Fucoidan isolated from fermented Sargassum fusiforme suppresses oxidative stress through stimulating the expression of superoxidase dismutase and catalase by regulating Nrf2 signaling pathway.

In this study, a fucoidan (SFF-PS-F5) with a molecular weight of 213.33 kDa was isolated from fermented Sargassum fusiforme and the antioxidant activity of SFF-PS-F5 was investigated in vitro in Vero cells and in vivo in zebrafish. SFF-PS-F5 contains 91.68% of fucoidan (72.06% of carbohydrate and 19.62% of sulfate content). SFF-PS-F5 protected hydrogen peroxide (HO)-stimulated Vero cells damage by suppressing apoptosis via scavenging intracellular reactive oxygen species (ROS) by up-regulating the intracellular antioxidants. Further results indicated that these actions worked by elevating Nrf2 levels. The in vivo test results displayed that SFF-PS-F5 improved the survival rate by attenuating cell death via suppressing lipid peroxidation by scavenging ROS in HO-stimulated zebrafish. These results indicated that SFF-PS-F5 isolated from S. fusiforme possesses potent in vitro and in vivo antioxidant effects and it is a potential ingredient in pharmaceutical, nutraceutical, and cosmeceutical industries.