Orangutan's Medicinal Plant Use Offers Clues to Human Wound Care Origins

In a groundbreaking observation, scientists have witnessed a wild Sumatran orangutan named Rakus treating a facial wound with a medically active plant, leading to the injury's full recovery within days. The incident, which took place in Indonesia's Gunung Leuser National Park in June 2022, marks the first systematically documented case of a wild animal applying a plant species known to contain biologically active substances directly to a wound.

Rakus, a male orangutan living at the Suaq Balimbing research site, sustained a facial wound believed to be the result of a fight with another male. Researchers observed Rakus selectively ripping leaves off an akar kuning vine, chewing them, and applying the juice to his wound. He then applied the pulp of the chewed leaves to the injury. "Rakus selectively treated his facial wound on his right flange and no other body parts with the plant juice," said Dr. Isabelle Laumer, lead researcher from the Max Planck Institute of Animal Behavior in Germany. "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."

Why this matters: This discovery sheds light on the origins of human wound care and highlights the importance of preserving the habitats of endangered species like the Sumatran orangutan, which may hold valuable knowledge that could benefit human health and medicine. The study's findings also have significant implications for our understanding of the cognitive abilities of animals and the evolution of medicine.

Akar kuning (Fibraurea tinctoria) is a liana species known for its painkilling and fever-reducing effects in traditional medicine in the region. Chemical analysis of the plant reveals the presence of alkaloids with antibacterial, anti-inflammatory, and anti-fungal activities, making it relevant to wound healing. The researchers continued to observe Rakus over the following days and found no signs of infection. Within five days, the wound had closed and healed completely, and two months later, the wound was barely visible.

This remarkable recovery suggests that Rakus may have intentionally used the plant to treat his wound, raising the possibility that medical behaviors in apes, including humans, may have their origins in a common ancestor that lived millions of years ago. "The treatment of human wounds was most likely first mentioned in a medical manuscript that dates back to 2200 BC, which included the cleaning, plastering, and bandaging of wounds with certain wound care substances," noted Dr. Caroline Schuppli, study senior author.

The incident is not an isolated case of self-medication in animals. Other species, such as Galápagos finches, blue-headed parrots, and ants, have been observed exhibiting similar behaviors. However, this is the first time a wild animal has been seen applying a plant with known medical properties to treat an injury. The study's findings have significant implications for our understanding of the origins of medicine and the cognitive abilities of animals.

Dr. Schuppli suggested that the behavior may have arisen through individual innovation and that Rakus may have accidentally touched his wounds while feeding on the plant, unintentionally applying the plant's juice to his wounds. "It is possible that wound treatment with Akar Kuning by the orangutans at Suaq emerges through individual innovation," she said. The study highlights the importance of observing and learning from wild animals, as they may possess knowledge and skills that can inform human medicine and healthcare.

The use of medicinal plants is a common practice in traditional medicine, and this observation provides evidence of the effectiveness of such treatments in a wild animal. As forms of active wound treatment are not just human but can also be found in both African and Asian great apes, it is possible that there exists a common underlying mechanism for the recognition and application of substances with medical or functional properties to wounds and that our last common ancestor already showed similar forms of ointment behavior.

The discovery of Rakus' self-medication behavior not only sheds light on the origins of human wound care but also emphasizes the critical importance of preserving the habitats of endangered species like the Sumatran orangutan. As their rainforest homes continue to vanish because of agriculture and climate change, these intelligent primates may hold valuable knowledge that could benefit human health and medicine. Protecting their environment is vital for both their survival and the potential insights they can offer into our shared evolutionary history.

Key Takeaways

• Wild Sumatran orangutan Rakus treated facial wound with medicinal plant, leading to full recovery.
• Rakus selectively used akar kuning plant, known for painkilling and fever-reducing effects.
• This is the first documented case of a wild animal using a plant with known medical properties to treat a wound.
• The discovery sheds light on the origins of human wound care and highlights the importance of preserving endangered species' habitats.
• Rakus' behavior suggests that medical behaviors in apes, including humans, may have originated from a common ancestor.