Browsing by Author "Ferreira, Isabel"
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- Estrutura e atividade imunoestimuladora dos polissacarídeos presentes em extratos aquosos de inflorescências secas de P. tridentatumPublication . Martins, Vitor Manuel Ramalheira; Cruz, Maria T.; Ferreira, Isabel; Coimbra, Manuel A.As inflorescências secas da carqueja (P. tridentatum L.) são utilizadas na preparação de extratos aquosos que, de acordo com a tradição popular, possuem propriedades terapêuticas. Durante a preparação dos extratos ocorre a extração de compostos bioativos, tais como polissacarídeos. O presente trabalho pretende determinar o tipo de polissacarídeos presente nos extraías e avaliar o seu possível contributo para as respetivas propriedades terapêuticas. Procedeu- se à extração, caracterização estrutural e avaliação da atívidade imunoestimuladora dos polissacarídeos presentes nos extratos. Foi detetada uma mistura de polissacarídeos, nomeadamente polissacarídeos pécticos, arabinogalactanas do Tipo-I e II, galactomananas e xiloglucanas, que apresenta atividade imunoestimuladora em macrófagos e que poderá contribuir para as propriedades terapêuticas atribuídas pela medicina popular a estes extratos.
- Extração de compostos bioativos de folhas de mirtilo por metodologias verdesPublication . Plasência, Paula; Ferreira, Isabel; Barreiro, Filomena; Garcia, Pablomirtilo faz parte do grupo de frutos de baga com a maior concentração de compostos antioxidantes, maioritariamente antocianinas e outros flavonoides. Como resultado do interesse nas suas propriedades antioxidantes, a sua produção mundial tem vindo a aumentar desde 2005, tendo atingido em 2017 um valor de quase 600 Kton, sendo a Europa responsável por 18,4% da sua produção líquida. Até ao momento, as folhas de mirtilo ainda não foram estudas em detalhe, mas alguns resultados apontam para que estas tenham potencial como fonte de compostos fenólicos antioxidantes. A biomassa resultante da cultura do mirtilo é um novo objeto de estudo, uma vez que os produtores estão cada vez mais interessados na sua valorização, nomeadamente em produtos de alto valor acrescentado. Neste contexto, as folhas são um bom exemplo de biomassa residual que pode ser explorada para aplicações cosméticas, entre outras. Já estão descritas aplicações da incorporação de extrato comercial de mirtilo em micropartículas com atividade antioxidante e boa estabilidade físico-química, posteriormente testadas em cosméticos multifuncionais
- Immunostimulatory polysaccharides from the hot water extracts of prickled broom (P. tridentatum (L.) Willk) dried inflorescencesPublication . Martins, Vitor Manuel Ramalheira; Simões, Joana; Ferreira, Isabel; Cruz, Maria T.; Domingues, Maria R.M.; Coimbra, Manuel A.The decoctions of prickled broom (Pterospartum trídentatum (L.) Willk.) dried inflorescences have claimed beneficial properties for various health disorders [1, 2]. These can be assigned to several constituents, among them, the polysacharides. In order to unveil the contribution of the polysacharides and their structural features to the modulation of the innate immune activity, the hot water extracts from P. tridentatum dried inflorescences were prepared and fractionated by ethanol precipitation and anion exchange chromatography. A fraction that mainly contained pectic polysaccharides and acetylated galactomannans was isolated. This fraction evidenced in vitro immunostimulatory activity without compromising cellular viability, as evidenced by the increase registered in the nitric oxide (NO) production by macrophages. This activity decreased 60-75% after saponification, confirming that acetylation is an important structural feature for this biological property. In addition, the treatment of pectic polysaccharides with endo-polygalacturonase showed that type-1 and type-11 arabinogalactans, as well as low molecular weight galacturonans and xyloglucans, may also contribute to macrophage NO production. Thus, the polysaccharides present in the dried inflorescences of P. trídentatum may contribute to the health beneficial properties frequently attributed to the decoctions of this plant.
- Structural characterization and macrophage immunostimulatory activity of polysaccharides present in the hot water extracts from Pterospartum tridentatum dried inflorescencesPublication . Martins, Vitor Manuel Ramalheira; Simões, Joana; Ferreira, Isabel; Cruz, Maria T.; Domingues, Maria R.M.; Coimbra, Manuel A.The hot water extracts from Pterospartum tridentatum dried inflorescences are used in the northeastern portuguese region of Tras-os-Montes due to its therapeutic properties. The therapeutic properties attributed to hot water extracts from plants are often related with polysaccharide macrophage immunostimulatory activity. This work intends to identify the structural features of polysaccharides from Pferospartum tridentatum hot water extracts and to evaluate their putative macrophage immunostimulatory activity. which may contribute to their therapeutic properties.
- Structural characterization and macrophage immunostimulatory activity of polysaccharides present in the hot water extracts from Pterospartum tridentatum dried inflorescencesPublication . Martins, Vitor Manuel Ramalheira; Simões, Joana; Ferreira, Isabel; Cruz, Maria T.; Domingues, Maria R.M.; Coimbra, Manuel A.The hot water extracts (HWE) from Pterospatum tridentatum dried inflorescences are used in the northeastern portuguese region of Trás-os-Montes due to its therapeutic properties, namely against rheumatism, bladder, liver and kidney disorders [1]. The therapeutic properties attributed to hot water extracts from plants are often related with polysaccharide macrophage immunostimulatory activity [2].
- Structural features and macrophage immunostimulatory activity of the polysaccharides from Fraxinus angustifolia and Mentha suaveolens hot water extractsPublication . Martins, Vitor Manuel Ramalheira; Simões, Joana; Ferreira, Isabel; Cruz, Maria T.; Domingues, Maria R.M.; Coimbra, Manuel A.The dried leaves of Fraxinus angustifolia and the dried shoots of Mentha suaveolens are used by the population of the Tras-os-Montes, which is a region located in the northeast of Portugal. to prepare hot water extracts due to their therapeutic properties. Recently, the contribution of potysaccharides for the therapeutic properties often attributed to various plants hot water extracts has been highlighted. This work will provide a structural characterization of the polysaccharides present in these hot water extracts and will also evaluate their possible macrophage immunostimutatory activity, which might contribute for the therapeutic properties reported for these hot water extracts.
- Structural features and macrophage immunostimulatory activity of the polysaccharides from Fraxinus angustifolia and Mentha suaveolens hot water extractsPublication . Martins, Vitor Manuel Ramalheira; Simões, Joana; Ferreira, Isabel; Cruz, Maria T.; Domingues, Maria R.M.; Coimbra, Manuel A.The dried leaves of Fraxinus angustifolia and the dried shoots of Mentha suaveolens are used by the population of the Trás-os-Montes, which is a region located in the northeast of Portugal, to prepare hot water extracts due to their therapeutic properties, particularly against rheumatism, high blood pressure and high levels of uric acid [1]. Recently, the macrophage immunomodulation and therapeutic potential of pectic polysaccharides from diverse plant hot water extracts has been highlighted [2,3].
- The polysaccharides from pterospartum tridentatum (l.) Willk. Inflorescences and their contribution to in vitro macrophage nitric oxide productionPublication . Martins, Vitor Manuel Ramalheira; Simões, Joana Ramalho; Ferreira, Isabel; Cruz, Maria T.; Domingues, Maria R.M.; Coimbra, Manuel A.The decoctions of prickled broom (Pterospartum tridentatum (L.) Willk.) dried inflorescences have claimed beneficial properties for various health disorders1'2'3. These can be assigned to several constituents, among them, the polysacharides. In order to unveil the contribution of the polysacharides and their structural features to the modulation of the innate immune activity, the hot water extracts from P. tridentatum dried inflorescences were prepared and fractionated by ethanol precipitation and anion exchange chromatography. A fraction that mainly contained pectic polysaccharides and acetylated galactomannans was isolated.
- Using mass spectrometry techniques for the elucidation of structural features of immunostimulatory polysaccharides from medicinal plantsaqueous extractsPublication . Martins, Vitor Manuel Ramalheira; Simões, Joana; Ferreira, Isabel; Cruz, Maria T.; Domingues, Maria R.M.; Coimbra, Manuel A.Polysaccharides are well known for their immunostimulatory properties, which are closely related to structural fèatures, such as molecular weight, branching, acetylation degree and acetylation pattem, and presence of speciflc structures [1, 2]. TTie electrospray ionization-mass spectrometry (ESI-MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS) have shown to be powerfül techniques that can provide detailed information regarding the structural features of polysaccharides and help to clarify its relation to some ofthe observed immunostimulatory properties [3-6]. TTie present work desenhes the use of ESI-MS and ESI-MS/MS in the confimation and elucidation of structural features of immunostimulatory polysaccharides present in lhe aqueous extracts of Fraxinus angustifolia dned leaws and Ptemapaitum tridentatum dried inflorescences. The polysaccharides present in the aqueous extracts of F. angustifolia dried leaves and P. fridentafum dried inflorescences were isolated and fractionated using dialysis, ethanol precipitation, and anionexchange chromatography. Sugar and linkage analysis suggested that the aqueous extracts of F. angustifolia were mostly composed of pectic polysaccharides, while those from P. tridentatum contained a mixture of pectic polysacchahdes, galactomannans, and also xyloglucans. Selected fractions isolated from lhe aqueous extracts of F. angustifolia and P. tridentatum evidenced an in vitro macrophage immunostimulatory activity, expressed through the production of nitric oxide (NO). Enzymatic hydrolysis of the isolated polysaccharides, fbllowed by size exclusion chromatography of the resulting oligosaccharides (OS), and ESI-MS and ESI-MS/MS characterization allowed to confirm the presence of pectic polysaccharides, possibly with xylogalaturonan domains, in the aqueous extracts of F. angustifolia. For the aqueous extracts of P. fridentatum it was possible to detect the presence of galactomannans acetylated at 0-2. Moreover, it was possible to identify acetylated OS that presented an acetylation pattem with much more acetyl groups than those observed for galactomannans from coffee infusions [3]. The saponification ofthe fraction isolated from the aqueous extracts of P. tridentatum dried inflorescences, which contained the acetylated galactomannans, caused a decrease in the NO macrophage production, confirming lhe galactomannans acetylation as an important structural feature for lhe expression of the in vitm macrophage immunostimulatory activity previously registered.