Super seaweed could produce future medicines

Underwater seaweed garden in Bat-Yam, Israel. Image: Doron Ashkenazi

It is a little known fact that seaweeds naturally produce substances that are highly beneficial for human health - and this ability has now been enhanced by researchers in Israel.

The study focused on enhancing the production of the bio-active compounds in seaweed that offer medical benefits to humans. This includes antioxidants - substances that may prevent or delay some types of human cell damage.

PhD student Doron Ashkenazi of Tel Aviv University, who led the study, explains: “Seaweed, also known as macro-algae, are marine plants that form the basis of the coastal marine ecosystem. The seaweed absorb carbon dioxide and release oxygen into the environment.

"They purify the water, provide food, habitat and shelter for numerous species of fish and invertebrates. Not many are aware of it, however on top of all that, seaweed produce a wide variety of distinct bio-active compounds that are beneficial to humans."

"Seaweed are a highly efficient natural factory for the production of valuable substances that may offer significant benefits to humans.”

Doron Ashkenazi, Tel Aviv University and Israel Oceanographic & Limnological Research Institute

The study combined the cultivation of seaweed and fish, with researchers using fish effluent to support the growth of three local seaweed species - Ulva, Gracilaria and Hypne. The method benefits the seaweed while at the same time helping to purify the seawater and minimising negative environmental Impacts.

The seaweeds were subsequently exposed to various stressors, namely light exposure, nutrient starvation, and high salinity. The researchers investigated how these changes affected concentrations of bioactive compounds in the seaweed that offer significant health benefits, with the aim of enhancing their production.

Ashkenazi continues, "The seaweed living in the intertidal zone face extreme stress conditions, which include changes in salinity, temperature, desiccation conditions, changes in the availability of nutrients, and high exposure to solar radiation, especially in the ultraviolet (UV) range. Therefore, in order to survive, the seaweed have developed a unique set of chemical defence mechanisms – natural chemicals that help them cope with these harsh environments.

"One could say that seaweed are a highly efficient natural factory for the production of valuable substances that may offer significant benefits to humans.”

Enhanced seaweed cultivated during the research. Image: Doron Ashkenazi

These substances include antioxidants, protective pigments, and natural UV radiation filters. The results were impressive - antioxidant levels doubled, natural sunscreen molecules tripled, and protective pigments increased by ten-fold.

“We developed optimal cultivation conditions and invented a new and clean way to increase the levels of healthy natural bio-active compounds in seaweed to an unprecedented level,” says Ashkenazi. “In fact we produced super seaweed, tailor-designed to be utilised by the emerging health industries for food and health applications.”

According to the researchers, these findings could be used in the pharmaceutical, cosmetics, food, and nutritional supplement industries. In the future, they believe it will be possible to elevate the natural medical properties of seaweed to develop anti-cancer, anti-diabetic, anti-inflammatory, anti-viral, and antibiotic substances.

In addition, seaweed aquaculture is environmentally-friendly, preserving the ecological balance, and reducing environmental risks by minimising excessive amounts of anthropogenic nutrients and other pollutants in seawater, reducing emission of greenhouse gases and lowering carbon footprint. In this way, seaweed aquaculture can help cope with global environmental challenges such as pollution, habitat loss, and the climate crisis.

Ashkenazi concludes, “In the future, humanity will focus on creating science-based environmental solutions, such as the one we offer in the current study: technologies that promote recycling and the sound use of natural resources without overexploiting them. The study demonstrates, in a practical manner, how we can enjoy nature services without harming it."

An article about the study was published in the journal Marine Drugs.