Fucoidan is a sulfated polysaccharide rich in fucose found in brown algae such as mozuku and kelp. Also, Fucoidan is a naturally occurring component with different physiological activities. Its benefits have been widely studied and especially recognized for its anti-cancer effects, such as colorectal cancer, pancreatic cancer, and breast cancer.
As Cancer research has been continuing, immunotherapy has also made great strides in the last decade. Fucoidan alone has an anti-cancer effect, but some studies have reported that it is more effective when combined with immunotherapy. However, the complete research is still unknown. Hence, in this blog, I would like to share the summary of a study “Fucoidan Independently Enhances Activity in Human Immune Cells and Has a Cytostatic Effect on Prostate Cancer Cells in the Presence of Nivolumab” by Ah Young Park et al. The study investigated the combined effect of fucoidan and human PBMC (peripheral blood mononuclear cells) activating action and T cell activator (αCD3) and anti-cancer drug nivolumab (molecular target drug) on hormone-resistant prostate cancer cell line PC-3.
First, they used PBMD (a lymphocyte population containing T cells, B cells, NK cells, dendritic cells, etc., isolated from blood) to investigate whether Fucoidan activates immunity. The index of PBMC activation was the amount of IFN-γ secreted, which has antitumor effects. This research prepared three types of Fucoidan extracted from mekabu, rockweed (Fucus), and Macrocystis pyrifera.
Furthermore, they focused on the effect of mekabu Fucoidan. Based on a preliminary test in which PBMC is activated by treatment with αCD3, an antibody that stimulates T cell receptors. The test was conducted in the presence of αCD3. As a result of testing in two groups, one in which Fucoidan was added to PMBC to which αCD3 was added at each concentration. The other in which Fucoidan was added with nivolumab, an immune checkpoint PD-1 inhibitor used for cancer target treatment, also known as OPDIVO.
When the concentration was one µg / mL, the amount of IFN-γ secretion was maximized. The result was that IFN-γ secretion was further increased when nivolumab was used in combination. (See Fig. 1)
Next, to investigate the combined effect of Fucoidan and anti-cancer drugs on cancer cells, PBMC, αCD3, nivolumab, and each concentrated Fucoidan were added to PC-3 cells. And the cell viability was monitored with a device that could count the cell numbers in real-time to see the cell number. As a result, a decrease in cell viability was observed after 120 hours at a fucoidan concentration of 5 µg/mL or higher. (See Fig. 2)
It was found that cell death was due to apoptosis. This study revealed that Fucoidan activates PBMCs by itself. Then it was noticed that Fucoidan works effectively at moderately low concentrations. When combined with an anti-cancer drug, the concentration-dependent effect of Fucoidan was further enhanced, and the impact of killing cancer cells was observed. From the results of this study, it was found that Fucoidan is effective by itself. Still, it is more effective when combined with an anti-cancer drug. It is expected to be used in combination therapy with cancer treatment.
