New research has identified a peptide named urumin found in the mucus on the skin of a specific frog species. This peptide is showing promise as a potential drug treatment for certain strains of flu.
Long ago, it was found that dropping live Russian Brown frogs into milk would prevent the milk from going sour. This long-standing fact led researchers in 2012 to wonder what the exact mechanism was for preserving the milk.
They discovered that when frogs are stressed, they secrete peptides via their skin and in the mucus that coats them. According to Louise Rollins-Smith, associate professor of pathology, microbiology, and immunology at Vanderbilt University School of Medicine, "Amphibians, especially certain groups of frogs, produce and store large amounts of antimicrobial peptides in specialized granular glands in the skin." She also said "When the skin is injured or the frog is alarmed, they release large amounts of the peptides to protect the skin."
These peptides have antimicrobial properties. They can kill various bacteria, viruses and even fungi. These findings have led to more recent research into the specific peptides secreted by a small orange frog named hydrophylax bahuvistara found in southern India.
They identified 32 distinct peptides secreted by this little orange frog. To their surprise, they found that four of them can successfully kill certain strains of flu virus. This has been demonstrated under a microscope and in lab mice. The next trials will likely involve ferrets. If that goes well, human testing could come soon after.
This study found that urumin specifically targets H1 flu viruses. The three other peptides were found to be harmful to human red blood cells. Thus, those three peptides are not currently deemed to be good candidates for developing a flu drug. But, so far, urumin has not been found to be harmful to human cells. Thus, the next stage of studies is being tentatively planned.
The effect of urumin on specific H1 flu viruses is fairly dramatic. It makes the individual flu particles simply fall apart. Unlike currently available drugs, the urumin peptide specifically targets the hemagglutinin. One researcher said "It just blows it up. It makes the virus particle fall apart."
One of the challenges still standing between our current understanding and a potential drug treatment is a good delivery method. In lab mice, the urumin peptide was delivered through their noses. They also exposed the mice to the flu viruses via the same pathway. But this may be ineffective as a treatment protocol. Researchers believe they may need to develop something injectable in order to deliver it to the human blood stream.
At the moment, the next step is simply to try to replicate their success with mice in a study using ferrets, which are often used for flu virus research. If the ferret studies are a success, human studies are likely to follow.
Every year, flu epidemics kill between 250,000 and 500,000 people. Developing an effective treatment, even if it only works for a specific subset of flu viruses, could save millions of lives.
There is an exciting new breakthrough holding out hope for future flu treatments. Research involving a small orange frog has led to the identification of a new peptide called urumin that dramatically causes some flu strains to simply fall apart when exposed to it.