In the rural Ga-Klopper village in Limpopo, young biochemist Thabo Lesiba Lekgoathi combines indigenous wisdom and modern science. Inspired by the pepper tree (peperboom) his grandmother used to treat respiratory ailments, Lekgoathi’s research uncovered a powerful compound with potential against respiratory viruses like Covid-19.
Food For Mzansi spoke with Lekgoathi as he navigates the journey from traditional healing practices to securing a provisional patent and envisioning a future where licensed medicine rooted in indigenous knowledge can address pressing global health challenges and the importance of planting and farming such crops.
Lisakanya Venna: What inspired you to research the pepper tree, and how did you identify the healing agent?
Thabo Lesiba Lekgoathi: The peperboom was one of three medicinal plants I investigated during my master’s research at Sefako Makgatho Health Sciences University, under the supervision of Professor Stanley Gololo and Dr Vuyisile Thibane.
The project emanated during the height of the Covid-19 pandemic, a time that made me ask myself, “How can I use my knowledge of biochemistry to contribute to the fight against a virus that has claimed so many lives?”
My goal was to scientifically evaluate traditional medicinal plants that had long been used to treat colds and flu-like symptoms in search of affordable and accessible interventions for communities with limited healthcare access.
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What are the potential health benefits of the healing agent, and how does it work to treat respiratory diseases?
The compound geranylgeranyl acetate demonstrated the ability to inhibit two key enzymes of the SARS-CoV-2 virus, PLpro (papain-like protease) and Mpro (main protease). These enzymes are critical for viral replication and help the virus evade the host immune system. By blocking their activity, the compound effectively disrupts the virus’s life cycle, giving the body a better fighting chance.
Beyond antiviral properties, preliminary findings suggest that this compound may also exhibit anti-inflammatory and antioxidant activities, which could further aid in alleviating respiratory symptoms associated with viral infections.
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Are there any potential interactions or contraindications with other medications, and what precautions should people with underlying health conditions take when using the pepper tree?
Traditionally, the pepper tree has been used safely for generations to relieve flu-like symptoms through practices such as steaming. However, scientific research now allows us to refine and improve the safety and standardisation of its use.
We will be developing a formulation accompanied by clear guidelines to ensure safe usage, something traditional methods did not standardise. Factors such as steam duration, leaf concentration, and exposure frequency can influence safety and efficacy.
What is the optimal dosage and preparation method for the healing agent, and are there any differences in efficacy between inhaling, steaming, or drinking the leaf extract?
Our findings so far indicate that steaming and inhalation are the most effective and culturally aligned delivery methods. In traditional use, steam carries the volatile and active compounds through water vapour, which allows direct delivery to the respiratory tract. The compound geranylgeranyl acetate is particularly suited for this route because it can volatilise without losing structural integrity.
We are developing oil-enriched formulations and pelletised extracts designed for steam inhalation, offering a natural, non-invasive option for managing respiratory symptoms. Since our tests focused on vapour extracts, we currently cannot recommend oral consumption, as the efficacy and safety profiles via drinking have not yet been established.
What are the next steps for commercialising the healing agent, and how do you envision it being used in mainstream medicine or traditional practices?
The foundation has been established through the discovery and provisional patent filing. The next critical steps include formulation development, stability testing, and optimisation of delivery systems. These scientific stages will determine whether our promising laboratory results can be translated into safe, standardised, and scalable real-world products.
Our vision is to develop a licensed, evidence-based treatment that can be integrated into respiratory disease management pathways, and we’re also open to licensing it to the pharmaceutical industry. We aim to produce a locally sourced and affordable therapeutic option, particularly valuable in resource-limited communities, while ensuring sustainable harvesting and community benefit-sharing.
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