29 research outputs found

    Babassu aqueous extract (BAE) as an adjuvant for T helper (Th)1-dependent immune responses in mice of a Th2 immune response-prone strain

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    <p>Abstract</p> <p>Background</p> <p>The aqueous extract of a Brazilian palm-tree fruit - the babassu - (BAE) exerts a clear immunostimulative activity <it>in vivo</it>. In the present work, the possibility that BAE can promote Th1 immune responses in mice of a Th2 immune response-prone strain - the BALB/c was investigated. BAE itself, and preparations consisting of <it>Leishmania amazonensis </it>promastigote extract (LE), adsorbed or not to Al(OH)<sub>3</sub>, and in the presence or not of BAE, were used as immunogens. LE and Al(OH)<sub>3 </sub>have been shown to preferentially elicit Th2 immune responses.</p> <p>Results</p> <p>The addition of BAE to LE-containing immunogenic preparations, adsorbed or not to Al(OH)<sub>3</sub>, clearly promoted the <it>in vitro </it>production of interferon γ (IFN-γ), a major Th1-dependent cytokine, and not of interleukin (IL-)4 (a Th2-dependent cytokine), by LE-stimulated splenocytes of immunized BALB/c mice. It also promoted the <it>in vivo </it>formation of IgG2a anti-LE antibodies. However, immunization with LE by itself led to an increased production of IL-4 by LE-stimulated splenocytes, and this production, albeit not enhanced, was not reduced by the addition of BAE to the immunogen. On the other hand, the IL-4 production by LE-stimulated splenocytes was significantly lower in mice immunized with a preparation containing Al(OH)<sub>3</sub>-adsorbed LE and BAE than in mice immunized with the control preparation of Al(OH)<sub>3</sub>-adsorbed LE without BAE. Moreover, an increased production of IFN-γ, and not of IL-4, was observed in the culture supernatants of splenocytes, from BAE-immunized mice, which were <it>in vitro </it>stimulated with BAE or which received no specific <it>in vitro </it>stimulus. No differences in IL-10 (an immunoregulatory cytokine) levels in the supernatants of splenocytes from mice that were injected with BAE, in relation to splenocytes from control mice, were observed. The spontaneous <it>ex vivo </it>production of NO by splenocytes of mice that had been injected with BAE was significantly higher than the production of NO by splenocytes of control mice.</p> <p>Conclusions</p> <p>Based on the results described above, BAE, or biologically active molecules purified from it, should be further investigated as a possible adjuvant, in association or not with aluminium compounds, for the preferential induction of Th1-dependent immune responses against different antigens in distinct murine strains and animal species.</p

    Syzygium jambolanum treatment improves survival in lethal sepsis induced in mice

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    <p>Abstract</p> <p>Background</p> <p>The leaves and the fruits from <it>Syzygium jambolanum </it>DC.(Myrtaceae), a plant known in Brazil as sweet olive or 'jambolão', have been used by native people to treat infectious diseases, diabetes, and stomachache. Since the bactericidal activity of <it>S. jambolanum </it>has been confirmed <it>in vitro</it>, the aim of this work was to evaluate the effect of the prophylactic treatment with <it>S. jambolanum </it>on the <it>in vivo </it>polymicrobial infection induced by cecal ligation and puncture (CLP) in mice.</p> <p>Methods</p> <p>C57Bl/6 mice were treated by the subcutaneous route with a hydroalcoholic extract from fresh leaves of <it>S. jambolanum </it>(HCE). After 6 h, a bacterial infection was induced in the peritoneum using the lethal CLP model. The mice were killed 12 h after the CLP induction to evaluate the cellular influx and local and systemic inflammatory mediators' production. Some animals were maintained alive to evaluate the survival rate.</p> <p>Results</p> <p>The prophylactic HCE treatment increased the mice survival, the neutrophil migration to infectious site, the spreading ability and the hydrogen peroxide release, but decreased the serum TNF and nitrite. Despite the increased migration and activation of peritoneal cells the HCE treatment did not decrease the number of CFU. The HCE treatment induced a significant decrease on the bone marrow cells number but did not alter the cell number of the spleen and lymph node.</p> <p>Conclusion</p> <p>We conclude that the treatment with <it>S. jambolanum </it>has a potent prophylactic anti-septic effect that is not associated to a direct microbicidal effect but it is associated to a recruitment of activated neutrophils to the infectious site and to a diminished systemic inflammatory response.</p

    American palm ethnomedicine: A meta-analysis

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    <p>Abstract</p> <p>Background</p> <p>Many recent papers have documented the phytochemical and pharmacological bases for the use of palms (<it>Arecaceae</it>) in ethnomedicine. Early publications were based almost entirely on interviews that solicited local knowledge. More recently, ethnobotanically guided searches for new medicinal plants have proven more successful than random sampling for identifying plants that contain biodynamic ingredients. However, limited laboratory time and the high cost of clinical trials make it difficult to test all potential medicinal plants in the search for new drug candidates. The purpose of this study was to summarize and analyze previous studies on the medicinal uses of American palms in order to narrow down the search for new palm-derived medicines.</p> <p>Methods</p> <p>Relevant literature was surveyed and data was extracted and organized into medicinal use categories. We focused on more recent literature than that considered in a review published 25 years ago. We included phytochemical and pharmacological research that explored the importance of American palms in ethnomedicine.</p> <p>Results</p> <p>Of 730 species of American palms, we found evidence that 106 species had known medicinal uses, ranging from treatments for diabetes and leishmaniasis to prostatic hyperplasia. Thus, the number of American palm species with known uses had increased from 48 to 106 over the last quarter of a century. Furthermore, the pharmacological bases for many of the effects are now understood.</p> <p>Conclusions</p> <p>Palms are important in American ethnomedicine. Some, like <it>Serenoa repens </it>and <it>Roystonea regia</it>, are the sources of drugs that have been approved for medicinal uses. In contrast, recent ethnopharmacological studies suggested that many of the reported uses of several other palms do not appear to have a strong physiological basis. This study has provided a useful assessment of the ethnobotanical and pharmacological data available on palms.</p

    Highly Sensitive and Selective Basal Plane Pyrolytic Graphite Electrode Modified with 1,4-Naphthoquinone/MWCNT for Simultaneous Determination of Dopamine, Ascorbate and Urate

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The present work describes the development of a highly selective and sensitive voltammetric sensor for dopamine (DA), ascorbic acid (AA) and uric acid (UA) using a basal plane pyrolytic graphite (BPPG) electrode modified with 1,4-naphthoquinone (NQ) adsorbed on multiwalled carbon nanotubes (MWCNT). The modified electrode showed an excellent electrochemical activity towards the oxidations of DA, AA and UA. Three well-defined voltammetric peaks, in a buffered solution at pH7.5, were obtained by differential pulse voltammetry (DPV) at 0.050, 0.145 and 0.270Vvs. Ag/AgCl for AA, DA and UA, respectively. Linear calibration plots were obtained in the range of 1070nmolL1 for DA, 40280 mu molL1 for AA and 214 mu molL1 for UA, with detection limits of 3nmolL1, 1.9 mu molL1 and 0.1 mu molL1, respectively. The sensor was successfully applied in human urine samples and the results showed that the modified electrode has no interferences from urine sample.253SI723731Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
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