890 resultados para Produtos naturais - Aspectos farmacológicos


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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective

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There are strong interests in the evaluation of the biological effects of natural and synthetic products. Blood constituents labeled with technetium-99m (99mTc) are used in nuclear medicine. The aim of this work was to study the effects of Clove (Caryophyllus aromaticas L.) and OZE (preparation used in the Health Sciences) on the labeling blood constituents with 99mTc and on the morphologic red blood cells (RBC) and the action of an extract of tomato (TO) on the labeling of blood constituents Blood samples were incubated with clove or OZE or TO, stannous chloride and 99mTc. Plasma (P), blood cells (BC), insoluble fractions (IF) of plasma and blood cells were separated. The radioactivity was counted and percentage of radioactivity (%ATI) to each blood fraction was calculated. The shape and morphometric parameter (perimeter/area ratio) were evaluated in the studies with clove and OZE. Clove extract and OZE altered significantly (p<0.05) the %ATI of blood constituents and the shape of red blood cells. However, clove extract not altered the red blood cells perimeter/area ratio. The tomato extract used at the highest concentrations reduced significantly (p<0.05) the %ATI in IF-P, although this extract did not modify the radiolabeling on BC, neither the radioactivity fixation on IFBC. The results indicate that these chemical compounds would have oxidative/chelating actions

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Cymbopogon citratus (DC.) Stapf é uma planta medicinal pertencente a família Poaceae, perene, importante para a indústria farmacêutica e alimentícia devido ao óleo essencial que produz. Um problema limitante para a produção comercial é a ferrugem, doença cujo agente etiológico é o fungo Puccinia nakanishikii Dietel. O presente trabalho objetivou avaliar a ação de produtos naturais no controle da doença in vitro e in vivo. Para os testes in vitro, empregaram-se os seguintes produtos sobre a germinação de esporos do patógeno: óleos essenciais de eucalipto, palma-rosa, cravo-da-índia, menta, limão, citronela e mil-folhas; extrato pirolenhoso de eucalipto e mentol cristalizado, em diferentes concentrações. Para os testes de campo foram selecionados quatro produtos, o óleo de citronela e de eucalipto, o extrato pirolenhoso, e o mentol. In vitro, todos os agentes mostraram-se promissores no controle do patógeno. Quando em condições in vivo, sob alta severidade da doença no ato da avaliação, os produtos testados foram capazes de reduzir a severidade da doença em comparação com a testemunha. O controle da doença com os agentes naturais variou de 38% (extrato pirolenhoso) a 61%(óleo essencial de eucalipto).

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Among the new drugs launched into the market since 1980, up to 30% of them belong to the class of natural products or they have semisynthetic origin. Between 40-70% of the new chemical entities (or lead compounds) possess poor water solubility, which may impair their commercial use. An alternative for administration of poorly water-soluble drugs is their vehiculation into drug delivery systems like micelles, microemulsions, nanoparticles, liposomes, and cyclodextrin systems. In this work, microemulsion-based drug delivery systems were obtained using pharmaceutically acceptable components: a mixture Tween 80 and Span 20 in ratio 3:1 as surfactant, isopropyl mirystate or oleic acid as oil, bidistilled water, and ethanol, in some formulations, as cosurfactants. Self-Microemulsifying Drug Delivery Systems (SMEDDS) were also obtained using propylene glycol or sorbitol as cosurfactant. All formulations were characterized for rheological behavior, droplet size and electrical conductivity. The bioactive natural product trans-dehydrocrotonin, as well some extracts and fractions from Croton cajucara Benth (Euphorbiaceae), Anacardium occidentale L. (Anacardiaceae) e Phyllanthus amarus Schum. & Thonn. (Euphorbiaceae) specimens, were satisfactorily solubilized into microemulsions formulations. Meanwhile, two other natural products from Croton cajucara, trans-crotonin and acetyl aleuritolic acid, showed poor solubility in these formulations. The evaluation of the antioxidant capacity, by DPPH method, of plant extracts loaded into microemulsions evidenced the antioxidant activity of Phyllanthus amarus and Anacardium occidentale extracts. For Phyllanthus amarus extract, the use of microemulsions duplicated its antioxidant efficiency. A hydroalcoholic extract from Croton cajucara incorporated into a SMEDDS formulation showed bacteriostatic activity against colonies of Bacillus cereus and Escherichia coli bacteria. Additionally, Molecular Dynamics simulations were performed using micellar systems, for drug delivery systems, containing sugar-based surfactants, N-dodecylamino-1-deoxylactitol and N-dodecyl-D-lactosylamine. The computational simulations indicated that micellization process for N-dodecylamino-1- deoxylactitol is more favorable than N-dodecyl-D-lactosylamine system.

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JUSTIFICATIVA E OBJETIVOS: Informações experimentais e clínicas têm sugerido que os b-bloqueadores apresentam efeitos hemodinâmicos importantes e protetores durante o ato anestésico-cirúrgico. O objetivo deste trabalho é revisar as informações farmacológicas e clínicas dos b-bloqueadores para sua utilização adequada na medicina per-operatória. CONTEÚDO: Os b-bloqueadores seletivos inibem preferencialmente os b1-receptores reduzindo a freqüência e inotropismo cardíacos e determinando redução no consumo de oxigênio do miocárdio. Os b-bloqueadores não seletivos inibem também os b2-receptores, aumentando a resistência bronquiolar e vascular periférica. Alguns b-bloqueadores são, também, vasodilatadores. O tratamento prolongado com os b-bloqueadores aumenta a densidade dos b-receptores na membrana celular, o que pode explicar a hiperatividade simpática que pode ocorrer durante a parada do tratamento desses medicamentos. em cirurgia não cardíaca, os efeitos benéficos do b-bloqueadores em pacientes hipertensos ou nos que apresentam doença coronariana têm sido demonstrados, com redução da incidência de isquemia miocárdica no pós-operatório e da mortalidade durante o período de dois anos que se segue à operação. CONCLUSÕES: O tratamento com b-bloqueadores deve ser mantido até o período da manhã da operação, exceto nos pacientes com sinais de intolerância à droga, como hipotensão ou bradicardia importante. Os b-bloqueadores exercem efeito benéfico na recuperação pós-operatória de pacientes com doenças cardiovasculares ou nos que apresentam fatores de risco. Por isso, o emprego desses medicamentos é importante na medicina per-operatória e deve ser ampliado.

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O objetivo deste trabalho foi avaliar os efeitos do ácido oxálico e de óleos essenciais de plantas no controle da infestação pelo ácaro Varroa destructor em colônias de Apis mellifera africanizadas. O experimento foi realizado em delineamento inteiramente casualizado, em 30 colônias, com seis tratamentos e cinco repetições. As colmeias foram tratadas com óleos essenciais de arruda (Ruta graveolens), eucalipto (Eucalyptus spp.) e hortelã (Mentha piperita), além de timol, ácido oxálico e do tratamento controle sem aplicação de produtos. Foram avaliadas a mortalidade de varroas e as taxas de mortalidade de crias e de infestação de varroas em crias e em abelhas adultas, antes e depois da aplicação de cada produto. O ácido oxálico e os óleos de arruda, timol, eucalipto e de hortelã reduziram a mortalidade de crias parasitadas pelo ácaro em 92,1, 83,3, 81,7, 86,4 e 81,3%, respectivamente. O tratamento com ácido oxálico reduziu em 87,4% a infestação de varroas em abelhas adultas. O uso desses produtos é eficiente na redução da mortalidade de crias de A. mellifera parasitadas por V. destructor.

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

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

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Plants are a valuable source of natural products for the maintenance of human health. The purpose of this paper was the study of immunologic activity of yarrow (Achillea millefolium L.), a largely used plant in popular medicine that has many different properties such as: antiinflammatory, astringent, antiseptic and antispasmodic. Macrophages stimulation was evaluated by the determination of H2O2, NO and TNF-α in supernatants of peritoneal macrophages cultures of mice in the presence of the yarrow leaves extract. The thin layer chromatography of extract was also analyzed, showing rutin. All concentrations showed a moderate release of H2O2 and the concentrations of 6, 8 and 10mg/mL had a higher release of NO. The TNF-a was produced in all concentrations, but the best result was obtained at 4mg/mL. Analyzing the results, it is suggested that the yarrow ethanolic extract can modulate the macrophages activation.

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Alzheimer's disease (AD) is a progressive neurodegenerative pathology with severe economic and social impact. There is currently no cure, although cholinesterase inhibitors provide effective temporary relief of symptoms in some patients. Nowadays drug research and development are based on the cholinergic hypothesis that supports the cognition improvement by regulation of the synthesis and release of acetylcholine in the brain. There are only four commercial medicines approved for treatment of AD and natural products have played an important role in the research for new acetylcholinesterase inhibitors.

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Natural products have been utilized by humans since ancient times and the relief and cure of their diseases was the first purpose for using natural products in medicine. The history of the oriental and occidental civilizations is very rich in examples of the utilization of natural products in medicine and health care. Chinese traditional medicine is one of the most important examples of how natural products can be efficient in the treatment of diseases, and it points to the importance of scientific research on natural products, concerning the discovery of new active chemical entities. The complexity, chemical diversity and biological properties of natural products always fascinated people, and during the last 200 years, this led to the discovery of important new drugs. In the last 30 years, the development of new bioassay techniques, biotechnology methods, bio-guided phytochemical studies, automated high throughput screening and high performance analytical methods, have introduced new concepts and possibilities of rational drug design and drug discovery. In this context, natural products have played an important and decisive role in the development of modern medicinal chemistry.