SBTX, a new toxic protein distinct from soyatoxin and other toxic soybean [Glycine max] proteins, and its inhibitory effect on Cercospora sojina growth

SBTX, a novel toxin from soybean, was purified by ammonium sulfate fractionation followed by chromatographic steps DEAE-Cellulose, CM-Sepharose and Superdex 200 HR fast-protein liquid chromatography (FPLC). Lethality of SBTX to mice (LD50 5.6 mg/kg) was used as parameter in the purification steps. SBTX is a 44-kDa basic glycoprotein composed of two polypeptide chains (27 and 17 kDa) linked by a disulfide bond. The N-terminal sequences of the 44 and 27 kDa chains were identical (ADPTFGFTPLGLSEKANLQIMKAYD), differing from that of 17 kDa (PNPKVFFDMTIGGQSAGRIVMEEYA). SBTX contains high levels of Glx, Ala, Asx, Gly and Lys and showed maximum absorption at 280 nm, epsilon(1 cm) (1%) of 6.3, and fluorescence emission in the 290-450nm range upon excitation at 280nm. The secondary structure content was 35% alpha-helix, 13% beta-strand and beta-sheet, 27% beta-turn, 25% unordered, and 1% aromatic residues. Immunological assays showed that SBTX was related to other toxic proteins, such as soyatoxin and canatoxin, and cross-reacted weekly with soybean trypsin inhibitor and agglutinin, but it was devoid of protease-inhibitory and hemagglutinating activities. The inhibitory effect of SBTX on growth of Cercospora sojina, fungus causing frogeye leaf spot in soybeans, was observed at 50 mu g/ml, concentration 112 times lesser than that found to be lethal to mice. This effect on phytopathogenic fungus is a potential attribute for the development of transgenic plants with enhanced resistance to pathogens. (c) 2007 Elsevier Ltd. All rights reserved.

16-Bromoepiandrosterone, an activator of the mammalian immune system, inhibits glucose 6-phosphate dehydrogenase from Trypanosoma cruzi and is toxic to these parasites grown in culture

Glucose 6-phosphate dehydrogenase (G6PDH) catalyzes the first step of the pentose-phosphate pathway which supplies cells with ribose 5-phosphate (R5P) and NADPH. R5P is the precursor for the biosynthesis of nucleotides while NADPH is the cofactor of several dehydrogenases acting in a broad range of biosynthetic processes and in the maintenance of the cellular redox state. RNA interference-mediated reduction of G6PDH levels in bloodstream-form Trypanosoma brucei validated this enzyme as a drug target against Human African Trypanosomiasis. Dehydroepiandrosterone (DHEA), a human steroidal pro-hormone and its derivative 16 alpha-bromoepiandrosterone (16BrEA) are uncompetitive inhibitors of mammalian G6PDH. Such steroids are also known to enhance the immune response in a broad range of animal infection models. It is noteworthy that the administration of DHEA to rats infected by Trypanosoma cruzi, the causative agent of Human American Trypanosomiasis (also known as Chagas` disease), reduces blood parasite levels at both acute and chronic infection stages. In the present work, we investigated the in vitro effect of DHEA derivatives on the proliferation of T. cruzi epimastigotes and their inhibitory effect on a recombinant form of the parasite`s G6PDH (TcG6PDH). Our results show that DHEA and its derivative epiandrosterone (EA) are uncompetitive inhibitors of TcG6PDH, with K(i) values of 21.5 +/- 0.5 and 4.8 +/- 0.3 mu M, respectively. Results from quantitative inhibition assays indicate 16BrEA as a potent inhibitor of TcG6PDH with an IC(50) of 86 +/- 8 nM and those from in vitro cell viability assays confirm its toxicity for T. cruzi epimastigotes, with a LD(50) of 12 +/- 8 mu M. In summary, we demonstrated that, in addition to host immune response enhancement, 16BrEA has a direct effect on parasite viability, most likely as a consequence of TcG6PDH inhibition. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.

Chromium ions phytoaccumulation by three floating aquatic macrophytes from a nutrient medium

In the present work, the trivalent and hexavalent chromium phytoaccumulation by three living free floating aquatic macrophytes Salvinia auriculata, Pistia stratiotes, and Eicchornia crassipes was investigated in greenhouse. These plants were grown in hydroponic solutions supplied with non-toxic Cr3+ and Cr6+ chromium concentrations, performing six collections of nutrient media and plants in time from a batch system. The total chromium concentrations into Cr-doped hydroponic media and dry roots and aerial parts were assayed, by using the Synchrotron radiation X-ray fluorescence technique. The aquatic plant-based chromium removal data were described by using a nonstructural kinetic model, obtaining different bioaccumulation rate, ranging from 0.015 to 0.837 1 mg(-1) d(-1). The Cr3+ removal efficiency was about 90%, 50%, and 90% for the E. crassipes, P. stratiotes, and S. auriculata, respectively; while it was rather different for Cr6+ one, with values about 50%, 70%, and 90% for the E. crassipes, P. stratiotes, and S. auriculata.

Dietary Quality and Associated Factors among Factory Workers in the Metropolitan Region of Sao Paulo, Brazil

The workplace is a manageable community-based setting for ensuring proper nutrition. This study aimed to evaluate dietary quality and associated factors among adult workers at a cosmetics factory in the metropolitan area of Sao Paulo, Brazil. This factory was actively participating in the Brazilian Workers` Meal Program, which was created to ensure workers` nutritional health. In this cross-sectional study, data on 202 adult workers were assessed using questionnaires (sociodemographic, anthropometric, and lifestyle characteristics) administered during August and September 2006. Dietary intake, measured by 24-hour dietary recall, was used to calculate the modified Healthy Eating Index (HEI). A repeated administration of the 24-hour dietary recall was applied in a random subsample to calculate the modified HEI adjusted for the within-person variation in intake. Mean adjusted modified HEI scores were analyzed using multiple linear regression adjusted for energy. The mean adjusted modified HEI score was 72.3 +/- 8.0. The lowest adjusted modified HEI components scores were ""milk and dairy products"" (4.4 +/- 3.2) and ""sodium"" (3.7 +/- 3.1). Two percent of workers had ""poor diet"" (adjusted modified HEI score <51 points) and the majority (87%) had ""diet that needs modification"" (adjusted modified HEI score between 51 and 80), despite their participation in the meal program. Adjusted modified HEI scores were considerably higher for men (74.7 +/- 7.0) than for women (66.9 +/- 8.2) and for normal body mass index (calculated as kg/m(2)) (73.3 +/- 7.8) than for overweight/obese (70.9 +/- 8.1). Based on these results, the vast majority of workers were found to have diets that needed improvement. Individuals with higher-quality diets were more likely to have lower body mass index and to be male. J Am Diet Assoc. 2010;110:786-790.

Modulatory effect of fatty acids on fungicidal activity, respiratory burst and TNF-alpha and IL-6 production in J774 murine macrophages

The reported effects of different families of fatty acids (FA; SFA, MUFA, n-3 and n-6 PUFA) on human health and the importance of macrophage respiratory burst and cytokine release to immune defence led us to examine the influence of palmitic acid (PA), oleic acid (OA), linoleic acid, arachidonic acid, EPA and DHA on macrophage function. We determined fungicidal activity, reactive oxygen species (ROS) and cytokine production after the treatment of J774 cells with non-toxic concentrations of the FA. PA had a late and discrete stimulating effect on ROS production, which may be associated with the reduced fungicidal activity of the cells after treatment with this FA. OA presented a sustained stimulatory effect on ROS production and increased fungicidal activity of the cells, suggesting that enrichment of diets with OA may be beneficial for pathogen elimination. The effects of PUFA on ROS production were time-and dose-dependently regulated, with no evident differences between n-3 and n-6 PUFA. It was worth noting that most changes induced after stimulation of the cells with lipopolysaccharide were suppressed by the FA. The present results suggest that supplementation of the diet with specific FA, not classes of FA, might enable an improvement in host defence mechanisms or a reduction in adverse immunological reactions.

Crotoxin alters lymphocyte distribution in rats: Involvement of adhesion molecules and lipoxygenase-derived mediators

Crotoxin is the main neurotoxic component of Crotalus durissus terrificus snake venom and modulates immune and inflammatory responses, interfering with the activity of leukocytes. In the present work, the effects of crotoxin on the number of blood and lymphatic leukocytes and on lymph nodes and spleen lymphocytes population were investigated. The toxin s.c. administered to male Wistar rats, decreases the number of lymphocytes in blood and lymph circulation and increases the content of B and T-lymphocytes in lymph nodes. These effects were detected 1-2 h after treatment. The crotoxin molecule is composed of two subunits, an acidic non-toxic polypeptide, named crotapotin and a toxic basic phospholipase A(2) (PLA(2)). PLA(2), but not crotapotin, decreased the number of circulating blood and lymph lymphocytes. Crotoxin promotes leukocyte adherence to endothelial cells of blood microcirculation and to lymph node high endothelial venules, which might contribute to the drop in the number of circulating lymphocytes. Crotoxin increases expression of the adhesion molecule LFA-1 in lymphocytes. The changes in the expression of the adhesion molecule might contribute, at least in part, for the increased leukocyte adhesion to endothelium. Zileuton, a 5-lipoxygenase inhibitor, blocked the decrease in the number of circulating leukocytes induced by crotoxin and also abolished the changes observed in leukocyte-endothelial interactions, suggesting the involvement of lipoxygenase-derived mediators in the effects of the toxin. (c) 2008 Elsevier Ltd. All rights reserved.

4-Fluoro-2-methoxyphenol, an apocynin analog with enhanced inhibitory effect on leukocyte oxidant production and phagocytosis

Apocynin, a methoxy-substituted catechol (4-hydroxy-3-methoxyacetophenone), originally extracted from the roots of Picrorhiza kurroa, has been extensively used as a non-toxic inhibitor of the multienzymatic complex NADPH oxidase. We discovered that the analogous methoxy-substituted catechol, 4-Fluoro-2-methoxyphenol (F-apocynin), in which the acetyl group present in apocynin was changed to a fluorine atom, was significantly more potent as an inhibitor of NADPH oxidase activity, myeloperoxidase (MPO) chlorinating activity and phagocytosis of microorganisms by neutrophils; it was also as potent as apocynin in inhibiting tumor necrosis factor-alpha (TNF alpha) release by peripheral blood mononuclear cells. We attribute the increased potency of F-apocynin to its increased lipophilicity, which could facilitate the passage of the drug through the cell membrane. The inhibition of MPO chlorination activity, phagocytosis and TNF alpha release shows that apocynin and F-apocynin actions are not restricted to reactive oxygen species inhibition, but further studies are needed to clarify if these mechanisms are related. Like apocynin, F-apocynin did not show cell toxicity, and is a strong candidate for use in the treatment of inflammatory diseases. (C) 2011 Elsevier B.V. All rights reserved.

Root uptake and reduction of hexavalent chromium by aquatic macrophytes as assessed by high-resolution X-ray emission

Aquatic macrophytes Salvinia auriculata, Pistia stratiotes and Eichhornia crassipes were chosen to investigate the Cr(VI) reduced by root-based biosorption in a chromium uptake experiment, using a high-resolution XRF technique. These plants were grown in hydroponics medium supplied with non-toxic Cr concentrations during a 27-day metal uptake experiment. The high-resolution Cr-K beta fluorescence spectra for dried root tissues and Cr reference material (100% Cr, Cr(2)O(3), and CrO(3)) were measured using an XRF spectrometer. For all species of aquatic plant treated with Cr(VI), the energy of the Cr-K beta(2,5) line was shifted around 8 eV below the same spectral line identified for the Cr(VI) reference, but it was also near to the line identified for the Cr(III) reference. Moreover, there was a lack of the strong Cr-K beta"" line assigned to the Cr(VI) reference material within the Cr(VI)-treated plant spectra, suggesting the reduction of Cr(VI) for other less toxic oxidation states of Cr. As all Cr-K beta spectra of root tissue species were compared, the peak energies and lineshape patterns of the Cr-K beta(2,5) line are coincident for the same aquatic plant species, when they were treated with Cr(III) and Cr(VI). Based on the experimental evidence, the Cr(VI) reduction process has happened during metal biosorption by these plants. (C) 2009 Elsevier Ltd. All rights reserved.

PIXE analysis of chromium phytoaccumulation by the aquatic macrophytes Eicchornia crassipes

The uptake of hexavalent chromium in free living floating aquatic macrophytes Eicchornia crassipes cultivated in non-toxic chromium-doped hydroponic solutions is presented. A Cr-uptake bioaccumulation experiment was carried out using healthy macrophytes grown in a temperature controlled greenhouse. Six samples of nutrient media and plants were collected during the 23 day experiment. Roots and leaves were acid digested with the addition of an internal Gallium standard, for thin film sample preparation and quantitative Cr analysis by PIXE method. The Cr(6+) mass uptake by the macrophytes reached up to 70% of the initial concentration, comparable to former results and literature data. The Cr-uptake data were described using a non-structural first order kinetic model. Due to low cost and high removal efficiency, living aquatic macrophytes E. crassipes are a viable biosorbent in an artificial wetland of a water effluent treatment plant. (c) 2009 Elsevier B.V. All rights reserved.

Heterogeneous photocatalytic degradation of acid dyes in aqueous TiO2 suspensions: Kinetics and toxicity

This work assesses the photocatalytic (TiO2/UV) degradation of a simulated acid dye bath (Yellow 3, Red 51, Blue 74, and auxiliary chemicals). Color and phytotoxicity removal were monitored by spectrophotometry and lettuce (Lactuca sativa) seeds as the test organism, respectively. Mineralization was determined by DOC analyses. Photocatalytic, photolytic, and adsorption experiments were performed, showing that adsorption was negligible. After 240 minutes of irradiation, it was achieved 96% and 78% of color removal with photocatalysis and photolysis, respectively. 37% of mineralization occurred with photocatalysis only. The dye bath was rendered completely non-toxic after 60 minutes of photocatalytic treatment; the same result was only achieved with photolysis after 90 minutes. A kinetic model composed of two first-order in series reactions was used. The first photocatalytic decolorization rate constant was k(1) = 0.062 min(-1) and the second k(2) = 0.0043 min(-1), approximately two times greater than the photolytic ones.