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- Phytochemical characterization and biological activities of green tea (Camellia sinensis) produced in the Azores, PortugalPublication . Barreira, Sérgio; Moutinho, Carla; Silva, André M.N.; Neves, José Manuel Gomes da Silva; Seo, Ean-Jeong; Hegazy, Mohamed-Elamir F.; Efferth, Thomas; Gomes, Lígia RebeloBackground: Green tea is not only one of the most widely consumed beverages worldwide, but is also known for its health promoting and therapeutic effects. Green tea is cultivated in areas with high humidity and acidic soils in China, Indonesia and Japan. Those places have well-marked dry and rainy seasons. In opposite, Azores have a climate with constant average annual rainfall and, unlike eastern regions, relatively constant air humidity throughout the year. While a brand implemented on the Portuguese market, the quality of green tea produced in Azores must be guaranteed. Quality control measures based on phytochemical determination of the chemical composition and biological activities are needed in order to address whenever climate changes interferes significantly with composition and biological effects. Purpose: Make the phytochemical characterization of various extracts of green tea leaves coming from Azores and evaluate the anti-cancer activities of the extracts in order to compare the obtained results with those of teas coming from eastern regions. Methods: Phytochemical characterization (catechins, oxyaromatic acids, flavonols, alkaloids and theanine) and total catechins contents (TCC) was performed by using HPLC-DAD analysis, in infusions (5–7 min and 30 min), maceration and methanolic extracts of Camellia sinensis samples coming from Azores, Portugal. The antioxidant activity of extracts was measured by the DPPH assay and the total phenolics contents (TPC) were estimated using the Folin-Ciocalteu colorimetric method. The cytotoxic activity towards drug sensitive and multidrug-resistant leukemia cell lines was determined by the resazurin assay. Results: The TCC was higher in methanolic extracts and lower in maceration, as epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) concentrations were significantly higher in methanolic extracts and were only residual in maceration extracts. Maceration extracts showed the highest content of gallic acid, indicating that methanol extracts contained more flavonols of higher molecular weight and/or that maceration may lead to the degalloylation of catechins. The amount of o-caffeoylquinic acid extracted was significantly higher in methanolic samples. Short-term extraction at high temperatures resulted in high amounts of neochlorogenic acid. The contents of glycosylated quercitin-3-d-galactoside and kaempferol-3-glucoside were small in maceration samples and high in methanolic samples. Caffeine was easily extracted by methanol (99%) compared with water, while extraction of the amino-acid l-theanine was impossible with methanol. TPC values correlated linearly with DPPH• IC50, with infusion samples showing the best antioxidant capacities. The aqueous and the methanol/water extracts were active in multidrug-resistant and drug sensitive cancer cells.
- Phytochemical characterization and biological activities of green tea (Camellia sinensis) produced in the Azores, PortugalPublication . Barreira, Sérgio; Moutinho, Carla; Silva, André M.N.; Neves, José Manuel Gomes da Silva; Seo, Ean-Jeong; Hegazy, Mohamed-Elamir F.; Efferth, Thomas; Gomes, Lígia RebeloBackground: Green tea is not only one of the most widely consumed beverages worldwide, but is also known for its health promoting and therapeutic effects. Green tea is cultivated in areas with high humidity and acidic soils in China, Indonesia and Japan. Those places have well-marked dry and rainy seasons. In opposite, Azores have a climate with constant average annual rainfall and, unlike eastern regions, relatively constant air humidity throughout the year. While a brand implemented on the Portuguese market, the quality of green tea produced in Azores must be guaranteed. Quality control measures based on phytochemical determination of the chemical composition and biological activities are needed in order to address whenever climate changes interferes significantly with composition and biological effects. Purpose: Make the phytochemical characterization of various extracts of green tea leaves coming from Azores and evaluate the anti-cancer activities of the extracts in order to compare the obtained results with those of teas coming from eastern regions. Methods: Phytochemical characterization (catechins, oxyaromatic acids, flavonols, alkaloids and theanine) and total catechins contents (TCC) was performed by using HPLC-DAD analysis, in infusions (5–7 min and 30 min), maceration and methanolic extracts of Camellia sinensis samples coming from Azores, Portugal. The antioxidant activity of extracts was measured by the DPPH assay and the total phenolics contents (TPC) were estimated using the Folin-Ciocalteu colorimetric method. The cytotoxic activity towards drug sensitive and multidrug-resistant leukemia cell lines was determined by the resazurin assay. Results: The TCC was higher in methanolic extracts and lower in maceration, as epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) concentrations were significantly higher in methanolic extracts and were only residual in maceration extracts. Maceration extracts showed the highest content of gallic acid, indicating that methanol extracts contained more flavonols of higher molecular weight and/or that maceration may lead to the degalloylation of catechins. The amount of o-caffeoylquinic acid extracted was significantly higher in methanolic samples. Short-term extraction at high temperatures resulted in high amounts of neochlorogenic acid. The contents of glycosylated quercitin-3-d-galactoside and kaempferol-3-glucoside were small in maceration samples and high in methanolic samples. Caffeine was easily extracted by methanol (99%) compared with water, while extraction of the amino-acid l-theanine was impossible with methanol. TPC values correlated linearly with DPPH• IC50, with infusion samples showing the best antioxidant capacities. The aqueous and the methanol/water extracts were active in multidrug-resistant and drug sensitive cancer cells.
- Plantas medicinaisPublication . Neves, José Manuel Gomes da Silva; Cunha, SílviaAs plantas são uma fonte importante de compostos com actividade biológica. As novas moléculas têm grande interesse científico, económico e social podendo contribuir, em muito, para a saúde das pessoas e da sua qualidade de vida. O rastreio de novos compostos com actividade biológica é fundamental e, os Açores, pelas suas características particulares e endemismos assumem particular importância. A construção de uma “biblioteca de actividades” e o controlo das vias metabólicas sem descartar a biotecnologia vegetal e a cultura hidropónica são aspectos fundamentais na exploração das plantas medicinais. Plants are an important source of active biological compounds. The new molecules discovered have substantial scientific, economical and social interest because may contribute to the health and quality of life so, the survey of these new compounds is fundamental. Azores islands because have particular characteristics in soil, climate, moisteness, temperature and have endemic plantsl, assume great interest. To make a “activities library”, control the metabolic pathways, vegetal biotech and hydroponic cultures are fundamental aspects to explore medicinal plants.
- Ethnopharmacological notes about ancient uses of medicinal plants in Trás-os-Montes (northern of Portugal)Publication . Neves, José Manuel Gomes da Silva; Matos, Carla; Moutinho, Carla; Queiroz, Glória; Gomes, Lígia RebeloAim of the study In order to preserve the ancestral knowledge, an ethnopharmacological study has been carried out in two councils belonging to Trás-os-Montes region a small area located in the northern of Portugal. In that area, medicinal plants, most of the species wild, are still in use among farmers, shepherds and other people who live far from villages and built-up areas. Materials and methods Among the 46 people that were interviewed (mean age of 66 years old), 88 species belonging to 42 families of vascular plants were identified for treatment of various human ailments. An ethnopharmacological report is made consisting of species names, vernacular names, popular uses of the plants and their pharmacological properties. Results and conclusion The most dominant family is Lamiaceae (18%) and the most frequently part of the plant used for the treatment of diseases are leaves (37.9%). The largest number of taxa is used to treat gastrointestinal disorders (73.9%).
- Valorização da flor do dragoeiro (Dracaena draco L.) dos Açores: caracterização de compostos bioativos de extratos aquosos, etanólicos e hidroalcoólicosPublication . Ferreira da Vinha, Ana; Barreira, Sérgio; Costa, Anabela; Neves, José Manuel Gomes da Silva; Alves, Rita C.; Oliveira, M. Beatriz P.P.O Dragoeiro (Dracaena draco L.) é uma espécie da família das Dracaenacea, pertencente à flora da Macaronésia, onde se incluem os arquipélagos da Madeira e dos Açores. Trata-se de uma espécie vulnerável devido à exploração e comércio excessivo da sua resina. É utilizada na medicina tradicional e apresenta atividade citotóxica e efeitos quimioprotetores. No presente estudo analisou-se a atividade antioxidante de vários extratos (etanólico, aquoso e hidroalcoólico) das flores secas do dragoeiro e quantificaram-se os teores totais de fenóis e flavonoides. Os extratos hidroalcoólicos mostraram uma relação positiva e superior entre os teores de compostos fenólicos totais e a sua atividade antioxidante. A incorporação deste tipo de extratos em peloides para dermocosmética poderá ser benéfica dada a sua atividade antioxidante.
- Actividade antioxidante e avaliação in vitro da citotoxicidade de extractos aquosos de folhas de mentha x piperitaPublication . Neves, José Manuel Gomes da Silva; Matos, Carla; Moutinho, Carla; Gomes, Lígia Rebelo; Teixeira, TâniaNeste estudo apresentam-se os resultados referentes à avaliação do potencial anti-oxidante de extractos aquosos de Menta x piperita recolhida da região de trás-os-montes. A capacidade anti-oxidante foi testada pelo método DppH•, tendo sido também feita a quantificação dos compostos fenólicos totais nos extractos pelo método de Folin-ciocalteu, apontados como os responsáveis pelas propriedades antioxidantes da planta. Adicionalmente, apresentam- se os resultados relativos à avaliação citotoxicidade dos mesmos extractos através de testes de citotoxicidade in vitro, utilizando como organismo modelo tetrahymena pyriformis (com viabilidade avaliada pelo ensaio colorimétrico mtt). The aim of the present study is to investigate the antioxidant potential of aqueous extracts of Menta x piperita from trás-os-montes by the DppH• method, as well as to quantify the total phenolic compounds in the extracts by the Folin-ciocalteu method, probably responsible for the plant antioxidant properties. Additionally, the research work presented herein seeks to assess the effects of Menta x piperita through a series of in vitro cytotoxicity tests, using tetrahymena pyriformis as model organism. Viability will be evaluated by the colorimetric mtt assay.
- Usos populares de plantas medicinais da flora transmontanaPublication . Neves, José Manuel Gomes da Silva; Matos, Carla; Moutinho, Carla; Gomes, Lígia RebeloNeste trabalho é apresentado um estudo sobre o uso tradicional das plantas medicinais de dois concelhos da região de Trás-os-Montes. Durante o estudo, foram obtidos resultados relativos às plantas com maior uso medicinal e suas aplicações terapêuticas bem como as partes da planta mais usadas de 88 espécies pertencentes a 47 famílias de plantas indígenas. As propriedades terapêuticas mais referenciadas são os efeitos diurético, antiasténico e como vulnerário. Partindo de um relatório etnofarmacológico de várias plantas serão, posteriormente, seleccionadas aquelas que, tendo larga aplicação na medicina tradicional, não tenham sido estudadas do ponto de vista bioquímico e de actividade terapêutica. In this work a study of folk use of the medicinal plants of two councils bellowing to Trás-os-Montes region is presented. During the study, data for 88 species were obtained belonging to 47 families of vascular plants. The most report therapeutic properties are as diuretic, as anti-asthenia and as vulnerary. From an ethnopharmacological report done, will be subsequently selected those plants that, having, not only, a wide range of usage in traditional medicine but also, have not yet been studied in biochemical or therapeutic activity terms.