Can snail poison replace morphine and opiates?

Scientist Bea Ramiro started to examine the sea snail species Conus rolani kind of by chance. 

She was with two fishermen off the coast of the Philippine island of Cebu collecting material in 2018. At the time, researchers were aware that poison from the sea snail species Conus magus worked as a painkiller which could replace morphine and opioids, and as a plus, some patients suffered fewer side effects. 

So Bea Ramiro was looking for a new, different sea snail species whose poison had a similar or even better effect.

To study sea snails, Ramiro had to bring in a lot of specimens from the same species. Once the fishermen took in their net and the snails were divided into groups according to species, Ramiro only had enough of the species Conus rolani to conduct a study on.

Fast forward to 2022, and Ramiro is pleased that this large, white and brown snail that is six to seven centimetres long, was the species she had collected the most samples of.

A new study from the University of Copenhagen, which she is a co-author, suggests that poison from Conus rolani can work as a painkiller. The researchers have discovered that a particular substance from the poison can alleviate pain in mice for a longer period of time than morphine.

“We have discovered a so-called toxin that blocks out pain in a completely different way than well-known drugs like morphine, and hopefully this will enable us to avoid some of the most damaging effects of morphine on humans,” explains Associate Professor Helena Safavi, who headed the study.

Today, medicine based on the Conus magus is available for human consumption, for example those suffering from back injuries or cancer. Yet the medication is pricey and hard to administer because it has to be injected into the central nervous system through a spinal implant.

That’s why the researchers behind the new study are working with the new poison, this time from Conus rolani, hoping it will help them develop a more efficient painkiller.

“We need a better alternative for people who are in great pain – an alternative that is less addictive than e.g. morphine and opioids. In Denmark, opioids do not represent a huge problem, but in other parts of the world it is quite extensive,” says Helena Safavi from the Department of Biomedical Sciences at the University of Copenhagen.

What is Conus rolani?

Conus rolani lives at a depth of 210 metres off the coast of Cebu in the Philippines. It is not extraordinary as it is merely one of the more than 800 sea snail species, most of which use poison when they scrounge for food. 

Yet according to Helena Safavi, it is one of the cleverer hunters. It injects its victim with poison, then waits patiently for the poison to take effect. Up to three hours later, when the victim no longer can save itself, Conus rolani attacks and catches it with its toothless mouth.

Other sea snails don’t do this; they attack their prey immediately, taking advantage of their poison that works much faster.

“But we believe it does this to protect itself. It waits until the fish is so weak that it cannot struggle, whereas other sea snails with more fast-working poison risk getting hurt by clinging to their victim,” says Helena Safavi.

A similar hunting strategy is found among rattlesnakes and adders, but this is the first time researchers have seen a sea snail use it.

Studying a sea snail for years

Safavi says she has studied Conus rolani for more than three years. “Far too long,” she laughs, explaining it was not always easy.

The researchers collected the sea snails in the Philippines and looked at their extraordinary hunting strategy in an aquarium. They then collected their poison and separated its various components to find out which had noteworthy effects on mice.

They characterised and produced synthetic ‘twins’ for the more than 100 toxins found in Conus rolani’s poison. Following this step, they X-rayed the one toxin that had promise.

“We could see that the structure of the toxin from the sea snail’s poison resembled a somatostatin, which is a hormone found in the human body regulating the sensation of pain. This suggested that the toxin might have a similar regulating effect,” says Safavi. 

Testing this toxin on mice showed the researchers that it was just as effective a painkiller as morphine, and lasting even longer to boot.

“I was surprised that the toxin was so effective and that it lasted longer than morphine. This reveals its great future potential,” says Safavi.

Other inspirations from nature

It isn’t only sea snails that inspire researchers to develop new drugs, says Safavi.

“There is a pretty common drug called Capoten in the market used as a treatment for high blood pressure, and it is based on snake poison,” she explains. 

“We can learn a lot from nature. And it makes good sense, because nature has had millions of years to refine e.g. sedative poisons, whereas we have only been at it for a couple of hundred years. So nature offers us a shortcut.”

Nature’s leading solutions also apply to technology, according to Safavi. 

As a press release on the study notes: “For example, researchers are studying the fingers of the gecko, which enable the small lizard to climb up walls and ceilings. The researchers thereby hope to be able to develop a strong material that easily attaches to things and can be removed again. In addition, polar bears serve as inspiration for researchers eager to develop better insulation for our buildings.”

“There is so much potential in nature, and if we are able to decode it, we can make the world a better place,” says Safavi.

THUMBNAIL IMAGE: The molluscs collection (IM) of the Museum National d’Histoire Naturelle (MNHN - Paris). (Wikimedia Commons/Marie Hennion)

HEADLINE IMAGE: Conus rolani collected off Panglao, Philippines The image was taken in May 2011. (Wikipedia/Nick Zantop)