What is Fucoidan Plus U-Fucoidan is a sulfated polysaccharide extracted from brown seaweed—is now thought to have a role to play in this stem-cell-induced repair of cardiovascular damage. Studies have begun to emerge indicating fucoidan might influence the mobilization of endothelial progenitor cells and their incorporation in ischemic tissue. Studies have shown that treatment with the sulfated polysaccharide fucoidan or the structurally similar dextran sulfate increases circulating mature white blood cells and progenitor/stem cells in mice and nonhuman primates. Recent studies suggest that fucoidan may work by enhancing the activity of stromal-derived factor 1 (SDF-1), which plays a critical role at several steps of progenitor cell mobilization.

Fucoidan, Stem Cells and Cardiovascular Health

In 1997, progenitor cells were first identified in human peripheral blood, meaning the cells were traveling in the blood stream rather than remaining static. Mobilization of these cells to ischemic sites is an important step in new vessel formation. After a period of ischemia—when blood vessels and cardiac tissue are injured due to lack of oxygen—these progenitor cells migrate from the bone marrow to the site of injury and encourage the growth of new blood vessels to help repair the damage, a process known as neovascularization. It is thought that the progenitor cells interact with endothelial cells (cells lining blood vessel walls), then escape from the vessels into the tissues to reach ischemic sites, where they proliferate and differentiate into new blood vessels.

Researchers reporting in the journal Blood recently discovered that plasma concentrations of the highly potent SDF-1 increased rapidly and dramatically after treatment with fucoidan in monkeys and in mice, coinciding with decreased levels in bone marrow. In vitro and in vivo data suggest that fucoidan displaces certain factors that normally trap the SDF-1 in bone marrow, on endothelial cell surfaces or other tissues, helping to release the SDF-1 and allowing it to more easily mobilize the stem cells. The researchers tested other mobilizing agents to see if they would have the same effect but fucoidan was the only substance tested able to increase SDF-1 activity and enhance stem cell mobilization to sites of injury.4 Endothelial progenitor cells, when transplanted into animals, are able to increase the formation of new blood vessels to a certain extent. However, in this case, the number of circulating endothelial progenitor cells is relatively small. Therefore, researchers in France decided to investigate whether fucoidan could empower the blood-vessel-building properties of the stem cells prior to injection in vivo. During this in vitro study, the scientists found that fucoidan could indeed enhance the proangiogenic (blood-vessel-building) properties of endothelial progenitor cells, indicating that it can enhance the cells’ ability to mobilize and repair damaged tissue.5 In another study, scientists used a rat model of atherosclerosis to test the effects of fucoidan on lesions on the inner lining of the arteries called the intima. The study authors transplanted atherosclerotic aortas into the animals. In animals given fucoidan, the proliferation of intimal lesions was significantly prevented compared to controls and fucoidan appeared to trigger a reduction in intimal thickening.  Furthermore, fucoidan helped stimulate the rebuilding of the endothelial cells in the grafted aorta. Treatment with a specific inhibitor of the SDF-1 receptor failed to prevent the protective effect of fucoidan on intimal thickening, indicating fucoidan’s effects in this study were not attributable to increased SDF-1 activity.6 The researchers concluded that fucoidan “reduced intimal thickness and induced the presence of an endothelial cell lining in the vascular graft at 30 days.” Fucoidan’s emerging ability to enhance the activity of stem cells adds to an impressive list of other potential uses for this substance. It appears to exert a number of other beneficial effects on the cardiovascular system. Because it is similar in structure to heparin it possesses anticoagulant abilities.7 Fucoidan also is known to block selectins, cell receptors important in the adhesion of white blood cells known as leukocytes to capillary walls.8 When leukocytes adhere to the blood vessel walls, it can lead to tissue damage, ultimately resulting in atherosclerosis. Fucoidan has been studied extensively for its ability to strengthen the immune system, and in a number of in vitro and animal studies, it has inhibited coated viruses such as herpes, HIV and human cytomegalovirus, a type of herpes virus that can cause blindness and fatal pneumonia in individuals with compromised immune systems. Experiments have suggested that fucoidan may not only inhibit the initial stages of viral infection, such as attachment to and penetration into host cells, but also the later replication stages after virus penetration.9 A newly published cell culture study also indicates fucoidan may reduce acute and chronic liver failure and liver fibrosis and may protect liver cells from damage.10 Despite fucoidan’s ability to promote blood vessel growth, the medical literature shows it is non-mutagenic and that it can actually inhibit cancer growth. Fucoidan is known to enhance the activity of natural killer cells, which seek out and destroy tumor cells and are a critical defense against malignancies. In a study investigating fucoidan’s effects on the tumor growth of mouse leukemia cells, animals fed fucoidan experienced a 65.4 percent inhibition of tumors. Additionally, natural killer cell activity significantly increased in the fucoidan-fed mice compared to animals fed a normal diet.11 Fucoidan also stimulates an increase in levels of interferon gamma, which generates increased immune activity during infections and cancer states.12-13 Furthermore, it can inhibit hyperplasia (abnormal cell overgrowth) in rabbits14 and induce apoptosis (spontaneous, programmed, cancer cell death) in human lymphoma cell lines.15 Conclusion Enhancing the activity of adult stem cells clearly is crucial to the proper functioning of the cardiovascular system. Unless these cells are functioning effectively, the body is unable to properly repair itself after injury. Fucoidan is a novel, marine-derived natural substance well researched for its immune enhancing abilities and now known to help mobilize stem cells, thereby enhancing cardiovascular and overall health.