Ação de tinturas e óleos essenciais de plantas medicinais sobre o crestamento bacteriano comum do feijoeiro e na produção de proteínas de indução de resistência

A exploração da atividade biológica de compostos secundários presentes nas tinturas ou em óleos essenciais de plantas podem representar, ao lado da indução de resistência, mais uma forma potencial de controle de doenças em plantas cultivadas. O presente trabalho objetivou avaliar o potencial de tinturas de Lippia alba, Lippia sidoides, Mikania glomerata, Equisetum sp. e Hedera helix e óleos essenciais de Rosmarinus officinalis e Cinnamomum zeylanicum nas atividades in vitro, in vivo e na produção de proteínas na indução de resistência, em plantas de feijão vagem cultivar Bragança. Os resultados obtidos demonstraram que as tinturas de L. alba e L. sidoides e os óleos essenciais (R. officinalis e C. zeylanicum) apresentaram atividade in vitro aos isolados de Xanthomonas axonopodis pv. phaseoli. Todas as tinturas ensaiadas apresentaram menores valores do progresso da doença (AACPD), em relação à testemunha, merecendo destaque a tintura de L. alba, que estavam correlacionadas com os maiores teores de polifenoloxidase, peroxidase e proteínas solúveis totais, evidenciando uma possível indução de resistência. Os óleos essenciais não apresentaram diferença na AACPD e nem na indução de proteínas.

Pesquisas agronômicas das plantas medicinais da Mata Atlântica regulamentadas pela ANVISA

Com a divulgação da lista das espécies medicinais pela Agência Nacional de Vigilância Sanitária (ANVISA), de acordo com a Resolução RDC Nº10, de 09 de março de 2010, o uso dessas plantas passa a ter a chancela oficial do órgão governamental regulamentando seu uso e, em consequência disso, ter sua demanda bastante aumentada. A obtenção desses materiais adquire então grande importância, uma vez que haverá a necessidade de se produzir essas plantas. Com o objetivo de se avaliar a situação das pesquisas agronômicas com essas espécies, particularmente as de ocorrência na Mata Atlântica, foi feito um levantamento do número de publicações a partir dos nomes científicos, na base de dados eletrônica CAB Abstract, de 1990 a 2011. A pesquisa mostrou que o número de publicações por espécie varia de 2 a 1129, sendo que as espécies com maior número de artigos são aquelas já cultivadas como alimentícias. Das 66 espécies listadas, 36 são exóticas, 24 são da Mata Atlântica e 6 são nativas de outros biomas. Dentre as espécies da Mata Atlântica, foram excluídas as ruderais, frutíferas e arbóreas, devido à maioria dos trabalhos na área agronômica estarem relacionados ao manejo, controle ou produção de frutos e não ao seu cultivo sobre o ponto de vista medicinal. A única exceção foi a espécie medicinal arbórea Maytenus ilicifolia. Assim, foram selecionadas 16 espécies, as quais tiveram as publicações divididas em quatro áreas: Agronomia; Fitoquímica, Ensaios biológicos e Outros. Nesta pesquisa foi possível identificar que 32% dos artigos publicados são agronômicos, área que apresenta menos publicações do que a área de atividade biológica, que tem 40% das publicações, e a área de fitoquimica tem 20% das publicações. Estes resultados mostram que os pesquisadores estão atentos à importância das pesquisas agronômicas com plantas medicinais, mas que se faz necessário realizar trabalhos de domesticação das espécies selvagens e de fitotecnia com as espécies menos estudadas, para viabilizar o cultivo, a conservação dos recursos genéticos vegetais e do meio ambiente.

Taking Advantage of Electrostatic Interactions To Grow Langmuir-Blodgett Films Containing Multilayers of the Phospholipid Dipalmitoylphosphatidylglycerol

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

Chemical Composition and Antioxidant and Antimycobacterial Activities of Bromelia balansae (Bromeliaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Topliss method in the optimization of salicylic acid derivatives as potential antimycobacterial agents

The Topliss method was used to guide a synthetic path in support of drug discovery efforts toward the identification of potent antimycobacterial agents. Salicylic acid and its derivatives, p-chloro, p-methoxy, and m-chlorosalicylic acid, exemplify a series of synthetic compounds whose minimum inhibitory concentrations for a strain of Mycobacterium were determined and compared to those of the reference drug, p-aminosalicylic acid. Several physicochemical descriptors (including Hammett's sigma constant, ionization constant, dipole moment, Hansch constant, calculated partition coefficient, Sterimol-L and -B-4 and molecular volume) were considered to elucidate structure-activity relationships. Molecular electrostatic potential and molecular dipole moment maps were also calculated using the AM1 semi-empirical method. Among the new derivatives, m-chlorosalicylic acid showed the lowest minimum inhibitory concentration. The overall results suggest that both physicochemical properties and electronic features may influence the biological activity of this series of antimycobacterial agents and thus should be considered in designing new p-aminosalicylic acid analogs.

Mutagenic and cytotoxic effect of planifolin: A naphthopyranone dimer isolated from Paepalanthus planifolius

A naphthopyranone dimer, named planifolin, was isolated from a methylene chloride extract of the capitula of Paepalanthus planifolius Koern. The molecule (C31H26O10) appeared to be made up of two monomeric portions, semi-vioxanthin and paepalantine (an isocoumarin), linked by an ether bond, and it may possess several kinds of biological activity that can be related to its polyphenolic structure. Short-term tests that detect genetic damage can afford the information needed to evaluate carcinogenic risks of chemicals to humans. The Ames test, recommended for testing the mutagenicity of chemical compounds with potential pharmacological application, was used in the present study. The mutagenic activity was evaluated in Salmonella typhimurium strains TA100, TA98, TA102 and TA97a and the cytotoxic effect in McCoy cells. The in vitro cytotoxicity of planifolin to McCoy cells, tested in microculture with neutral red, showed a significant cytotoxic index (CI50) of 12.83 mu g/mL. Planifolin showed mutagenic activity for TA100, TA98 and TA97a. The results indicate that this new naphthopyranone dimer causes mutations by substitution and by addition and deletion of bases in the sequence of DNA. Moreover, its mutagenic potential was increased by metabolic activation. (c) 2005 Elsevier Ltd. All rights reserved.

A Prodrug Approach to Improve the Physico-Chemical Properties and Decrease the Genotoxicity of Nitro Compounds

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

Molecular Modeling Suggests Cruzain Specificity for Peptide Primaquine Prodrugs

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

Scarification, temperature and light in germination of Senna occidentalis seed (Caesalpinaceae)

The purpose of the present work was to study various aspects of the germination of seeds of Senna occidentalis Link, which had presented promising results in biological activity against the etiological agent of malaria. These aspects were dormancy, temperatures of germination and photoblastic response. In the dormancy studies, the treatments used were: unscarified seed (control); tegument puncture with sharp point; and scarification with sand-paper and immersion in concentrated sulfuric acid during 5, 10, 15 and 20 minutes. For the study of temperature and photoblast, the seeds were immersed in sulfuric acid for 20 minutes, submitted to temperatures of 10 to 45degreesC, at intervals of 5degreesC, both under light and in the dark. The seeds presented dormancy related to tegument, the best treatments for breaking dormancy were immersion in sulfuric acid for 15 and 20 minutes. At temperatures 25 and 30degreesC, the best results of percentage and index of velocity of germination were observed, at which the seeds behaved as neutral photoblastic; there was no germination at 10 or at 45degreesC.

The GABAergic system contributes to the anxiolytic-like effect of essential oil from Cymbopogon citratus (lemongrass)

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

Identification of continuous interaction sites in PLA(2)-based protein complexes by peptide arrays

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The shielding effect of glycerol against protein ionization in electrospray mass spectrometry

Most commercial recombinant proteins used as molecular biology tools, as well as many academically made preparations, are generally maintained in the presence of high glycerol concentrations after purification to maintain their biological activity. The present study shows that larger proteins containing high concentrations of glycerol are not amenable to analysis using conventional electrospray ionization mass spectrometry (ESI-MS) interfaces. In this investigation the presence of 25% (v/v) glycerol suppressed the signals of Taq DNA polymerase molecules, while 1% (v/v) glycerol suppressed the signal of horse heart myoglobin. The signal suppression was probably caused by the interaction of glycerol molecules with the proteins to create a shielding effect that prevents the ionization of the basic and/or acidic groups in the amino acid side chains. To overcome this difficulty the glycerol concentration was decreased to 5% (v/v) by dialyzing the Taq polymerase solution against water, and the cone voltage in the ESI triple-quadrupole mass spectrometer was set at 80-130 V. This permitted observation of a mass spectrum that contained ions corresponding to protonation of up to 50% of the ionizable basic groups. In the absence of glycerol up to 85% of the basic groups of Taq polymerase became ionized, as observed in the mass spectrum at relatively low cone voltages. An explanation of these and other observations is proposed, based on strong interactions between the protein molecules and glycerol. For purposes of comparison similar experiments were performed on myoglobin, a small protein with 21 basic groups, whose ionization was apparently suppressed in the presence of 1% (v/v) glycerol, since no mass spectrum could be obtained even at high cone voltages. Copyright (C) 2003 John Wiley Sons, Ltd.

Expression and processing of recombinant sarafotoxins precursor in Pichia pastoris

Sarafotoxins are peptides isolated from the Atractaspisw snake venom. with strong constrictor effect on cardiac and smooth muscle. They are structurally and functionally related to endothelins. The sarafotoxins precursor cDNA predicts an unusual structure 'rosary-type', with 12 successive similar stretches of sarafotoxin (SRTX) and spacer, in the present work, the recombinant precursor of SRTXs was sub-cloned and expressed in the yeast Pichia pastoris. and secreted to the culture medium, Characterization by SDS-PAGE, immunoblot, mass spectrometry and biological activity, suggests that intact precursor was expressed but processing into mature toxins also occurred. Furthermore, our results indicate that the correct proportion of sarafotoxin types as contained in the precursor, is obtained in the yeast culture medium. Contractile effects of the expressed toxins, on rat and Bothrops jararaca isolated aorta, were equivalent to 5 X 10(-10) M and 5 x 10(-11) M of sarafotoxin b, respectively. The enzymes responsible for the complete maturation of sarafotoxins precursor are still unknown. Our results strongly suggest that the yeast Pichia pastoris is able to perform such a maturation process. Thus, the yeast Pichia pastoris may offer an alternative to snake venom gland to tentatively identify the molecular process responsible for SRTXs release. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

The use of biodiversity as source of new chemical entities against defined molecular targets for treatment of malaria, tuberculosis, and T-cell mediated diseases: a review

The modern approach to the development of new chemical entities against complex diseases, especially the neglected endemic diseases such as tuberculosis and malaria, is based on the use of defined molecular targets. Among the advantages, this approach allows (i) the search and identification of lead compounds with defined molecular mechanisms against a defined target (e.g. enzymes from defined pathways), (ii) the analysis of a great number of compounds with a favorable cost/benefit ratio, (iii) the development even in the initial stages of compounds with selective toxicity (the fundamental principle of chemotherapy), (iv) the evaluation of plant extracts as well as of pure substances. The current use of such technology, unfortunately, is concentrated in developed countries, especially in the big pharma. This fact contributes in a significant way to hamper the development of innovative new compounds to treat neglected diseases. The large biodiversity within the territory of Brazil puts the country in a strategic position to develop the rational and sustained exploration of new metabolites of therapeutic value. The extension of the country covers a wide range of climates, soil types, and altitudes, providing a unique set of selective pressures for the adaptation of plant life in these scenarios. Chemical diversity is also driven by these forces, in an attempt to best fit the plant communities to the particular abiotic stresses, fauna, and microbes that co-exist with them. Certain areas of vegetation (Amazonian Forest, Atlantic Forest, Araucaria Forest, Cerrado-Brazilian Savanna, and Caatinga) are rich in species and types of environments to be used to search for natural compounds active against tuberculosis, malaria, and chronic-degenerative diseases. The present review describes some strategies to search for natural compounds, whose choice can be based on ethnobotanical and chemotaxonomical studies, and screen for their ability to bind to immobilized drug targets and to inhibit their activities. Molecular cloning, gene knockout, protein expression and purification, N-terminal sequencing, and mass spectrometry are the methods of choice to provide homogeneous drug targets for immobilization by optimized chemical reactions. Plant extract preparations, fractionation of promising plant extracts, propagation protocols and definition of in planta studies to maximize product yield of plant species producing active compounds have to be performed to provide a continuing supply of bioactive materials. Chemical characterization of natural compounds, determination of mode of action by kinetics and other spectroscopic methods (MS, X-ray, NMR), as well as in vitro and in vivo biological assays, chemical derivatization, and structure-activity relationships have to be carried out to provide a thorough knowledge on which to base the search for natural compounds or their derivatives with biological activity.

A single nucleotide deletion at the C1 inhibitor gene as the cause of hereditary angioedema: insights from a Brazilian family

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)