Findings are a great first step because they show that the Mauritius sea sponge produces compounds that can kill liver cancer cells.

 Natural ingredients, primarily plants, have been used to create medicines for thousands of years. But in recent years, researchers hunting for novel drugs have begun to focus on the enormous diversity of marine organisms.

Sponge species found in the sea have drawn a lot of interest. They are regarded as the best producers of molecules (sometimes referred to as "natural products"). These are created by them because they use toxic substances to ward off predators, communicate with their neighbours, or keep bacteria and algae from growing on them.

With over 9,000 species, marine sponges are a highly varied group of organisms. They come in a vast range of colours, sizes, and shapes, from tiny, unnoticeable forms to enormous, colourful reef-building species. Their name comes from the way they appear—a stationary lump of porous tissue on the seafloor.

They are among the planet's most primitive organisms, lacking sophisticated organs and tissues. They have evolved to survive by creating chemical compounds because they lack physical and mechanical traits to flee (fins, legs), attack (spines), and protect themselves (shells). Some of these substances have been discovered to have beneficial qualities against microbial infections and cancer.

Early in the 1950s, two new natural compounds derived from the Caribbean sponge species Tectitethya crypta sparked interest in these qualities. Later, the products were authorised for use as leukaemia and HIV medications.

Such findings have greatly increased interest in the therapeutic uses of compounds obtained from sponges.

Mauritius, where I'm from, has a tonne of promise in this area. There are many different species of sponge on Mauritius, providing the chance to find bioactive substances.

At the University of Mauritius, I earned a PhD in applied marine biochemistry. I conducted research on the anticancer potential of the sponge Neopetrosia exigua from the waters of Mauritius under the supervision of Ranjeet Bhagooli, Theeshan Bahorun, Vidushi Neergheen, and the late Alexander Kagansky as part of my studies.

We recently released a publication in which we demonstrate, for the first time, the ability of compounds produced by N. exigua to selectively kill liver cancer cells while causing little harm to healthy cells. We indicate that the Mauritian sponge N. exigua has the potential to be developed into a less hazardous treatment candidate against liver cancer based on our findings about its pharmacological properties.

Our research represents the initial step in the biodiscovery process. From the time when active chemicals are discovered until they are used as medicines in humans, there are a number of procedures that can take 15 to 20 years.

Studying how a sponge kills cancer cells

The initial stage in our investigation was to snorkel and scuba dive to collect a sample of N. exigua sponge from the Mauritian coral reefs. What could be more ideal for a dedicated ocean lover than to work in one of the world's most pristine marine ecosystems?

Once we obtained our sample, we carefully treated the sponge in the lab to produce various extracts that each contained unique natural compounds. The University of Edinburgh examined the toxicity of these extracts against a variety of human cancer cell lines. Cell lines are collections of living organism-derived cells that can continue dividing and expanding in the laboratory. They help researchers understand how cells behave, test novel treatments, and understand how diseases manifest.

To determine how hazardous the sponge extracts were to healthy cells, we also examined their effects on non-cancerous cells. This is especially intriguing because some anticancer medications indiscriminately cause DNA damage, killing both healthy and cancerous cells. Patients receiving those treatments for cancer may experience unfavourable side effects such as infections, anaemia, exhaustion, and nausea.

We discovered that one particular extract had a very low toxicity towards normal cells and the capacity to selectively kill liver cancer cells at extremely low concentrations.

We also saw the mechanism by which the extract accomplished this: N. exigua components triggered a number of proteins that resulted in the destruction of the liver cancer cells via a process known as apoptosis. By removing undesirable or potentially hazardous cells, this process aids in maintaining the general balance and health of an organism. These dangerous cells may continue to grow and divide if apoptosis isn't working properly, with the potential to develop into a cancer.

Biodiscovery process

The next stage will be to isolate and identify the natural components responsible for the extract's anticancer activity using cutting-edge analytical techniques like chromatography and mass spectrometry in order to validate its prospective usage.

This will pave the way for later assessments to examine its efficacy and toxicity in appropriate experimental animal models. If this stage is successful, the testing move on to clinical trials with humans.

Scientific data about the pharmacological properties of Mauritian marine organisms could create opportunities to promote marine biodiscovery research and sustainable use of the ocean resources in Mauritius. It will also add another reason to conserve the country’s marine biodiversity.

The marine sponge Neopetrosia exigua is highly distributed in the Indian Ocean, Atlantic Ocean (Caribbean Sea) and Pacific Ocean. However, its population density has significantly declined over the last few years in Mauritius due to a continued rise in ocean temperatures.