Tumor growth rates for certain cancers were reduced in different animal models.

Researchers at the McGovern Medical School within the University of Texas Health Science Center (UTHealth) reported promising results for two compounds isolated from seaweed extracts.

The two compounds are both fucoidans developed and manufactured by Australian biotechnology company Marinova. Fucoidans exist in the cell walls of brown seaweeds and protect.

Fucoidans are long-chain polysaccharides with complex molecular structures and varying degrees of sulfation and acetylation. They occur naturally in the cell walls of brown seaweeds and protect the plant from waterborne pathogens and environmental pollutants.

In the current study, fucoidan extracts were evaluated in six different mouse models, including cervical, breast and ovarian cancers alone and in conjunction with the widely used chemotherapy drugs tamoxifen and paclitaxel. The extracts were administered to the mice orally for 30 days.

In the ovarian and cervical cancer models, the fucoidan extracts were shown to reduce the growth of tumors by up to 33% and 70%, respectively. When given with tamoxifen, the extracts decreased breast cancer tumor growth an additional 26% over that achieved with tamoxifen, alone.

In vitro studies also showed that the two fucoidan extracts directly inhibited a number of human cancer cell lines. It was also demonstrated that the extracts not only do not interfere with key metabolic pathways necessary for chemotherapy function, but exhibit strong synergistic activity with paclitaxel, tamoxifen and topotecan.

The head of the research project, Associate Professor Dr Judith A. Smith, Director of the Women’s Health Integrative Medicine Research Program at UTHealth, said: “This was the first research program to comprehensively assess the metabolism of fucoidan compounds for possible chemotherapy drug interactions. A pharmacokinetic study is now underway at UTHealth to further assess safety and observe quality of life parameters in human cancer patients. 

As a separate part of the program, the researchers also investigated the impact of the fucoidan extracts on immune function in the cancer models. Two immune markers - immunoglobulin G (IgG) and interleukin 6 (IL-6) - were both significantly modulated. IgG controls infections by binding to pathogens and alerting immune cells and is the main type of antibody found in humans. In the fucoidan-treated mice, IgG levels increase 500% after one week.

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