When most people think about the consumption of sea creatures and other organisms, they think about food. But scientists are now discovering that our seas and oceans hold much deeper secrets.

Within the scope of EU-CONEXUS, there are two recent studies that explore how different compounds found in seaweed could be applied in medicine, and one that found cancer-fighting potential in compounds derived from fish.

The first study (see reference 1 below) suggests that seaweed can produce antiviral, anti-inflammatory, and antioxidant compounds which could be used to treat breast cancer and lymphoma. Focusing on a key enzyme called heparanase (HPSE), which helps to spread cancer cells (and helps tumours grow faster), researchers found that some seaweed sugars have the power to block HPSE without causing blood clotting, which is a common effect of similar compounds. This discovery is especially important because it shows the possibility of new, gentler cancer therapies that would target how cancer spreads instead of attacking the cells.

Another recent study (see reference 2 below) focuses on applying λ-carrageenan – a long-chain sugar found in some types of seaweed – to improve MRI imaging. Standard MRI scans are often blurry, making it difficult to distinguish between tumours and soft tissues. Contrast agents offer a solution, but they often leave the bloodstream too quickly. In its natural form, λ-carrageenan is too sticky and causes inflammation, so it’s rarely used by scientists in medicine. But when it was modified and tested on mice, it became much safer and less inflammatory, and allowed to make clearer MRI images of the heart and liver.

Coming back to alternative cancer treatments, another recent study explores cancer-fighting potential in fish protein hydrolysates (FPH). Because of their bitter taste and fishy smell, they are mostly used as animal feed today, but there’s more to FPH than meets the eye. This recent study tested 18 FPH samples on two breast cancer cell lines, and noticed that several samples from blue whiting, cod, plaice, and salmon significantly slowed down cancer cell growth in lab conditions. More research is necessary to further investigate this new application of FPH, but there is a prospect of adopting it in human medicine. Besides, protein hydrolysates can be extracted from fish parts that often go to waste – and since the fishing industry is so vast, they are easy to access. 

References:

  1. Groult H, Cousin R, Chot-Plassot C, Maura M, Bridiau N, Piot J-M, Maugard T, Fruitier-Arnaudin I. λ-Carrageenan Oligosaccharides of Distinct Anti-Heparanase and Anticoagulant Activities Inhibit MDA-MB-231 Breast Cancer Cell Migration. Marine Drugs. 2019; 17(3):140. https://doi.org/10.3390/md17030140
  2. L. Picot, S. Bordenave, S. Didelot, I. Fruitier-Arnaudin, F. Sannier, G. Thorkelsson, J.P. Bergé, F. Guérard, A. Chabeaud, J.M. Piot, Antiproliferative activity of fish protein hydrolysates on human breast cancer cell lines, Process Biochemistry, Volume 41, Issue 5, 2006, Pages 1217-1222, ISSN 1359-5113. https://doi.org/10.1016/j.procbio.2005.11.024