This chimpanzee’s behaviour, one of many observed over an eight-month period, suggests that the animals may be using the forest as a natural pharmacy. The study, published Thursday in the journal PLOS One, The study, conducted by a team led by Elodie Freimann of the University of Oxford and Fabian Schulz of the Neubrandenburg University of Applied Sciences in Germany, found that when chimpanzees had health problems such as injuries or parasites, they ingested a variety of plants that had medicinal properties but little other nutritional value.
The findings provide strong support for “a novel self-medicating behavior in wild chimpanzees,” the researchers wrote, adding that studying animal behavior “may benefit humanity and lead to the discovery of new human medicines.”
Schultz said in an email that the next area of research will be “the most interesting plant extracts” ingested by chimpanzees. “There are a lot of what-ifs,” he said, but in theory, “chimpanzee knowledge could one day save human lives.”
He was particularly intrigued by the possibility that chimpanzees’ favorite plants could be used to treat antibiotic-resistant bacteria and chronic inflammatory diseases, but cautioned that there is a long way to go between this research and pharmaceutical breakthroughs.
The team followed two chimpanzee groups in Budongo Forest for four months each. They tracked what the apes ate and analysed the compounds in 13 plants that are completely unappetising to chimpanzees, such as bark and resins, to see if they had any health benefits for the animals. It had a healing effect.
“Pharmacological results suggest that Budongo chimpanzees consume several plants with potent medicinal properties,” the authors write.
The chimps most plagued by parasites ate the plants with the strongest antibacterial properties, something scientists confirmed by examining their feces. The injured chimps ate ferns, which have anti-inflammatory properties, something other groups rarely ate. When tested in the lab, all of the plant species inhibited the growth of E. coli, and some have been shown in previous studies to have anti-cancer and pain-relieving properties.
The authors noted that 11 of the 13 plants have been recorded for use in traditional medicine.
The researchers were surprised by the range of ailments chimpanzees turn to plants for, and the benefits they provide. “Perhaps it shouldn’t have been all that surprising,” Freiman said in an email. “Chimpanzees are incredibly intelligent, so it wouldn’t be surprising if by now they’d figured out which plants are helpful in the case of illness or injury.”
He said the study showed it was “highly unlikely” that chimpanzees were accidentally eating medicinal plants as part of their diet: “In many of these cases, sick or injured chimpanzees were seeking out resources when others in the group were not,” he said.
The study adds to a growing body of research suggesting that some animals may use plants and insects to medicate themselves, and our closest relatives, the great apes, have often played starring roles in this field known as animal pharmacology.
Last month, scientists Published According to a study published in the journal Scientific Reports, an orangutan in Indonesia applied the juice and chewed leaves of a medicinal plant to a wound on his face, which healed without incident. The signs are infection: Another study of chimpanzees in Gabon’s Loango National Park two years ago reported that the animals were observed repeatedly applying insects to wounds.
Isabelle Romer, a primatologist and cognitive biologist at the Max Planck Institute for Animal Behavior in Germany and lead author of the orangutan report but who was not involved in the PLOS One study, said in an interview that the new research has made “really important discoveries” and paves the way for further research.
“It’s always so interesting to see that our closest relatives exhibit behaviors that we humans exhibit,” she said. “I think this study once again shows the similarities that we share.”
The authors of the PLOS One study called for strong conservation efforts to continue this research and explore how discovering medicinal plants could benefit humans. “Conservation of wild forest medicinal plants and their primate relatives must be an urgent priority,” they said.
