Emulsão e microemulsão: novos sistemas de liberação controlada

 A utilização de forma indiscriminada dos medicamentos veterinários não compromete apenas a eficiência, mas também elevam os custos dos tratamentos, independente da espécie animal. Diante da importância da indústria farmacêutica veterinária para a economia brasileira visando contribuir diretamente para manutenção da saúde e da produtividade animal, com essa revisão objetivou-se abordar sobre novos sistemas de liberação controlada de fármacos, especialmente as emulsões e microemulsões utilizadas no tratamento veterinário. As emulsões são misturas uniformes de pequenas partículas de uma substância num determinado fluído, no qual não é solúvel. Essas emulsões são dispersões coloidais formadas pelas fases dispersa e dispersante, além do agente emulsivo que contribui para estabilizar a emulsão. As microemulsões são sistemas homogêneos pouco viscosos e termodinamicamente estáveis. Apresentam dimensões variando entre a escala micrométrica e nanométrica, transparência ótica, capacidade de veicular fármacos hidrofílicos e lipofílicos, além de serem formadas facilmente pela mistura de seus componentes. Nos sistemas de liberação controlada de fármacos, mesmo utilizando pequenas quantidades de princípios ativos, ocorre uma otimização da ação do fármaco com consequente melhoria de sua biodisponibilidade e diminuição de sua toxicidade, além de facilitar sua administração. Finalizando, os sistemas de liberação controlada de fármacos, como as emulsões e as microemulsões, podem contribuir significativamente para a evolução da terapêutica veterinária por proporcionar o desenvolvimento de fármacos mais eficientes e atender as necessidades da indústria animal moderna

A novel antimicrobial lectin from Eugenia malaccensis that stimulates cutaneous healing in mice model

Objective The present work reports the purification and partial characterization of an antibacterial lectin (EmaL) obtained from Eugenia malaccensis seeds as well as the evaluation of its effect in the daily topical treatment of repairing process of cutaneous wounds in mice. Materials and methods The cutaneous wound was produced by the incision of the skin and use of lectin in the treatment of mice cutaneous wounds was evaluated. Surgical wounds were treated daily with a topical administration of EmaL and parameters such as edema, hyperemia, scab, granulation and scar tissues as well as contraction of wounds were analyzed. Results A novel lectin, with a molecular mass of 14 kDa, was isolated from E. malaccensis using affinity chromatography. The lectin (EmaL) agglutinated glutaraldehyde-treated rabbit and human erythrocytes; the lectin-induced rabbit erythrocyte agglutination was inhibited by glucose, casein, ovalbumin and fetuin. Also, Emal was very effective in the inhibition of bacterial growth, with the best inhibition results obtained for Staphylococcus aureus. Inflammatory signals such as edema and hyperemia were statistically less intense when EmaL was applied compared to the control. The histopathological analysis showed that the treated injured tissue presented reepithelialization (complete or partial) and areas of transition more evidenced than those of the control group, especially due to well organized pattern of collagen fibers presented in the granulation fibrous tissue. Conclusion Presented results are a preliminary indication of the pharmacological interest in using EmaL as antimicrobial agent and in the repairing process of cutaneous wounds.This paper was financially supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), FACEPE and CAPES, Brazil. The authors are deeply grateful for the technical assistance of Maria Barbosa Reis da Silva and João Antonio Virgínio and Alfa/VALNATURA Project.info:eu-repo/semantics/publishedVersio

Immobilized Cratylia mollis lectin as a potential matrix to isolate plasma glycoproteins, including lecithin-cholesterol acyltransferase

A crude seed extract from the native Brazilian forage, Cratylia mollis Mart., and its purified lectin (termed Cra), were found to precipitate glycoproteins from serum. An affinity column of Cra lectin coupled to Sepharose CL-4B was prepared and its ability to isolate glycoproteins from human plasma compared to that of a commercial immobilized lectin, Concanavalin (Con) A-Sepharose. Although both lectins are of the alpha-D-mannose/alpha-D-glucose binding class, clear differences in the type and amount of serum glycoproteins adsorbed were seen on analysis by denaturing polyacrylamide gel electrophoresis. Similarly, when a semipurified preparation of the plasma glycoprotein, lecithin-cholesterol acyltransferase (LCAT, EC 2.3.1.43) was applied to the columns some differences were evident; most LCAT was not retained by either matrix but when the bound fractions were eluted and analyzed electrophoretically the LCAT isolated by the Cra-Sepharose column was much purer. These findings suggest that immobilized Cra lectin has the potential for use in studies both to isolate and to characterize certain serum glycoproteins. (C) 1997 Elsevier B.V.UNIV LONDON,ROYAL FREE HOSP,SCH MED,DEPT MED,LONDON NW3 2PF,ENGLANDUNIV FED PERNAMBUCO,CTR CIENCIAS BIOL,DEPT BIOQUIM,BR-50670420 RECIFE,PE,BRAZILESCOLA PAULISTA MED,DEPT BIOQUIM,BR-04023 São Paulo,BRAZILESCOLA PAULISTA MED,DEPT BIOQUIM,BR-04023 São Paulo,BRAZILWeb of Scienc

A lectin from Bothrops leucurus snake venom raises cytosolic calcium levels and promotes B16-F10 melanoma necrotic cell death via mitochondrial permeability transition

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)BIL, a galactose-binding C-type lectin purified from Bothrops leucurus snake venom, exhibits anticancer activity. The current study was designed to elucidate the cellular mechanisms by which BR, induces melanoma cell death. The viabilities of B16-F10 melanoma cells and HaCaT keratinocytes treated with BIL were evaluated. Necrotic and apoptotic cell death, cytosolic Ca2+ levels, mitochondrial Ca2+ transport and superoxide levels were assessed in B16-F10 melanoma cells exposed to BIL. We found that treatment with BIL caused dose-dependent necrotic cell death in B16-F10 melanoma cells. Conversely, the viability of non-tumorigenic HaCaT cells was not affected by similar doses of BIL. BIL-induced B16-F10 necrosis was preceded by a significant (2-fold) increase in cytosolic calcium concentrations and a significant (3-fold) increase in mitochondrial superoxide generation. It is likely that BlL treatment triggers B16-F10 cell death via mitochondrial permeability transition (MPT) pore opening because the pharmacological MPT inhibitors bongkrekic acid and Debio 025 greatly attenuated BIL-induced cell death. Experiments evaluating mitochondrial Ca2+ transport in permeabilized B16-F10 cells strongly supported the hypothesis that BIL rapidly stimulates cyclosporine A-sensitive Ca2+-induced MPT pore opening. We therefore conclude that BIL causes selective B16-F10 melanoma cell death via dysregulation of cellular Ca2+ homeostasis and Ca2+-induced opening of MPT pore. (C) 2014 Elsevier Ltd. All rights reserved.8297103Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE) [APQ-1119-2.08/08, APQ-0852-2.08/12]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [2011/50400-0, 2011/51800-1, 2012/07424-8]Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE) [APQ-1119-2.08/08, APQ-0852-2.08/12

Drought sensitivity of Amazonian carbon balance revealed by atmospheric measurements

Feedbacks between land carbon pools and climate provide one of the largest sources of uncertainty in our predictions of global climate(1,2). Estimates of the sensitivity of the terrestrial carbon budget to climate anomalies in the tropics and the identification of the mechanisms responsible for feedback effects remain uncertain(3,4). The Amazon basin stores a vast amount of carbon(5), and has experienced increasingly higher temperatures and more frequent floods and droughts over the past two decades(6). Here we report seasonal and annual carbon balances across the Amazon basin, based on carbon dioxide and carbon monoxide measurements for the anomalously dry and wet years 2010 and 2011, respectively. We find that the Amazon basin lost 0.48 +/- 0.18 petagrams of carbon per year (Pg C yr(-1)) during the dry year but was carbon neutral (0.06 +/- 0.1 Pg C yr(-1)) during the wet year. Taking into account carbon losses from fire by using carbon monoxide measurements, we derived the basin net biome exchange (that is, the carbon flux between the non-burned forest and the atmosphere) revealing that during the dry year, vegetation was carbon neutral. During the wet year, vegetation was a net carbon sink of 0.25 +/- 0.14 Pg C yr(-1), which is roughly consistent with the mean long-term intact-forest biomass sink of 0.39 +/- 0.10 Pg C yr(-1) previously estimated from forest censuses(7). Observations from Amazonian forest plots suggest the suppression of photosynthesis during drought as the primary cause for the 2010 sink neutralization. Overall, our results suggest that moisture has an important role in determining the Amazonian carbon balance. If the recent trend of increasing precipitation extremes persists(6), the Amazon may become an increasing carbon source as a result of both emissions from fires and the suppression of net biome exchange by drought