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1.
PLoS One ; 9(8): e104258, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25119298

RESUMO

Wheat bran (WB) from Triticum aestivum has many beneficial effects on human health. To the best of our knowledge, very little has been published about its ability to prevent pathogenic bacterial adhesion in the intestine. Here, a WB extract was fractionated using different strategies, and the obtained fractions were tested in different in vitro methodologies to evaluate their interference in the attachment of enterotoxigenic Escherichia coli (ETEC) K88 to intestinal porcine epithelial cells (IPEC-J2) with the aim of identifying the putative anti-adhesive molecules. It was found that a proteinaceous compound in the >300-kDa fraction mediates the recognition of ETEC K88 to IPEC-J2. Further fractionation of the >300-kDa sample by size-exclusion chromatography showed several proteins below 90 kDa, suggesting that the target protein belongs to a high-molecular-weight (MW) multi-component protein complex. The identification of some relevant excised bands was performed by mass spectrometry (MS) and mostly revealed the presence of various protease inhibitors (PIs) of low MW: Serpin-Z2B, Class II chitinase, endogenous alpha-amylase/subtilisin inhibitor and alpha-amylase/trypsin inhibitor CM3. Furthermore, an incubation of the WB extract with ETEC K88 allowed for the identification of a 7S storage protein globulin of wheat, Globulin 3 of 66 kDa, which may be one of the most firmly attached WB proteins to ETEC K88 cells. Further studies should be performed to gain an understanding of the molecular recognition of the blocking process that takes place. All gathered information can eventually pave the way for the development of novel anti-adhesion therapeutic agents to prevent bacterial pathogenesis.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Fibras na Dieta/farmacologia , Escherichia coli Enterotoxigênica/fisiologia , Células Epiteliais/microbiologia , Proteínas de Plantas/farmacologia , Animais , Células Cultivadas , Fracionamento Químico , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Suínos , Triticum/química
2.
Environ Microbiol ; 16(5): 1346-53, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24588934

RESUMO

Some plant extracts, have been demonstrated to interfere with the microbial metabolism of several pathogenic bacteria. Within this antimicrobial properties it has been described the potential to inhibit or destroy biofilms or to interfere in quorum-sensing (QS) systems. However, to our knowledge, no study exploring this potential of wheat-bran (WB) has been published. The purpose of the present study is to evaluate the anti-biofilm activity of WB against a cow mastitis strain of Staphylococcus aureus and also its possible interference with bacterial QS systems. The potential of inhibition and destruction of the biofilm was studied by different in vitro assays. Also, we tested the ability of WB to interfere in bacterial QS by degrading acyl-homoserine lactones (AHL) as one of the most studied QS signal molecules for Gram-negative bacteria. The soluble extract of WB at 0.5% showed anti-biofilm activity, inhibiting biofilm formation and also destroying it. Similarly, the > 300 kDa fraction from WB had significant anti-biofilm activity in both in vitro assays. The WB also showed a potential to interfere with bacterial QS systems, as it was demonstrated to contain certain lactonase activity able to reduce AHL concentration in the medium. The present study reveals two additional beneficial properties of WB extract never explored before, which may be related to the presence of defence compounds in the plant extract able to interfere with microbial biofilms and also QS systems.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Fibras na Dieta , Percepção de Quorum/efeitos dos fármacos , Acil-Butirolactonas/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/metabolismo , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
3.
Bioorg Med Chem Lett ; 12(12): 1567-70, 2002 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-12039563

RESUMO

Inspired by the structure of tannic acid, first- to third-generation dendrimers containing two, four, and eight galloyl moieties were synthesized. Stability, antioxidant activity and collagen cross-linking activity of the natural product and its dendrimer analogues were compared. The experimental results indicate that polygalloyl dendrimers might be used as new lead compounds to improve the long-term healing characteristics of burn wounds.


Assuntos
Ácido Gálico/química , Taninos Hidrolisáveis/química , Mimetismo Molecular , Antioxidantes/química , Antioxidantes/farmacologia , Taninos Hidrolisáveis/farmacologia
4.
Environ Toxicol Pharmacol ; 12(4): 195-211, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21782639

RESUMO

Within the group of botanical products there is a large range of variation with regard to their properties. Some products are identical to foods while others come close to or are medicines. Botanical products are regulated differently within the different member states of the European Union (EU) and globally. They are regulated either as food or as medicinal products, and in the latter case often with simplified registration procedures. These differences are caused by differences in traditional use, in cultural and historical background, in scientific substantiation and in enforcement of current legislation. One may expect that in the future differences will remain, unless EU legislation is enacted with sufficient room for different approaches. The strengths and weaknesses of the different regulatory procedures have been reviewed and evaluated as well as the current methods for quality, efficacy and safety evaluation. Criteria to categorize botanical products have been defined, such that botanical products can be regulated under the current food and medicinal regulations. Furthermore, a decision tree has been developed as a tool to distinguish herbal medicinal products from botanical health products and vice versa, and to provide a stepwise framework for the assessment of safety and efficacy.

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