Alginate from Ericaria crinita Possesses Antioxidant Activity and Attenuates Systemic Inflammation via Downregulation of Pro-Inflammatory Cytokines

Alginates are anionic polysaccharides present in the cell walls of brown seaweeds. Various biological activities of alginate and its derivatives have been described. In this study, we assessed the potential of alginate obtained from <i>Ericaria crinita</i> (formerly <i>Cystoseira crinita</i>) to scavenge free radicals and function as a ferric ion reductor. The anti-inflammatory effect on the serum levels of TNF-α, IL-1β, IL-6, and IL-10 of rats with LPS-induced systemic inflammation after 14 days of treatment was also examined. <i>Ericaria crinita</i> alginate showed antioxidant activities of IC₅₀ = 505 µg/mL (DPPH) and OD₇₀₀ > 2 (ferric reducing power). A significant decrease in serum levels of IL-1β was observed only in animals treated with the polysaccharide at a dose of 100 mg/kg bw. Both doses of <i>E. crinita</i> alginate (25 and 100 mg/kg bw) significantly reduced the serum concentrations of pro-inflammatory cytokines TNF-α and IL-6, but no statistical significance was observed in the levels of the anti-inflammatory cytokine IL-10. Our findings show the potential of <i>E. crinita</i> alginate to act as an antioxidant and anti-inflammatory agent. It is likely that the exhibited antioxidant ability of the polysaccharide contributes to its antiphlogistic effects. More in-depth studies are needed to fully understand the specific mechanisms and the molecular pathways involved in these activities.