National Public Radio’s health blog Shots has an interesting story about new research regarding the antimicrobial properties of Russian brown frog (Rana temporaria) skin. It seems that before refrigeration, at least some Russians resorted to dipping a live frog in the family milk bucket to keep it from spoiling.
No one knew why it worked (or even if it really did), but the practice persisted until more appetizing alternatives were found.
It’s well-known now, of course, that some frogs secrete substances through their skin that possess antibacterial and antifungal properties, both of which are handy when you’re constantly damp. In a new paper, published in the Journal of Proteome Research, Moscow State University scientists have parsed the particular properties of Russian brown frogs, reporting that their skin secretions contain at least 76 different protein fragments called peptides.
The specific functions of all of these peptides aren’t known. Some may be antimicrobial, but others may be used as deterrents against predators. Dart frogs, for example, are notorious for their toxic secretions, which some indigenous South American tribes have historically used to poison the tips of blowdarts used in hunting.
The Russian research, though, represents a more benign interest. The Russian frog peptides might provide the basis for new drugs, such as antibiotics. William Fenical, William Gerwick and colleagues at the Center for Marine Biotechnology and Biomedicine, based at UC San Diego, have long pursued discovery and development of health compounds derived from marine organisms, such as sea snails, sponges and other organisms.
There’s a downside to this kind of research, however. It involves the unlicensed, uncontrolled, illegal harvesting of animals for ancient, but usually dubious, medicinal uses. Recently, for example, Russian authorities reportedly broke up a smuggling operation and confiscated roughly 50 pounds of Asiatic grass frog fat. The fat is popular in China where it’s used to make an expensive cosmetic cream and as a tonic for the kidneys.