Fucoidan is most widely known and used for its potential anti-cancer properties. A considerable amount of research has been undertaken in this area, with some researchers proposing that fucoidan not only increases patient wellbeing, but also assists in the treatment of disease. The potential for fucoidan as an anti-cancer agent is explored in several review publications, including those by Fitton (2015), Kwak (2014) and Lowenthal (2014).
Cancer cell inhibition
Research confirms that fucoidan has direct in vitro effects on cancer cells. Studies have shown that cancer cells apoptose in the presence of fucoidan and may also enter a cell cycle arrest, making them unable to multiply. Immune cells also clear cancer cells and fucoidan enhances this effect (Jin, 2014). Whilst apoptosis pathways are not always identified, there is evidence to support the induction of both intrinsic and extrinsic apoptosis pathways. Studies have demonstrated the induction of these apoptosis pathways is via the activation of ERK1/2 MAPK, the down-regulation of Wnt/beta-catenin signalling (Boo, 2013), the induction of caspase 8 in breast cancer cells (Yamasaki, 2012) and the induction of endoplasmic reticulum stress cascades (Chen, 2014). Fucoidan has also been shown to enhance the activity of chemotherapeutic agents against breast cancer cells (Zhang, 2013).
Reduction of tumour growth
A variety of animal models have demonstrated reductions in tumour growth when fucoidan is administered orally, intravenously or intraperitoneally. The models include blood, ovarian, breast, prostate, liver and head and neck cancers, as explored by Kwak (2014) and Fitton (2015). These studies have shown marked differences in the rate of growth of tumours when fucoidan is administered either intraperitoneally or orally. In one colon cancer model (Azuma, 2012), tumour weights were up to 6 times lower in fucoidan groups than the control group, and life span increased by up to 100%. Aside from direct inhibition and immune clearance of cancer cells, studies have also indicated that fucoidan inhibits angiogenesis (Yang, 2016) and metastasis (Gassmann, 2010).
Amelioration of side effects & improved quality of life
There is increasing interest in the potential for fucoidan to improve quality of life and ameliorate the side effects of conventional cancer treatments. Research in this area has included clinical studies involving the co-administration of fucoidan with common chemotherapies. A recent interaction study has shown that orally delivered fucoidan does not alter serum levels of the commonly used drugs tamoxifen and letrozole in breast cancer patients (Tocaciu, 2016, in press). In some patients, reduced side effects were also noted. In another study, colon cancer patients undergoing chemotherapy experienced reduced fatigue when taking fucoidan and were able to tolerate more rounds of therapy (Ikeguchi, 2011). Ingesting fucoidan has also been shown to reduce cachexia, the debilitating muscle wasting and fat loss that can often occur during cancer (Chen, 2016).