The slime that coats the skin of a species of colorful frogs found in southern India may help kill strains of the flu virus.

In a new study involving mice, researchers found that certain peptides present in the skin mucus of the Hydrophylax bahuvistara frogs can kill the H1 variety of influenza viruses.

What Are Peptides?

Peptides are short chains of amino acids that are known as the building blocks of protein. The skin of frogs secretes peptides that can kill viruses and bacteria.

Findings of a new research published in the journal Immunity on April 18 suggest that these peptides could be a potential source of new antiviral and antimicrobial treatments.

Such treatments can help when vaccines are not available to deal with new strains of pandemic flu or once currently known flu strains develop resistance to available drugs. Flu comes in several varieties and may evolve into new forms, which is why researchers need to develop new vaccines for a specific type of the virus every flu season.

Frogs As Source Of Defense Peptides

All animals produce at least a few antimicrobial host defense peptides since these are involved in the workings of their immune systems. Frogs, however, are of interest to researchers as a source of these peptides because it is relatively easy to isolate peptides that are found in their mucus.

All the researchers need to do is give the amphibians an electric shock. They can also rub a powder on the animals so they would secrete their defense peptides.


Jacob and his colleagues looked at 32 frog defense peptides for use against a flu strain and found that four of these had flu-busting abilities.

Unfortunately, when they exposed isolated human red blood cells to these peptides, they found that three of the four peptides were toxic.

Urumin, one of the peptides present in the frog's mucus, appeared harmless to human cells but was found lethal to a range of flu viruses.

How Urumin Works Against Flu Viruses

Urumin works by targeting the viral surface protein hemagluttinin, the H in H1N1.

"The virus needs this hemagglutinin to get inside our cells," said study researcher Joshy Jacob of Emory University. "What this peptide does is it binds to the hemagglutinin and destabilizes the virus. And then it kills the virus."

In experiments involving mice, urumin, was found to provide protection to unvaccinated mice. The peptide binds to a protein that is identical across many strains of influenza. Researchers found that the peptide can neutralize dozens of flu strains ranging from the 1934 archival viruses to those that sprung in modern times.

Urumin As Potential Antiviral Treatment For Flu

Urumin appears to have limitation. The peptide protected mice against a lethal dose of H1 flu strain but it was not found effective against the H3N2. Researchers though remain optimistic of its potentials as a treatment for flu.

"Urumin represents a unique class of anti-influenza virucide that specifically targets the hemagglutinin stalk region, similar to targeting of antibodies induced by universal influenza vaccines," Jacob and colleagues wrote in their study.

"Urumin therefore has the potential to contribute to first-line anti-viral treatments during influenza outbreaks."

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