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Revisiting ancient wisdom to solve modern problems
THUS WROTE THE ROMAN NATURALIST PLINY THE ELDER almost two thousand years ago, referencing an earlier observation on African biodiversity by Aristotle. Wise words, but what were novel discoveries to these philosopher-scientists were probably old hat to the thousands of Khoi-San people roaming southern Africa at that time.
Africa’s natural pharmacopoeia continues to draw the attention of modern scientists, with regular announcements of the latest wonder drug confi rming the effi cacy of Africa’s indigenous medicines.
Rooibos, buchu, pelargonia, hoodia, sutherlandia, aloe, cannabis and hundreds of other plants were deployed alongside animal and mineral-derived medicines in Khoi-San healing techniques that included poultices, aromatherapy, massage and ingested pharmaceuticals. One of the latest plants to excite the research interest of UWC’s Medical Biosciences Department is the unassuming kraalbos (Galenia africana).
Known variously as brakkraalbossie, kraalbrak, geelbos, iqina, muisbos, perdebos and waterpensbos, kraalbos is an aromatic woody shrub native to South Africa and Namibia that often colonises land where animals have concentrated or overgrazed other vegetation, such as in and around a livestock kraal.
Farmers regard it as a problem plant, since it is toxic if ingested and causes a potentially deadly form of ascites known as waterpens (water belly) in grazing livestock.
The Khoi-San, however, used it to treat dermatitis, fungal growths, inflammation and even venereal diseases. Chewing kraalbos leaves relieves toothache and an infusion will ease bronchial problems and coughs. Scientists believe its antibacterial properties may be useful in treating tuberculosis and it is being investigated as a potential treatment for skin and other cancers and neurodegenerative diseases such as Alzheimer’s.
A research team led by UWC professor of molecular biology, Burtram Fielding, found that a kraalbos extract successfully killed melanomas and breast cancer cells in laboratory conditions.
“We found that efficacy varied in the different scenarios, but that didn’t disappoint us. That’s good because this wasn’t going to be a magic bullet. Testing showed kraalbos efficacy was specific to particular, different cancers,” Prof Fielding says.
Another study by Dr Farzana Rahiman of the department’s skin research laboratory and postgraduate student Banele Ndlovu compared the anti-proliferative eff ect of kraalbos on normal human skin cells (HaCaT) and human malignant melanoma cells (A375). They discovered kraalbos signifi cantly reduced the cell viability of the A375 cells in a dose and time-dependent manner, while having no eff ect on the HaCaT cells. This suggests a clinical rationale for kraalbos’s potential use as an anti-melanoma agent off ering effi cacy and low toxicity.
Prof Fielding and Dr Tiza Ng’uni have conducted toxicity testing and other research to determine whether kraalbos was safe for use as a topical treatment. Indications are that it can be safely used as a therapeutic agent, although more research is needed before market-ready pharmaceuticals can be developed.
Kraalbos is also showing promise as an element in the future treatment of multidrugresistant pathogens, a growing global concern. For example, Methicillin-resistant Staphylococcus aureus (MRSA) is already resistant to more than 20 antibiotic medications. MRSA is a common hospitalacquired infection that can cause sepsis, skin diseases, abscesses, sinusitis and food poisoning. A few years ago, Prof Jeremy Klaasen began exploring other applications of kraalbos and developed a biopesticidal adjuvant that can reverse the resistance of plant pathogens when mixed with conventional chemical pesticides. An eventual commercial application will likely reduce the amount of pesticide used and the risk and extent of environmental contamination.
A further discovery proved that a kraalbos extract can increase the chlorophyll level, polyphenolic content and total soluble solids content of plants, thereby improving overall plant health and yield. Kraalbos therefore has potential as a bio-fertiliser in the organic food production market.
Lastly, seeding degraded land with kraalbos can enrich soil and restore other wild plant populations, promoting sustainable land management. While bioscience today is a specialised research discipline in which UWC is playing a prominent role, and the commercial exploitation of indigenous knowledge systems holds both risks and promises for the communities who traditionally ‘own’ the knowledge and universities that may develop it, one cultural aspect of ‘progress’ is worth refl ecting on.
By the time they reached adulthood, Khoi-San people often possessed extensive knowledge of indigenous natural medicine and the ability to treat almost all common ailments using nothing but the fl ora and fauna around them. How many people today can make that claim?
