This Frog’s Slime Fights the Flu

We’re not going to tell you to start kissing frogs (please don’t), but you might want to shake their hands: Scientists have found that the slime from one species can kill certain strains of the flu virus. The researchers published their findings in the journal Immunity.

The skin of amphibians like frogs and salamanders secretes a gooey mucus that has previously been shown to have antibacterial properties. Scientists were curious to see if the slime could also fight off viruses. They collected goo samples from an Indian fungoid frog (Hydrophylax bahuvistara), then extracted 32 peptides that looked promising. Next, they pitted those 32 peptides against the H1 flu virus, just to see what would happen. Expectations were low.

The results were astonishing: four out of 32 peptides clobbered the virus. “I was almost knocked off my chair,” senior author Joshy Jacob of Emory University said in a statement.

"In the beginning, I thought that when you do drug discovery, you have to go through thousands of drug candidates, even a million, before you get one or two hits. And here we did 32 peptides, and we had four hits."

Jacob and his colleagues named the most successful peptide urumin, after the Indian whip-sword known as the urumi. They brewed up a urumin compound and gave it to unvaccinated mice, then exposed those mice to the flu. Not only did the mice not get H1—they also didn’t get any side effects. The urumin only killed the virus, not anything else.

The scientists’ next steps will include trying to create a stable version of urumin that can be tested in people, and to look through other frog slime.