Benign prostatic hyperplasia (BPH) is a nonmalignant enlargement of the prostate Prunus domestica bark contains three groups of active constituents: phytosterols (including beta-sitosterol), pentacyclic triterpenoids (including ursolic and oleaic acids) and ferulic esters of long-chain fatty alcohols (including ferulic esters of docosanol and tetracosanol).