Hobbies And Interests
Poison
Tips of arrows scraped along the backs of the Colombian poison dart frog retain a bit of the toxin secreted from the frog's skin. Batrachotoxin, which has allowed native hunters to efficiently kill small animals, has proved lethal to humans upon contact with human skin. Following failed attempts to extract the toxin from laboratory-raised frogs, scientists found that the frogs did not manufacture the chemical themselves. The toxin actually originates in the Coresine beetles -- one of the frog's favorite foods -- that scurry across the rainforest floor. Batrachotoxin acts on the nervous system and causes erratic heartbeats and, eventually, heart failure. No antidote exists, but treatment with another poison, the tetrodotoxin of puffer fish, can ameliorate batrachotoxin's effects.
Painkiller
Skin secretions from poison arrow frogs of the species Epipedobates tricolor provide a potential painkiller 200 times more effective than morphine that does not have addictive properties. John Daly, a researcher with the National Institutes of Health, isolated the toxin, epibatidine, but later found the substance to be too dangerous for use in humans. Frog conservation legislation and destruction of the frog's habitat curtailed further attempts to procure additional frog specimens for research. Dr. Daly froze his samples and, in the 1990s, biochemists were able to use those samples to make synthetic epibatidine for experimentation. Abbott Labs finally created a derivative of epibatidine, AB-594, for the treatment of pain.
Antimicrobial
Frog skins harbor more than 100 types of antibiotics that eradicate disease-causing bacteria, fungi and viruses. Until recently, researchers have not had much success in isolating the antibiotic components and applying them to humans because some substances proved either too toxic or were broken down by the human body. Michael Conlon, a researcher at the United Arab Emirates University in the Abu Dhabi Emirate, discovered that by altering the raw antibiotic chemicals, he and his colleagues could bypass the body's defenses and create safer, more effective antibiotics to replace ones to which bacteria have already proved resistant. A type of antibiotic effective against methicillin-resistant Staphylococcus aureus, a hard-to-treat infection found in hospital settings, has been isolated from an endangered Californian amphibian, the foothill yellow-legged frog.
Mosquito Repellent
Fear of the spread of malaria has prompted scientists to find a more effective mosquito repellent. The dumpy tree frog of Australia has led researchers from the University of Adelaide to test its skin secretions on laboratory mice. The researchers found that mosquitoes avoided mice injected with the frog skin secretions for 50 minutes while untreated mice were bitten within 12 minutes. The research also showed that DEET, a mosquito repellent currently on the market, protected mice for more than two hours. Skeptics cite that certain plants also offer mosquito-repelling properties, but in a more cost-effective way.
Cancer Treatment
Professor Chris Shaw of the Queen's School of Pharmacy at Queen's University in Belfast discovered that proteins in the skin of the waxy monkey frog stopped angiogenesis, or the creation of new blood vessels. Cancerous growths, or tumors, grow to a certain size before they need to stimulate growth of more blood vessels to bring oxygen and food to the rapidly multiplying, abnormal cells. Dr. Shaw and his colleagues theorized that if they could somehow use these newfound proteins to deprive the tumors of needed blood vessels, they could shrink the tumors, keep them from spreading and eventually destroy the tumor itself.
Diabetes Treatment
The paradoxical frog of South America may provide a possible treatment for people suffering from Type 2 diabetes, a disease that commonly affects obese, middle-aged individuals. Sufferers either cannot make enough insulin, a chemical that helps the body use sugar, or their bodies do not respond to the insulin they do make. Pseudin-2, a chemical with antibiotic properties found in the skin of the paradoxical frog, could stimulate the human body to produce more insulin, according to a joint investigative effort between researchers at the University of Ulster and the United Arab Emirates University. The next step would be to test the drug on human subjects.