Application: β-Elemonic acid is a triterpene isolated from Boswellia that exhibits anticancer activity. It inhibits growth of non-small cell lung cancer (NSCLC) A549 cells (IC50 = 6.92 µM) in vitro. β-Elemonic acid induces apoptosis and cytotoxicity in A549 cells in a dose-dependent manner but has no effect on normal epithelial WI-38 cells. It inhibits phosphorylation of p42/44, MAPK/JNK, and p38 and induces production of reactive oxygen species (ROS) and COX-2 expression in vitro. β-Elemonic acid also inhibits prolyl endopeptidase (IC50 = 39.74 µM) in vitro.