Airdate: Nov 13, 2006
Scientist: Valerie C. Clark
Poison Frogs - Bioprospectors
Natural toxins are the source of many pharmaceuticals. Researcher think that poisonous frogs may be a shortcut to finding these compounds.
ambience: Madagascar forest
Could poisonous frogs be a key to developing new medicines? I'm Jim Metzner, and this is the Pulse of the Planet. Valerie Clark is a chemistry graduate student at Cornell University studying the poison frogs of Madagascar. She thinks they may be able to help us develop new drugs by showing us where the most toxic and also the most potentially useful substances in the environment are to be found.
"The frogs themselves in Madagascar are really little bioprospectors because they're going out there and sampling the environment - a great variety of different insects that may or may not have different defensive compounds. In general, things that are toxic that are found in nature are often drug leads and can give rise to new pharmaceuticals. About 25% of all pharmaceuticals are from natural product leads."
Frogs sample toxic compounds by eating poisonous insects and other arthropods.
"The frogs effectively are going out there and sampling the environment for us. They had over 80 alkaloids in their skin all together at all my sites and we only found the sources for a handful of them. So, they're sort of like a little short cut to finding new, interesting natural products. What's really, I guess, critical to me is that by seeing what the frogs have in their skin, that's a direct reflection of what's available in the environment, so far as toxins and insects go. And by sampling and looking at frogs, you are getting an idea of the insect community at each of the places where you're collecting frogs from. So, that's giving you an idea of that kind of diversity as well. Which also gives you an indication of how rich the environment is. And this can give you insights into what kind of effect disturbance and fragmentation is having and how many alkaloids are found in the frog. So the frogs are a measure of the health of an ecosystem because you are able see hat kind of diversity is existing lower down on the food chain."
Please visit our website at pulseplanet.com. Pulse of the Planet is made possible by the National Science Foundation.