406 research outputs found

    Hepatoprotection of mentha aquatica L., lavandula dentata L. and leonurus cardiaca L.

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    The phenolic composition of hydroethanolic extracts of Mentha aquatica L., Lavandula dentata L. and Leonurus cardiaca L., obtained from plants grown under organic cultivation, was determined and their hepatoprotective effects were investigated in vitro . L. cardiaca extract was rich in phenylethenoid glycosides, especially lavandolifolioside (254 ± 36 μg/mg), whereas rosmarinic acid and eriodictyol-O-rutinoside were the major phenolic compounds of L. dentata and M. aquatica extracts, accounting for 68 ± 7 μg/mg and 145 ± 22 μg/mg, respectively. These differential phenolic components presumably account for their dissimilar antioxidant properties. While L. cardiaca extract showed moderate biological effects, M. aquatica extract displayed high antioxidant activity in chemical models, and that of L. dentata was effective in counteracting potassium dichromate-induced ROS generation in human hepatocarcinoma cells. Moreover, M. aquatica extract (50 μg/mL) and its mixture (50%/50%) with L. dentata extract displayed an effective cytoprotective effect.Aveiro and FCT/MCT financed the QOPNA research Unit (FCT UID/QUI/00062/2019) through national funds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement, to the Portuguese NMR Network and to the Portuguese Mass Spectrometry Network (RNEM, LISBOA-01-0145-FEDER-402-022125). This study was supported in part by the CIBERehd (EHD15PI05/2016) and Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Spain (PI16/00598, co-funded by European Regional Development Fund/European Social Fund, “Investing in your future”); Spanish Ministry of Economy, Industry and Competitiveness (SAF2016-75197-R); Junta de Castilla y Leon (SA063P17); AECCScientific Foundation (2017/2020), Spain; and “Centro Internacional sobre el Envejecimiento” (OLD-HEPAMARKER, 0348_CIE_6_E), Spain. Project AgroForWealth (CENTRO-01-0145-FEDER-000001) funded by Centro2020, through FEDER and PT2020, financed the research contract of Susana M. Cardoso.info:eu-repo/semantics/publishedVersio

    Protective effects of phenolic constituents from Cytisus multiflorus, Lamium album L. and Thymus citriodorus on liver cells

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    The present study investigated the antioxidant and cytoprotective effects of purified ethanolic extracts of Cytisus multiflorus, Lamium album L. and Thymus citriodorus plants. These extracts showed high antioxidant activity in DPPH and reducing power assays. Using a model of chemical stress induced by potassium dichromate (DK) in human hepatoblastoma HepG2 cells, 50 ug/mL of C. multiflorus, L. album and T. citriodorus extracts decreased the rate of reactive oxygen species (ROS) production by 35%, 26% and 20%, respectively, when exposed to 25 mu M of DK. This effect was also observed for the treatment of cells with individual polyphenolic compounds determined in the extracts, or with mixtures prepared with individual polyphenolic compounds simulating the phenolic composition of the extracts. Additionally, the purified ethanolic extracts and the prepared polyphenolic mixtures showed a cytoprotective effect against DK-induced toxicity. The overall results emphasize the contribution of polyphenols in antioxidant and cytoprotective properties of the studied plants

    Thermal impact from a thermoelectric power plant on a tropical coastal lagoon

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    Tropical coastal areas are sensitive ecosystems to climate change, mainly due to sea level rise and increasing water temperatures. Furthermore, they may be subject to numerous stresses, including heat releases from energy production. The Urias coastal lagoon (SE Gulf of California), a subtropical tidal estuary, receives cooling water releases from a thermoelectric power plant, urban and industrial wastes, and shrimp farm discharges. In order to evaluate the plant thermal impact, we measured synchronous temperature time series close to and far from the plant. Furthermore, in order to discriminate the thermal pollution impact from natural variability, we used a high-resolution hydrodynamic model forced by, amongst others, cooling water release as a continuous flow (7.78 m3 s?1) at 6 °C overheating temperature. Model results and field data indicated that the main thermal impact was temporally restricted to the warmest months, spatially restricted to the surface layers (above 0.6 m) and distributed along the shoreline within ?100 m of the release point. The methodology and results of this study can be extrapolated to tropical coastal lagoons that receive heat discharges.<br/

    Volatiles from Coriandrum sativum: comparation of in vitro and ex vitro grown plants

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    Coriandrum sativum (coriander) is commonly used, raw or cooked, in Portuguese Gastronomy. Coriander is also used in traditional medicine as a carminative and as a digestive aid. The fruits essential oil is used in food flavouring and in perfumery and is also responsible for the digestive and stimulant effect as well as for fungicide and bactericidal activity

    Green manure in coffee systems in the region of Zona da Mata, Minas Gerais: characteristics and kinetics of carbon and nitrogen mineralization.

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    The use of green manure may contribute to reduce soil erosion and increase the soil organic matter content and N availability in coffee plantations in the Zona da Mata, State of Minas Gerais, in Southeastern Brazil. The potential of four legumes (A. pintoi, C. mucunoides, S. aterrimum and S. guianensis)to produce above-ground biomass, accumulate nutrients and mineralize N was studied in two coffee plantations of subsistence farmers under different climate conditions. The biomass production of C. mucunoides was influenced by the shade of the coffee plantation.C. mucunoides tended to mineralize more N than the other legumes due to the low polyphenol content and polyphenol/N ratio. In the first year, the crop establishment of A. pintoi in the area took longer than of the other legumes, resulting in lower biomass production and N2 fixation. In the long term, cellulose was the main factor controlling N mineralization. The biochemical characteristics, nutrient accumulation and biomass production of the legumes were greatly influenced by the altitude and position of the area relative to the sun

    Em busca de antioxidantes e agentes hepatoprotetores em plantas

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    As plantas são usadas desde há séculos pelo Homem devido aos seus efeitos benéficos para a saúde, no entanto na maior parte dos casos, nem a composição química nem o mecanismo associado a cada efeito se encontram descritos. De entre as plantas mediterrânicas mais usadas, podem destacar-se espécies das famílias Lamiaceae e Fabaceae, que são reconhecidas fontes de compostos fenólicos. Dado o largo espetro de efeitos biológicos que são atribuídos a este tipo de compostos, vários estudos têm sido desenvolvidos com vista à sua aplicação na indústria farmacêutica, alimentar e cosmética. Esta apresentação focará alguns dos efeitos biológicos descritos na literatura para plantas das famílias Lamiaceae e Fabaceae, com especial ênfase nos géneros Cytisus, Lamium, Lavandula, Leonurus, Mentha e Thymus. Exemplos dos compostos naturais associados a esses benefícios serão igualmente indicados. Adicionalmente, serão apresentados resultados relativos ao efeito antioxidante e efeito hepatoprotetor de extractos etanólicos obtidos a partir de plantas de espécies dos géneros mencionados e que estão pouco exploradas até ao momento, nomeadamente a Cytisus multiflorus, Lamium album, Lavandula dentata, Leonurus cardiaca, Mentha aquatica e o Thymus citriodorus. Os resultados mostram que a maior parte dos extratos das plantas estudadas possuem uma elevada capacidade antioxidante, tal como demonstrado em modelos químicos e num modelo biológico. Alguns extratos, em particular os das plantas L. album e C. multiflorus, demonstraram ainda moderado poder hepatoprotetor. Para além disso, experiências efetuadas com compostos fenólicos puros permitem afirmar que estes efeitos estão intimamente relacionados com o seu conteúdo em compostos fenólicos. Os estudos até à data sugerem que estas plantas podem ter potencial para aplicação industrial. Estudos adicionais, incluindo modelos in vivo, são agora necessários para determinarem essa aplicação

    Decomposition and nutrient release of leguminous plants in coffee agroforestry systems.

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    Leguminous plants used as green manure are an important nutrient source for coffee plantations, especially for soils with low nutrient levels. Field experiments were conducted in the Zona da Mata of Minas Gerais State, Brazil to evaluate the decomposition and nutrient release rates of four leguminous species used as green manures (Arachis pintoi, Calopogonium mucunoides, Stizolobium aterrimum and Stylosanthes guianensis) in a coffee agroforestry system under two different climate conditions. The initial N contents in plant residues varied from 25.7 to 37.0 g kg-1 and P from 2.4 to 3.0 g kg-1. The lignin/N, lignin/polyphenol and(lignin+polyphenol)/N ratios were low in all residues studied. Mass loss rates were highest in the first 15 days, when 25 % of the residues were decomposed. From 15 to 30 days, the decomposition rate decreased on both farms. On the farm in Pedra Dourada (PD), the decomposition constant k increased in the order C. mucunoides < S. aterrimum < S. guianensis < A. pintoi. On the farm in Araponga (ARA), there was no difference in the decomposition rate among leguminous plants. The N release rates varied from 0.0036 to 0.0096 d-1. Around 32 % of the total N content in the plant material was released in the first 15 days. In ARA, the N concentration in the S. aterrimum residues was always significantly higher than in the other residues. At the end of 360 days, the N released was 78 % in ARA and 89 % in PD of the initial content. Phosphorus was the most rapidly released nutrient (k values from 0.0165 to 0.0394 d-1). Residue decomposition and nutrient release did not correlate with initial residue chemistry and biochemistry, but differences in climatic conditions between the two study sites modified the decomposition rate constants

    Planck intermediate results. VIII. Filaments between interacting clusters

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    About half of the baryons of the Universe are expected to be in the form of filaments of hot and low density intergalactic medium. Most of these baryons remain undetected even by the most advanced X-ray observatories which are limited in sensitivity to the diffuse low density medium. The Planck satellite has provided hundreds of detections of the hot gas in clusters of galaxies via the thermal Sunyaev-Zel'dovich (tSZ) effect and is an ideal instrument for studying extended low density media through the tSZ effect. In this paper we use the Planck data to search for signatures of a fraction of these missing baryons between pairs of galaxy clusters. Cluster pairs are good candidates for searching for the hotter and denser phase of the intergalactic medium (which is more easily observed through the SZ effect). Using an X-ray catalogue of clusters and the Planck data, we select physical pairs of clusters as candidates. Using the Planck data we construct a local map of the tSZ effect centered on each pair of galaxy clusters. ROSAT data is used to construct X-ray maps of these pairs. After having modelled and subtracted the tSZ effect and X-ray emission for each cluster in the pair we study the residuals on both the SZ and X-ray maps. For the merging cluster pair A399-A401 we observe a significant tSZ effect signal in the intercluster region beyond the virial radii of the clusters. A joint X-ray SZ analysis allows us to constrain the temperature and density of this intercluster medium. We obtain a temperature of kT = 7.1 +- 0.9, keV (consistent with previous estimates) and a baryon density of (3.7 +- 0.2)x10^-4, cm^-3. The Planck satellite mission has provided the first SZ detection of the hot and diffuse intercluster gas.Comment: Accepted by A&
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