The effect of sixteen medicinal plants used in the Brazilian pharmacopoeia on the expression and activity of glutathione S-transferase in hepatocytes and leukemia cells

Glutathione S-transferase (GST) is a family of enzymes involved in the detoxification of electrophilic compounds. Different classes of GST are expressed in various organs, such as liver, lungs, stomach and others. Expression of GST can be modulated by diet components and plant-derived compounds. The importance of controlling GST expression is twofold: increasing levels of GST are beneficial to prevent deleterious effects of toxic and carcinogenic compounds, while inhibition of GST in tumor cells may help overcoming tumor resistance to chemotherapy. A screening of 16 plants used in the Brazilian pharmacopoeia tested their effects on GST expression in hepatocytes and Jurkat (leukemia) T-cells. The methanol extracts of five plants inhibited GST expression in hepatocytes. Three plants significantly inhibited and four others induced GST expression in Jurkat cells. Among these, the extracts of Bauhinia forficata Link. (Leguminosae) and Cecropia pachystachya Trec. (Urticaceae) inhibited GST expression at relatively low concentrations. With the exception of B. forficata, all plants were cytotoxic when administered to Jurkat cells at high doses (1 mg/mL) and some extracts were considerably cytotoxic even at lower concentrations.

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.

Physical analyses of compost from composting plants in Brazil

Nowadays the composting process has shown itself to be an alternative in the treatment of municipal solid wastes by composting plants. However, although more than 50% of the waste generated by the Brazilian population is composed of matter susceptible to organic composting, this process is, still today, insufficiently developed in Brazil, due to low compost quality and lack of investments in the sector. The objective of this work was to use physical analyses to evaluate the quality of the compost produced at 14 operative composting plants in the Sao Paulo State in Brazil. For this purpose, size distribution and total inert content tests were done. The results were analyzed by grouping the plants according to their productive processes: plants with a rotating drum, plants with shredders or mills, and plants without treatment after the sorting conveyor belt. Compost quality was analyzed considering the limits imposed by the Brazilian Legislation and the European standards for inert contents. The size distribution tests showed the influence of the machinery after the sorting conveyer on the granule sizes as well as the inert content, which contributes to the presence of materials that reduce the quality of the final product. (C) 2007 Elsevier Ltd. All rights reserved.

The oscillatory bioelectrical signal from plants explained by a simulated electrical model and tested using Lempel-Ziv complexity

This paper demonstrates the oscillatory characteristics of electrical signals acquired from two ornamental plant types (Epipremnum pinnatum and Philodendron scandens - Family Araceae), using a noninvasive acquisition system. The electrical signal was recorded using Ag/AgCl superficial electrodes inside a Faraday cage. The presence of the oscillatory electric generator was shown using a classical power spectral density. The Lempel and Ziv complexity measurement showed that the plant signal was not noise despite its nonlinear behavior. The oscillatory characteristics of the signal were explained using a simulated electrical model that establishes that for a frequency range from 5 to 15 Hz, the oscillatory characteristic is higher than for other frequency ranges. All results show that non-invasive electrical plant signals can be acquired with improvement of signal-to-noise ratio using a Faraday cage, and a simple electrical model is able to explain the electrical signal being generated. (C) 2010 Elsevier B.V. All rights reserved.

Antimicrobial and cytotoxic activities of medicinal plants of the Brazilian cerrado, using Brazilian cachaca as extractor liquid

Ethnopharmacological importance: Many species of plants in the Brazilian cerrado (savanna) are widely used in ethnomedicine. However, the safety and effectiveness of medicinal plants used in communities with little or no access to manufactured drugs should be evaluated. Aim of the study: Evaluate the antimicrobial and cytotoxic activities of extracts from eight plant species, obtained using Brazilian cachaca as the extractor liquid. Materials and methods: The extracts were tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Candida parapsilosis, promastigote forms of Leishmania amazonensis, and poliovirus. In addition, cytotoxic activity was assayed in Vero cells and in human erythrocytes. Results: The plant species Curatella americana, Sclerolobium aureum, and Plathymenia reticulata showed the best activity against yeasts, especially the crude extract of C. americana and its ethyl-acetate fraction. Kielmeyera lathrophyton showed a minimum inhibitory concentration of 250 mu g/ml against S. aureus, and was inactive against Gram-negative bacteria. The extract obtained from Annona coriacea showed the best activity against the promastigote forms of Leishmania amazonensis (IC(50) = 175 mu g/ml). Only C. americana showed potential for antipoliovirus activity. The concentrations of the crude extracts that showed toxicity to VERO cells had CC(50) between 31 and 470 mu g/ml, and the lyophilized Brazilian cachaca showed a CC(50) of 307 mu g/ml. None of the extracts showed toxicity against human erythrocytes. Conclusions: Among the plant species studied. C americana proved to be effective against microorganisms, especially as an antifungal. The results will help in the search for alternative drugs to be used in pharmacotherapy, and will contribute to establish safe and effective use of phytomedicines in the treatment of infectious diseases. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Incidence of Listeria monocytogenes in Cheese Manufacturing Plants from the Northeast Region of Sao Paulo, Brazil

The incidence of Listeria monocytogenes in three cheese manufacturing plants from the northeastern region of Sao Paulo, Brazil, was evaluated from October 2008 to September 2009. L. monocytogenes was found in samples from two plants, at percentages of 13.3% (n = 128) and 9.6% (n = 114). Samples of raw and pasteurized milk, water, and Minas Frescal cheese were negative for L. monocyto genes, although the pathogen was isolated from the surface of Prato cheese and in brine from one of the plants evaluated. L. monocytogenes was also isolated from different sites of the facilities, mainly in non food contact surfaces such as drains, floors, and platforms. Serotype 4b was the most predominant in the plants studied. The results of this study indicate the need for control strategies to prevent the dispersion of L. monocytogenes in the environment of cheese manufacturing plants.

Caesium, potassium and ammonium distributions in different organs of tropical plants

In the present work the distribution of ions in aboveground plant parts was studied in order to establish the suitability of using radiocaesium as a tracer for the plant absorption of nutrients, such as potassium (K(+)) and ammonium (NH(4)(+)). We present the results for the distributions of (137)Cs, (40)K and NH(4)(+) from four tropical plant species: lemon (Citrus aurantifolia), orange (Citrus sinensis), guava (Psidium guajava) and chili pepper (Capsicum frutescens). Activity concentrations of (137)Cs and (40)K were measured by gamma spectrometry and concentrations of free NH(4)(+) ions by a colorimetric method. Similarly to potassium and ammonium, caesium showed a high mobility within the plants, exhibiting the highest values of concentration in the growing parts of the tree (fruits, new leaves, twigs, and barks). A significant correlation between activity concentrations of (137)Cs and (40)K was observed in these tropical plants. The K/Cs discrimination ratios were approximately equal to unity in different compartments of each individual plant, suggesting that caesium could be a good tracer for (40)K in tropical woody fruit species. Despite the similarity observed for the behaviour of caesium and ammonium in the newly grown plant compartments, (137)Cs was not well correlated with NH(4)(+). Significant temporal changes in the NH(4)(+) concentrations were observed during the development of fruits, while the (137)Cs activity concentration alterations were not of great importance, indicating, therefore, that Cs(+) and free NH(4)(+) ions could have distinct concentration ratios for each particular plant organ. (C) 2008 Elsevier B.V. All rights reserved.

Ecological niche modeling and geographical distribution of pollinator and plants: A case study of Peponapis fervens (Smith, 1879) (Eucerini: Apidae) and Cucurbita species (Cucurbitaceae)

The bees of the Peponapes genus (Eucerini, Apidae) have a Neotropical distribution with the center of species diversity located in Mexico and are specialized in Cucurbita plants. which have many species of economic importance. such as squashes and pumpkins Peponapis fervens is the only species of the genus known from southern South America The Cucurbita species occurring in the same area as P fervens Include four domesticated species (C ficifolia, C maxima maxima, C moschata and C pepo) and one non-domesticated species (Cucurbita maxima andreana) It was suggested that C. in andreana was the original pollen source to P fervens, and this bee expanded its geographical range due to the domestication of Cucurbita The potential geographical areas of these species were determined and compared using ecological niche modeling that was performed with the computational system openModeller and GARP with best subsets algorithm The climatic variables obtained through modeling were compared using Cluster Analysis Results show that the potential areas of domesticated species practically spread all over South America The potential area of P fervens Includes the areas of C m andreana but reaches a larger area, where the domesticated species of Cucurbita also Occur The Cluster Analysis shows a high climatic similarity between P fervens and C. m. andreana Nevertheless. P fervens presents the ability to occupy areas with wider ranges of climatic variables and to exploit resources provided by domesticated species (C) 2009 Elsevier B V All rights reserved

Invasive plants: representativeness of research from tropical countries in the global context

Biological invasions threaten the native biota of several countries and this threat is even greater in the tropical regions that have the greatest biodiversity. In order to evaluate the representativeness of studies on invasive plants in tropical countries compared to the world, as well as the region of origin and habits of the most reported invasive plants in research, we analyzed the publications from eight of the most important international journals that address the theme, from January 1995 to December 2004. The articles on biological invasions were classified as theoretical or as case studies, and according to their approach, main question, where the study was conducted, region of origin and habit of the invasive plant. Case studies predominated, as did questions about the environment`s susceptibility to the invasion, the species` invasive power and the impacts it had. The most reported invasive species were herbaceous plants from Asia and Europe. Few articles address tropical environments and only one referred to Brazil. Most referred to North America and Europe. This small number of publications in the tropics indicates the need for a global projection on this subject and underscores the lack of consistent and organized data to understand the phenomenon and propose effective strategies to combat biological invasion.

Nitrosyl ethylenediaminetetraacetate ruthenium(II) complex promotes cellular growth and could be used as nitric oxide donor in plants

Over recent years nitric oxide (NO) not only has appeared as an important endogenous signaling molecule in plants and as a mediator in many developmental and physiological processes, but has also received recognition as a plant hormone. The impressive recent achievements in elucidating the role of NO in plants have come about by the application of NO donors. The aim herein was to study the effects of the different NO donors, sodium nitroprusside (SNP) and the nitrosyl ethylenediaminetetraacetate ruthenium(II) ([Ru(NO)(Hedta)]) complex on cellular growth in embryogenic suspension cultures of Araucaria angustifolia. Appraisal of our data revealed that [Ru(NO)(Hedta)] stimulated about 60% of cellular growth in embryogenic suspension cultures of A. angustifolia, with results similar to those observed with the SNP donor. Nevertheless, application of the NO scavenger PTIO (2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) inhibited this cellular growth in both. Cellular growth was correlated with an increase in endogenous NO levels after 21 days of culture, especially in treatments with NO donors. Our results demonstrated that the [Ru(NO)Hedta] complex could possibly be used as a NO donor in plants. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Evaluation of Fungal Burden and Aflatoxin Presence in Packed Medicinal Plants Treated by Gamma Radiation

This study was developed to evaluate the fungal burden, toxigenic molds, and mycotoxin contamination and to verify the effects of gamma radiation in four kinds of medicinal plants stored before and after 30 days of irradiation treatment. Eighty samples of medicinal plants (Peumus boldus, Camellia sinensis, Maytenus ilicifolia. and Cassia angustifolia) purchased from drugstores, wholesale, and open-air markets in Sao Paulo city, Brazil, were analyzed. The samples were treated using a (60)Co gamma ray source (Gammacell) with doses of 5 and 10 kGy. Nonirradiated samples were used as controls of fungal isolates. For enumeration of fungi on medicinal plants, serial dilutions of the samples were plated in duplicate onto dichloran 18% glycerol agar. The control samples revealed a high burden of molds, including toxigenic fungi. The process of gamma radiation was effective in reducing the number of CFU per gram in all irradiated samples of medicinal plants after 30 days of storage, using a dose of 10 kGy and maintaining samples in a protective package. No aflatoxins were detected. Gamma radiation treatment can be used as an effective method for preventing fungal deterioration of medicinal plants subject to long-term storage.

Genetic diversity and toxic activity of Aggregatibacter actinomycetemcomitans isolates

Introduction: Very little is known of the diversity and expression of virulence factors of serotypes of Aggregatibacter actinomycetemcomitans. Toxic activity on Chinese hamster ovary (CHO) cells and cdt and ltx genotyping were evaluated in A. actinomycetemcomitans serotypes. Methods: Forty-one A. actinomycetemcomitans isolates were analysed for CHO cell growth inhibition. Genotyping was performed by polymerase chain reactions specific to the ltx promoter region, serotype-specific and cdt region and by sequencing of cdtB. Results: cdtABC was detected in 40 strains. Analysis of the cdtA upstream region revealed 10 cdt genotypes. Toxicity to CHO cells was detected for 92.7% of the isolates; however, no correlation between the toxic activity and the cdt genotype was detected. Serotype c was more prevalent among Brazilian samples (68.0%). Four serotype b isolates from subjects with aggressive periodontitis were associated with high leukotoxin production and exhibited moderate to strong toxic activity in CHO cells, but were classified in different cdt genotypes. High levels of toxicity in CHO cells were not associated with a particular serotype; 57.1% of serotype a isolates presented low toxicity to CHO cells whereas the highly toxic strains belonged to serotypes b and c. Sequencing of cdtB revealed a single nucleotide polymorphism of amino acid 281 but this was not related to the toxic activity in CHO cells. Conclusion: Differences in prevalence of the low and highly cytotoxic strains among serotypes reinforce the hypothesis that serotype b and c isolates of A. actinomycetemcomitans are more virulent than serotype a strains.

Biochemical characterization of serine acetyltransferase and cysteine desulfhydrase from Leishmania major

Cysteine metabolism exhibits atypical features in Leishmania parasites. The nucleotide sequence annotated as LmjF32.2640 encodes a cysteine desulfhydrase, which specifically catalyzes the breakdown of cysteine into pyruvate, NH(3) and H(2)S. Like in other pathogens, this capacity might be associated with regulatory mechanisms to control the intracellular level of cysteine, a highly toxic albeit essential amino acid, in addition to generate pyruvate for energy production. Besides, our results provide the first insight into the biochemical properties of Leishmania major serine acetyltransferase (SAT), which is likely involved in the two routes for de novo synthesis of cysteine in this pathogen. When compared with other members of SAT family, the N-terminal region of L. major homologue is uniquely extended, and seems to be essential for proper protein folding. Furthermore, unlike plant and bacterial enzymes, the carboxy-terminal-C(10) sequence stretch of L major SAT appears not to be implicated in forming a tight bi-enzyme complex with cysteine synthase. (C) 2010 Elsevier B.V. All rights reserved.

On the catalytic hydrogenation of polycyclic aromatic hydrocarbons into less toxic compounds by a facile recoverable catalyst

Here we present the catalytic hydrogenation of polycyclic aromatic hydrocarbons (PAHs) to less toxic mixtures of saturated and partial unsaturated polycyclic hydrocarbons under mild reaction conditions using a magnetically recoverable rhodium catalyst and molecular hydrogen as the exclusive H source. The catalyst is easily recovered after each reaction by placing a permanent magnet on the reactor wall and it can be reused in successive runs without any significant loss of catalytic activity. As an example, anthracene was totally converted into the saturated polycyclic hydrocarbon form (ca. 60%) and the partially hydrogenated form, 1,2,3,4,5,6,7,8-octahydroanthracene (ca. 40%). The catalyst operates in a broad range of temperature and H(2) pressure in both organic and aqueous/organic solutions of anthracene and it also exhibits significant activity at low substrate concentrations (20 ppm). This can be an efficient recycling process for hydrogenation of PAHs present in contaminated fluid waste streams. (C) 2009 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.