Cancer-fighting seaweed

Animal studies undertaken at the University of Texas Health Science Center in Houston (UTHealth) have shown that the two seaweed extracts — known as fucoidans — have reduced tumour growth in select cancers and significantly improved the effectiveness of the common chemotherapy drug tamoxifen.

The extracts, developed and manufactured by Australian biotechnology company Marinova, were tested in six human tumour mouse models, including cervical, breast and ovarian cancers. Following oral administration over 30 days, the extracts were found to decrease the growth of a human ovarian cancer tumour line by up to 33% and a human cervical cancer tumour line by up to 70% compared to controls.

The same breast and ovarian cancer models were also used to assess fucoidan activity in combination with paclitaxel or tamoxifen, two commonly used chemotherapy agents. The results showed fucoidan considerably improved the efficacy of tamoxifen towards breast cancer. Fucoidan decreased breast cancer tumour growth in this animal model by up to an additional 26% when taken alongside tamoxifen.

The findings build on results from a series of in vitro studies performed under the same research program, which showed that the two fucoidan extracts did not interfere with key metabolic pathways necessary for chemotherapy function and directly inhibited a number of human cancer cell lines. Strong synergistic activity between fucoidan and both paclitaxel and tamoxifen was also observed, as well as additive activity with topotecan.

A further study in the research program found that both fucoidan extracts enhanced the immune function of cancer-affected mice. Immune markers immunoglobulin G (IgG, the main type of antibody in humans) and interleukin 6 (IL-6) were both significantly modulated in fucoidan-fed mice, with a 500% increase in IgG levels relative to controls after one week. This is important given that IgG levels are often suppressed in oncology patients, making them vulnerable to a wide range of infections.

“These results confirm the potential for fucoidan to help restore functional immunity in cancer patients,” said Dr Helen Fitton, chief scientist at Marinova. “To have identified a safe, natural compound that has such a significant effect on immunity in an oncology setting is really quite remarkable.”

Published in the journal Integrative Cancer Therapies, the studies demonstrate the potential for fucoidan to be used as a complementary cancer therapy alongside traditional chemotherapy. A pharmacokinetic study is now underway at UTHealth to further assess safety and observe quality of life parameters in human cancer patients.