Evaluation of the benefit/risk associated to the consumption of seaweed based on the bioaccessibility/bioavailability of omega 3 fatty acids, essential elements, antioxidant compounds and contaminants

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Study of the seasonal variations of the fatty acid profiles of selected macroalgae

Publication . Pereira, Tatiana; Horta, André; Barroso, Sonia; Mendes, Susana; Gil, Maria M.

Due to the high consumption of fat-rich processed foods, efforts are being done to reduce their saturated fat (SFA) contents and replace it with polyunsaturated fatty acids (PUFA), creating a necessity to find alternative PUFA sources. Macroalgae, being a promising natural source of healthy food, may be such an alternative. The fatty acid (FA) profile of Fucus spiralis, Bifurcaria bifurcata, Ulva lactuca, and Saccorhiza polyschides were determined through direct transesterification and their seasonal variation was studied. F. spiralis showed the highest FA content overall, B. bifurcata presented the higher PUFA amounts, and U. lactuca and S. polyschides the higher SFA. The production of FA was shown to be influenced by the seasons. Spring and summer seemed to induce the FA production in F. spiralis and B. bifurcata while in U. lactuca the same was verified in winter. U. lactuca presented a !6/!3 ratio between 0.59 and 1.38 while B. bifurcata presented a ratio around 1.31. The study on the seasonal variations of the macroalgal FA profile can be helpful to understand the best season to yield FA of interest, such as ALA, EPA, and DHA. It may also provide valuable information on the best culturing conditions for the production of desired FAs.

2021Journal article

Open access

Identification of Asparagopsis armata‐associated bacteria and characterization of their bioactive potential

Publication . Alves, Celso; Pinteus, Susete; Lopes, Cláudia; Fino, Nádia; Silva, Joana; Ribeiro, Joana; Rodrigues, Daniel; Francisco, João; Rodrigues, Américo; Pedrosa, Rui; Horta, André

Macroalgae‐associated bacteria have already proved to be an interesting source of compounds with therapeutic potential. Accordingly, the main aim of this study was to characterize Asparagopsis armata‐associated bacteria community and evaluate their capacity to produce substances with antitumor and antimicrobial potential. Bacteria were selected according to their phenotype and isolated by the streak plate technique. The identification was carried out by the RNA ribosomal 16s gene amplification through PCR techniques. The antimicrobial activities were evaluated against seven microorganisms (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Salmonella enteritidis, Staphylococcus aureus, Saccharomyces cerevisiae, Candida albicans) by following their growth through spectrophotometric readings. Antitumor activities were evaluated in vitro on human cell lines derived from hepatocellular (HepG‐2) and breast carcinoma (MCF‐7) using the MTT method. The present work identified a total of 21 bacteria belonging to the genus Vibrio, Staphylococcus, Shewanella, Alteromonadaceae, Bacillus, Cobetia, and Photobacterium, with Vibrio being the most abundant (42.86%). The extract of Shewanella sp. ASP 26 bacterial strain induced the highest antimicrobial activity, namely against Bacillus subtilis and Staphylococcus aureus with an IC50 of 151.1 and 346.8 μg/mL, respectively. These bacteria (Shewanella sp.) were also the ones with highest antitumor potential, demonstrating antiproliferative activity on HepG‐2 cells. Asparagopsis armata‐associated bacteria revealed to be a potential source of compounds with antitumor and antibacterial activity.

2019Journal article

Open access

Algae from Portuguese Coast Presented High Cytotoxicity and Antiproliferative Effects on an In vitro Model of Human Colorectal Cancer

Publication . Alves, Celso; Pinteus, Susete; Rodrigues, Ana; Horta, André; Pedrosa, Rui

Background: The marine environment has shown to be an interesting source of new antitumor agents, representing an important tool in cancer research. Objective: The aim of this study was to evaluate the antitumor activities of 12 algae from Peniche coast (Portugal) on an in vitro model of human colorectal cancer (Caco‑2 cells). Materials and Methods: The antitumor potential was accessed by evaluating Caco‑2 cell’s viability and proliferation through the 3‑[4, 5‑dimethylthiazol‑2‑yl]‑2, 5‑diphenyl tetrazolium bromide and calcein‑AM methods. Results: The dichloromethane extracts of Asparagopsis armata and Sphaerococcus coronopifolius induced the highest decrease on cell’s viability (1 mg/mL; 24 h), 98.96% ± 0.39% and 98.08% ± 0.89%, respectively, followed by the methanolic extracts of S. coronopifolius (96.47% ± 1.26%) and A. armata (92.68% ± 1.17%). Regarding cell proliferation, the highest decrease of Caco‑2 cell’s proliferation (1 mg/mL; 24 h) was induced by the dichloromethane extract of A. armata (100% ± 0.48%), S. coronopifolius (99.04 ± 0.51%), and Plocamium cartilagineum (95.05% ± 1.19%). The highest potency was shown by the dichloromethane extract of S. coronopifolius in both, cytotoxicity and antiproliferative tests, with an IC50 of 21.3 and 36.5 µg/mL, respectively. Conclusion: The extracts of A. armata and S. coronopifolius are promising sources of new bioactive molecules with application in cancer therapeutics.

2018Journal article

Open access