Four plants eaten by gorillas, also used in traditional medicine, provide clues for new drug discovery

Four plants consumed by wild gorillas in Gabon and used by local communities in traditional medicine show antibacterial and antioxidant properties, find researchers.

Wild great apes often consume medicinal plants that can treat their ailments. The same plants are often used by local people in traditional medicine.
To investigate, researchers observed the behavior of western lowland gorillas (Gorilla gorilla gorilla) in Moukalaba-Doudou National Park in Gabon and recorded the plants they ate. Next, they interviewed 27 people living in the nearby village of Doussala, including traditional healers and herbalists, about the plants that were used in local traditional medicine.

The team identified four native plant species that are both consumed by gorillas and used in traditional medicine: the fromager tree (Ceiba pentandra), giant yellow mulberry (Myrianthus arboreus), African teak (Milicia excelsa) and fig trees (Ficus). They tested bark samples of each plant for antibacterial and antioxidant properties and investigated their chemical composition.

The researchers found that the bark of all four plants had antibacterial activity against at least one multidrug-resistant strain of the bacterium Escherichia coli. The fromager tree showed "remarkable activity" against all tested E.coli strains. All four plants contained compounds that have medicinal effects, including phenols, alkaloids, flavonoids, and proanthocyanidins. However, it's not clear if gorillas consume these plants for medicinal or other reasons.

But Zoopharmacognosy* is one of these new approaches, aimed at discovering new drugs.

*  the study of how animals self-medicate by selecting and consuming plants, soils, and insects with medicinal properties.

Here are some examples of animals that self-medicate:

Pregnant lemurs: Nibble on tamarind leaves to help with milk production

Chacma baboons: Eat small amounts of leaves from specific plants that have stimulant properties

Dogs and cats: May eat grass to relieve nausea, even though they can't digest it because they lack the necessary enzymes.

Antibacterial and antioxidant activities of plants consumed by western lowland gorilla (Gorilla gorilla gorilla) in Gabon, PLoS ONE (2024). DOI: 10.1371/journal.pone.0306957

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Animal self-medication against parasites is more widespread than previously thought, with profound implications for host-parasite biology.

Birds, bees, lizards, elephants, and chimpanzees all share a survival trait: They self-medicate. These animals eat things that make them feel better, or prevent disease, or kill parasites like flatworms, bacteria, and viruses, or just to aid in digestion. Even creatures with brains the size of pinheads somehow know to ingest certain plants or use them in unusual ways when they need them. (7)

Anyone who has seen a dog eat grass during a walk has witnessed self-medication. The dog probably has an upset stomach or a parasite. The grass helps them vomit up the problem or eliminate it with the feces. It’s not clear how much knowing or learning is involved, but many animals seem to have evolved an innate ability to detect the therapeutic constituents in plants. Although the evidence is entirely circumstantial, the examples are plentiful. The practice is spreading across the animal kingdom in sometimes surprising ways

A wide range of animals self-prescribe the plants around them when they need a remedy (7).

The concept of antiparasite self-medication in animals typically evokes images of chimpanzees seeking out medicinal herbs to treat their diseases (1,2). These images stem partly from the belief that animals can medicate themselves only when they have high cognitive abilities that allow them to observe, learn, and make conscious decisions (3). However, any concept of self-medication based solely on learning is inadequate. Many animals can use medication through innate rather than learned responses. The growing list of animal pharmacists includes moths (4), ants (5), and fruit flies (6). The fact that these animals self-medicate has profound implications for the ecology and evolution of animal hosts and their parasites.

The scientists researching zoopharmacognosy are convinced that humans can learn from the animals, particularly in finding new medications.

Footnotes:

1. Huffman M. A., Proc. Nutr. Soc. 62, 371 (2003).