I wanted to pass on this cool discovery and story of how an Orangutan had the knowledge to heal himself with herbs in the jungle he was not taught this by humans but most likely trial and error over hundreds of years if not longer.Reminds me how Chinese Herbal Medicine started thousands of years ago when a leaves fell into a pot of hot water and green tea was discovered.

Then with trial and error men started consuming herbs and notating their effects, they had assistants who recorded the effects and if someone died they made a note of it and kept on experimenting and after several thousand years of this we had a complete Materia Medica of what these herbs could do for us. Below you will how an Orangutan followed these same concepts.

In the early 1960s Jane Goodall first described the presence of whole leaves in the feces of chimpanzees (Pan troglodytes) at Gombe Stream, Tanzania1. By the late 1990s, this behavior, now called whole leaf swallowing, was documented at several African great ape study sites, along with bitter pith chewing, and demonstrated to have therapeutic, anti-parasitic functions2. Since then, various forms of self-medication have been observed in wild great apes. Some of the most detailed evidence for animal self-medication comes from research in primates.

Rakus

A male Sumatran orangutan named Rakus was first observed in March 2009. At that time, Rakus was an unflanged male (i.e., adult but without secondary sexual characteristics42) and was estimated to be born in the late 1980s. He is either a resident to the area or a frequent visitor. Rakus went through a secondary growth spurt in 2021 and has been a fully flanged male since August 2021.

Rakus was a focal individual from June 22 (on the day this fresh wound was first noted) to June 26, from June 28 to 30, on July 5, July 19, and August 5, 2022. The wound treatment data was collected on June 25, 2022, and described in detail in the notes section of the data sheets. Unfortunately, no photos or videos were taken of the wound treatment.

We took detailed pictures of the plant specimen that was used by the orangutan to ensure reliable identification (see Fig. 2). However, due to a lack of the necessary permits, we were unable to collect and store a physical sample of the specimen. The pictures of the specimen were compared to the site’s detailed picture-based herbarium which was established at the beginning of the research activities at Suaq Balimbing via samples collected at the site in partnership with the National Herbarium of Indonesia and the National University of Indonesia (UNAS).

Observations

On June 22, 2022, our research team (including UA) first noticed that Rakus had a fresh wound on his right flange (see Fig. 1) and inside his mouth, first visible when he emitted a long calls. How he got the wound is unknown, however typically flanged males acquire these kinds of wounds during fights with other flanged males. Vocal evidence of a fight between orangutan males was reported earlier on the same day of this observation.

On June 25 at 11:16, Rakus started feeding on the stem and the leaves of the liana of Fibraurea tinctoria (see Fig. 2), also known as ‘Akar Kuning’ (for other synonyms and classification of the plant, which is part of the orangutans’ diet in this area. The liana is rarely eaten (0.3% of all feeding scans, n = 390′000), but 47 out of a total of the 132 orangutans on which we have collected feeding data were observed consuming its leaves, fruits, or parts of the stem. Thirteen minutes after Rakus had started feeding on the liana, he began chewing the leaves without swallowing them and using his fingers to apply the plant juice from his mouth directly onto his facial wound. This behavior was repeated several times and lasted seven minutes. After this period, at 11:36, flies of an unknown species appeared on the wound. Rakus then smeared the entire wound with the plant pulp until the red flesh was fully covered with the green leaf material. He then continued feeding on this plant for a total of 34 min. The next day (June 26), but not on any other of the following observation days (June 28, 29, 30; July 5, 19, 20), he ate leaves of Fibraurea tinctoria again for two minutes (pictures (Figs. 1 and 2) and one video were taken on June 26th while he was feeding on Fibraurea tinctoria).

Observations over the following days did not show any signs of the wound becoming infected (see photos taken on June 26 and 28; Fig. 1) and by June 30 the facial wound was already closed (see Fig. 1). By July 19, 2022, the wound appeared to have fully healed and only a faint scar remained (see Fig. 1).

Furthermore, UA (who collected the focal data) noted that Rakus rested more than usual after being wounded, which may positively affect wound healing as growth hormone release, protein synthesis and cell division are increased during sleep46,47. When considering the percentage of time spent resting (based on 2-min interval activity scans) between January 30, 2021 (since then he has been considered a flanged male; this is important to consider, as flanged males in general rest more than unflanged males to February 22, 2023, we noticed that resting time increased after being wounded (June 22, 2022, to July 20, 2022; mean = 33 ± 17.2%) compared to the time before (January 30, 2021, to November 8, 2021; mean = 14.8 ± 7.4%) and that resting time decreased again after the wound had closed (August 5, 2022, to February 22, 2023; mean = 23.6 ± 12.9%; see SI, Figure S1). He spent more than 50% the day resting after he was found with the fresh wound (June 23, 2022; 52.2% of resting), the day after wound treatment (June 26, 2023; 51%), and four days after treatment (June 29, 2023; 54.3%; see, Fig. S1).

 

To the best of our knowledge, this study is the first systematic documentation of the putative active wound treatment with a biologically active plant substance in great apes and other non-human species. In this study, the flanged male orangutan Rakus was observed to selectively detach, chew, and repeatedly apply the chewed leave juice directly on his three-day-old facial wound for several minutes and covered the entire wound with a chewed-up leaf mash. Additionally, Rakus rested more when the wound was fresh compared to before and after wounding.

The treatment of human wounds was most likely first mentioned in a medical manuscript that dates back to 2200 BC, which included cleaning, making plasters and bandaging of wounds. One of the earliest known wound care products used by the Sumerians, Greek, Mayans and Egyptians were oil, herbs, maggots, beer, vinegar, wine, green paint containing copper and honey.

Fibraurea tinctoria, has other generic names such as Akar Kuning (Central Kalimantan), Akar Palo (Aceh), and Yellow Root (East Kalimantan51). It is an evergreen, climbing plant in the family Menispermaceae, with a broad distribution across Mainland China, Indonesia, Malaysia, Thailand, Vietnam and other areas of Southeast Asia, and is known for its analgesic, antipyretic, antidote, and diuretic effects, and is used in traditional medicine to treat condition such as dysentery, diabetes, and malaria. All plant parts have been reported to be used for these medical applications, including leaves, stems, roots and bark.

Chemical Compounds

Pharmacological analysis of the plant’s chemical compounds shows the presence of furanoditerpenoids56, a special group of diterpenoids composed of one or more aromatic furan rings (with four carbon atoms and one oxygen), which are reported to have antibacterial, anti-inflammatory, anti-fungal, antioxidant, and anticarcinogenic biological activities. Fibraurea tinctoria also has a high concentration of protoberberine alkaloids, which have anti-inflammatory, analgesic, anticonvulsant, antiamnesic, narcotic, antiarrhythmic, antihemorrhagic, hypotensive, antioxidant, antitumoral, antidiuretic, antiulcer, and muscle relaxant properties57. It also contains jatrorrhizine (antidiabetic, antimicrobial, antiprotozoal, anticancer, and hypolipidemic properties; reviewed in58) and palmatine (anticancer, antioxidation, anti-inflammatory, antibacterial, antiviral properties; reviewed. Among 38 plants used in ethnomedicine and grown in South Vietnam, Fibraurea tinctoria showed the highest activity tested for antimalarial effects61. It has also been shown that the leaves and stems of Fibraurea tinctoria inhibit the growth of several bacteria species, including Bacillus cereus, Staphylococcus aureus, and Escherichia coli53,62. Fibraurea tinctoria also showed a significant anti-inflammatory effect in reducing mouse paw edema.

Behavior

Like all self-medication behavior in non-human animals, the case reported in this study raises questions about how intentional these behaviors are and how they emerge. Similar to plant ointment behavior in Bornean orangutans, the behavior of the Sumatran flanged male orangutan reported here appeared to be intentional as he selectively treated his facial wound on his right flange with the plant juice (and no other body parts), (II) the behavior was repeated several times, not only plant juice but later also more solid plant material was applied until the wound was fully covered and the entire process took a considerable amount of time. It is possible, that wound treatment with Fibraurea tinctoria emerges through accidental individual innovation63. Individuals may accidentally touch their wounds while feeding on Fibraurea tinctoria 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 and subsequently apply solid plant matter possibly to also cover the wound as a protection against flies (as the case reported here suggests). Immature orangutans rely on observational social learning for the acquisition of their skill repertoires64 and recent evidence suggests that social learning continues into adulthood65. Therefore, given that it occurs frequent enough and in social contexts, wound treatment with Fibraurea tinctoria may also spread socially from individual to individual.

21 Years of Observation

However, up to date, in 21 years and 28′000 observation hours, we never observed any other orangutans at Suaq using Fibraurea tinctoria to treat their wounds. On the one hand, this may be due to the fact that we rarely encounter injured orangutans at Suaq. Due to high food availability, high social tolerance between orangutans and relatively stable social hierarchies (each area is usually inhabited by a dominant male and several females66), there are few physical fights. However, during the time of this study, there was no clearly dominant male present in the research area. Rakus had just gone through his secondary sexual development in the year before the incident and, as a newly flanged male, he seemed to try to establish himself as the new dominant local male which is reflected in our behavioral data collected during this time. As a result of that, Rakus was involved in several long-call battles66 and physical altercations with other flanged males that were resident in and around the area at that time. On the other hand, it may be that wound treatment with Fibraurea tinctoria has so far been absent in the behavioral repertoire of the Suaq orangutan population. Like all adult males in the area, Rakus was not born in Suaq (his origin is unknown). Orangutan males disperse from their natal area during/after puberty over long distances to either establish a new home range in another area (mostly as dominant flanged male) or are moving between other’s home ranges (as unflanged males or flanged males)67. Therefore, any adult male in an area does not originate from the area67. Thus, as of now, it is impossible to find out where the males come from. Therefore, it is possible that the behavior is shown by more individuals in his natal population.

Of the few injured orangutans that we observed at Suaq so far, we observed one other instance of possible wound soothing/treatment behavior. Flanged male named Pluto repeatedly put his injured finger into the water of a pitcher plant. The water may have had a cooling effect that could eventually relieve pain or help clean the wound.

In Conclusion

Taken together, chemical analyzes of the properties of the Fibraurea tinctoria and the orangutan’s particular goal-oriented behavior are consistent with the hypothesis that the process of preparing and applying herbal ointments may be a form of self-medication that reduces pain, prevents inflammation, and accelerates wound healing. The present study may thus present the first report of active wound management with a biological active substance in a great ape species and provides new insights into the existence of self-medication in our closest relatives and in the evolutionary origins of wound medication more broadly. As forms of active wound treatment are not just a human universal 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.