Browsing by Author "Urbatzka, Ralph"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- Bioactivity screening of marine cyanobacteria for the isolation of novel compounds for hepatic steatosisPublication . Moreira, Gabriela A.; Rosa, Filipa; Vasconcelos, Vítor; Urbatzka, RalphNonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease and effective therapeutics has been widely study. Cyanobacteria, previously known as blue-green algae, are known to produce many secondary metabolites including toxins, with applications to the pharmaceutical industry. The aim of this study is to investigate the effect of extract from cyanobacteria to reduce lipid accumulation in a model of hepatic steatosis using HepG2 cells in vitro.
- 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.
- Hierridin B Isolated from a Marine Cyanobacterium Alters VDAC1, Mitochondrial Activity, and Cell Cycle Genes on HT-29 Colon Adenocarcinoma CellsPublication . Freitas, Sara; Martins, Rosario; Costa, Margarida; Leão, Pedro; Vitorino, Rui; Vasconcelos, Vitor; Urbatzka, RalphHierridin B was isolated from a marine cyanobacterium Cyanobium sp. strain and induced cytotoxicity selectively in HT-29 adenocarcinoma cells. The underlying molecular mechanism was not yet elucidated.
- Insights into the potential of picoplanktonic marine cyanobacteria strains for cancer therapies – Cytotoxic mechanisms against the RKO colon cancer cell linePublication . Freitas, Sara; Martins, Rosario; Campos, Alexandre; Azevedo, Joana; Osório, Hugo; Costa, Margarida; Barros, Piedade; Vasconcelos, Vitor; Urbatzka, RalphIn this work, we analysed the potential of picoplanktonic marine cyanobacteria strains as a source of anticancer compounds by elucidating the cytotoxic mechanisms of an ethyl acetate fraction of Cyanobium sp. (LEGE06113) and the Synechocystis salina (LEGE06155) on the RKO colon adenocarcinoma cell line.
- A natural oxadiazine isolated from cyanobacteria kills cancer cells in multicellular culture systems by impairing cellular respirationPublication . Sousa, Maria Lígia; Preto, Marco; Martins, Rosário; Vasconcelos, Vítor; Linder, Stig; Urbatzka, RalphCyanobacteria are versatile microorganisms that ubiquitously inhabit terrestrial and aquatic ecosystems. They adapt to external threats by mainly producing secondary metabolites. Therefore, cyanobacteria have been recognized as producer of natural products with potential biotechnological applications, such as bioplastics, antifouling, antibiotics, antiprotozoal or anticancer treatment.