Ever wonder where new drugs come from? It might surprise you that many come from the sea, including a potential new drug for treating COVID-19! 

Aplidium albicans is a species of sea squirt found in the Mediterranean Sea off the coast of Spain. Sea squirts are small sack-like marine invertebrates that live on rocks, large seashells, and other underwater surfaces. Like all sea squirts, A. albicans pulls water in through a large pore, absorbs its nutrients and oxygen, and then squirts it out it through another pore. But A. albicans differs from other sea squirts in a very special way: It produces plitidepsin, a compound that someday may be used to treat COVID-19. 

Aplidium albicans, found in the Balearic Islands. [Photo credit: PharmaMar]

Dr. Nevan Krogan (University of California San Diego), Dr. Kris M. White (Icahn School of Medicine at Mount Sinai), and Dr. Adolfo García-Sastre (Icahn School of Medicine at Mount Sinai) lead a team that aims to fight COVID-19 by repurposing existing drugs—including plitidepsin, a drug already approved as a cancer treatment by Australia’s Therapeutic Goods Administration. The team’s research found that plitidepsin is more than 27 times as effective at fighting SARS-CoV-2, the virus that causes COVID-19, as the well-known drug remdesivir! 

So how does it work? Like all viruses, SARS-CoV-2 can’t reproduce on its own. Instead, it relies on its human host’s cellular machinery to create more viral particles. In a clever trick, plitidepsin inhibits a protein in human cells that the COVID-19 virus needs to reproduce, stopping the infection in its tracks. Because many viruses use this same human protein to reproduce, plitidepsin may be effective against many viral strains. In fact, promising early research suggests that plitidepsin is just as effective at treating the new more virulent strain of SARS-CoV-2 discovered in the UK as it is at treating the original strain. And because plitidepsin targets the slowly evolving human host rather than the fast-breeding virus, it may be harder for viruses to develop resistance to this new drug.  

The discovery of drugs like plitidepsin is just one reason that marine research and conservation are so important! When we take care of our oceans, we’re not only protecting millions of amazing species, but we’re saving potential solutions to human problems. 

Interested in ensuring our collection is available to researchers for the advancement of medicine? Support OGL here.