ESS - CM - Posters apresentados em eventos científicos
Permanent URI for this collection
Browse
Browsing ESS - CM - Posters apresentados em eventos científicos by Author "Barros, Piedade"
Now showing 1 - 10 of 12
Results Per Page
Sort Options
- 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.
- 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.
- 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
- Differential toxicity responses of green algae and cyanobacteria to formamidePublication . Moreira, Teresa; Sousa, Maria; Barros, PiedadeFormamide is used as a softener for paper and gums, as na ionizing solvent and in the manufacture of hydrocyanic acid and formic esters.
- Ecotoxicological effect of 1-(2-hydroxyethyl)-3- methylimidazolium chloride and cetylpyridinium chloride towards the microalgae Chlorella vulgarisPublication . Pacheco, Elisabete; Ferraz, Ricardo; Prudêncio, Cristina; Barros, PiedadeIonic liquids (ILs) are salts that are stable over their melting temperature and are made exclusively of ions. ILs have received considerable interest due to their unique properties. The growing interest in ILs predicts an increase of their manufacture and use at industrial scale, which may result in the increased release of these compounds into the environment. In the past years, ILs have been used as a greener alternative to hazardous conventional solvents.
- Effects of low doses of external radiation from 137Cs on Lactuca sativa seedling and Daphnia magna reproductionPublication . Teles, Luís; Henriques, Marta; Santos, Rubim; Barros, PiedadeNaturally occurring cesium exists as a stable isotope 133Cs in the earth crust in granites and in sedimentary rocks. Cesium has very low mobility in soil surfaces.
- 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.
- Environmental epigenetics and Daphnia as a model organismPublication . Pereira, Ana Rita; Silva, Regina; Barros, PiedadeDaphnia’s cyclic parthenogenesis life cycle is controlled by environmental cues and determines the population genetic variability. The asexual reproduction maintains the genetic background. This, allied to the fact that epigenetic changes were already described in Daphnia turns it in a useful model to study the effect of epigenetic changes in the organism.
- Evaluation of valproic acid toxicity in duckweed, Lemna minorPublication . Machado, Beatriz; Prudêncio, Cristina; Ferraz, Ricardo; Barros, PiedadeIn the last years the contamination of water caused by drugs has increased significantly. The main cause is the increase of the number and quantities of drugs that is being used. Many of these compounds cannot be removed effectively by wastewater treatment plants. This problem affects the water cycle and, consequently, all the environment as well as the human health, so it is important to find new methods that can help the removal of drugs from the water. This research is aimed to understand the influence of different concentrations of valproic acid on the growth of the duckweed Lemna minor. After 7 days of exposure it was analysed the number of fronds, the length of the root and the chlorophylls content. The chlorophylls of the Lemna minor samples were analysed by spectrophotometry. The number of fronds was influenced by the concentration of valproic acid. The higher concentrations (0,1 mg/mL; 0,05 mg/mL; 0,025 mg/mL) showed an inhibitory effect while the lower concentrations (0,005 mg/mL; 0,0001 mg/mL) showed a stimulating effect. Relative to the control, the number of fronds was lower in the higher concentrations and higher in the lower concentrations. The root length was affected in all the concentrations. Comparative to the control the higher concentrations presented a diminution of the root’s length while the higher ones had an increase. Like the other parameters the concentration of chlorophylls was affected in all the samples. In the higher concentrations (0,1 mg/mL; 0,05 mg/mL; 0,025 mg/mL) the quantity was lower, comparatively to the control, and in the lower ones (0,01 mg/mL; 0,005 mg/mL; 0,0001 mg/mL) it was higher. In general, the valproic acid influenced all the parameters evaluated: number of fronds, length of the root and concentration of chlorophylls. In the higher concentrations it is notable an inhibitory effect while the lower concentrations have a stimulating one.
- In vivo exposure to formamide on lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase activity of Helix aspersaPublication . Moreira, Teresa; Sousa, Maria; Barros, PiedadeFormamide is produced and used as an intermediate in the chemical industry, in the production of heterocyclic compounds, pharmaceuticals, fungicides, and pesticides.