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1.
Biol. Res ; 54: 35-35, 2021. ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1505820

RESUMO

BACKGROUND: Urushiols are pro-electrophilic haptens that cause severe contact dermatitis mediated by CD8+ effector T-cells and downregulated by CD4+ T-cells. However, the molecular mechanism by which urushiols stimulate innate immunity in the initial stages of this allergic reaction is poorly understood. Here we explore the sub-cellular mechanisms by which urushiols initiate the allergic response. RESULTS: Electron microscopy observations of mouse ears exposed to litreol (3-n-pentadecyl-10-enyl-catechol]) showed keratinocytes containing swollen mitochondria with round electron-dense inclusion bodies in the matrix. Biochemical analyses of sub-mitochondrial fractions revealed an inhibitory effect of urushiols on electron flow through the mitochondrial respiratory chain, which requires both the aliphatic and catecholic moieties of these allergens. Moreover, urushiols extracted from poison ivy/oak (mixtures of 3-n-pentadecyl-8,11,13 enyl/3-n-heptadecyl-8,11 enyl catechol) exerted a higher inhibitory effect on mitochondrial respiration than did pentadecyl catechol or litreol, indicating that the higher number of unsaturations in the aliphatic chain, stronger the allergenicity of urushiols. Furthermore, the analysis of radioactive proteins isolated from mitochondria incubated with 3H-litreol, indicated that this urushiol was bound to cytochrome c1. According to the proximity of cytochromes c1 and b, functional evidence indicated the site of electron flow inhibition was within complex III, in between cytochromes bL (cyt b566) and bH (cyt b562). CONCLUSION: Our data provide functional and molecular evidence indicating that the interruption of the mitochondrial electron transport chain constitutes an important mechanism by which urushiols initiates the allergic response. Thus, mitochondria may constitute a source of cellular targets for generating neoantigens involved in the T-cell mediated allergy induced by urushiols.


Assuntos
Animais , Camundongos , Alérgenos , Citocromos b , Catecóis , Citocromos c1 , Citocromos c , Transporte de Elétrons , Mitocôndrias
2.
J. appl. oral sci ; 29: e20210209, 2021. graf
Artigo em Inglês | LILACS | ID: biblio-1340103

RESUMO

Abstract Objective Oral squamous cell carcinoma (OSCC) is one of the common type of cancer that leads to death; and is becoming a global concern. Due to the lack of efficient chemotherapeutic agents for patients with oral cancer, the prognosis remains poor. 6-shogaol, a bioactive compound of ginger, has a broad spectrum of bioactivities and has been widely used to relieve many diseases. However, its effects on human oral cancer have not yet been fully evaluated. In our study, we investigated the anticancer effects of 6-shogaol on the proliferation, migration, invasion, apoptosis, and underlying mechanisms within human OSCC cell lines. Methodology We investigated the effect of 6-shogaol on the growth of OSCC cells by cell viability and soft agar colony formation assay. Migration and invasion assays were conducted to confirm the effect 6-shogaol on OSCC cell metastasis. Apoptosis was detected by flow cytometry and the underlying mechanism on the antigrowth effect of 6-shogaol in OSCC cells was assessed using western blotting. Results In our results, 6-shogaol not only suppressed proliferation and anchorage-independent cell growth in OSCC cells, but also induced apoptosis by regulating the apoptosis-associated factors such as p53, Bax, Bcl-2, and cleaved caspase-3. Migration and invasion of OSCC cells were inhibited following the regulation of E-cadherin and N-cadherin by 6-shogaol. Additionally, 6-shogaol treatment significantly inhibited the PI3K/AKT signaling pathway. Conclusion Therefore, our results may provide critical evidence that 6-shogaol can be a potential new therapeutic candidate for oral cancer.


Assuntos
Humanos , Neoplasias Bucais/metabolismo , Catecóis/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Transdução de Sinais , Movimento Celular , Apoptose , Fosfatidilinositol 3-Quinases/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Proteínas Proto-Oncogênicas c-akt/metabolismo
3.
Braz. arch. biol. technol ; 62: e19180360, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1055421

RESUMO

Abstract Catecholase (EC 1.10.3.1), an oxidoreductase enzyme is a key member of polyphenol oxidase family which catalyze the degradation of catechol. This enzyme possesses vast applications in diverse areas and is found in bacteria, fungi, mushrooms, higher plants, arthropods, amphibians and mammals. Catechol, a phenolic compound, is used as a starting material in the synthesis of various industrial compounds such as inhibitors, antioxidants, pesticides etc. The release of this phenolic compound in the environment causes toxicity to both flora and fauna. In the present studies, emphasis has been laid on isolation, screening and characterization of catechol degrading bacterium coupled with synthesis of catecholase enzyme. Further, the selected isolated strain was phenotypically characterized and was found to be member of genus Pseudomonas. Among all the isolates, BSC-6 was found as best isolate with maximum extracellular catecholase activity of 152.32 IU/L obtained after scale up studies. The herein synthesized bacterial catecholase may be employed for wide applications particularly in bioremediation of phenol enriched polluted sites.


Assuntos
Oxirredutases , Catecóis , Polifenóis , Pseudomonas , Biodegradação Ambiental
4.
An. acad. bras. ciênc ; 89(4): 2707-2717, Oct.-Dec. 2017. graf
Artigo em Inglês | LILACS | ID: biblio-886861

RESUMO

ABSTRACT 6-Gingerol is the major active constituent of ginger. In the current study, we aimed to investigate the mechanisms underlying the effects of 6-Gingerol on hair growth. Mice were randomly divided into five groups; after hair depilation (day 0), mice were treated with saline, or different concentrations of 6-Gingerol for 11 days. The histomorphological characteristics of the growing hair follicles were examined after hematoxylin and eosin staining. The results indicated that 6-Gingerol significantly suppressed hair growth compared with that in the control group. And choose the concentration of 6-Gingerol at 1 mg/mL to treated with mice. Moreover, 6-Gingerol (1 mg/mL) significantly reduced hair re-growth ratio, hair follicle number, and hair follicle length, which were associated with increased expression of MMP2 and MMP9. Furthermore, the growth factors, such as EGF, KGF, VEGF, IGF-1 and TGF-β participate in the hair follicle cycle regulation and regulate hair growth. We then measured the concentrations of them using ELISA assays, and the results showed that 6-Gingerol decreased EGF, KGF, VEGF, and IGF-1 concentrations, and increased TGF-β concentration. Thus, this study showed that 6-Gingerol might act as a hair growth suppressive drug via induction of MMP2 and MMP9 expression, which could interfere with the hair cycle.


Assuntos
Animais , Masculino , Feminino , Coelhos , Extratos Vegetais/farmacologia , Catecóis/farmacologia , Folículo Piloso/efeitos dos fármacos , Metaloproteinase 2 da Matriz/biossíntese , Metaloproteinase 9 da Matriz/biossíntese , Álcoois Graxos/farmacologia , Fator de Crescimento Insulin-Like I/biossíntese , Distribuição Aleatória , Indução Enzimática , Fator de Crescimento Transformador beta/biossíntese , Folículo Piloso/patologia , Fator A de Crescimento do Endotélio Vascular/biossíntese , Fator 7 de Crescimento de Fibroblastos/biossíntese , Camundongos Endogâmicos C57BL
5.
Rev. paul. pediatr ; 33(1): 28-33, Jan-Mar/2015. tab
Artigo em Inglês | LILACS | ID: lil-744701

RESUMO

OBJECTIVE: To develop a homologous human milk supplement for very low-birth weight infant feeding, using an original and simplified methodology, to know the nutritional composition of human milk fortified with this supplement and to evaluate its suitability for feeding these infants. METHODS: For the production and analysis of human milk with the homologous additive, 25 human milk samples of 45mL underwent a lactose removal process, lyophilization and then were diluted in 50mL of human milk. Measurements of lactose, proteins, lipids, energy, sodium, potassium, calcium, phosphorus and osmolality were performed. RESULTS: The composition of the supplemented milk was: lactose 9.22±1.00g/dL; proteins 2.20±0.36g/dL; lipids 2.91±0.57g/dL; calories 71.93±8.69kcal/dL; osmolality 389.6±32.4mOsmol/kgH2O; sodium 2.04±0.45mEq/dL; potassium 1.42±0.15mEq/dL; calcium 43.44±2.98mg/dL; and phosphorus 23.69±1.24mg/dL. CONCLUSIONS: According to the nutritional contents analyzed, except for calcium and phosphorus, human milk with the proposed supplement can meet the nutritional needs of the very low-birth weight preterm infant. .


OBJETIVO: Elaborar com metodologia original e simplificada um aditivo homólogo do leite humano para a alimentação do recém-nascido de muito baixo peso, conhecer a composição nutricional do leite humano fortificado com esse aditivo e avaliar sua adequação para a alimentação desses recém-nascidos. MÉTODOS: Para a produção e análise do leite humano com o aditivo homólogo, 25 amostras de 45 mL de leite humano passaram por processos de retirada de lactose, liofilização e foram diluídas em 50 mL de leite humano. Foram feitas dosagens de lactose, proteínas, lipídios, energia, sódio, potássio, cálcio, fósforo e osmolalidade. RESULTADOS: A composição do leite aditivado foi lactose 9,22 ± 1 g/dL; proteínas 2,20 ± 0,36 g/dL; lípides 2,91 ± 0,57 g/dL; calorias 71,93 ± 8,69 kcal/dL; osmolalidade 389,6 ± 32,4mOsmol/kgH2O; sódio 2,04 ± 0,45mEq/dL; potássio 1,42 ± 0,15mEq/dL; cálcio 43,44 ± 2,98 mg/dL; e fósforo 23,69 ± 1,24 mg/dL. CONCLUSÕES: De acordo com os teores nutricionais analisados, com exceção do cálcio e do fósforo, o leite humano com o aditivo proposto pode atender às necessidades nutricionais do recém-nascido pré-termo de muito baixo peso. .


Assuntos
Aldose-Cetose Isomerases/antagonistas & inibidores , Antibacterianos/farmacologia , Catecóis/farmacologia , Inibidores Enzimáticos/farmacologia , Escherichia coli/efeitos dos fármacos , Rodanina/farmacologia , Aldose-Cetose Isomerases/metabolismo , Antibacterianos/química , Antibacterianos/síntese química , Catecóis/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Escherichia coli/enzimologia , Escherichia coli/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Estrutura Molecular , Rodanina/química , Relação Estrutura-Atividade
6.
Braz. j. med. biol. res ; 46(9): 780-788, 19/set. 2013. graf
Artigo em Inglês | LILACS | ID: lil-686573

RESUMO

4-Nerolidylcatechol (4-NC) is found in Pothomorphe umbellata root extracts and is reported to have a topical protective effect against UVB radiation-induced skin damage, toxicity in melanoma cell lines, and antimalarial activity. We report a comparative study of the antioxidant activity of 4-NC and α-tocopherol against lipid peroxidation initiated by two free radical-generating systems: 2,2′-azobis(2-aminopropane) hydrochloride (AAPH) and FeSO4/H2O2, in red blood cell ghost membranes and in egg phosphatidylcholine (PC) vesicles. Lipid peroxidation was monitored by membrane fluidity changes assessed by electron paramagnetic resonance spectroscopy of a spin-labeled lipid and by the formation of thiobarbituric acid-reactive substances. When lipoperoxidation was initiated by the hydroxyl radical in erythrocyte ghost membranes, both 4-NC and α-tocopherol acted in a very efficient manner. However, lower activities were observed when lipoperoxidation was initiated by the peroxyl radical; and, in this case, the protective effect of α-tocopherol was lower than that of 4-NC. In egg PC vesicles, malondialdehyde formation indicated that 4-NC was effective against lipoperoxidation initiated by both AAPH and FeSO4/H2O2, whereas α-tocopherol was less efficient in protecting against lipoperoxidation by AAPH, and behaved as a pro-oxidant for FeSO4/H2O2. The DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical assay indicated that two free radicals were scavenged per 4-NC molecule, and one free radical was scavenged per α-tocopherol molecule. These data provide new insights into the antioxidant capacity of 4-NC, which may have therapeutic applications for formulations designed to protect the skin from sunlight irradiation.


Assuntos
Humanos , Antioxidantes/farmacologia , Catecóis/farmacologia , Membrana Eritrocítica/efeitos dos fármacos , Peróxidos/análise , Fosfolipídeos/farmacologia , alfa-Tocoferol/farmacologia , Amidinas/administração & dosagem , Amidinas/farmacologia , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres/análise , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/análise , Fosfatidilcolinas/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química
7.
Rev. argent. microbiol ; 44(2): 113-121, jun. 2012. graf, tab
Artigo em Inglês | LILACS | ID: lil-657621

RESUMO

A phenol-degrading fungus was isolated from crop soils. Molecular characterization (using internal transcribed spacer, translation elongation factor and beta-tubulin gene sequences) and biochemical characterization allowed to identify the fungal strain as Penicillium chrysogenum Thorn ERK1. Phenol degradation was tested at 25 °C under resting mycelium conditions at 6, 30, 60, 200, 350 and 400 mg/l of phenol as the only source of carbon and energy. The time required for complete phenol degradation increased at different initial phenol concentrations. Maximum specific degradation rate (0.89978 mg of phenol/day/mg of dry weight) was obtained at 200 mg/l. Biomass yield decreased at initial phenol concentrations above 60 mg/l. Catechol was identified as an intermediate metabolite by HPLC analysis and catechol dioxygenase activity was detected in plate assays, suggesting that phenol metabolism could occur via ortho fission of catechol. Wheat seeds were used as phototoxicity indicators of phenol degradation products. It was found that these products were not phytotoxic for wheat but highly phytotoxic for phenol. The high specific degradation rates obtained under resting mycelium conditions are considered relevant for practical applications of this fungus in soil decontamination processes.


Un aislamiento fúngico capaz de degradar fenol como única fuente de carbono y energía fue aislado de suelos agrícolas. La caracterización molecular (basada en el empleo de secuencias de espaciadores de transcriptos internos, de factores de la elongación de la traducción y del gen de la beta-tubulina) y la caracterización bioquímica permitieron identificar a esta cepa como Penicillium chrysogenum Thom ERK1. Se estudió la degradación de fenol a 25 °C en cultivos estáticos con 6, 30, 60, 200, 350 y 400 mg/l de fenol inicial. El tiempo requerido para completar la degradación de fenol aumentó al elevarse las concentraciones iniciales de dicho compuesto. La máxima tasa de degradación específica (0,89978 mg de fenol/día/mg de peso seco) se obtuvo con 200 mg/l. El rendimiento en biomasa disminuyó con concentraciones Iniciales de fenol mayores de 60 mg/l. Se identificó al catecol como intermediarlo metabolico por HPLC y se observó actividad de catecol dioxigenasa en placa, lo que sugiere que el metabolismo de degradación del fenol ocurre vía orto fisión del catecol. Se utilizaron semillas de trigo como indicadores de fitotoxicidad de los productos de degradación. Estos productos no fueron fitotóxicos para trigo, mientras que el fenol mostró una alta fitotoxicidad. La alta tasa de degradación específica obtenida en condiciones estáticas resulta de gran interés para la aplicación de este hongo en procesos de descontaminación de suelos.


Assuntos
Biodegradação Ambiental , Micélio/metabolismo , Penicillium chrysogenum/metabolismo , Fenol/metabolismo , Biomassa , Catálise , Cromatografia Líquida de Alta Pressão , Carbono/metabolismo , Catecóis/metabolismo , DNA Fúngico/genética , Proteínas Fúngicas/genética , Concentração Osmolar , Filogenia , Penicillium chrysogenum/classificação , Penicillium chrysogenum/genética , Penicillium chrysogenum/isolamento & purificação , Fenol/toxicidade , Alinhamento de Sequência , Análise de Sequência de DNA , Microbiologia do Solo , Sementes/efeitos dos fármacos , Fatores de Tempo , Triticum/efeitos dos fármacos , Tubulina (Proteína)/genética
8.
Bol. latinoam. Caribe plantas med. aromát ; 10(6): 590-594, ene. 2011. tab
Artigo em Inglês | LILACS | ID: lil-618854

RESUMO

Epicuticular components were obtained using methylene chloride extraction of fresh leaves from two populations of Lithrea caustica. The methylene chloride extracts were analyzed using GC and GC-MS. The extracts from both sampled populations showed a mixture of a hydrocarbon fraction of n-alkanes from C-21 to C-33 as their main components and small amounts of monoterpene hydrocarbons. The allergen 3-(pentadec-10-enyl)-catechol was also identified in the epicuticular sample in very different proportions in both extracts. A second extract obtained after the epicuticle had been removed from the sample revealed oxygenated monoterpenes, sesquiterpene hydrocarbons and an increased amount of the allergen 3-(Pentadec-10-enyl)-catechol. These results demonstrate that the cuticle hydrocarbons of the leaves function as a lipophylic barrier that controls allergen release.


Los componentes epicuticulares se obtuvieron mediante la extracción con cloruro de metileno de hojas frescas de dos poblaciones de Lithrea caustica. Los extractos de cloruro de metileno fueron analizados mediante CG y CG-EM. Los extractos de ambas poblaciones mostraron una mezcla de una fracción de hidrocarburos n-alcanos de C-21 a C-33 como sus componentes principales y pequeñas cantidades de hidrocarburos monoterpenicos. El alérgeno 3 - (pentadec-10-enil)-catecol también fue identificado en epicuticula en proporciones muy diferentes en ambos extractos. Un segundo extracto obtenido después que la epicutícula había sido eliminada de la muestra mostró monoterpenos oxigenados, hidrocarburos sesquiterpenos y una mayor cantidad del alérgeno 3 - (Pentadec-10-enil)-catecol. Estos resultados demuestran que los hidrocarburos de la cutícula de las hojas funcionan como una barrera lipofílica que controla la liberación del alérgeno.


Assuntos
Alérgenos/análise , Anacardiaceae/química , Catecóis/análise , Extratos Vegetais/química , Hidrocarbonetos/análise , Terpenos/análise , Cromatografia Gasosa , Folhas de Planta/química , Espectrometria de Massas , Cloreto de Metileno , Plantas Tóxicas
9.
West Indian med. j ; 58(4): 295-300, Sept. 2009. graf
Artigo em Inglês | LILACS | ID: lil-672490

RESUMO

OBJECTIVE: We previously reported that 6-shogaol, a phenolic compound from ginger, has anti-inflammatory properties in a Complete Freund's Adjuvant (CFA) model of mono-arthritic rats. In the present study, we investigated the effects of 6-shogaol on the production of inflammatory mediators from lipopolysaccharide (LPS) activated RAW 264.7 macrophages. These mediators (TNF-α, IL-1-and NO) and their output from macrophages are involved in various pathophysiological events of chronic inflammation and arthritis. METHODS: Effects of 6-shogaol were investigated on the production of the mediators TNF-α, IL-1-and NO (measured as nitrate) from macrophages. Lipopolysaccharide activated RAW 264.7 macrophages were cultured in the presence and absence of 6-shogaol (2 M, 10 M and 20 µM) and ELISA was used to quantify the output of the mediators. RESULTS: 6-shogoal (2 M, 10 M and 20 M) significantly inhibited the production of nitric oxide (NO), IL-1 and TNF-α from the LPS activated RAW264.7 macrophages. CONCLUSION: The results suggest that macrophages are targets for the anti-inflammatory effects of 6 shogaol. Also, the inhibitory effects against TNF-α, IL-1 and NO production from LPS activated macrophages are cellular mechanisms by which 6-shogaol produced its anti-inflammatory effects. These mechanisms provide an explanation of the protection by 6-shogaol against development of joint inflammation and cartilage degradation in CFA induced mono-arthritis that we previously demonstrated (1). Based on these results with 6-shogaol, there is evidence that it exhibits exploitable anti-inflammatory properties.


OBJETIVO: Con anterioridad reportamos que el 6-shogaol - un compuesto fenólico del jengibre - posee propiedades anti-inflamatorias en un modelo CFA de ratas monoartríticas. En el presente estudio, investigamos los efectos del 6-shogaol sobre la producción de mediadores inflamatorios de macrófagos 264.7 RAW estimulados por lipopolisacáridos. Estos mediadores (TNF-α, IL-1-y NO) y su producción de macrófagos están involucrados en varios eventos patofisiológicos de inflamación crónica y artritis. MÉTODOS: Se investigaron los efectos del 6-shogaol sobre la producción de los mediadores TNF-α, IL-1-y NO (medidos como nitratos) de los macrófagos. Macrófagos 264.7 RAW estimulados por lipopolisacáridos fueron cultivados en presencia y ausencia de 6-shogaol (2 M, 10 M y 20 M) y se usó la técnica de ensayo por inmunoabsorción ligado a enzimas (ELISA) a fin de cuantificar la producción de mediadores. RESULTADOS: El 6-shogaol (2 M, 10 M y 20 M) inhibieron significativamente la producción de óxido nítrico (NO), IL-1 βy TNF-α de los macrófagos RAW 264.7 activados mediante LPS. CONCLUSIÓN: Los resultados sugieren que los macrófagos son blancos de los efectos anti-inflamatorios del 6-shogaol. Por otro lado, los efectos inhibitorios contra la producción de TNF-α, IL-1 y NO a partir de macrófagos activados por LPS, son mecanismos celulares mediante los cuales 6-shogaol produjo sus efectos anti-inflamatorios. Estos mecanismos ofrecen una explicación de la protección mediante 6-shogaol contra el desarrollo de inflamación en las articulaciones y la degradación de los cartílagos en la monoartritis inducida mediante CFA que demostramos con anterioridad (1). Sobre la base de estos resultados con 6-shogaol, hay evidencia de que posee propiedades anti-inflamatorias explotables.


Assuntos
Humanos , Catecóis/farmacologia , Interleucina-1beta/biossíntese , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Óxido Nítrico/biossíntese , Extratos Vegetais/farmacologia , Fator de Necrose Tumoral alfa/biossíntese , Linhagem Celular , Lipopolissacarídeos/farmacologia
10.
Acta cir. bras ; 20(supl.1): 72-77, 2005.
Artigo em Inglês | LILACS | ID: lil-414639

RESUMO

OBJETIVO: Testar a hipótese do catecol inibir a respiração basal associada ao FADH2 em frações mitocondriais hepáticas de rato. Além disso, estudou-se também a capacidade do catecol de induzir peroxidação de biomoléculas nas frações nucleares. MÉTODOS: Os homogeneizados de fígado de ratos foram incubados com catecol a 1 mM em pH fisiológico. Depois disso, as frações mitocondriais foram isoladas por centrifugação diferencial. O consumo basal de oxigênio foi medido com um eletrodo do tipo Clark após injeção de succinato a 10 mM. Frações nucleares foram incubadas com catecol por 17 horas à temperatura ambiente e a peroxidação de biomoléculas foi investigada pela reação com o ácido tiobarbitúrico e mensurada espectrofotometricamente. RESULTADOS: O catecol induziu uma inibição parcial da respiração basal mitocondrial associada ao FADH2 de forma dependente do tempo, contudo essa substância não induziu peroxidação direta das biomoléculas presentes nas frações nucleares hepáticas. CONCLUSÃO: O catecol produz inibição da respiração basal associada ao FADH2 em mitocôndrias isoladas de fígado, o que pode levar à toxicidade, produção de espécies reativas e morte celular.


Assuntos
Animais , Ratos , Catecóis/toxicidade , Flavina-Adenina Dinucleotídeo/análogos & derivados , Peroxidação de Lipídeos/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Respiração Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Flavina-Adenina Dinucleotídeo/antagonistas & inibidores , Mitocôndrias Hepáticas/metabolismo , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo
11.
J. bras. patol. med. lab ; 40(4): 280-285, jul.-ago. 2004. graf
Artigo em Inglês | LILACS | ID: lil-364499

RESUMO

It is known that the exposure to benzene in the petroleum industry causes lympho-haematopoietic cancer among workers. However, there is little data concerning the toxicity of benzene to the central nervous system. Benzene easily penetrates the brain where it is metabolized to catechol. Since catechol autoxidizes in physiological phosphate buffer, we hypothesized that it could be toxic towards glial cells due to the generation of reactive oxygen species and quinones. In this work we studied the cytotoxic properties of catechol towards human glioblastoma cells. We found that catechol was toxic towards these cells after 72 hours and this toxicity was related to the formation of quinones. Catechol at 230µM killed 50% of cells. The catechol-induced cytotoxicity was prevented by the addition of 100U superoxide dismutase, which also inhibited the formation of quinones. These data suggest that catechol induces cytotoxicity via the extracellular generation of superoxide and quinones.


Sabe-se que a exposição de trabalhadores ao benzeno na indústria petrolífera é uma causa de câncer do sistema linfo-hematopoiético. Pouco se sabe, contudo, a respeito da toxicidade do benzeno no sistema nervoso central. O benzeno penetra facilmente no cérebro, onde é metabolizado a catecol. Como o catecol se auto-oxida em tampão fosfato no pH fisiológico, supôs-se que esse composto poderia ser tóxico para células gliais por gerar espécies reativas do oxigênio e quinonas. Nesse trabalho estudou-se a citotoxicidade do catecol para células de glioblastoma humano. O catecol foi tóxico após 72 horas e essa toxicidade relacionou-se com a formação de quinonas. O catecol a 230mM matou metade das células em cultura. A toxicidade do catecol e a produção de quinonas foram inibidas por 100U de superóxido dismutase. Esses dados sugerem que a toxicidade induzida pelo catecol deve-se à produção extracelular de superóxido e quinonas reativas.


Assuntos
Humanos , Benzeno/toxicidade , Sistema Nervoso Central , Catecóis/toxicidade , Glioblastoma/metabolismo , Exposição Ocupacional , Petróleo , Quinonas/análise , Superóxido Dismutase/farmacologia , Superóxido Dismutase/metabolismo , Superóxidos/análise
12.
Pesticidas ; 13: 123-128, jan.-dez. 2003. tab, graf
Artigo em Português | LILACS | ID: lil-387519

RESUMO

Uma linhagem de Acinetobacter baumanii, isolada da rizosfera de cana-de-açúcar, cultivada em solos tratados com Diuron foi incubada em diferentes substratos para verificar a presença de catecol 1,2--dioxigenase (pirocatecase). Diferentes indutores foram adicionados ao meio de cultura (glicose, benzoato de sódio, Diuron, dicloroanilina, benzoato de sódio + glicose). As células bacterianas, obtidas pelo processo fermentativo, foram coletadas após centrifugação e rompidas por sonificação para extração da enzima intracelular. A linhagem apresentou alta atividade enzimática quando benzoato de sódio ou benzoato de sódio + glicose ou benzoato de sódio + dicloroanilina foram adicionados ao meio de cultura. A atividade enzimótica acompanhou a produção de biomassa. No estudo da cinética de crescimento, usando Diuron como fonte de carbono e em tres diferentes pH, essa linhagem apresentou melhor resultado quando cultivada em pH6.8. Verificou-se pela avaliação da capacidade de A. baumanii transformar o Diuron, que o metabólito 3,4-dicloroanilina (3,4-DCA) não foi produzido


Assuntos
Acinetobacter , Biodegradação Ambiental , Catecóis , Diurona , Poluentes Ambientais , Fermentação , Herbicidas
13.
Rev. invest. clín ; 35(2): 149-54, 1983.
Artigo em Espanhol | LILACS | ID: lil-14576

RESUMO

Se describe un metodo para cuantificar la concentracion urinaria de MHPG, que es el principal metabolito de la norepinefrina cerebral, utilizando la cromatografia liquido-gas con detector de captura de electrones. Los resultados obtenidos en 27 sujetos sanos muestran un rango que oscila entre sanos y 3066 microgamo/24 ha con un promedio +/- E.E. de 2040 +/- 113 microgramo 24 hs. Los percentiles de los valores de referencia fueron" P5 = 1060 microgramo/24 hs P50 = 2015 microgramo/24 hs y P95 = 2820 microgramo/24 hs. Tanto la variacion del metodo como los valores encontrados, son consistentes con los reportados en otros paises. Los autores discuten la importancia del desarrollo de esta y otras metodologias similares para algunas areas de la investigacion en neurociencias


Assuntos
Adulto , Humanos , Masculino , Feminino , Catecóis , Urina
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