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An Insight into Sargassum muticum Cytoprotective Mechanisms against Oxidative Stress on a Human Cell In Vitro Model
Publication . Pinteus, Susete; Lemos, Marco; Silva, Joana; Alves, Celso; Neugebauer, Agnieszka; Freitas, Rafaela; Duarte, Adriana; Pedrosa, Rui
Sargassum muticum is a brown seaweed with strong potential to be used as a functional food ingredient, mainly due to its antioxidant properties. It is widely used in traditional oriental medicine for the treatment of numerous diseases. Nevertheless, few studies have been conducted to add scientific evidence on its effects as well as on the mechanisms of action involved. In this work, the human cell line MCF-7 was used as an in vitro cellular model to evaluate the capability of Sargassum muticum enriched fractions to protect cells on an oxidative stress condition. The concentration of the bioactive compounds was obtained by vacuum liquid chromatography applied on methanol (M) and 1:1 methanol:dichloromethane (MD) crude extracts, resulting in seven enriched fractions from the M extraction (MF2-MF8), and eight fractions from the MD extraction (MDF1-MDF8). All fractions were tested for cytotoxic properties on MCF-7 cells and the nontoxic ones were tested for their capacity to blunt the damaging effects of hydrogen peroxide-induced oxidative stress. The nontoxic effects were also confirmed in 3T3 fibroblast cells as a nontumor cell line. The antioxidant potential of each fraction, as well as changes in the cell's real-time hydrogen peroxide production, in the mitochondrial membrane potential, and in Caspase-9 activity were evaluated. The results suggest that the protective effects evidenced by S. muticum can be related with the inhibition of hydrogen peroxide production and the inhibition of Caspase-9 activity.
Neuroprotective effects of seaweeds against 6-hydroxidopamine-induced cell death on an in vitro human neuroblastoma model
Publication . Silva, Joana; Alves, Celso; Pinteus, Susete; Mendes, Susana; Pedrosa, Rui
Background: Parkinson’s disease (PD) is a progressive neurodegenerative disorder of the central nervous system. Although the causes of PD pathogenesis remain incomplete, some evidences has suggested that oxidative stress is an important mediator in its pathogenesis. The aim of this study was to evaluate the protective effects of seaweeds with high antioxidant activity on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in the human neuroblastoma cell line SH-SY5Y, as well as the associated intracellular signaling pathways. Methods: Cell viability studies were assessed by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium (MTT) bromide assay and the intracellular signaling pathways analyzed were: hydrogen peroxide (H2O2) production, changes in the mitochondrial membrane potential and Caspase-3 activity. Results: Exposure of SH-SY5Y cells to 6-OHDA (10–1000 μM) reduced cell’s viability in a concentration and timedependent manner. The data suggest that the cell death induced by 6-OHDA was mediated by an increase of H2O2 production, the depolarization of mitochondrial membrane potential and the increase of Caspase-3 activity. Extracts from S. polyshides, P. pavonica, S. muticum, C. tomentosum and U. compressa revealed to efficiently protect cell’s viability in the presence of 6-OHDA (100 μM; 24 h). These effects appear to be associated with the reduction of H2O2 cell’s production, the protection of mitochondrial membrane’s potential and the reduction of Caspase-3 activity. Conclusions: These results suggest that seaweeds can be a promising source of new compounds with
neuroprotective potential.
Marine invasive macroalgae: Turning a real threat into a major opportunity - the biotechnological potential of Sargassum muticum and Asparagopsis armata
Publication . Pinteus, Susete; Lemos, Marco F.L.; Alves, Celso; Neugebauer, Agnieszka; Silva, Joana; Thomas, Olivier P.; Botana, Luis M.; Gaspar, Helena; Pedrosa, Rui
Marine invasive species are widely recognized as one of the worst threats to marine ecosystems integrity, un-balancing native communities, which may lead to paramount ecological and economic impacts. Within invasiveseaweeds, Sargassum muticum and Asparagopsis armata are recognized as successful invaders in Europe andAmerica. Despite several attempts to control the spread of marine invaders, until now, all have proven to beelusive, and therefore, alternative strategies should be embraced.Worldwide, seaweeds have been increasingly explored due to their ability to produce bioactive compounds.However, one of the main problems associated with the production/extraction of these bioactive compounds fornew products development, is the source availability and the potential negative environmental consequences ofthis exploitation.Within this framework, the use of invasive species to obtain natural bioactive compounds presents us with atwo-folded opportunity - high availability of the biological material for the extraction of unique bioactivecompounds for new products development, and through specimen collection, mitigating negative effects causedby alien species, contributing for ecosystem integrity and sustainability.Over the last decades, the brown seaweed S. muticum and the red A. armata have been studied all over theworld for their capacity to produce bioactive compounds, with main results pointing towards their high potentialas producers of antioxidant, antifouling, antimicrobial, and antitumor compounds.The present review summarizes the biotechnological potential of S. muticum and A. armata as producers ofbioactive compounds, while addressing the potential use of global threats as important blue growth pawns.
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.
From marine origin to therapeutics: the antitumor potential of marine algae-derived compounds
Publication . Alves, Celso; Silva, Joana; Pinteus, Susete; Gaspar, Helena; Alpoim, Maria C.; Botana, Luís M.; Pedrosa, Rui
Marine environment has demonstrated to be an interesting source of compounds with
uncommon and unique chemical features on which themolecularmodeling and chemical
synthesis of new drugs can be based with greater efficacy and specificity for the therapeutics. Cancer is a growing public health threat, and despite the advances in
biomedical research and technology, there is an urgent need for the development of
new anticancer drugs. In this field, it is estimated that more than 60% of commercially
available anticancer drugs are natural biomimetic inspired. Among the marine organisms, algae have revealed to be one of the major sources of new compounds of marine origin, including those exhibiting antitumor and cytotoxic potential. These compounds demonstrated ability to mediate specific inhibitory activities on a number of key cellular processes, including apoptosis pathways, angiogenesis, migration and invasion, in both in vitro and in vivo models, revealing their potential to be used as anticancer drugs. This review will focus on the bioactive molecules from algae with antitumor potential, from their origin to their potential uses, with special emphasis to the alga Sphaerococcus coronopifolius as a producer of cytotoxic compounds.
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Funding agency
Fundação para a Ciência e a Tecnologia
Funding programme
SFRH
Funding Award Number
SFRH/BD/96203/2013