Frog Slime Kills Flu Virus

Jacob and his colleagues named one of the antiviral peptides they identified urumin, after a whip-like sword called “urumi” used in southern India centuries ago. Urumin was found in skin secretions from the Indian frog Hydrophylax bahuvistara, which were collected after mild electrical stimulation.

Peptides are short chains of amino acids, the building blocks of proteins. Some anti-bacterial peptides work by punching holes in cell membranes, and are thus toxic to mammalian cells, but urumin was not.

Instead, urumin appears to only disrupt the integrity of flu virus, as seen through electron microscopy. It binds the stalk of hemagglutinin, a less variable region of the flu virus that is also the target of proposed universal vaccines. This specificity could be valuable because current anti-influenza drugs target other parts of the virus, Jacob says.

Because flu viruses from humans cannot infect frogs, producing urumin probably confers on frogs an advantage in fighting some other pathogen, he says.

Delivered intranasally, urumin protected unvaccinated mice against a lethal dose of some flu viruses. Urumin was specific for H1 strains of flu, such as the 2009 pandemic strain, and was not effective against other current strains such as H3N2.

Developing antimicrobial peptides into effective drugs has been a challenge in the past, partly because enzymes in the body can break them down. Jacob’s lab is now exploring ways to stabilize antiviral peptides such as urumin, as well as looking for frog-derived peptides that are active against other viruses like dengue and Zika.

 

 

Contacts and sources: 

Quinn Eastman

Emory Health Sciences