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  • Evaluation of the anticancer potential of the macrofungus Pisolithus arhizus mycelium and culture medium
    Publication . Santos, Germana; Preto, Marco; Vasconcelos, Vítor; Martins, Rosário; Oliveira, Rui S.; Martins, Rosario
    Macrofungi 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.
  • Neuroprotective effects of cyanobacterial extracts
    Publication . Rodrigues, Flávia; Grosso, Clara; Ferreira, Leonor; Vasconcelos, Vítor; Reis, Mariana; Martins, Rosário; Martins, Rosario
    Neurodegenerative diseases (ND), namely Alzheimer’s disease (AD) affects millions of people worldwide. Despite their high incidence there is still no effective medical therapy. Cyanobacteria have been in the frontline of the search for therapies for ND. Several in silico, in vitro, and in vivo studies have provided support for the neuroprotective potential of cyanobacterial natural products, particularly in AD. In this context, the aim of this work was to screen cyanobacterial strains from the Blue Biotechnology and Ecotoxicology Culture Collection (LEGE-CC) for its anti-AD potential. 10 cyanobacterial strains (LEGE CC 06072, 06131, 06155, 06361, 07168, 07175, 07189, 11394, 11439, 16525) were cultivated and their dry biomass was extracted and fractionated by reverse-phase HPLC resulting in 8 fractions per strain. Fractions were evaluated for their ability to inhibit enzymes associated with AD pathogenesis, such as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), using Ellman’s colorimetric method. In addition, their cytotoxicity was assessed against three cell lines, two of them related to the nervous system. The neuroblastoma cell line SH-SY5Y, usually used as model for neurotoxicity studies and the human cerebral microvascular endothelial cell line hCMEC/D3, representative of the blood-brain barrier. The mouse fibroblast cell line 3T3-L1 was used as a representation of the conjunctive tissue. Cell viability was measured after 24 and 48 hours using the MTT assay. Results: The fractions did not shown cytotoxicity against the cell lines used. The preliminary results regarding enzyme inhibition were not promising, with less than 30% inhibition. Our preliminary suggest that further confirmation tests need to be performed on the AD related enzymes (AChE and BuChE), and the study should be extended to include other cyanobacterial strains.
  • Anticancer potential of spores of the soil fungus Pisolithus tinctorius
    Publication . Oliveira, Rui S.; Alves, Ricardo; Preto, Marco; Martins, Rosário
    Cancer 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.
  • Evaluation of the potential of marine cyanobacteria towards Alzheimer’s disease
    Publication . Moreira, Ana Rita; Silva, Ana Margarida; Vieira, Mónica; Martins, Rosário
    Alzheimer’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.
  • Cyanobacteria for skin care and cosmeceutical formulations
    Publication . Melo, Luísa; Morone, Janaína; Silva, Margarida; Ferraz, Ricardo; Martins, Rosário
    Skin 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.
  • Isolation of Hierridin B from a culturable Cyanobium sp. strain isolated from the Portuguese coast
    Publication . Leão, Pedro N.; Pereira, Alban R.; Costa, Margarida; Ramos, Vítor; Martins, Rosário; Gerwick, William H.; Vasconcelos, Vitor
    Cyanobacteria 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.
  • Cytotoxic activity of marine cyanobacteria against cancer cell lines
    Publication . Ribeiro, Maria João; Costa, Margarida; Leão, Pedro; Barros, Piedade; Vasconcelos, Vítor; Martins, Rosário
    Marine 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.
  • Citotoxicity of marine cyanobacteria from the portuguese coast agains breast cancer cells
    Publication . Costa, Margarida; Leão, Pedro; Ribeiro, Maria João; Costa-Rodrigues, João; Garcia, Mónica; Barros, Piedade; Fernandes, Helena; Vasconcelos, Vítor; Martins, Rosário
    The 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 test
    Publication . Barros, Piedade; Martins, Rosário
    Microcystis 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.
  • Cytotoxicity of picocyanobacteria strains of the genera Cyanobium on osteosarcoma cells
    Publication . Martins, Rosário; Costa, Margarida; Garcia, Mónica; Barros, Piedade; Costa-Rodrigues, João; Vasconcelos, Vítor; Fernandes, Maria
    Marine 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