Percorrer por autor "Martins, Ana"
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- Antioxidant activity of Rubus ulmifolius Schott and Trifolium angustifolium L.Publication . Martins, Ana; Barros, Lillian; Fernandes, Ângela; Carvalho, Ana Maria; Ferreira, Isabel C.F.R.Rubus ulmifolius Schott (wild blackberry) from Rosaceae and Trifolium angustifolium L. (narrowleaf crimson clover) from Fabaceae are widespread medicinal plants from Portuguese wild flora. These species are common in the Iberian Peninsula, growing spontaneously under conditions of Mediterranean climate and being commonly used in folk medicine[1 ]. 1n Portugal, local consumers consider that the decoctions of R. ulmifolius have anti-inflammatory and analgesic properties and may be administered orally for the treatment of diabetes, diarrhea, and menopause[2]. They are also externally applied to relieve hoarseness, inflamed gums, sores and skin ulcers [2]. T. angustifoliumis a species known for centuries in folk medicine due to its phytochemical characteristics and biological activity. The decoction of its inflorescencesis used to treat stomach affections and to control diarrhea[3].This work aimed to evaluate the antioxidant properties of methanolic extracts and decoctions of R. ulmifolius flower buds and T. angustifolium inflorescences. Four in vitro assays were performed: scavenging effects on DPPH (2,2-diphenyl-1 -picrylhydrazyl) radicals, reducing power, inhibition of ~ -carotene bleaching and inhibition of lipid peroxidation in brain cell homogenates by TBARS (thiobarbituric acid reactive substances) assay. Methanolic extracts proved to have higher antioxidant activity than the corresponding decoctions. R. ulmifolius revealed the highest antioxidant activity in all the assays (EC50:5 70j..lg/ml for the methanolic extract and EC50:5 200j..lg/ml for the decoction). The studied medicinal plants have interesting antioxidant properties that are certainly related to the presence of phenolic compounds (reported in another abstract present to this symposium) and could be explored as a source of antioxidants for food preservation or pharmaceutical uses.
- Consumo de frutos secos na população portuguesaPublication . Costa, Maria; Morais, Maria Martins; Mendes, Jacinta; Santos, Ana; Martins, Ana; Fernandes, António; Ferro-Lebres, VeraQuando se fala de frutos secos, é importante distinguir os oleaginosos (amêndoa, avelã, pistácio e noz) dos do grupo dos amiláceos (castanha), estes últimos têm normalmente na sua constituição hidratos de carbono, principalmente amido, proteínas, vitaminas e minerais que são essenciais para a saúde, promovendo uma diminuição dos níveis de colesterol e melhora a sensibilidade à insulina. Os frutos oleaginosos contêm gorduras, proteínas e fibras. O seu perfil nutricional tem-se revelado interessante para a saúde, com benefícios cardiovasculares e metabólicos, havendo também evidências do seu efeito de alguns cancros.
- Extratos fenólicos de flores de Rubus ulmifolius Schoot: caracterização química, microencapsulação e incorporação em iogurtes para benefícios antioxidantsPublication . Martins, Ana; Barros, Lillian; Carvalho, Ana Maria; Santos-Buelga, Celestino; Fernandes, Isabel P.; Barreiro, M.F.; Ferreira, Isabel C.F.R.Rubus ulmifolius Schoot (Rosaceae), conhecida como amora silvestre, é um arbusto perene encontrado em habitats silvestres e cultivados da Europa, Ásia e África do Norte. Tradicionalmente é conhecido pelas suas propriedades medicinais, incluindo atividade antioxidante. Neste trabalho caracterizaram-se quimicamente dois extratos fenólicos obtidos a partir de botões florais de R. ulmifolius, decocção e extrato hidroalcoólico, tendo sido identificados vários compostos fenólicos, maioritariamente derivados de elagitaninos nomeadamente, os isómeros sanguiin H-10 e lambertianina. Comparativamente à decocção, o extrato hidroalcoólico apresentou um conteúdo em compostos fenólicos superior e uma maior atividade antioxidante. A sua forma liofilizada foi a escolhida para microencapsular pela técnica de spray seguida de coagulação tendo-se produzido microesferas de alginato que foram posteriormente incorporadas num iogurte natural. Os resultados obtidos mostraram que o extrato microencapsulado originou produtos com atividade antioxidante superior e com melhor preservação desta ao longo do tempo. Ambas as formas (extrato direto e microencapsulado) mostraram maior atividade que o controlo. Em síntese, os resultados obtidos demonstraram o potencial antioxidante do extrato hidroalcoólico R. ulmifolius e a eficiência da microencapsulação para a sua preservação, abrindo assim possibilidades para a sua exploração em aplicações na indústria alimentar.
- Phenolic extracts of Rubus ulmifolius Schoot flowers: characterization, microencapsulation and incorporation into yogurts as nutraceutical sourcesPublication . Martins, Ana; Barros, Lillian; Carvalho, Ana Maria; Santos-Buelga, Celestino; Fernandes, Isabel P.; Barreiro, M.F.; Ferreira, Isabel C.F.R.Rubus ulmifolius Schott (Rosaceae), known as wild blackberry, is a perennial shrub found in wild and cultivated habitats in Europe, Asia and North Africa. Traditionally, it is used for homemade remedies because of its medicinal properties, including antioxidant activity. In the present work, phenolic extracts of R. ulmifolius flower buds obtained by decoction and hydroalcoholic extraction were chemically and biologically characterized. Several phenolic compounds were identified in both decoction and hydroalcoholic extracts of flowers, ellagitannin derivatives being the most abundant ones, namely the sanguiin H-10 isomer and lambertianin. Additionally, comparing with the decoction form, the hydroalcoholic extract presented both higher phenolic content and antioxidant activity. The hydroalcoholic extract was thereafter microencapsulated in an alginate-based matrix and incorporated into a yogurt to achieve antioxidant benefits. In what concerns the performed incorporation tests, the obtained results pointed out that, among the tested samples, the yoghurt containing the microencapsulated extract presented a slightly higher antioxidant activity, and that both forms (free and microencapsulated extracts) gave rise to products with higher activity than the control. In conclusion, this study demonstrated the antioxidant potential of the R. ulmifolius hydroalcoholic extract and the effectiveness of the microencapsulation technique used for its preservation, thus opening new prospects for the exploitation of these natural phenolic extracts in food applications
- Phenolic profile of hydromethanolic extract and decoction of Rubus ulmifolius SchottPublication . Martins, Ana; Barros, Lillian; Dueñas, Montserrat; Carvalho, Ana Maria; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Rubus ulmifolius Schoot (Rosaceae), known as wild blackberry, is a perennial shrubfound in wild and cultivated habitats in Europe, Asia and North Africa[1]. Traditionally, R. ulmifoliusis considered to be anticatarrhal, antiseptic, diuretic, anti-inflammatory, antioxidant, astringent, and antispasmodic. Oral dosage forms are used for diarrhea, menstrual pain, menopause disorders, liver diseases, aphtha, gingivitis, hypertension and diabetes [2].Different classes of bioactive constituents are present in R. ulmifolius, including phenolic compounds. This study aimed to determine the phenolic composition of different preparations (decoction and hydromethanolic extract)of R. ulmifoliusflower buds. The analysis of phenolic compounds was carried out by reversed-phase high performance liquid chromatography coupled to diode array detection and mass spectrometry with electron spray ionization (HPLC-DAD-ESI/MS), in order to establish the specific phenolic profile of each preparation. The phenolic profile of both preparations was identical, varying only in the concentrations found. Twenty-three phenolic compounds were identified in both samples, in which seven were identified as phenolic acids (di- and caffeolyqui nic, p-coumaroylquinicand feruloylquinic acids),ten flavonoids (quercetin and kaempferol derivatives and catechin), and five ellagitannin derivatives (lambertianin and di -HHDP-galloyl glucose). These compoundswere found in both preparations. The most abundant compounds foundwere ellagitannin derivatives, such as lambertianin and di-HHDP-galloyl glucose. Gasperotti et al. [3]have identified these compounds in R. fruticosus fruits. To our knowledge, this is the first time that these compounds were identified and quantified inR. ulmifolius flowers buds.
- Wild mushroom extracts potentiate the action of standard antibiotics against multi-resistant bacteriaPublication . Lourenço, Inês; Alves, Maria José; Ferreira, Isabel C.F.R.; Martins, Ana; Pintado, ManuelaThe indiscriminate use of antibiotics and chemotherapeutic agents and the genetic ability of bacteria to transmit and acquire resistance resulted in the development of resistant species. In the last few years, several studies have been conducted in different countries to demonstrate the efficacy of natural products, not only studying their direct antimicrobial activity but also their capacity as resistance-modifying agents. The main objective of the present work was to evaluate the capacity of five wild mushroom extracts to potentiate the action of standard antibiotics, through synergisms that allow a decrease in their therapeutic doses and ultimately contribute to the reduction of resistances.