Humans aren’t the only animals that can find and apply medicinal substances. In fact, recent research shows that orangutans use medicinal plants to self-medicate.
Scientists report they have observed Bornean orangutans chewing on the leaves of the Dracaena cantleyi plant, producing a soapy lather they then spread onto their skin. The researchers say their study provides the first scientific evidence of deliberate, external self-medication in great apes.
The medicinal plant (Dracaena cantleyi) used by orangutans for health benefits, is a nondescript species with big leaves found in Southeast Asia. Its leaves contain saponin, a chemical compound that generally makes them bitter and unattractive as a food source.
Saponin foams when agitated and, despite its bitterness, scientists report that unequivocally Bornean orangutans chew D. cantleyi leaves until that soapy lather forms. They then rub the lather on their skin as if applying a lotion.
The orangutans spit out any leaves they didn’t apply to their skin, which made scientists believe they weren’t simply eating them. But they didn’t know for sure if D. cantleyihad any medicinal properties that would help explain the behavior.
To answer this question, a team of researchers from various institutions around the world set to work to figure out if the plant contained anything that might explain why orangutans are braving its bitter taste to make it into a salve.
Their pharmacological analysis indicated D. cantleyihas anti-inflammatory properties. Most orangutans observed using it were females who spread it onto their arms, and the researchers suggest they may have been using it to treat arms that became sore from carrying offspring.
Curiously, residents of human communities in Borneo reportedly also use D. cantleyi to treat joint and muscle pain.
Examples of self-medicating animals aren’t exactly uncommon. Some birds engage in “anting” by rubbing ants over their bodies; scientists think the formic acid produced by ants may be used by birds as a fungicide or bactericide.
Capuchin monkeys have been observed rubbing their fur with plants that have anti-insect properties. And researchers believe chimpanzees often swallow whole the leaves of bitter plants they normally wouldn’t eat in order to rid their bodies of nematodes.
But never before has this behavior been confirmed in Asia’s great apes.
(Source: news.mongabay.com)
