A scientific study has identified euphol, a powerful toxin found in the Damara milk bush (Euphorbia damarana), as the primary cause of the plant's toxicity. The research, however, also reveals that this same compound shows promise as a potential new tool in the fight against cancer.
Published in the South African Journal of Botany, the article "Isolation and identification of the primary toxin in the smoke of the Namibian milk bush, Euphorbia damarana" by M. P. Degashu et al., details the isolation and identification of the main toxin in the smoke of this poisonous plant. Native to the desert regions of Namibia and southern Angola, the Damara milk bush has long been known for its dangers. Traditionally, Bushmen used its toxic milky sap to create poisoned arrows for hunting, and while its sap is lethal to most animals and humans, some species like the oryx and black rhino are known to feed on its stems.

A Scientific Explanation for a Tragic Legend
The research was inspired by a tragic event from the 1960s. A group of 27 migrant miners, working in a lithium mine near the Namibian town of Uis, used dried branches of the Damara milk bush to fuel a barbecue. Unaware of the plant's toxic smoke, they cooked their meat over the fire. The volatile compounds released during combustion infused the meat, making it deadly. All 27 miners died that same night after eating the meal.

This tragic event became a local legend, and the miners' burial site is located next to the remains of a dead E. damarana plant, a detail documented by a photo in the scientific paper. The new research provides a definitive scientific explanation for this decades-old story, confirming that euphol was the culprit behind this horrific incident.

Toxin Identified: A New Hope Against Cancer
The researchers identified the triterpenoid euphol as the main compound present in both the smoke and stem extracts of the plant. They also detected smaller concentrations of phorbol ester compounds. When purified euphol was tested on eight different human cancer cell lines (A549, PC-3, HeLa, HepG2, MCF-7, MCF-12A, MRC-5, and HaCaT), the results were significant.
Both the purified euphol and the plant extracts showed strong cytotoxic activity on all tested cell lines, meaning they were highly effective at killing the cells. The very low IC50 values—the concentration needed to inhibit 50% of cell growth—indicate euphol's potent effect. Given the high concentration of euphol in the smoke (10.3 mg/g) and its proven toxicity, the study concludes that euphol is indeed the main toxin in E. damarana and was responsible for the miners' deaths.

This research has major implications for public safety, especially for communities living near the plant. It scientifically validates traditional knowledge about the plant's dangers and provides a clear chemical and biological explanation for its toxic effects. The finding that the smoke, and not just the sap, is highly toxic highlights a less-obvious and often underestimated risk.
Beyond its importance in toxicology, this study also offers concrete data on the cytotoxicity of a natural compound. This could pave the way for future pharmacological research, including the development of new anti-cancer drugs. The study serves as a powerful example of how science can validate traditional wisdom and explain mysterious historical events, ultimately improving the safety and health of local populations.