Anti-Inflammatory Activity of Fucoidan Extracts In Vitro.

Fucoidans are sulfated, complex, fucose-rich polymers found in brown seaweeds. Fucoidans have been shown to have multiple bioactivities, including anti-inflammatory effects, and are known to inhibit inflammatory processes via a number of pathways such as selectin blockade and enzyme inhibition, and have demonstrated inhibition of inflammatory pathologies in vivo . In this current investigation, fucoidan extracts from Undaria pinnatifida, Fucus vesiculosus, Macrocystis pyrifera, Ascophyllum nodosum, and Laminaria japonica were assessed for modulation of pro-inflammatory cytokine production (TNF-α, IL-1β, and IL-6) by human peripheral blood mononuclear cells (PBMCs) and in a human macrophage line (THP-1). Fucoidan extracts exhibited no signs of cytotoxicity in THP-1 cells after incubation of 48 h. Additionally, all fucoidan extracts reduced cytokine production in LPS stimulated PBMCs and human THP-1 cells in a dose-dependent fashion. Notably, the 5-30 kDa subfraction from Macrocystis pyrifera was a highly effective inhibitor at lower concentrations. Fucoidan extracts from all species had significant anti-inflammatory effects, but the lowest molecular weight subfractions had maximal effects at low concentrations. These observations on various fucoidan extracts offer insight into strategies that improve their efficacy against inflammation-related pathology. Further studies should be conducted to elucidate the mechanism of action of these extracts.