Exploring Bioactive Properties of Marine Cyanobacteria Isolated from the Portuguese Coast: High Potential as a Source of Anticancer Compounds

Abstract

The oceans remain a major source of natural compounds with potential in pharmacology. In particular, during the last few decades, marine cyanobacteria have been in focus as producers of interesting bioactive compounds, especially for the treatment of cancer. In this study, the anticancer potential of extracts from twenty eight marine cyanobacteria strains, belonging to the underexplored picoplanktonic genera, Cyanobium, Synechocystis and Synechococcus, and the filamentous genera, Nodosilinea, Leptolyngbya, Pseudanabaena and Romeria, were assessed in eight human tumor cell lines. First, a crude extract was obtained by dichloromethane:methanol extraction, and from it, three fractions were separated in a Si column chromatography. The crude extract and fractions were tested in eight human cancer cell lines for cell viability/toxicity, accessed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactic dehydrogenase release (LDH) assays. Eight point nine percent of the strains revealed strong cytotoxicity; 17.8% showed moderate cytotoxicity, and 14.3% assays showed low toxicity. The results obtained revealed that the studied genera of marine cyanobacteria are a promising source of novel compounds with potential anticancer activity and highlight the interest in also exploring the smaller filamentous and picoplanktonic genera of cyanobacteria.

Bioprospecting Portuguese Atlantic coast cyanobacteria for bioactive secondary metabolites reveals untapped chemodiversity

“…In this current study, 61 isolates belonging to different genera of the orders Chroococcales, Pleurocapsales, Oscillatoriales and Nostocales (corresponding to Subsections I through IV) were tested. These isolates comprise the majority of those previously characterized strains [16] as well as six others deposited at the LEGE culture collection [18,20].…”

“…However, there have been a few investigations aimed at assessing their bioactive potential [18][19][20]36]. In this current study, 61 isolates belonging to different genera of the orders Chroococcales, Pleurocapsales, Oscillatoriales and Nostocales (corresponding to Subsections I through IV) were tested.…”

“…This previous study showed that the crude extracts from these two picocyanobacteria had stronger effects than partially purified ones, suggesting the presence of different compounds and synergistic effect(s). Other recent studies, also using isolates from the Portuguese coast, revealed that extracts from these strains can have high activity in ecologically-relevant bioassays and toxicity against human cancer cell lines [18][19][20].…”

Picocyanobacteria From a Clade of MarineCyanobiumRevealed Bioactive Potential Against Microalgae, Bacteria, and Marine Invertebrates

“…The biological activity displayed by marine and estuarine picocyanobacteria strains has been previously studied in our lab (Martins et al, 2007(Martins et al, , 2008Frazao et al, 2010;Lopes et al, 2011;Costa et al, 2014) and by other investigators (Hamilton et al, 2014). Since bioactivity effects were predominantly reported for strains of the Synechocystis and Synechococcus genera, the aim of this study was to assess the potential of novel marine Cyanobium strains as producers of bioactive compounds.…”

“…Nevertheless, and owing to their ecological and biochemical diversity, cyanobacteria were found to be a prolific source of compounds with potential biotechnological applications, namely in the field of pharmacological agents. In fact, a wide range of secondary metabolites exhibiting pharmacodynamic properties such as antibacterial, antiviral, antifungal, and anticancer has been reported (Berry et al, 2008;Costa et al, 2014).…”