Protective effect of fucoidans from tropical seaweeds against oxidative stress in HepG2 cells

Fucoidans are sulfated polysaccharides with proven pharmacological effects localized in the cell wall of marine brown algae. The majority of studies have been performed with temperate brown algal species, but in recent years, the evaluation of species from tropical areas has been growing. The aim of this study was to determine the protective effect of fucoidans extracted from the tropical brown seaweeds Dictyota ciliolata, Padina sanctae-crucis, and Sargassum fluitans, against oxidative stress (OS). The D. ciliolata fucoidan (FDc) exhibited the highest reactive oxygen species (ROS) scavenging activity (26%), followed by P. sanctae-crucis fucoidan (FPs) (22%) and S. fluitans fucoidan (FSf) (14%). No cytotoxic effect was detected for any of the extracted fucoidans at a concentration of 2 mg mL−1. Not only did the fucoidans tested show protective effect against OS by reducing ROS generation, but they also increased the glutathione (GSH) level and restored catalase (CAT) activity. Fucoidans obtained from tropical seaweeds could be used as a potential natural ingredient for functional foods.