria chamomilla resulted in the isolation of a new natural product, matriisobenzofuran (72), along with four known compounds: apigenin (73), apigenin-7-O-β-glucopyranoside (74), scopoletin (75), and fraxidin (76). The structures of compounds 72-76 were elucidated with the aid of extensive NMR and mass spectroscopic studies. All of the aforementioned compounds showed moderate to good inhibitory activities against glutathione S-transferase, an enzyme which has been implicated in the resistance of cancer cells to chemotherapeutic agents. These compounds were also evaluated for antioxidant activity and displayed moderate to good free radical scavenging activity. Additionally, compounds 72-76 were screened for anti-leishmanial activity. Compounds 75 and 76 were significantly active in this assay, while the remaining compounds were weakly active. In the antibacterial and antifungal assays, compounds 72-76 were not active. 2. The second part of this thesis deals with the biotransformation studies on oxymatrine (85) and harmine (87). Oxymatrine (85) was metabolized to the deoxy analogue, matrine (84) by Penicillum chrysogeneum (ATCC 9480), Cunninghamella bainieri (ATCC 9244), Cunninghamella blakesleena (ATCC 9245 and 8688A), Curvularia lunata (ATCC 12017), and Fusarium sp. In the time-based analysis of this transformation, the metabolism of oxymatrine (85) could be detected after 48 hours of incubation. Additionally, incubation of harmine (87) with Mucor plumbeus (ATCC 4740) resulted in the isolation of harmine-N-oxide (94). The biotransformed products (84 and 94) were identified using IR, UV, NMR, and mass spectroscopic techniques. Compound 94 was evaluated for its ability to inhibit the enzyme acetylcholinestrase, whose overexpression has been linked to Alzheimer’s disease, and was found to possess weaker activity than harmine (87).

In the recent years, environmental pollution becomes a health threatening issue for human beings. Technological developments introduce industrial wastes and heavy metals, and developments in agriculture introduce pesticides into the world that we live. All these toxic wastes accumulate in drinking water and food consumed by humans. Therefore, detection of toxic wastes in all kinds of environmental samples, and development of new detection techniques become an important issue. In this study, development of a protein-based biosensor for detection of heavy metals in environmental samples, by expressing genetically modified glutathione S-transferase (GST-(His)6) protein in E.Coli BL21 (DE3) expression system, was designed. Recombinant GST proteins was expressed in E.Coli BL21 (DE3) expression system and purified with Glutathione Sepharose 4B affinity column and Ni-NTA spin kit. GST activities were determined using the GST substrate 1-chloro-2,4-dinitrobenzene (CDNB). Protein expression was tested by SDS-PAGE and Western blot analysis. Product formation linearly increased up to 1 mM CDNB, 1 mM GSH, 1.7 &micro / g proteins in 0.05 M, pH 6.9 phosphate buffer in the final volume of 1.0 ml at 25&amp / #9702 / C. The Vmax and Km values for GST-(His)6 towards CDNB and GSH were calculated with Lineweaver-Burk as CDNB Vmax / 22.88 &micro / mol/min/mg, Km / 4.29 mM,and as GSH Vmax / 6.42 &micro / mol/min/mg, 24.45 &micro / mol/min/mg, Km / 3.69 mM, respectively. Biosensor working electrode was prepared by immobilizing the GST-(His)6 by 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride (EDC) coupling on the gold surface. Electrode preparation was confirmed by cyclic voltammetry measurements. The biosensor was inserted as the working electrode in the constructed three(four)-electrode flow cell. The conformational change resulting from the binding of the metal ions to the recombinant protein causing a capacitance change proportional to the concentration of the metal ions was determined. After the working electrode is standardized and calibrated, the heavy metal concentration in water samples was measured. The GST-(His)6 biosensor has a large operational range between 1 fM and 10 mM and a storage stability of approximately 2 weeks. The GST-(His)6 biosensor is very sensitive to, Cu+2&gt / Cd+2&gt / Zn+2&gt / Hg+2 metal ions, at low concentrations.

Made available in DSpace on 2014-06-11T19:32:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-28Bitstream added on 2014-06-13T20:43:03Z : No. of bitstreams: 1 estevao_if_dr_sjrp_parcial.pdf: 122795 bytes, checksum: 747e86122e594e13887a3ebfff701723 (MD5) Bitstreams deleted on 2015-08-07T12:19:53Z: estevao_if_dr_sjrp_parcial.pdf,. Added 1 bitstream(s) on 2015-08-07T12:20:55Z : No. of bitstreams: 1 000642193.pdf: 2022251 bytes, checksum: 43e74970fe45b54e28f7ac29e1ec9d71 (MD5) / A beta talassemia heterozigota pode ser decorrente de mutações β 0 ou β + , de acordo com ausência ou redução na produção das cadeias da beta globina, respectivamente. Poucos estudos na literatura correlacionam possíveis efeitos deletérios dessas mutações, quando em heterozigose. A coerança com mutações em genes, não localizados no cluster do gene da β-globina, podem modificar o fenótipo talassêmico. O estresse oxidativo gerado pelo aumento de ERO é um dos mecanismos responsáveis pala aceleração da apoptose celular. Há evidências que o excesso de cadeias alfa, mesmo em pequenas quantidades, seja suficiente para iniciar a geração de ERO e, portanto, estresse oxidativo em beta talassêmicos heterozigotos. Nas formas homozigotas ou com dupla heterozigose os pacientes apresentam anemia grave, transfusão dependente, e a sobrecarga de ferro é uma das mais frequentes e graves complicações nesses indivíduos. Na forma heterozigota a ocorrência de sobrecarga de ferro é rara, porém alterações no perfil do ferro são observadas. O objetivo desse trabalho foi analisar a influência dos níveis de ferritina sérica, das mutações no gene da β-globina, das mutações no gene HFE, da atividade das enzimas de detoxificação GST e CAT e dos polimorfismos das GSTs na expressão fenotípica de indivíduos beta talassêmicos heterozigotos. Foram avaliados 158 portadores de beta talassemia heterozigota diagnosticados previamente por metodologias clássicas. Todos adultos, de origem caucasóide, residentes na região Central do Estado de São Paulo e acompanhados em serviços públicos ou privados da região. O grupo controle foi composto de 24 adultos, caucasóides e residentes na mesma região. A avaliação hematológica foi realizada pelo hemograma, em contadores automatizados de células e quantificação das sub frações de Hb A2 e Hb F por HPLC. O perfil... / Beta thalassemia may occur due to mutations β 0 or β +, according to absence or reduction in the production of beta globin chains, respectively. Few studies have been done correlating possible deleterious effects of these mutations, when in heterozygous. Co-inheritance with mutations in the genes, not located in the cluster of β-globin gene may modify the phenotype of the thalassemic. Stress oxidative generated by the increase of ROS is one of the mechanisms responsible for the acceleration of cell apoptosis. There are evidences that alpha chains in excess, even in small quantities, are sufficient to start ROS generation and thus oxidative stress in heterozygous beta thalassemic. In homozygous form or genetic heterozygous compound present severe anemia, transfusion dependent and iron overload is one of the complications more frequent and severe in these patients. In the heterozygous form the presence of iron overload is rare, but alterations in the profile of iron are observed. The aim of this study was to examine influence of the levels of serum ferritin, the mutations in the β-globin gene, the mutations in the HFE gene, activity of enzymes detoxification, GST and CAT, and polymorphisms of GSTs in the expression phenotypic of individuals heterozygous beta thalassemic. We evaluated 158 patients with beta thalassemia heterozygous previously diagnosed by classic methodologies. They were all adults, Caucasian origin, residents in the Central Region of São Paulo state and accompanied in public or private services of the region. The control group consisted of 24 adults, Caucasians and residents in the same region. Hematologic evaluation was carried out by hemogram, in automated counters of cells and quantification of the subfractions of Hb A2 and Hb F by HPLC; the iron profile was based on the transferrin saturation , calculated on the serum iron and total iron binding capacity... (Complete abstract click electronic access below)

As septinas constituem uma conservada família de proteínas de ligação a nucleotídeos de guanina e formação de heterofilamentos. Em mamíferos, tais proteínas estão envolvidas em uma variedade de processos celulares tais como citocinese, exocitose e tráfego de vesículas. A SEPT4 tem sido identificada em depósitos filamentosos e inclusões citoplasmáticas em Alzheimer e doença de Parkinson, respectivamente. A SEPT4 é a única proteína em associação com proteínas aberrantes em depósitos em ambos os tipos de doenças Assim, estudos adicionais de propriedades bioquímicas estruturais e funções fisiológicas para a SEPT4 podem promover importantes insights em relação ao mecanismo das doenças neurodegenerativas citadas acima. O desenovelamento térmico do domínio GTPase do SEPT4-G revelou um intermediário que agrega rapidamente na forma de fibras tipo amilóide em condições fisiológicas. Neste estudo a análise cinética da agregação do SEPT4-G foi monitorada utilizando fluorescência extrínseca e dicroísmo circular. Com os resultados e análises realizados durante este trabalho de mestrado foi possível compreender com mais detalhes a cinética de formação de agregados tipo amilóide do domínio SEPT4-G. Este trabalho também descreve a cristalização, coleta de dados, resolução e refinamento do modelo cristalográfico para a enzima Glutationa-S-Transferase de Xylella fastidiosa. Tal enzima está associada à patogenicidade da bactéria X. fastidiosa, responsável por várias doenças em plantas economicamente importantes, incluindo a Clorose Variegada dos Citros (CVC) ou Amarelinho. Algumas análises também foram realizadas após a obtenção do modelo cristalográfico demonstrando as diferenças estruturais entre GSTs bacterianas. / The septins are a conserved family of guanine nucleotides-binding and hetero-filament forming. proteins. In mammals they are involved in a variety of cellular processes, such as cytokinesis, exocytosis, and vesicle trafficking. SEPT4 has been reported to accumulate in tau-based filamentous deposits and cytoplasmic inclusions in Alzheimers and Parkinsons diseases respectively. Sept4 is unique in its association with the aberrant protein depositions in both types of diseases. Further studies on the biochemical, structural properties and physiological functions of Sept4 may therefore provide important insights into the common mechanism underlying diverse neurodegenerative disorders. Thermal unfolding of the GTPase domain of SEPT4 (SEPT4-G) revealed an unfolding intermediary which rapidly aggregates into amyloid-like fibers under physiological conditions. In this study, the kinetic analysis of aggregation of SEPT4-G was monitored using extrinsic fluorescence and circular dichroism spectroscopy. The aggregates have the ability to bind specific dyes such as Thioflavin-T (ThT), suggesting that they are amyloid in nature. Fibrils formation was monitored by the increase in ThT emission and electron microscopy as a function of temperature, pH, metal ions and protein concentration. Glutathione S-transferases (GSTs) form a group of multifunctional isoenzymes that catalyze the glutathione-dependent conjugation and reduction reactions involved in the cellular detoxification of xenobiotic and endobiotic compounds. GST from Xylella fastidiosa (XfGST) was crystallized by the vapour-diffusion method and its crystallography structure was solved for molecular replacement and refined. Afterwards, sequential and structural analyses were carried out for XfGST and others GSTs.

Made available in DSpace on 2016-08-10T10:38:29Z (GMT). No. of bitstreams: 1 Ariane Bocaletto Frare.pdf: 1200781 bytes, checksum: 8bd7ce42ea14c46d6e84c7f5311b07ca (MD5) Previous issue date: 2011-06-16 / Endometriosis is a benign gynecological pathology dependent on estrogen, which affects 10% of women of reproductive age, it is characterized by the presence of endometrial tissue outside the uterine cavity. Its etiology remains unknown, thus an increasing number of researches have been conducted in the search for associations between endometriosis and alterations or polymorphisms in candidate genes, among these genes are the GSTM1 and GSTT1. This study aimed to verify the possible correlation between endometriosis and polymorphisms of presence / absence of GSTM1 and GSTT1, and the association between GSTM1 and GSTT1 polymorphisms and p53 Arg / Pro. We analyzed the frequency of GSTM1 and GSTT1 polymorphisms in 50 women diagnosed with endometriosis and in control group with 46 women without complaints related to this pathology, the genotypes for these polymorphisms were determined using PCR. We found an increased frequency of absence of GSTM1 (61%) and presence of GSTT1 genes (55%) in the group of women studied, which corroborate with the literature. When we relate the endometriosis with the studied polymorphisms we verified that the endometriosis group had a higher presence of both polymorphisms 50% of GTSM1 and 68% of GSTT1 whereas in the control group there was the opposite, a higher absence of polymorphisms, 74% of GSTM1 and 59% of GSTT1, showing that these polymorphisms has no relation to the proliferation of endometriosis, however the analysis of the pathology with the association of GSTM1, GSTT1 polymorphisms with the p53 codon 72 gene was statistically significant. / A endometriose é uma patologia ginecológica benigna dependente de estrógeno, que afeta 10% das mulheres em idade reprodutiva, é caracterizada pela presença de tecido endometrial fora da cavidade uterina. Sua etiologia permanece desconhecida, com isso um número cada vez maior de pesquisas tem sido realizado na procura de associações entre endometriose e alterações ou polimorfismo em genes candidatos, entre esses genes estão o GSTM1 e o GSTT1. Este estudo teve como objetivo verificar a possível correlação entre a endometriose e os polimorfismos de presença/ausência GSTM1 e GSTT1. Nós analisamos a freqüência dos polimorfismos GSTM1 e GSTT1 em 50 mulheres diagnosticadas com endometriose e no grupo controle, com 46 mulheres sem queixas relacionadas com a patologia, os genótipos para esses polimorfismos foram determinados por PCR. Encontramos maior freqüência de ausência dos genes GSTM1 (61%) e de presença do GSTT1 (55%) no grupo de mulheres estudadas, o que corroboram com a literatura. Quando relacionamos endometriose com os polimorfismos estudados verificamos que o grupo endometriose apresentou maior presença de ambos os polimorfismo 50% GTSM1 e 68% GSTT1, enquanto que no grupo controle verificou-se o contrário, maior ausência dos polimorfismos, 74% do GSTM1 e 59% do GSTT1, mostrando que esses polimorfismos não tem relação com a proliferação da endometriose.

Uma das formas de se quantificar os possíveis efeitos de metais sobre o estado de saúde de organismo é analisar os biomarcadores do estresse oxidativo. Bioensaios foram realizados com a tilápia do Nilo (Oreochromis niloticus) com concentrações de cádmio (4,25 \'mü\'g/L), cobre (45,0 \'mü\'g/L ) e zinco (260,0 \'mü\'g/L). Os peixes foram expostos aos metais separados (\'CD\', \'CU\' e \'ZN\'), associados dois a dois (\'CD\'/\'CU\', \'CD\'/\'ZN\' e \'CU\'/\'ZN\') e aos três metais juntos (\'CD\'/\'CU\'/\'ZN\'), por doze dias. Foram retiradas amostras de rim, fígado e brânquias para análise de biomarcadores de estresse oxidativo, a superóxido dismutase (SOD), catalase (CAT) e glutationa peroxidase (GPx), o efeito da peroxidação de lipídios (HP), a glutationa S-transferase (GST) e a metalotionéina (MT). Pelos reusltados obtidos constatou-se que, mesmo nas baixas concentrações de exposição aos metais, ocorreram alterações no sitema de defesa antioxidante de O. niloticus. A primeira barreira antioxidante, composta pela SOD, não foi suficiente para barrar os efeitos da exposição aos metais. Em brânquias, onde a ativação desta enzima foi proeminente, formação de HP ocorreu. E, mesmo inicialmente em rim e fígado, tecidos onde ocorreu diminuição da atividade da SOD, ocorreu também a formaçao de HP nas etapas seguintes. A CAT e a GPx também atuaram no sentido de tentar evitar o aparecimento de HP, mas não foram bem sucedidas neste processo. A GST, como enzima da fase II de biotransformação pode ter auxiliado no processo de eliminação dos metais, mas como ocorre de forma tardia em relação à defesa antioxidante, acarretando danos celulares. Em relação às enzimas que compõem o sistema de defesa antioxidante não se verificou também especificidade de tecidos nas respostas. No entanto, a brânquia foi o órgão que teve maior intensidade nas respostas (em termos de ativação das enzimas), nos tratamentos de metais combinados dois a dois, evidenciando que este órgão, por estar em contato com a água e ser sede de processos fisiológicos de homeostase, desempenhou papel importante na tentativa de neutralizar os efeitos dos metais. / One way of quantifying metals effects upon organisms\' health state is to analyse oxidative stress biomarkers. Bioassays were conducted with Nile tilapia (Oreochromis niloticus) with cadmium (4,25 \'mü\'g/L), copper (45,0 \'mü\'g/L ) and zinc (260,0 \'mü\'g/L). Fishes were exposed to metals separatelly (\'CD\', \'CU\' e \'ZN\'), associated two by two (\'CD\'/\'CU\', \'CD\'/\'ZN\' e \'CU\'/\'ZN\') and to three metals together (\'CD\'/\'CU\'/\'ZN\'), for twelve days. Gills, liver and kidney samples were taken to analyse oxidative stress biomarkers, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), the effect of lipid peroxidation (HP), an enzyme of phase II biotransformation, glutathione S-transferase (GST) and metallothionein (MT). From results obtained, it was stablished that, even in low concentrations of metals, O. niloticus antioxidant defense system was modified. The first antioxidant barrier, SOD, wasn\'t able to minimize metal exposition effects. In gills, where activaton of this enzyme was prominent, didn\'t avoi HP formation. And even in liver and kidney, tissues where SOD activity decreased, HP formation also occurred. CAT and GPx also acted trying to avoid HP formation, but weren\'t successfull. GST, like a phase I enzyme, could help eliminating metals, but in a late moment in relation to antioxidant defense, leading to cell damage. For antioxidant enzymes no relation to tissue-specificity response was observed. But gills were the organ which had more intense responses (in terms of enzyme activation), mainly in metals combined two by two, evidencing that gills are important like a first organ in antioxidant defense because it is in direct contact with water and determine the main processes in homeostasis, trying to neutralize metals effects.

Introdução: A polipose nasal (PN) é considerada uma condição inflamatória crônica da mucosa da cavidade nasal e seios paranasais de etiologia não muito clara. Há poucos dados sobre alterações epiteliais em PN e sua relação com a ação dos radicais livres. Muitas doenças estão ligadas a danos causados por espécies reativas de oxigênio (ROS) e de nitrogênio (RNSS) e ocorrem de um desequilíbrio entre eles e antioxidantes, o que for maior atividade de espécies reativas, o que chamamos de estresse oxidativo. Objetivo: O objetivo principal deste estudo é avaliar o estresse oxidativo em pólipos removidos cirurgicamente em 3 grupos de pacientes com polipose nasal (com PN unicamente, PN associado à asma e PN associado à asma e intolerância ao ácido acetilsalicílico) a fim de elucidar possíveis diferenças no perfil redox nestes grupos. Material e Métodos: Cinquenta e nove pacientes com diagnóstico de polipose nasal foram divididos em três grupos clínicos: um grupo controle PN unicamente, um grupo asma (PN associado à asma) e um grupo Widal (PN associado à asma e intolerância ao ácido acetilsalicílico). Medição e Resultados Principais: Neste trabalho defesas enzimáticas (superóxido dismutase, consumo de peróxido de hidrogênio, glutationa peroxidase e glutationa S-transferase) e defesas não enzimáticas (glutationa total, nitritos e nitratos, vitamina C e E) foram analisados. Também foi realizada a medição de danos em lipídios (malondialdeído) e proteínas (carbonila). No grupo asma, o consumo de peróxido de hidrogênio, atividade da glutationa peroxidase, níveis de malondialdeído e vitamina E foram significativamente menores do que no grupo de controle. Também foi realizada a medição de danos em lipídios (malondialdeído) e proteínas (carbonila). No grupo Widal foram encontrados níveis significativamente maiores de glutationa e nitritos e nitratos em relação ao grupo controle. Não foram encontradas diferenças entre os grupos em relação ao nível de carbonila e glutationa, tamanho dos pólipos, atividades da superóxido dismutase e S-transferase. Conclusões: A classificação redox dos grupos de PN foi parcialmente alcançada. Os pólipos do grupo asma possuem alterações nas defesas enzimáticas relacionadas com o peróxido de hidrogênio e a peroxidação lipídica, enquanto pólipos do grupo Widal apresentaram alterações nos níveis de óxido nítrico e glutationa. / Introduction: Nasal polyposis (NP) is considered a chronic inflammatory condition of the mucosa of the nasal cavity and paranasal sinuses of etiology is not very clear. There are few data on epithelial changes in nasal polyposis and its relation to the action of free radicals. Many diseases are linked to damage caused by reactive oxygen species (ROS) and nitrogen (RNSs) and occur from an imbalance between them and antioxidants, whichever is greater activity of reactive species, what we call oxidative stress. Objective: The primary objective of this study is to evaluate oxidative stress in polyps surgically removed in 3 groups of patients with nasal polyposis, in order to elucidate possible differences in redox profile in these groups. Methods: Fifty nine patients diagnosed with nasal polyposis were divided into three groups: a control group, an asthma group (NP with asthma) and a Widal group (NP with asthma and aspirin intolerance) in which patients had an association of NP, asthma and aspirin intolerance. Measurement and main results: In this work enzymatic defenses (superoxide dismutase, hydrogen peroxide consumption, glutathione peroxidase and glutathione S-transferase) and non-enzymatic defenses (total glutathione, measurement of nitrites and nitrates, vitamin C and E) were analyzed. Also the measurement of damage in lipids (malondialdehyde) and proteins (carbonyl) was conducted. In the asthma group, hydrogen peroxide consumption, glutathione peroxidase activity, malondialdehyde, and vitamin E levels were significantly lower than in the control group. The Widal group showed significant higher glutathione levels, nitrite and nitrate levels than found in the control group. No differences were found among the groups regarding carbonyl level, polyp size, superoxide dismutase, and glutathione S-transferase activities. Conclusions: The redox classification of the groups of NP was partly achieved. Polyps of patients with asthma have changes in enzymatic defense pathways related to hydrogen peroxide and lipid peroxidation while polyps of patients with Widal triad present changes in nitric oxide and glutathione.