Chimpanzee, Heal Thyself

Sick or wounded chimpanzees can't go to the doctor, per se, but they can and apparently do serve as their own. In a new study, researchers describe the medicinal properties of various plants eaten by poorly chimps in the wild, "providing some of the strongest evidence yet that our close relatives practice self-medication," per New Scientist. Over eight months in Uganda's Budongo Forest, researchers looked for signs of an ill or injured chimp, including from urine and stool samples, then took samples of the plants the chimp ate. Across 53 extracts from nine trees and four herbaceous plants, 88% inhibited bacterial growth and a third had anti-inflammatory properties, the BBC reports.

One male chimp with a badly wounded hand was seen limping away from his group to seek out a fern. It was only the second time ever that a chimp in the group was observed eating a fern, per Science. The plant, Christella parasitica, turned out to have potent anti-inflammatory properties. The chimp who ate it "was using his hand again within the next few days," recalls Dr. Elodie Freymann of Oxford University, lead author of the study published Thursday in PLOS One. Another chimp with diarrhea and tapeworms was observed chewing on dead wood from the Alstonia boonei tree, long used in traditional medicine, which tests showed had antibacterial and anti-inflammatory properties, per the Washington Post. That chimp also recovered.

Interestingly, "those struggling the most with parasites ... had eaten plant material with the strongest antibacterial properties," per the Post. Freymann said it was "highly unlikely" the chimps were eating tree bark, resin, and fruit skin coincidentally since they have little nutritional value. While there's no proof the chimps recovered as a direct result of eating the plants, they appear to be taking advantage of a "forest pharmacy," researchers say. Indeed, they say such observations could "benefit our own species, potentially leading to the discovery of novel human medicines." Most of the plant species sampled had recorded uses in traditional medicine, but two did not, per the Post. (Chimps in Gabon were previously found to apply insects to wounds.)