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- 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.
- 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.
- Cyanobacteria for skin care and cosmeceutical formulationsPublication . Melo, Luísa; Morone, Janaína; Silva, Margarida; Ferraz, Ricardo; Martins, RosárioSkin acts as a barrier from external stimulus such as pollutants and ultraviolet radiation. Disturbs in the skin are involved in skin aging, which mostly results on a thinner epidermis, dryness, wrinkles, and loss of elasticity. Synthetic ingredients in cosmetics are known to be more toxic and to cause negative impact on the environment. In a society increasingly worried with human and environment health, natural skin care products gain special attention and boosted the search for natural sources. Due to the production of bioactive compounds, cyanobacteria emerged as an excellent source for cosmetic ingredients. Cyanobacteria strains of CIIMAR culture collection (LEGE-CC) have already proven to be interesting for cosmetic purposes [1,2]. In this project we aimed to evaluate the potential of four LEGE-CC cyanobacteria strains for skin care purposes. The cytotoxicity of acetonic and aqueous extracts was evaluated in keratinocytes (HaCAT), fibroblasts (3T3L1) and endothelial cells (hCMEC/D3) along with the total phenolic content and antioxidant properties. Cytotoxic assays revealed toxicity of acetonic extracts to keratinocytes in the higher concentrations tested. Aqueous extracts revealed low or non-cytotoxicity. Mainly in low concentrations of extracts, cellular proliferation was registered. Aqueous extracts from strain JM/RS021A and acetone extracts from strain JM/RS035B revealed higher values for total phenolic compounds. The acetone extracts of strain JM/RS021A showed the greatest scavenging activity values on the DPPH assay.
- 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
- 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.
- Evaluation of the anticancer potential of the macrofungus Pisolithus arhizus mycelium and culture mediumPublication . Santos, Germana; Preto, Marco; Vasconcelos, Vítor; Martins, Rosário; Oliveira, Rui S.; Martins, RosarioMacrofungi produce remarkable biomedical products that can make a significant contribution to health. Pisolithus arhizus is a fungal species of the phylum Basidiomycota. It is mainly found in association with the roots of some trees species, establishing a mutualistic relationship with them, facilitating the absorption of nutrients from the soil in exchange for carbohydrates produced by the host plant. As recently reviewed by us, this macrofungus has aroused great interest due to its promising therapeutic properties and bioactive effects. Crude extracts were prepared from the mycelium and culture medium of P.arhizus using a mixture of dichloromethane:methanol (2:1. The extracts were then separated into nine fractions using vacuum liquid chromatography. The fractions were tested for cytotoxicity against the RKO colon adenocarcinoma cell line and 3T3 fibroblasts cell line. Cell viability was assessed using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) reduction assay. Preliminary results revealed a dose dependent cytotoxicity against RKO cell line with no significant cytotoxicity to 3T3 cell lines, in fractions B and C. Those fractions corresponded to extraction with 70% Hex:30% EtOAc and 60% Hex:40% EtOAc, respectively. The results indicate that P.arhizus mycelium is a source of compounds with anticancer activity. However, more in-depth studies are needed to analyze the chemical compounds from the various parts of P. arhizus and investigate their biological and toxicological activities. Exploring the bioactive potential of P. arhizus is key to developing a complete understanding of its therapeutic benefits.
- Evaluation of the potential of marine cyanobacteria towards Alzheimer’s diseasePublication . Moreira, Ana Rita; Silva, Ana Margarida; Vieira, Mónica; Martins, RosárioAlzheimer’s disease (AD) is one of the most prevalent neurodegenerative diseases (NDs) and the major cause of dementia. Despite the constant efforts to achieve cure, no treatment is currently effective and new approaches are urgently needed. Marine biotechnology has been at the frontline for the bioprospection of natural sources to treat ND. Several marine compounds have already provided evidence for anti-AD drugs by acting in mechanisms such as the inhibition of acetylcholinesterase (AChE). Among marine organisms, cyanobacteria have been recognized as a major source of bioactive compounds and the potential towards AD has been highlighted, namely AChE inhibitors. This project is included in a screening program that aims to evaluate the potential of cyanobacteria from the Culture Collection of CIIMAR -LEGE-CC against AD. In this work, 80 fractions of marine cyanobacteria were screened for the potential to inhibit AChE since this is a proven enzyme target to ameliorate the loss of cholinergic signal and to induce cytotoxicity in the neuroblastoma cell line SHY5Y, in the normal fibroblasts cell line 3T3L1, and in the endothelial cells from central nervous system capillaries hCMEC/D3. Results considering the enzymatic assays and cytotoxic assays revealed that the fractions are not toxic or with low toxicity. The strains Phormidium sp; an unidentified filamentous Synechococcales and Nodosilinea nodulosa revealed moderate toxicity towards AChE.
- 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.
- 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.