Frog-In-Bucket-Of-Milk Folklore Leads to Potential New Antibiotics – via Herp Digest

Dec. 12, 2012 — Following up on an ancient Russian way of keeping milk from going sour -- by putting a frog in the bucket of milk -- scientists have identified a wealth of new antibiotic substances in the skin of the Russian Brown frog. The study appears in ACS' Journal of Proteome Research.

A. T. Lebedev and colleagues explain that amphibians secrete antimicrobial substances called peptides through their skin. These compounds make up the majority of their skin secretions and act as a first line of defense against bacteria and other microorganisms that thrive in the wet places frogs, toads, salamanders and other amphibians live. A previous study identified on the skin of the Russian Brown frog 21 substances with antibiotic and other potential medical activity. Lebedev's team set out to find more of these potential medical treasures.

They used a sensitive laboratory technique to expand the list of such substances on the frogs' skin, identifying 76 additional substances of this kind. They describe lab tests in which some of the substances performed as well against Salmonella and Staphylococcus bacteria as some prescription antibiotic medicines. "These peptides could be potentially useful for the prevention of both pathogenic and antibiotic resistant bacterial strains while their action may also explain the traditional experience of rural populations," the scientists concluded.

Journal Reference:

T. Yu. Samgina, E. A Vorontsov, V. A. Gorshkov, E. Hakalehto, O. Hanninen, R. A. Zubarev, A. T. Lebedev. Composition and Antimicrobial Activity of the Skin Peptidome of Russian Brown FrogRana temporaria. Journal of Proteome Research, 2012; : 121113155850001 DOI:10.1021/pr300890m