Flexural behavior of Sisal/Castor oil-Based Polyurethane and Sisal/Phenolic Composites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mode of Action of Pulegone on the Urinary Bladder of F344 Rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antiulcerogenic effect and cytotoxic activity of semi-synthetic crotonin obtained from Croton cajucara Benth.

Trans-dehydrocrotonin, the major diterpene isolated from the bark of Croton cajucara, has good antiulcerogenic activity which, however, is accompanied by toxic effects. on the basis of these results, a semi-synthetic crotonin, named 4SRC, was prepared to determine whether this substance has similar antiulcerogenic activity with lower or no toxicity. The natural crotonin was also isolated from the bark of C. cajucara but was not used due to the small amount obtained. The cytotoxic effect of semi-synthetic crotonin, expressed as cell viability, was assessed in (a) lung fibroblast cell line (V79) derived from Chinese hamsters, a system commonly used for cytotoxicity studies, and (b) rat hepatocytes isolated from male Wistar rats. After treatment, cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide reduction (MTT reduction), total acid content and neutral red uptake assays. To evaluate V79 cell viability, different concentrations of semi-synthetic crotonin were incubated with the cells. To evaluate the antiulcerogenic effects of semi-synthetic crotonin (50, 100 and 200 mg/kg), we used the models of gastric ulcer induced by ethanol/HCl, stress, indomethacin/bethanechol, and ethanol in male Swiss mice and male Wistar rats. The substance had an IC50 = 500 muM in the neutral red uptake and MTT reduction tests and an IC50 = 200 muM in the nucleic acid content test. With regard to hepatocyte viability after treatment with semi-synthetic crotonin at different concentrations, semi-synthetic crotonin had an IC50 = 10-500 muM in the nucleic acid content and MTT reduction tests and an IC50 = 120 muM in the neutral red uptake test. In another experiment, V79 cells were incubated with the metabolites produced by hepatocytes treated with different concentrations of semi-synthetic crotonin. After a 4-h incubation, semi-synthetic crotonin had an IC50 = 500 muM in the MTT reduction and neutral red uptake tests and an IC50 = 370 muM in nucleic acid content test. The substance had significant antiulcerogenic activity in all models studied, suggesting the presence of a possible antisecretory effect combined with a cytoprotective effect. For this reason, the effect of semi-synthetic crotonin was also evaluated on biochemical parameters of gastric juice and gastric wall mucus, both obtained from pylorus-ligated mice. No significant differences were observed in these parameters between semi-synthetic crotonin-treated and control animals. The results obtained with semi-synthetic crotonin are promising, with a significant preventive effect against gastric ulcer induced by different agents. Our data also show that semi-synthetic crotonin was less toxic than dehydrocrotonin and that the cytotoxic effects decreases with the time that isolated hepatocytes were in culture. (C) 2003 Elsevier B.V. B.V. All rights reserved.

ANTIOXIDANT PROPERTIES of LENTINUS EDODES and AGARICUS BLAZEI EXTRACTS

This work aimed to evaluate the antioxidant activity of Lentinus edodes and Agaricus blazei mushrooms, as well as to measure the content of total phenolic compounds of mushroom extracts and verify the oxidative stability of soybean oil added with mushroom extracts that showed higher antioxidant activity according to the methods of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and the beta-carotene/linoleic acid system. According to the DPPH method, the maximum antioxidant activity for L. edodes and A. blazei methanol extracts was 92.84 and 95.10%, respectively. For the beta-carotene/linoleic acid system, the highest values of antioxidant activity were 93.06% for L. edodes and 78.96% for A. blazei. The content of total phenolic compounds ranged from 7.21 to 128.44 and 26.67 to 134.67 mg gallic acid equivalent/g for L. edodes and A. blazei, respectively. The oxidative stability values provided by the Rancimat method indicated that the two varieties presented similar induction period of 19.85 h.

Evaluation of the use of Syzygium cumini fruit extract as an antioxidant additive in orange juice and its sensorial impact

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cytotoxicity and Genotoxicity of Root Canal Sealers Based on Mineral Trioxide Aggregate

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modeling of organic light-emitting diodes with graded concentration in the emissive multilayer

We model the electrical behavior of organic light-emitting diodes whose emissive multilayer is formed by blends of an electron transporting material, tris-(8-hydroxyquinoline) aluminum (Alq(3)) and a hole transporting material, N,N-'-diphenyl-N,N-'-bis(1,1(')-biphenyl)-4,4-diamine. The multilayer is composed of layers of different concentration. The Alq(3) concentration gradually decreases from the cathode to the anode. We demonstrate that these graded devices have higher efficiency and operate at lower applied voltages than devices whose emissive layer is made of nominally homogeneous blends. Our results show an important advantage of graded devices, namely, the low values of the recombination rate distribution near the cathode and the anode, so that electrode quenching is expected to be significantly suppressed in these devices. (C) 2004 American Institute of Physics.

Amino acid, Antioxidant and Ion Profiles of Carpolobia lutea Leaf (Polygalaceae)

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

Antioxidant activity, ascorbic acid and total phenol of exotic fruits occurring in Brazil

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

Determination of nitrite in meat products and water using dapsone with combined spot test/diffuse reflectance on filter paper

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Antioxidant Properties of Plant Extracts: an EPR and DFT Comparative Study of the Reaction with DPPH, TEMPOL and Spin Trap DMPO

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

Phenolic Derivatives from Fruits of Dipteryx lacunifera DUCKE and Evaluation of Their Antiradical Activities

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Constituintes químicos e atividade antioxidante de extratos das folhas de Terminalia fagifolia Mart. et Zucc

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relative antioxidant activity of Brazilian medicinal plants for gastrointestinal diseases

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

Avaliação do potencial alelopático, atividade antimicrobiana e antioxidante dos extratos orgânicos das folhas de Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae)

Este trabalho apresenta os resultados de atividade alelopática, antimicrobiana e antioxidante dos extratos orgânicos (hexano, acetato de etila e metanol) das folhas de Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae). Para alelopatia, foi estudado o desenvolvimento de Cucumis sativus (pepino), sendo avaliados o comprimento da raiz principal, o número de raízes secundárias e o comprimento do hipocótilo. Os dois primeiros parâmetros foram afetados por todos os três extratos testados enquanto o comprimento do hipocótilo só não foi afetado pelo extrato acetato de etila. Quanto à atividade antimicrobiana, avaliada pelo ensaio de CIM, o extrato hexânico apresentou inibição moderada frente ao Staphylococcus aureus (0,9 mg mL-1) e forte ao Enterococcus hirae (0,5 mg mL-1). O extrato acetato de etila apresentou forte atividade frente Candida albicans (0,3 mg mL-1) enquanto o extrato metanólico não mostrou-se ativo para os microrganismos testados. Por outro lado, o extrato metanólico apresentou a maior capacidade de seqüestrar radicais livres (Concentração Efetiva 50%-CE50 =102,0 ± 56,9 mg mL-1, com TCE50 = 30 min) no ensaio com DPPH (2,2-difenil-1-picril-hidrazila) e o maior teor de compostos fenólicos (116,2 ± 83,0 mg ácido gálico g amostra-1), avaliado pelo ensaio de Folin-Ciocalteau.