Kiss A Frog, Fight the Flu

There is always speculation about particular compounds that exist naturally in the wild that may have benefits for human health. Indeed, history is full of stories like this from quinine to aspirin. New research from Emory shows that frog mucus contains a potentially flu-fighting antimicrobial peptide. 

For the study peptides contained in the mucus from Hydrophylax bahuvistara frogs were screening for both anti-influenza activity and non-toxicity to human cells. Of these screens, one peptide, named urumin, emerged as the leading candidate. Urumin was noted to interact directly with the influenza virus at an important site: the conserved stalk area of the H1 hemagglutinin. Because it is a "conserved" region (i.e. one not highly mutable) the frog peptide retained activity against drug-resistant variants. This region is one of the targets of the long sought after universal flu vaccine. In the study, urumin worked not only in vitro but also in a mouse model.  The peptide was specific for just H1 variant influenza A viruses.

I found the paper to be very interesting and the discoveries may have wide-ranging implications not only for novel antivirals but for understanding influenza. As the authors note, innate defense mechanisms are less likely to be prone to resistance because they presumably were selected  via natural selection for their durability against their target. It is unclear what role amphibians have with influenza A epidemiology but it appears they can be infected and perhaps urumin is one of its natural defenses against the virus. Future studies with ferrets will be important to perform as they are important surrogates for humans.