According to the American Cancer Society, "available evidence from well-designed, controlled studies does not support this substance as an effective treatment for cancer in humans".[90] Pygeum – an extract made from Prunus africana, the African Cherry. Following excitement at the end of the Twentieth Century about Pygeum's therapeutic potential for treating benign prostatic hyperplasia, subsequent research has found it to have no benefit.[91] Rauvolfia serpentina (or snakeroot) – a plant used as the basis of a herbal remedy that some believe may treat cancer.