Paco Cardenas: Looking for the future of pharmacy among the planet's first animals

Paco Cardenas, researcher in Pharmacognosy at Uppsala University

Despite numerous technological advances, nature is still our main source of pharmaceutical drugs. Today, two out of three pharmacy products originate in substances from the plant and animal kingdoms. Unfortunately, science has yet only managed to map a few percent of all known organisms and the clock is ticking fast: exploitation and climate change threaten to eliminate countless species, and today many scientists are turning their focus to the last unknown outpost of our planet.

“The deep sea with its biological diversity is a gold mine for new chemistry. We do not have to travel further than the Swedish west coast to find fascinating organisms. Going on excursions in the Pacific Ocean, which is much older than the Atlantic, is like entering another planet. Studies show that marine environments can have greater biological diversity than rainforests, and we document everything of interest,” says Paco Cardenas, researcher in Pharmacognosy at Uppsala University.

Pharmacognostic research is often based on remarkable observations in nature that, through analysis and understanding, can lay the foundation for pharmaceutical progress. Already as a PhD student at the University of Bergen, located on the Norwegian coast, Paco Cardenas chose the sea as his workplace, conducting his first deep sea diving in a German submarine just outside Lofoten. At a depth of 400 meters, he discovered sponges that fourteen years later continue to generate important knowledge.

“Marine sponges are extremely complex creatures that provide lots of unexplored possibilities. Today we are aware of close to ten thousand species, and every year hundreds of new sponge metabolites are identified. In addition, we recently discovered 700 million-year-old remains of sponges, indicating that they were the first living animals on earth, so they can also provide us with insights in natural history.”

Pharmaceutical interest in marine organisms evolved in the 1940s. Half a century later, technology had advanced enough to explore the structurally complex metabolites of sponges, and with the breakthrough of genetics, the pharmacognostic horizon shifted even further. In Uppsala, Karin Steffen, a PhD student at the Faculty of Pharmacy, recently completed the mapping of the genome of Geodia barretti, a species found in the Swedish West coast that was described scientifically as early as 1855 and shows remarkable properties.

“Marine organisms need strategies other than mobile animals to survive. Many of them defend themselves by releasing potent toxins. If we look at sponges, they take up nutrients from the seawater via microscopic holes, so they must keep their surface free of vegetation. My colleague Lars Bohlin, discovered that Geodia barretti secretes a substance that we are now trying to reproduce as an environmentally friendly alternative to for example, keep boat hulls clean from barnacles,” says Paco Cardenas.

For the past two years, the coronavirus has paused all excursions outside Sweden. An involuntary break which, on the other hand, has provided time to take on at least some of the many samples waiting in the laboratory. And who knows, maybe the football-sized sponge that was once discovered in a river in Mozambique and since then is carefully frozen in Uppsala's Biomedical Center will provide healthcare with the next, much needed antibiotic?

“The fact that 70 percent of the earth's surface is sea and that the number of pharmacognosists is relatively small creates a difficult equation. While each collected sample contains material for a dissertation in chemistry, we see how coral reefs are dying from rising water temperatures, and it is reasonable to assume that sponge reefs are also affected in a corresponding way. Thus, we have to use our resources strategically. In spring I will travel to Sri Lanka to combine diving and teaching. If the pandemic does not stop me, I hope that it will be of help for one more country to take the next step in mapping its marine flora and fauna.”