Published papers have reported that fucoidans may exert a range of beneficial effects on the human immune system, including the reduction of allergic responses and the activation of dendritic cells, natural killer cells and T cells. It has also been shown that fucoidans have the potential to aid important anti-viral and anti-tumour responses.
Immune responses to vaccines or infections can be compromised, particularly during ill health and in older people. In a clinical setting, ingestion of a fucoidan extract from Undaria pinnatifida was shown to help boost the immune responses to seasonal influenza vaccinations (Negishi, 2013). The ingestion of one of Marinova's fucoidan extracts was also shown to increase the anti-pathogenic activity of granulocytes and macrophages in healthy people (Myers, 2011). Increased immune activity has been reported following the ingestion of other fucoidan extracts, with studies demonstrating the elimination of the tropical protozoan parasite Leishmania in a mouse model (Kar, 2011). Fucoidans have also been shown to promote the maturation of dendritic cells, activate NK cells and promote cytotoxic activity (Zhang, 2015).
High purity fucoidan, from Undaria pinnatifida and Fucus vesiculosus, produced by Marinova have been shown to restore the secretion of anti-microbial peptides and contribute to the regulation of mucosal immune health (Cox, 2020). A recent Australian study assessed gut markers of immunity and inflammation, including lysozyme - a known indicator of innate immune function. The intense physical activity of athletes is often associated with depressed lysozyme levels and associated with changes in immune function. The study demonstrated a ~45% increase in fecal lysozyme in a group of elite athletes following a period of supplementation with high purity fucoidan. Lysozyme levels in the elite athletes normalized and were restored to levels consistent with those of a healthy control group.
Published research has reported that Undaria pinnatifida fucoidan may reduce allergic responses after ingestion (Maruyama, 2015) and after topical application (Yang, 2012). Some fucoidan extracts have also been shown to suppress the over-expression of the antibody IgE in immune cells in people with allergic dermatitis and to decrease the actual number of cells producing IgE (Iwamoto, 2011). It has been proposed that the mechanism of action for this damping of allergic responses is via upregulation of galactin-9, a protein integral to the regulation of cell-to-cell interactions (Tanino, 2016, Mizuno 2020).
Stem cell modulation
Immune function is fundamentally dependent upon the release and mobilisation of stem cells from bone marrow. As stem cells are released from bone marrow, they differentiate into all the different types of immune cells, including neutrophils, macrophages, cytotoxic natural killer (NK) cells, granulocytes and dendritic cells. Certain fucoidan extracts have been reported to increase levels of the chemokine SDF1 in the blood and elicit the release of stem cells into the peripheral circulation when used intravenously in animal models (Sweeney, 2002). In humans, it has been shown that the oral ingestion of Undaria pinnatifiida fucoidan, produced by Marinova, over a period of days increased the number/release of CD34+ haemopoeitic stem cells (Irhimeh, 2007). The same study also showed the Undaria pinnatifiida fucoidan increased SDF1 and the number of CXCR4 receptors on stem cells, which may assist in the lodgement of those cells.
Some fucoidans have been shown to block the entry of coated viruses to cells, thereby potentially preventing or halting the progress of infections. Undaria pinnatifida fucoidan produced by Marinova has been shown to be a highly effective in vitro inhibitor of Herpes Simplex viruses (HSV1 and HSV2) (Thompson, 2004) whilst other fucoidans have been shown to inhibit influenza viruses (Hayashi, 2008). Oral delivery of an Undaria pinnatifida fucoidan extract has also been shown to inhibit lung damage and clinical signs of respiratory infection in vivo via indirect anti-inflammatory activity. Research in a severe Influenza A H1N1 mouse model using orally administered Undaria pinnatifida fucoidan produced by Marinova (equivalent to 1-2g day human dose) showed attenuation of both clinical signs and lung damage (Richards, 2020). The mechanism of action appeared to be modulation of pathology, rather than inhibition of virus, indicating that this fucoidan may have utility regardless of the pathogen causing damage.
In vitro, some fucoidans have been shown to inhibit several different strains of influenza, including H1N1 (Hayashi, 2008; Wang, 2017), H5N1 (Makarenkova, 2010), H5N3 and H7N2 (Synytsa, 2014) and parainfluenza (Taoda, 2008). Clinically, one fucoidan extract reduced pro-viral loads in patients with HTLV-1 (Araya, 2011) and another showed benefits for patients with chronic hepatitis C (Mori, 2012). Other fucoidan extracts have also been shown to exhibit activity against Newcastle virus (Elizondo-Gonzalez, 2012), canine distemper (Trejo-Avila, 2014) and the measles virus (Morán-Santibañez, 2016).
Compromised lung function is a feature of both infection driven and non-infective pathologies. Viral infections, including the pandemic strain SARS-CoV-2, that affect lung function can cause both acute and long-term chronic damage. SARS-CoV-2 infection suppresses innate immunity and promotes an inflammatory response. Targeting these aspects of SARS-CoV-2 is not only important as the pandemic affects greater proportions of the population, but is also important in addressing regular colds and flu. In clinical and animal studies investigating general immune functions, various fucoidan extracts have been shown to increase innate immunity and decrease inflammation (Kuznetsova 2020, Fitton 2015, Fitton 2019). In addition, high purity fucoidan extracts produced by Marinova have been shown to attenuate pulmonary damage in a model of acute viral infection (Richards, 2020). A recent review published by Marinova (Fitton 2021) summarizes the current research on fucoidan extractswith regard to viral lung infections and lung damage and highlights key areas for further research in this application.