Oxford scientists have identified 13 plant species that have powerful wound-healing and infection-fighting properties, with the help of wild chimpanzees.
The research team observed that the chimpanzees were feeding on bark, dead wood and plant leaves, which were not part of their normal diet, after becoming ill.
Scientists said that this chimpanzee behavior could accelerate the discovery of new drugs to treat chronic diseases and infections.
In the study, published in the journal Plos One, the team tracked 51 chimpanzees in the Budongo Central Forest Reserve in Uganda for several months.
The goal was to collect "behavioral evidence" and see if chimpanzees were intentionally self-medicating.
The team found a wounded male chimpanzee eating the leaves of a fern known as Christella parasetica, which has been shown to have anti-inflammatory properties when tested in the laboratory.
Scientists said the fern may have helped relieve pain and swelling.
They also observed another chimpanzee "infected with a parasitic infection" eating the bark of the Scutia myrtina tree, a behavior never seen before in this group.
Tests have shown that other plant extracts, such as dead wood from a tropical forest tree called Alstonia bonii and the bark and resin from the Khaya anthotheca tree in East Africa, have powerful wound-healing and infection-fighting properties.
The team said that the majority of plant samples (88%) analyzed in the laboratory had antibiotic properties, and 33% of them showed anti-inflammatory benefits.
Dr Elodie Freeman, from the School of Anthropology and Museum Ethnography at the University of Oxford, said: “Our study highlights the medical knowledge that can be gained from observing other species in the wild. After spending months in the field collecting behavioral evidence that led us to specific plant species, it was exciting to analyze "Pharmacological results and the discovery that many of these plants showed high levels of bioactivity."