976 resultados para ethanol extracts


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Shiitake (Lentinula edodes (Berkeley) Pegler) is one of the most consumed mushrooms, for both therapeutic purposes and as food, therefore, the study of its biological properties is of great interest for producers and consumers. Aqueous extracts of the shiitake mushroom (L. edodes (Berkeley) Pegler) were evaluated by the micronucleus test (MN) in HEp-2 cells in vitro, to analyze their possible mutagenic and antimutagenic activities. None of the three extract concentrations tested (0.5, 1.0 and 1.5 mg/mL) presented mutagenicity at any of the preparation temperatures (4 degrees C, 22 +/- 2 degrees C and 60 degrees C). In the antimutagenicity evaluation, all extract concentrations at all preparation temperatures presented a strong protective activity for the HEp-2 cells in response to the alkylating agent methyl methanesulfonate (MMS) in the different treatment protocols: pre-treatment, simultaneous treatment and post-treatment. The extracts prepared at 22 +/- 2 degrees C presented the lowest frequencies of MN in the evaluations of mutagenicity and antimutagenicity, indicating these as the best option for potential therapeutic use. (c) 2006 Elsevier Ltd. All rights reserved.

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The mutagenic activity of waste material originating from an aluminum products factory was determined by the Salmonella/microsome assay, using the bacterial strains TA100, TA98 and YG1024. The material was obtained by sweeping the factory floor at the end of the work shift. Organic compounds were extracted by ultrasound for 30 min in dichloromethane or 70% ethanol. After evaporation of solvent, these extracts were dissolved in dimethylsulfoxide, and tested for the mutagenic activity at varying concentrations. All the extracts from the factory had mutagenic activity, especially in the YG1024 strain, suggesting the presence of aromatic amines, later confirmed by chemical analysis. The TA98 strain also showed mutagenic activity, though it did not exhibit the highest mutagenicity index observed with the YG1024 strain. In TA100, mutagenic activity was not observed. This study should serve as an alert to management and those who are occupationally exposed, and as a warning that this type of waste should not be discarded in the environment without any control. (C) 2004 Elsevier Ltd. All rights reserved.

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The cyclic voltammetric behavior of acetaldehyde and the derivatized product with 2,4-dinitrophenylhydrazine (DNPHi) has been studied at a glassy carbon electrode. This study was used to optimize the best experimental conditions for its determination by high-performance liquid chromatographic (HPLC) separation coupled with electrochemical detection. The acetaldehyde-2,4-dinitrophenyl.hydrazone (ADNPH) was eluted and separated by a reversed-phase column, C-18, under isocratic conditions with the mobile phase containing a binary mixture of methanol/LiCl(aq) at a concentration of 1.0 x 10(-3) M (80:20 v/v) and a flow rate of 1.0 mL min(-1). The optimum condition for the electrochemical detection of ADNPH was +1.0 V vs. Ag/AgCl as a reference electrode. The proposed method was simple, rapid (analysis time 7 min) and sensitive (detection limit 3.80 mu g L-1) at a signal-to-noise ratio of 3:1. It was also highly selective and reproducible [standard deviation 8.2% +/- 0.36 (n = 5)]. The analytical curve of ADNPH was linear over the range of 3-300 mg L-1 per injection (20 mu L), and the analytical recovery was > 99%.

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Drimys angustifolia Miers. (Winteraceae) is a Brazilian medicinal plant used as analgesic, antiulcer and anti-inflammatory without studies to assure its efficacy and safety Leaf and stem bark extracts were evaluated to determine the antiulcer, analgesic, antiinflammatory and antioxidant activities. Preliminary toxic effects and qualitative phytochemical profile were also performed. The antiulcer activity was detected in both extracts. Administration of the leaf extract at 250 mg/kg inhibited total lesion area by 76.50% (p < 0.01 in ethanol/HCl method), while carbenoxolone at 250 mg/kg reduced lesions by 69.48%. Stem bark extract (250 mg/kg) inhibited lesion by 81.42%, while carbenoxolone by 74.10%. Similar effects were observed in the ethanol-induced ulcer method, but no activity was observed in piroxican model. The effects involve nitric oxide in gastric protection, since the L-NAME treatment reversed the protection given by the extracts. Antioxidant effects suggest an involvement against oxidative stress. In the pain (writhing, tail-flick and hot-plate tests) and inflammation (carrageenan-induced paw edema) models, the extracts did not present any effect. The phytochemical studies demonstrated that both extracts contain flavonoids, saponins, glycosilated triterpenoids, fixed acids, cyanogenic glycosides, quinones, tannins, xanthone and steroidal aglycones. Toxicological studies showed that the extracts are safe at the effective antiulcer doses. (c) 2006 Elsevier B.V.. All rights reserved.

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Agaricus blazei Murrill ss. Heinem, known as the sun mushroom or himematsutake, is a basidiomycete native to Brazil, which is popular for its medicinal properties. The aim of this study was to test hexane extracts (one fraction and its four sub-fractions) of A. blazei for bioactivity in cultured mammalian cells (CHO-K1). The comet assay, the colony forming assay (CFA) and CHO/HGPRT gene mutation assay were used respectively to determine genotoxicity, cytotoxicity and antimutagenicity of these extracts at different concentrations. The cells were incubated in culture medium and treated for 3 h according to the standard protocol for each assay. The DNA damage-inducing agent ethylmethane sulfonate (EMS) was utilized as the positive control and also in combination with extracts to test for a protective effect. Statistical analysis of the data was performed using analysis of variance (ANOVA) and Tukey's test. A relationship between cytotoxicity and genotoxicity could be established and two extracts EH6B and EH6D showed a protective tendency, while the others did not, with the primary extract EH6 causing the most substantial damage to genetic material. These findings warrant more in-depth studies of the active principles of this mushroom. (c) 2005 Elsevier Ltd. All rights reserved.

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A new methodology was developed for analysis of aldehydes and ketones in fuel ethanol by high-performance liquid chromatography (HPLC) coupled to electrochemical detection. The electrochemical oxidation of 5-hydroxymetkylfurfural, 2-furfuraldehyde, butyraldehyde, acetone and methyl ethyl ketone derivatized with 2,4-dinitrophenylhydrazine (DNPH) at glassy carbon electrode present a well defined wave at +0.94 V; +0.99 V; +1.29 V; +1.15 V and +1.18 V, respectively which are the basis for its determination on electrochemical defector. The carbonyl compounds derivatized were separated by a reverse-phase column under isocratic conditions with a mobile phase containing a binary mixture of methanol /LiClO4(aq) at a concentration of 1.0 x 10(-3) mol L-1 (80:20 v/v) and a flow-rate of 1.1 mL min(-1). The optimum potential for the electrochemical detection of aldehydes-DNPH and ketones-DNPH was +1.0 V vs. Ag/AgCl. The analytical curve of aldehydes-DNPH and ketones-DNPH presented linearity over the range 5.0 to 400.0 ng mL(-1), with detection limits of 1.7 to 2.0 ng mL(-1) and quantification limits from 5.0 to 6.2 ng mL(-1), using injection volume of 20 mu L. The proposed methodology was simple, low time-consuming (15 min/analysis) and presented analytical recovery higher than 95%.

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In the present study, 1220 plant extracts obtained from 352 plants belonging to 73 families that grow in the Amazon and Atlantic rain forests were screened for cytotoxicity against PC-3 prostate cancer cell lines. Extracts were tested in the single dose of 100 mu g/mL. Activity was observed in 17 aqueous or organic extracts belonging to Annonaceae, Apocynaceae, Araceae, Capparaceae, Commelinaceae, Flacourtiaceae, Lecythiclaceae, Leguminosae, Passifloraceae, Rutaceae, and Violaceae.

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

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

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"Isolation and evaluation of the biological activity related to the major alkaloids in Tabernaemontana angulata Mart. ex Mull Arg., Apocynaceae." Introducing-new chemotherapeutic agents is a, great demand. in the control of infections diseases.' Brazil is one of the richest countries in biodiversity and the Laboratorio de Extracao at UNIP has been collecting plants from. the Amazon and Atlantic Rain Forests with the aim of screening for new antibacterial and antitumor plant extracts. Previous studies demonstrated that the ethanol fraction obtained from the crude extract of Tabernaemontana angulata stems showed antibacterial activity against Staphylococcus aureus (ATCC 6538 in the microdilution broth assay. Two alkaloids were the major compounds in the active fraction, verified by thin layer chromatography analysis. In the present study, the total alkaloids were obtained from the crude extract and were fractionated by preparative thin layer chromatography for the isolation of the main components. The isolated. compounds were identified by GC/MS and (1)H-NMR as coronaridine,e and voacangine. The alkaloid fractions obtained from the isolation procedure were tested for antibacterial activity, but no activity was detected.