In Europe, pygeum extract (trade name: Tadenan®) from the African plum tree has been used as a licensed medical treatment for benign prostatic hyperplasia (BPH) for decades. BPH is a non-cancerous enlargement of the prostate gland. Numerous clinical trials have demonstrated that pygeum extract improved overall health and urinary symptoms in men with BPH.

The two main bioactive compounds in pygeum extract, N-butylbenzenesulfonamide and atraric acid, have been found to decrease the (i) secretion of growth factors and inflammatory mediators and (ii) activation of androgen receptors in human cells. Such growth factors and androgens (e.g., dihydrotestosterone) are known to drive the growth of both non-cancerous and cancerous prostate tumours. Thus, pygeum extract is also beneficial in treating prostate cancer. A study has demonstrated that pygeum extract prevented prostate cancer growth in both cell culture and animal experiments. Specifically, only 35% of the mice fed with pygeum extract developed prostate cancer compared to 63% in the control group, indicating a nearly two-fold reduction in cancer incidence. Further laboratory studies confirmed that pygeum extract stops androgen signalling in prostate cancer cells by binding to and inhibiting androgen receptors on the cell surface.

Beyond androgen modulation, pygeum extract also exerts another anticancer mechanism called apoptosis, i.e., programmed cell death. In fact, pygeum extract has also been shown to kill colorectal, liver, breast, and even multidrug-resistant cancer cells via apoptosis. Indeed, a 2017 literature review concurred that pygeum extract is capable of preventing cancer growth and killing cancer cells directly by activating apoptotic signalling. Altogether, these findings point towards pygeum as a promising plant agent against cancer. Importantly, pygeum extract is deemed non-toxic and suitable for long-term use for humans by the European Medicines Agency.

Cover Image attribution: SAplants Prunus africana 1DS-II 0042 CC BY-SA 4.0