Screening of Phaeodactylum tricornutum extracts regarding their bioactive and functional properties

The expanding interest in addressing a more sustainable and eco-friendlier product development regarding the problem of ecological preservation results in a growing community search for bioactive natural-based formulations. Microalgae extracts potential for their interesting bioactive properties has been widely recognized, with antioxidant activity accounting for a major application in cosmetics, pharmaceutics and nutrition fields, due to its health-promoting effects. Moreover, microalgae generally contain large amounts of structural biopolymers, which might possibly display interesting rheological properties. This work was designed to enhance microalgae potential biotechnology exploration by attaining at least two different main fractions, namely with bioactive and texturizing functions. Phaeodactylum tricornutum was used under a biorefinery concept, by performing extractions with several solvent systems with a wide polarity spectrum. Previous work enhanced this microalgae species potential as an antioxidant agent, regardless of the antioxidant quantification method used, when compared to Nannochloropsis oceanica and Chlorella vulgaris extracts. P. tricornutum powdered biomass was extracted (4% dry weight) using water or hydroethanolic mixtures (25-96%) under same conditions of extraction, namely, over one hour at three different temperatures: 40ºC, 60ºC and 80ºC. All extracts were screened for their bioactive potential by three different antioxidant activity measurement assays: FRAP, ABTS and DPPH, as well as chemical characterized regarding their phenolic and pigment content. Lipidic fraction was evaluated for ethanol 25%, 50% and 96% extracts. Rheological properties and emulsifying capacity and stability were determined for water and ethanol 25% extracts, while protein and carbohydrate content were also assessed. Overall, findings from this study suggest that P. tricornutum extracts have a great potential for biotechnology purposes: aqueous extracts were particularly interesting for their functional properties while bioactive properties were more relevant for the ethanolic extracts. These may due to a higher protein and carbohydrate fraction present in more aqueous extracts. On the other hand, extracts with higher concentration of ethanol evidenced a greater amount of pigments, phenolics and lipids. In this manner, further studies should be fulfilled in order to explore their application in natural-based product formulation.This work was supported by the Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UID/BIO/04469/2020 unit. This study has also received funding from the European Fund for Regional Development (FEDER), COMPETE 2020 – Competitiveness and Internationalization Operational Program (Portugal 2020) and the European Regional Development Fund (Algarve 2020 and Lisboa 2020), under the scope of the project AlgaValor (grant agreement nº POCI-01-0247-FEDER-035234; LISBOA-01-0247-FEDER-035234; ALG-01-0247-FEDER-035234).info:eu-repo/semantics/publishedVersio

Screening of Phaeodactylum tricornutum extracts regarding theirbioactive and functional properties

The expanding interest in addressing a more sustainable and eco-friendlier product development regarding the problem of ecological preservation results in a growing community search for bioactive natural-based formulations. Microalgae extracts potential for their interesting bioactive properties has been widely recognized, with antioxidant activity accounting for a major application in cosmetics, pharmaceutics and nutrition fields, due to its health-promoting effects. Moreover, microalgae generally contain large amounts of structural biopolymers, which might possibly display interesting rheological properties. This work was designed to enhance microalgae potential biotechnology exploration by attaining at least two different main fractions, namely with bioactive and texturizing functions. Phaeodactylum tricornutum was used under a biorefinery concept, by performing extractions with several solvent systems with a wide polarity spectrum. Previous work enhanced this microalgae species potential as an antioxidant agent, regardless of the antioxidant quantification method used, when compared to Nannochloropsis oceanica and Chlorella vulgaris extracts. P. tricornutum powdered biomass was extracted (4% dry weight) using water or hydroethanolic mixtures (25-96%) under same conditions of extraction, namely, over one hour at three different temperatures: 40ºC, 60ºC and 80ºC. All extracts were screened for their bioactive potential by three different antioxidant activity measurement assays: FRAP, ABTS and DPPH, as well as chemical characterized regarding their phenolic and pigment content. Lipidic fraction was evaluated for ethanol 25%, 50% and 96% extracts. Rheological properties and emulsifying capacity and stability were determined for water and ethanol 25% extracts, while protein and carbohydrate content were also assessed. Overall, findings from this study suggest that P. tricornutum extracts have a great potential for biotechnology purposes: aqueous extracts were particularly interesting for their functional properties while bioactive properties were more relevant for the ethanolic extracts. These may due to a higher protein and carbohydrate fraction present in more aqueous extracts. On the other hand, extracts with higher concentration of ethanol evidenced a greater amount of pigments, phenolics and lipids. In this manner, further studies should be fulfilled in order to explore their application in natural-based product formulation.This work was supported by the Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UID/BIO/04469/2020 unit. This study has also received funding from the European Fund for Regional Development (FEDER), COMPETE 2020 – Competitiveness and Internationalization Operational Program (Portugal 2020) and the European Regional Development Fund (Algarve 2020 and Lisboa 2020), under the scope of the project AlgaValor (grant agreement nº POCI-01-0247-FEDER-035234; LISBOA-01-0247-FEDER-035234; ALG-01-0247-FEDER-035234).info:eu-repo/semantics/publishedVersio

Ruthenium(II)–cyclopentadienyl-derived complexes as new emerging anti-colorectal cancer drugs

Colorectal cancer (CRC) is one of the most common malignancies and one of the leading causes of cancer-related death worldwide, urging the need for new and more efficient therapeutic approaches. Ruthenium complexes have emerged as attractive alternatives to traditional platinum-based compounds in the treatment of CRC. This work aims to evaluate anti-CRC properties, as well as to identify the mechanisms of action of ruthenium complexes with the general formula [Ru(η5-C5H4R)(PPh3)(4,4'-R'-2,2'-bipyridine)][CF3SO3], where R = CH3, CHO or CH2OH and R' = H, CH3, CH2OH, or dibiotin ester. The complexes (Ru 1-7) displayed high bioactivity, as shown by low IC50 concentrations against CRC cells, namely, RKO and SW480. Four of the most promising ruthenium complexes (Ru 2, 5-7) were phenotypically characterized and were shown to inhibit cell viability by decreasing cell proliferation, inducing cell cycle arrest, and increasing apoptosis. These findings were in accordance with the inhibition of MEK/ERK and PI3K/AKT signaling pathways. Ruthenium complexes also led to a decrease in cellular clonogenic ability and cell migration, which was associated with the disruption of F-actin cytoskeleton integrity. Here, we demonstrated that ruthenium complexes, especially Ru7, have a high anticancer effect against CRC cells and are promising drugs to be used as a new therapeutical strategy for CRC treatment.Fundação para a Ciência e Tecnologia (FCT), I.P./MCTES through national funds (PIDDAC)—UIDB/00100/2020, UIDB/04050/2020 and through PTDC/QUI-QIN/28662/2017. A.V. acknowledges the CEECIND 2017 Initiative (CEECCIND/01974/2017). A.R.B. and R.G.T. thank FCT for their Ph.D. Grants (SFRH/BD/139271/2018 and SFRH/BD/135830/2018, respectively

Sustainable extraction of biocompounds from the green seaweed ulvarigida using ohmic heating

The development of new green and sustainable extraction technologies with low environmental impact and providing high nutritional functionalities, safety and applicability, has become relevant. Ohmic heating (OH) has emerged as a novel electric-based technology which allows high heating rates, higher selectivity of interest compounds, less energy and solvent consumption and energetically more efficient.[1,2] Ulva rigida is a green seaweed with high exploitation potential for commercial application. Its major compound of interest is ulvan, a sulfated polysaccharide present in the cell wall that has a wide range of possible applications in nutraceuticals, functional foods, agriculture and biomaterials.[3] The aim of this work was to access the feasibility of OH assisted extraction as an alternative extraction technology in the recovery of biocompounds (e.g.: polysaccharides, proteins, phenolic compounds and pigments) from Ulva rigida using different ratios of water/ethanol in different times of extraction. Extractions were made using a solid:solvent ratio of 1:30 and water/ethanol mixtures ranging from 0 to 75 % ethanol to extract different seaweeds fractions. The extractions were performed at 82 °C during 1 h, 2 h and 3 h, and the frequency was set at 25 kHz. Control extractions were made using a water bath (conventional extraction) with the same conditions, but without the presence of an electric field. Different parameters were assessed including extraction yield, lipids, ashes, moisture, total polysaccharides, protein, total phenolic compounds and pigments (chlorophylls and carotenoids) content, antioxidant activity and gelling ability. Higher extraction and ulvan-fraction yields, as well as total polysaccharides were obtained after 3 h of extraction for aqueous extracts. Total phenolic compounds, proteins and pigments content and antioxidant activity were higher for mixtures with higher amounts of ethanol. For antioxidant activity and total phenolic compounds, the 50:50 H2O/EtOH mixture under OH proved to be more efficient, with an increase up to 10 %, when compared to conventional extraction. Also, for pigments and protein content, the 25:75 H2O/EtOH mixture allowed promising results for 1 h of extraction. Gelling ability was identical in all produced extracts. As conclusion, these results showed that OH is a good alternative for a low cost and environmental-friendly extraction technology, for the recovery of bioactive compounds from green seaweeds.info:eu-repo/semantics/publishedVersio

Polarização e construção da força discursiva em manifestos políticos: o caso das presidenciais portuguesas de 2016

O presente estudo analisa o manifesto político apresentado publicamente por um dos dez candidatos às eleições presidenciais portuguesas de janeiro de 2016. O objetivo do estudo é, através do quadro de análise proposto por Adam (2001) para a descrição dos gêneros textuais em oito componentes (semântica; composicional; enunciativa; pragmática; estilístico-fraseológica; metatextual; peritextual e material), proceder a uma análise completa e integrada do texto, que torne visíveis os princípios centrais da sua organização argumentativa enunciativa e pragmática e, logo, os princípios da sua força discursiva. Ao mesmo tempo, a análise contribuirá para a descrição deste gênero de texto, pertencente ao tipo de discurso político, situando o texto numa zona prototípica do gênero.The present study analyzes the political manifesto publicly presented by one of the ten candidates to the Portuguese presidential elections of January 2016. The objective of the study is, through the framework of analysis proposed by Adam (2001) for the description of the textual genres in eight components (semantic, compositional, enunciative, pragmatic, stylistic-phraseological, metatextual, peritextual and material), to carry out a complete and integrated analysis of the text that makes visible the main principles of its argumentative, enunciative and pragmatic organization and hence the principles of its discursive force. At the same time, the analysis will contribute to the description of this text genre belonging to the political discourse type, placing the text in aprototypical area of the genre

Biological and chemical valorization potential of portuguese seaweeds: Ulva rigida, Gracilaria sp. and Fucus vesiculosus

info:eu-repo/semantics/publishedVersio

Effect of chaetomellic acid on hematocrit, urine specific gravity and urinary volume values in a rat model of renal mass reduction

Chaetomellic acid (CA) is a potent and highly specific inhibitor of ras farnesyl-protein transferase that seems to reduce both functional and histological damage in uninephrectomized rats subjected to renal ischaemia-reperfusion injury. The aim of this work was to evaluate the effect of chronic treatment with CA on hematocrit, urine specific gravity and urinary volume in a model of renal mass reduction. Male Wistar rats were subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after surgery, rats have been placed in four experimental groups: RMR rats without treatment (n=13); RMR rats treated with CA (n=13); SO rats without treatment (n=13); SO rats treated with CA (n=13). CA was intraperitoneally administered in a dose of 0.23 μg/kg three times a week for three months. We observed that animals from SO groups showed a higher hematocrit and urine specific gravity, and a lower urinary volume than animals from RMR groups (p<0.05). We did not observe differences between treated and no treated animals. These results suggest that three months of treatment with CA does not have a beneficial effect on hematocrit, urine specific gravity and urinary volume. However, these are preliminary data that warrant a larger scale study

Enzymatic approach for the extraction of bioactive fractions from red, green and brown seaweeds

Although several enzymatic approaches have been applied with this intent, the sequential use of enzymes covering both cellulolytic and proteolytic activity has never been performed in seaweeds. Sequential use of these enzymes improved the overall extraction yield by up to 160%, 30% and 80% in the different seaweeds when compared to the control condition (water extraction), use of a carbohydrases’ cocktail alone and use of proteases alone, respectively. Regarding the proximate composition of extracts, it proved to be an efficient approach for the solubilization of carbohydrates (up to 28% in G. vermiculophylla, 66% in P. dioica, 77% in U. rigida and 35% in F. vesiculosus) and protein (up to 55% in G. vermiculophylla, 47% in P. dioica, 52% in U. rigida and 42% in F. vesiculosus). For all biomasses, the combination of enzymes induced a significant increase in antioxidant activity, not only by the increase of phenolic compounds but also by the hydrolysis of protein to peptides. Moreover, extracts from red seaweeds displayed prebiotic activity which can be ascribed to their increased content in oligosaccharides and protein/peptides. Overall, the sequential use of enzymes with different activities demonstrated to be an efficient approach for extracting functional fractions to be used as functional ingredients to improve the nutritional value (e.g. in proteins) and/or to include antioxidant and prebiotic features in the food product.info:eu-repo/semantics/publishedVersio

Qualificar para melhor intervir: identificação de tipologias de espaços verdes urbanos com base no potencial de serviços de ecossistema

Os espaços verdes urbanos (EVU) contribuem para a qualidade do ambiente nas cidades, sendo reconhecidos como uma das soluções baseadas na natureza mais eficazes na promoção da resiliência local. Além da importância ambiental são também grandes promotores de estilos de vida saudáveis contribuindo para a saúde e bem-estar dos seus utilizadores. Os líderes municipais são responsáveis pela gestão e manutenção de muitos EVU, mas as evidências atuais identificam um conhecimento limitado sobre a governança da infraestrutura verde urbana, sendo a falta de dados identificada como uma das principais restrições a uma intervenção eficiente. Perante esta lacuna, este estudo teve como objetivo identificar aglomerados de EVU tendo por base a aplicação in situ de uma grelha de avaliação do potencial de serviços de ecossistema (PSE), através de um estudo de caso de 25 EVU da cidade de Porto. Os resultados das análises estatísticas multivariadas permitem identificar como dimensões preditoras do PSE a qualidade ambiental e comodidades. Para além disso, foram validados cinco aglomerados de EVU: i) ambientalmente capacitados e socialmente expectantes, ii) socioambientalmente capacitados, iii) ambientalmente capacitados mas socialmente adinâmicos, iv) socioambientalmente incapacitados e v) socioambientalmente inexplorados. Estas evidências são úteis no desenho de intervenções mais adequadas às características dos EVU, contribuindo para o aumento do PSE e da qualidade do ambiente urbano.info:eu-repo/semantics/publishedVersio

In vivo and in vitro effects of RAD001 on bladder cancer

Objective: To evaluate the influence of Everolimus (RAD001) on chemically induced urothelial lesions in mice and its influence on in vitro human bladder cancer cell lines. Methods: ICR male mice were given N-butyl-N-(4-hydroxybutyl) nitrosamine in drinking water for a period of 12 weeks. Subsequently, RAD001 was administered via oral gavage, for 6 weeks. At the end of the experiment, all the animals were sacrificed and tumor development was determined by means of histopathologic evaluation; mammalian target of rapamycin (mTOR) expressivity was evaluated by immunohistochemistry. Three human bladder cancer cell lines (T24, HT1376, and 5637) were treated using a range of RAD001 concentrations. MTT assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry were used to assess cell proliferation, apoptosis index, and cell cycle analysis, respectively. Immunoblotting analysis of 3 cell line extracts using mTOR and Akt antibodies was performed in order to study the expression of Akt and mTOR proteins and their phosphorylated forms. Results: The incidence of urothelial lesions in animals treated with RAD001 was similar to those animals not treated. RAD001 did not block T24 and HT1376 cell proliferation or induce apoptosis. A reduction in cell proliferation rate and therefore G0/G1 phase arrest, as well as a statistically significant induction of apoptosis (P 0.001), was only observed in the 5637 cell line. Conclusion: RAD001 seems not to have a significant effect on chemically induced murine bladder tumors. The effect of RAD001 on tumor proliferation and apoptosis was achieved only in superficial derived bladder cancer cell line, no effect was observed in invasive cell lines