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-1ß, 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.

Oral Fucoidan Attenuates Lung Pathology and Clinical Signs in a Severe Influenza a Mouse Model.

Fucoidans are known to be effective inhibitors of inflammation, and of virus binding and cellular entry. Undaria pinnatifida-derived fucoidan (UPF) was assessed in a severe influenza A (H1N1, PR8) infection model in mice. Initially, UPF was gavaged at 3.52 mg daily in a treatment model. Gross lung pathology (consolidation) was significantly reduced as compared to controls. UPF was then presented as a feed supplement at a rate of either nil, 3.52 mg/day or 7.04 mg/day in a prophylactic model, dosed three days before infection. A significant improvement was observed in the clinical signs of ill-health, as well as a reduction in gross lung pathology in animals treated with the higher dose, although there was no significant reduction in lung viral titres.

Effect of a Fucoidan Extract on Insulin Resistance and Cardiometabolic Markers in Obese, Nondiabetic Subjects: A Randomized, Controlled Trial.

OBJECTIVES: To determine whether a fucoidan extract reduced insulin resistance and/or altered other cardiometabolic markers in an obese, nondiabetic population. DESIGN: Single-site, double-blinded, placebo-controlled, randomized controlled trial. SETTING/LOCATION: Hobart, Tasmania, Australia. SUBJECTS: Eligible subjects were obese, with no history of diabetes, and ages between 18 and 65 years. INTERVENTIONS: Subjects were randomly assigned, in even blocks of 10, to either active fucoidan 500 mg or placebo capsules twice daily for 90 days, with identical measurements performed at baseline and follow-up. OUTCOME MEASURES: The primary outcome was insulin resistance, defined by the homeostasis model of assessment (HOMA) values. Secondary outcomes were lipid profile, glycosylated hemoglobin, urea electrolytes and creatinine, liver function tests, full/complete blood count, fasting insulin, fasting glucose, quantitative insulin sensitivity check index, glucose area under the curve, weight, body mass index, waist circumference, and systolic and diastolic blood pressure. The trial was registered with the Australian New Zealand Clinical Trial Registry (ACTRN12614000495628) and the Therapeutic Goods Administration (2014/0348), and was funded by Marinova Pty. Ltd. RESULTS: There were no differences in the 90-day outcome measures between placebo and active treatment in the intention-to-treat-analysis (n = 35 for active, n = 37 for placebo). The mean change in HOMA scores was 0 for the placebo and -0.1 for the active groups (p = 0.73). Self-reported adherence was high, consistent with capsule counting at the conclusion of the trial. CONCLUSIONS: Fucoidan taken twice daily for a period of 90 days did not markedly affect insulin resistance or other measured parameters of cardiometabolic health in an obese, nondiabetic cohort. This could be due to an intrinsic lack of efficacy, lower than measured adherence, or because longer therapy and/or higher baseline insulin resistance are required to exert a significant effect.