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- Cytotoxity induced by extracts of Pisolithustinctorius spores on human cancer and normal cell lines – evaluation of the anticancer potentialPublication . Alves, Ricardo; Preto, Marco; Oliveira, Rui S.; Martins, RosárioCancer is one of the most important causes of death and morbidity worldwide. According to the World Health Organization 8.2 million people have died from cancer in 2012. The treatment of this fast growing disease is regarded as a major challenge in health for the XXI century. Conventional anti-cancer therapy is usually aggressive to the patients due to systemic toxicity caused by lack of specificity of the chemotherapy drugs (Kidd, 2000). This has triggered the interest of the scientific community to search for new and more effective therapies, less aggressive than conventional treatments. Used since antiquity in oriental civilizations, fungi, in particular mushrooms have been shown to limit or reverse tumor growth (Kidd, 2000). Pisolithustinctorius (Basidiomycota) is a soil fungus with world-wide distribution that it known to form ectomycorrhizal symbioses in forest ecosystems (Kope & Fortin, 1990). The sporocarps of this fungus contain Pisosterol, a triterpene that has been shown to have antitumor activity against some cancer cell lines (Montenegro et al., 2004). Nevertheless, no studies have focused on the anticancer potential of other structures such as spores and thus the anticancer potential of P. tinctorius , remains largely unknown.
- 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
- 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.
- Marine cyanobacteria compounds with anticancer properties: a review on the implication of apoptosisPublication . Costa, Margarida; Costa-Rodrigues, Joao; Fernandes, Maria Helena; Barros, Piedade; Vasconcelos, Vítor; Martins, RosarioMarine cyanobacteria have been considered a rich source of secondary metabolites with potential biotechnological applications, namely in the pharmacological field. Chemically diverse compounds were found to induce cytoxicity, anti-inflammatory and antibacterial activities. The potential of marine cyanobacteria as anticancer agents has however been the most explored and, besides cytotoxicity in tumor cell lines, several compounds have emerged as templates for the development of new anticancer drugs. The mechanisms implicated in the cytotoxicity of marine cyanobacteria compounds in tumor cell lines are still largely overlooked but several studies point to an implication in apoptosis. This association has been related to several apoptotic indicators such as cell cycle arrest, mitochondrial dysfunctions and oxidative damage, alterations in caspase cascade, alterations in specific proteins levels and alterations in the membrane sodium dynamics. In the present paper a compilation of the described marine cyanobacterial compounds with potential anticancer properties is presented and a review on the implication of apoptosis as the mechanism of cell death is discussed.