Skin mucus secreted by a colourful, tennis ball-sized frog species found in Kerala can be used to develop an anti-viral drug that can treat various strains of flu, according to a new study.
Frog mucus is loaded with molecules that kill bacteria and viruses and researchers are beginning to investigate it as a potential source for new anti-microbial drugs.
Defence peptides
One of these “host defence peptides”, found in a frog species ( Hydrophylax bahuvistara ) native to Kerala can destroy many strains of human flu and protect mice against flu infection, researchers found.
An international team of researchers, including those from Rajiv Gandhi Centre for Biotechnology in Kerala, screened about 32 frog defence peptides against an influenza strain and found that four of them had flu-busting abilities. When researchers delivered small electric shocks, they collected the secretion that contained a peptide, or chain of amino acids, that appears to fight off the H1 strain of flu virus.
“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,” said Joshy Jacob of Emory University in the U.S.
When the researchers exposed isolated human red blood cells in a dish to the flu-buster peptides, three out of the four proved toxic.
However, the fourth seemed harmless to human cells but lethal to a wide range of flu viruses.
Named after ‘urumi’
The researchers named the newly identified peptide “urumin” after the urumi, a sword with a flexible blade that snaps and bends like a whip. Electron microscope images of the virus after exposure to urumin reveal a virus that has been completely dismantled, researchers said.
Urumin is not toxic to mammals, but “appears to only disrupt the integrity of flu virus”. When researchers squeezed some urumin into the noses of lab mice, the peptide protected them against what would have otherwise been a lethal dose of H1 flu virus, the kind responsible for the 2009 swine flu pandemic.
It seems to work by binding to a protein that is identical across many influenza strains, and in lab experiments, it was able to neutralise dozens of flu strains, from the 1934 archival viruses up to modern ones, researchers said.
More research is needed to determine if urumin could become a preventive treatment against the flu in humans, and to see if other frog-derived peptides could protect against viruses like dengue and Zika.
The study was published in the journal Immunity .
(With inputs from AFP)
