ESS - CIIMAR@E2S - Posters apresentados em eventos científicos
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- Citotoxicity of marine cyanobacteria from the portuguese coast agains breast cancer cellsPublication . Costa, Margarida; Leão, Pedro; Ribeiro, Maria João; Costa-Rodrigues, João; Garcia, Mónica; Barros, Piedade; Fernandes, Helena; Vasconcelos, Vítor; Martins, RosárioThe marine environment possesses an unmeasured chemical and biological diversity, being considered an extraordinary resource for the discovery of new therapeutic drugs. Between others, marine cyanobacteria have emerged as a prominent source of bioactive secondary metabolites with a promising anticancer potential, as the described and intensively studied dolastatins.
- Embryotoxicity assessment of a Microcystis extract with Daphnia in vitro egg testPublication . Barros, Piedade; Martins, RosárioMicrocystis aeruginosa is a colonial unicellular cyanobacteria, usually found in eutrophic and hipereutrophic waters. Microcystins are the main toxins produced. As chronic toxicity test for daphnid is time consuming, the developmental stages of Daphnia eggs in vitro has been used in several works as an alternative to the 21 days reproduction test.
- Cytotoxic activity of marine cyanobacteria against cancer cell linesPublication . Ribeiro, Maria João; Costa, Margarida; Leão, Pedro; Barros, Piedade; Vasconcelos, Vítor; Martins, RosárioMarine cyanobacteria possess an extensive capacity to produce compounds that were found to induce biological activities against cell lines and organisms. Many of the marine cyanobacteria compounds already described were found to induce toxicity against cancer cells.
- Isolation of Hierridin B from a culturable Cyanobium sp. strain isolated from the Portuguese coastPublication . Leão, Pedro N.; Pereira, Alban R.; Costa, Margarida; Ramos, Vítor; Martins, Rosário; Gerwick, William H.; Vasconcelos, VitorCyanobacteria are a genetically diverse group of phototrophic prokaryotes. On a secondary metabolite perspective, however, filamentous and benthic forms have been the major sources of compounds isolated from these organisms. Nevertheless, unicellular free-living, planktonic cyanobacteria also contain enzymatic machinery for secondary metabolite biosynthesis.
- Cytotoxicity of picocyanobacteria strains of the genera Cyanobium on osteosarcoma cellsPublication . Martins, Rosário; Costa, Margarida; Garcia, Mónica; Barros, Piedade; Costa-Rodrigues, João; Vasconcelos, Vítor; Fernandes, MariaMarine cyanobacteria have been recognized as an important source of bioactive compounds. The cytotoxicity on cancer cell lines has been extensively explored and several cyanobacteria metabolites are already described as potential anticancer compounds or are considered useful templates for the design of new anticancer drugs. The majority of compounds have been isolated from filamentous or colonial cyanobacteria that growth in high densities along shores. In contrast, picoplanktonic forms have rarely been explored since, for these strains, there is a need for culture for biomass production. From our LEGE cyanobacteria culture collection we selected a panel of seven strains of the picocyanobacteria genera Cyanobium in order to explore it’s potential as anticancer agents. Strains were cultured under laboratory conditions. Freeze-dried biomass was extracted using methanol and dichloromethane to a crude extract and then fractionated using hexane, ethyl acetate and methanol. The cytotoxicity of crude extracts and fractions was evaluated in the osteosarcoma cell line MG63 by the reduction of the bromide 3-(4,5-dimetil-tiazol-2-il)-2,5-difenil-tetrazolio (MTT) and confirmed by the lactate dehydrogenase (LDH) assay. From the results, four of the seven Cyanobium strains were found to induce a significant decrease in cell viability. The highest percentage of inhibition of tumor cells growth was observed within the ethyl acetate, which is therefore, promising in terms of isolation of bioactive compounds
- Bioaccessibility and changes on cylindrospermopsin concentration in edible mussels over storage and processing time.Publication . Freitas, Marisa; Azevedo, Joana; Carvalho, António Paulo; Mendes, Vera; Manadas, Bruno; Campos, Alexandre; Vasconcelos, VítorThe cyanotoxin cylindrospermopsin has been recognized of increased concern due to the global expansion of its main producer, Cylindrospermopsis raciborskii. Previous studies have shown that aquatic organisms, especially bivalves, can accumulate high levels of cylindrospermopsin. Based on the potential for human health risks, a provisional tolerable daily intake of 0.03 µg/kg body-weight has been recommended. However, human exposure assessment has been based on the cylindrospermopsin concentration in raw food items. This study aimed to assess the changes on cylindrospermopsin concentration in edible mussels over storage and processing time as well as cylindrospermopsin bioaccessibility. Mussels, (Mytilus galloprovincialis) fed cylindrospermopsin-producing C. raciborskii, were subjected to the treatments and then analyzed by LC-MS/MS. Mussels stored frozen allowed a significantly higher recovery of cylindrospermopsin (52.5%/48 h and 57.7%/one week). The cooking treatments did not produce significant differences in cylindrospermopsin concentration in mussel matrices (flesh), however, cylindrospermopsin was found in the cooking water, suggesting that heat processing can be used to reduce the availability of cylindrospermopsin in this food item. The in vitro digestion with salivary and gastrointestinal juices considerably decreased the cylindrospermopsin availability in uncooked and steamed mussels, highlighting the importance in integrating the bioaccessibility in the human health risk assessment.
- Generation of spheroids of cancer cells for screening of antitumour activity of cyanobacterial extracts and isolated compounds.Publication . Sousa, Maria Lígia; Preto, Marco; Vasconcelos, Vítor; Martins, Rosário; Linder, Stig; Leão, Pedro; Urbatzka, RalphThe use of 3D cell culture for modelling cancer research is gaining interest, and in particular for screening of bioactive compounds. In the presented work, three compounds isolated from cyanobacteria and 92 chromatographic fractions obtained from crude organic extracts of 28 cyanobacterial strains from the Portuguese coast were tested on multicellular spheroids generated from the human cell lines HCT116 (colon colorectal carcinoma), HT-29 (colon adenocarcinoma) and A549 (lung carcinoma). Spheroids were incubated and analysed in an IncuCyte® ZOOM System, and M30 Cytodeath ELISA was performed for apoptosis. Portoamides isolated from Oscillatoria sp. LEGE 05292 reduced HCT116 spheroid integrity. Bartoloside B from Synechocystis salina LEGE 06155 decreased the size of HCT116 spheroids. Compound A isolated from Nodularia sp. LEGE 06071 induced a loss of the boundaries of the spheroid. Beyond that, portoamides induced apoptosis on HCT116 and HT29 spheroids, and compound A on HCT116 and A549 spheroids. The screening revealed that five fractions reduced the spheroid integrity; isolation of the active components will be done in the future by bioassay-guided fractionation. We conclude that the tested compounds and extracts show biological activities on multicellular spheroids and are therefore interesting candidates to be further developed as therapeutics for solid tumors.
- Anticancer potential of spores of the soil fungus Pisolithus tinctoriusPublication . Oliveira, Rui S.; Alves, Ricardo; Preto, Marco; Martins, RosárioCancer is one of the major causes of death worldwide being the search for new anticancer drugs essential for the treatment of this disease. The sporocarps of the soil fungus Pisolithus tinctorius contain pisosterol, a triterpene that has been shown to have antitumor activity against some cancer cell lines. Nevertheless, no studies have focused on the anticancer potential of other structures such as spores, and so the anticancer potential of P. tinctorius, remains largely unknown. The main objective of this study was to evaluate the potential of P. tinctorius spores as a source of anticancer compounds.
- Effects of glyphosate and cylindrospermopsin at environmental concentrations on growth, photosynthesis and mineral content in lettuce plantsPublication . Sengupta, Soumi; Freitas, Marisa; Pinto, Edgar; Azevedo, Joana; Oliveira, Flávio; Campos, Alexandre; Vasconcelos, VítorGlyphosate is the most widely used herbicide, mainly due to the extensive cultivation of glyphosate resistant plants. The intensification of agriculture has increased water eutrophication and the presence of natural cyanobacterial toxins, such as ylindrospermopsin. Previous studies support the hypothesis that glyphosate and cylindrospermopsin can affect the yield of crop plants, depending on the exposure concentration. Lettuce (Lactuca sativa L.)
- Phytochemical profile, antioxidant activity and cytotoxicity against keratinocytes, fibroblasts and endothelial cells of picoplanktonic marine cyanobacteriaPublication . Morone, Janaína; Lopes, Graciliana; Preto, Marco; Vasconcelos, Vítor; Martins, RosárioCombining the increase demand for natural products in skin care formulations, and the bioactive arsenal of cyanobacteria, we aimed with this study to evaluate the potential of a 70% ethanolic extract of picocyanobacteria strains of the genera Cyanobium and Synechocystis for skin care applications.
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