New study reports Orangutan use of a medicinal plant
Do animals use plants as medicine? Absolutely! I offer my thoughts on a new research article reporting an orangutan's use of a plant to heal a facial wound.
I've received numerous texts and emails from friends and colleagues about this exciting new research paper published today. Thanks, friends! In the study, the authors report on the active self-treatment of a facial wound by a male Sumatran orangutan. Incredibly, researchers observed the orangutan, named Rakus, not only consuming the leaves of a liana (vine) that are not a normal part of his diet but also chewing the leaves and applying the poultice directly to his facial wound. This is exciting because of the detailed documentation of this wound-healing practice based on firsthand observations by researchers.
The paper is freely available online, I encourage you to check it out:
Laumer, I.B., Rahman, A., Rahmaeti, T. et al. Active self-treatment of a facial wound with a biologically active plant by a male Sumatran orangutan. Sci Rep 14, 8932 (2024). https://doi.org/10.1038/s41598-024-58988-7
My first question, of course, was ‘Which plant did Rakus use to heal his wound?’
Unfortunately, due to a major methods flaw in the study, I don’t think we have a credible answer to this question. I explain more below.
What is Zoopharmacognosy, or Animal Self-Medication?
Zoopharmacognosy can be broken down to ‘zoo’ (animal) - ‘pharmakon’ (medicine) - ‘gnosy’ (knowledge). There are many examples of animals, from primates to insects, who use the chemistry of plants to self-medicate. Check out my prior post on this topic published last June.
Animal Self-Medication with Plants
Today, chemicals derived from plants or developed based on the structures of plant compounds serve as vital drugs in various fields, including pain management, oncology, cardiology, gastroenterology, dermatology, and many more. To understand the current role of plants in medicine, it is imperative to first grasp their longstanding and essential signific…
What plant did Rakus use?
The authors report that Rakus used leaves of the plant Fibraurea tinctoria in the Menispermaceae family. A search of Pubmed revealed a few studies on this species, including reports of potential antioxidant and antidiabetic, anticancer, and antimalarial activities in laboratory studies.
But wait, how confident are we in the plant ID?
When I first read the news reports of the study, I was so excited! When I read the actual scientific paper, however, that excitement turned to disappointment and some shouted expletives. The authors DID NOT COLLECT AN HERBARIUM SPECIMEN. Ahhh!!!
They based the species match on images of the leaves. No flowers or fruit. They just took photos of some leaves and compared them to pictures of other leaves from an herbarium. I’m sorry, but this is not solid enough evidence to actually name which species Rakus used, and this is hugely disappointing. Many plant leaves have similar features, and one can never be confident in identifying a plant even just with leaves; the full specimen in fruit or flower is necessary for a true identification. This is why herbarium specimens should always include the reproductive parts of the plant.
The cited reason for not collecting and verifying the actual plant was due to issues with collection permits. I can only hope that they recorded the GPS coordinates and can someday acquire permits (if the forest remains intact) to verify this claim. At a minimum, perhaps they could run a DNA sequencing analysis or even a chemical analysis of the plant in comparison to other standards available in herbarium-backed samples (or existing herbarium specimens themselves)!
With the correct plant identification, scientists could follow up on this discovery with laboratory studies to investigate the pharmacological properties of this species to better understand its chemistry, mechanism of action, and targets (microbe and/or host) in the promotion of wound healing. This was a huge opportunity lost. I can only hope they will resolve this failing with the assistance of a botanist and properly authenticated herbarium specimens in the future.
The Takeaway
Despite my intense disappointment in the sloppy botany in this paper, I am nevertheless excited about the detailed documentation of self-medication by an orangutan and the attention that folks in the general public are giving to the topic. To me, it makes complete sense that animals use plants as medicine. After all, they learn from their family members which plants are safe to eat. They also experiment with new foods based on trial and error. Why, then, wouldn’t they also use the chemical properties of plants to heal their bodies when sick?
Yours in health, Dr. Quave
Cassandra L. Quave, Ph.D. is a scientist, author, speaker, podcast host, wife, mother, explorer, and professor at Emory University School of Medicine. She teaches college courses and leads a group of research scientists studying medicinal plants to find new life-saving drugs from nature. She hosts the Foodie Pharmacology podcast and writes the Nature’s Pharmacy newsletter to share the science behind natural medicines. To support her effort, consider a paid or founding subscription, with founding members receiving an autographed 1st edition hardcover copy of her book, The Plant Hunter.
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So interesting! This certainly needs more study.
Would the lack of proper collection permits prevent collecting the post used leaves by Rakus? Couldn't they have taken photos of the rest of the plant and certainly, recorded the gps coords easily? Truly disappointing after such serious observations.