• Posted May 3, 2024

An Orangutan Healed Himself With Medicinal Plant

Primates are capable of tending to wounds using medicinal plants, a new case report says.

A male Sumatran orangutan treated a facial wound with a climbing plant known to have anti-inflammatory and pain-relieving properties, researchers say in the journal Scientific Reports.

The orangutan, named Rakus by observers, plucked leaves from a vine called Akar Kuning (Fibraurea tinctoria) and chewed on them, researchers said.

Rakus then repeatedly applied the resulting juice onto his facial wound for several minutes, before fully covering the wound with a poultice formed by the chewed leaves, researchers said.

This is the first documented case of a primate applying a known naturally occurring medicinal substance to a wound, researchers said.

It indicates that the medical wound treatment people receive at home and in urgent care clinics might have arisen in a common ancestor shared by humans and orangutans, the research team says.

"The treatment of human wounds was most likely first mentioned in a medical manuscript that dates back to 2200 BC, which included cleaning, plastering, and bandaging of wounds with certain wound care substances,"researcher Caroline Schuppli, an evolutionary biologist with the Max Planck Institute of Animal Behavior in Germany, said in a news release.

Rakus' behavior shows "it is possible that there exists a common underlying mechanism for the recognition and application of substances with medical or functional properties to wounds"between primates and humans, Schuppli said.

Rakus belongs to a group of about 150 critically endangered Sumatran orangutans living in a protected rainforest area at the Suaq Balimbing research site in Indonesia, researchers said.

"During daily observations of the orangutans, we noticed that a male named Rakus had sustained a facial wound, most likely during a fight with a neighboring male,"lead researcher Isabelle Laumer, a cognitive biologist at the Max Planck Institute, said in a news release.

Rakus started treating his wound with the vine three days after he sustained his injury, researchers said.

The vine with which Rakus treated his wound is used in traditional medicine to treat various diseases, such as malaria, Laumer said.

Analysis of the plant showed the presence of chemical compounds known to have antibacterial, anti-inflammatory, antifungal and antioxidant effects that would aid wound healing, she added.

Five days after Rakus applied the chewed leaves, the wound had already closed. It never showed any signs of becoming infected.

"Interestingly, Rakus also rested more than usual when being wounded,"Laumer said. "Sleep positively affects wound healing as growth hormone release, protein synthesis and cell division are increased during sleep."

Researchers believe Rakus' behavior was intended to heal his wound, because he only treated the wound area and no other body parts with the plant juice.

"The behavior was also repeated several times, not only with the plant juice but also later with more solid plant material until the wound was fully covered,"Laumer said. "The entire process took a considerable amount of time."

It's possible that the orangutans at this specific Indonesian rainforest figured out on their own the healing properties of the vine, Schuppli said.

"Orangutans at the site rarely eat the plant,"Schuppli said. "However, individuals may accidentally touch their wounds while feeding on this plant and thus unintentionally apply the plant's juice to their wounds. As Fibraurea tinctoria has potent analgesic effects, individuals may feel an immediate pain release, causing them to repeat the behavior several times."

It's also possible that Rakus learned this treatment elsewhere and then brought it with him to the protected rainforest. Like all males in the area, Rakus was not born in Suaq, Schuppli said.

"Orangutan males disperse from their natal area during or after puberty over long distances to either establish a new home range in another area or are moving between other's home ranges,"she said.

More information

Cleveland Clinic has more on wound care.

SOURCE: Max Plank Institute of Animal Behavior, news release, May 2, 2024