Plants have historically been a rich source of medicine. Many antibiotics used today were originally derived from natural compounds. But humans aren’t the only ones who use medicine. Granted, we’ve taken things way further than any other species on Earth, but other creatures have their own type of pharmacy.

Animals from primates to bees have been found to self-medicate in one form or another — and great apes are no exception. One day, plants consumed by gorillas may provide new avenues for drug discovery, especially in the fight against drug-resistant bacteria.

Wild great apes in Gabon often consume medicinal plants when they are ill. Intriguingly, some of these plants are also used in local traditional medicine. So, a team of researchers led by Leresche Even Yinda wanted to see whether those plants have useful properties. They also conducted interviews with 27 people living in a nearby village.

Ultimately, they zoomed in on four plants, testing for antibacterial and antioxidant properties and investigating their chemical composition.

• Ceiba pentandra (fromager tree): Known for its large, silk-producing pods, the bark of Ceiba pentandra has been used in traditional medicine to treat inflammation, colic, and diarrhea.
• Myrianthus arboreus (giant yellow mulberry): This species is commonly used to treat stomach ulcers, coughs, and hypertension.
• Ficus species (fig trees): Often used in wound care, Ficus bark is believed to have anti-inflammatory and antibacterial properties.
• Milicia excelsa (African teak): this plant is highly valued for its timber and medicinal properties, particularly in treating diarrhea and other digestive issues.

Zoopharmacognosy: A natural medicine cabinet

Zoopharmacognosy is the study of how animals use plants, minerals, and other natural substances for self-medication. In many cases, plants that animals consume for health benefits have also been found useful in human medicine. The western lowland gorilla (Gorilla gorilla gorilla) has been previously observed consuming plants that could play a role in regulating their health. Particularly, they may help to fend off infections from multidrug-resistant (MDR) bacteria like Escherichia coli.

The researchers collected bark samples from these four plant species in the Moukalaba-Doudou National Park, a region known for its rich biodiversity. Traditional healers from local communities provided valuable insight into the medicinal uses of these plants.

Using a combination of biochemical assays, the team evaluated the antioxidant and antibacterial activity of the plants’ bark extracts. Basically, researchers tested how well the plants can neutralize harmful free radicals in the body and how well they fare against ten multidrug-resistant E. coli isolates using specialized methods.

Antioxidants are essential in reducing oxidative stress, which can lead to chronic diseases like cancer and heart disease. They work by neutralizing reactive oxygen species (ROS), harmful byproducts of normal cellular processes. Notably, the study found that all four plant species had significant antioxidant properties.

Even more interesting, the antioxidant activities of these plants align with their traditional use in treating ailments related to inflammation and oxidative stress. This suggests that the gorillas may benefit from these properties, possibly aiding in their immune function and overall health.

Can we make better drugs from the plants?

The results in this study were promising, with each plant showing varying degrees of activity against the bacteria. Ceiba pentandra was particularly effective, showing inhibitory activity against all the tested E. coli strains. And the ethanolic extract of Myrianthus arboreus displayed strong antibacterial activity, though it was less effective than Ceiba pentandra.

Antimicrobial resistance is one of the most pressing health concerns globally. The World Health Organization (WHO) estimates that antibiotic resistance could lead to 10 million deaths annually by 2050. The rise of multidrug-resistant bacteria highlights the urgent need for new antimicrobial agents. These pathogens are notoriously difficult to treat with existing antibiotics, thus causing more severe infections.

The ability of these plants to inhibit E. coli highlights their potential as sources for new antimicrobial agents. Given the alarming rise in antibiotic resistance, natural products like these could serve as valuable alternatives to synthetic drugs.

The researchers also conducted a phytochemical analysis to identify the active compounds responsible for the plants’ medicinal properties. The analysis revealed the presence of several important secondary metabolites, including flavonoids (known for antioxidant and anti-inflammatory properties), tannins (known to promote wound healing and prevent infection), and phenolic compounds.

The presence of these compounds not only supports the medicinal use of these plants but also provides a scientific basis for their potential in drug development.

Another reason to protect these areas

The findings from this study underscore the importance of traditional knowledge in the discovery of new medicines. By studying the plants consumed by western lowland gorillas, the researchers may have found some valuable candidates for the development of new drugs. We may develop new approaches to combating antibiotic-resistant infections and oxidative stress-related conditions.

But none of this will matter if we don’t protect the gorillas’ habitat.

This study highlights the need for conservation efforts. The plants studied here are part of the rich biodiversity of Gabon, a country that plays a critical role in preserving the natural resources that could one day provide life-saving medicines. And these are far from the only promising drug candidates found in ecosystems both on land and in the oceans.

As researchers continue to explore the intersection of animal behavior, traditional medicine, and modern drug discovery, it becomes increasingly clear that the natural world holds immense untapped potential. The wisdom of animals like the western lowland gorilla may teach us a thing or two.

Journal Reference: 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