According to scientists, wild chimpanzees eat plants that have analgesic and antibacterial properties to heal themselves.
They described their “sleuthing” in the forests of Uganda, observing animals that appeared injured or sick to find out if they were self-medicating with plants.
When an injured animal sought something specific from the forest to eat, the researchers collected samples of that plant and had them analyzed. Most plants tested were found to have antibacterial properties.
The scientists, who published their findings in the journal PLOS One, think that the chimpanzees could even help in the search for new medicines.
“We can’t test everything in these forests for their medicinal properties,” says lead researcher Dr Elodie Freymann from the University of Oxford. “So why not test the plants we have this information about – plants that chimpanzees are looking for?”
Over the past four years, Dr. Freymann has spent months monitoring and carefully observing two communities of wild chimpanzees in the Budongo Central Forest Reserve.
In addition to looking for signs of pain — an animal limping or holding its body in an unusual way — she and her colleagues collected samples of feces and urine to check for disease and infection.
They paid particular attention when an injured or sick chimpanzee sought out something they wouldn’t normally eat, such as tree bark or fruit skin.
“We were looking for these behavioral clues that the plants might have medicinal properties,” explains Dr. Freymann.
She described a particular chimpanzee – a male – who had a badly injured hand.
“He wasn’t using his hand to walk, he was limping,” she recalled. While the rest of the group was eating this animal, the injured chimpanzee limped away in search of ferns. “He was the only chimpanzee that sought out and ate these ferns.”
The researchers collected and analyzed the fern, a plant called Christella parasitica, which was found to have powerful anti-inflammatory properties.
In total, the researchers collected 17 samples from 13 different plant species and sent them to be tested by Dr. Fabien Schultz from the Neubrandenburg University of Applied Sciences in Germany.
It found that almost 90% of the extracts inhibited bacterial growth, and a third had natural anti-inflammatory properties, meaning they could reduce pain and promote healing.
All injured and sick chimpanzees reported in this study recovered fully, Dr. Freymann said. “The one who ate ferns used his hand again within a few days,” she explained.
“Of course we cannot prove 100% that these cases were a direct result of eating these resources,” she told BBC News.
“But it highlights the medicinal knowledge that can be gained from observing other species in the wild and underlines the urgent need to preserve these ‘forest pharmacies’ for future generations.”
