Pinteus, SuseteLemos, MarcoSilva, JoanaAlves, CelsoNeugebauer, AgnieszkaFreitas, RafaelaDuarte, AdrianaPedrosa, Rui2018-11-122018-11-122017http://hdl.handle.net/10400.8/3639This work was supported through funding provided by the Fundação para a Ciência e Tecnologia (FCT) Strategic Project UID/MAR/04292/2013 granted to MARE and by the Fundação para a Ciência e Tecnologia (FCT) R&D Project “Red2Discovery—The Red macro-algae Sphaerococcus coronopifolius and Asparagopsis armata as targets for marine drug Discovery” (P2020-PTDC/MAR-BIO/6149/2014). This work was also supported by the European Union through EASME Blue Labs project AMALIA—Algae-to-MArket Lab IdeAs (EASME/EMFF/2016/1.2.1.4/03/SI2.750419) and the Integrated Programme of SR&TD “Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate” (reference Centro-01-0145-FEDER-000018), co-funded by Centro 2020 program, Portugal 2020, European Union, through the European Regional Development Fund. Susete Pinteus, Joana Silva and Celso Alves are financial supported by a Grant from FCT—Fundação para a Ciência e Tecnologia (SFRH/BD/96203/2013, SFRH/BD/103255/2014 and SFRH/BD/97764/2013, respectively).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.engAntioxidantsBiological ProductsCaspase 9Hydrogen PeroxideMCF-7 CellsMembrane Potential, MitochondrialOxidative StressSargassumjournal article10.3390/md15110353