Betulinic acid is a natural pentacyclic triterpenoid that selectively induces apoptosis in tumor cells by directly activating the mitochondrial pathway of apoptosis through a p53- and CD95-independent mechanism. Betulinic acid also displays TGR5 agonist activity (EC50 =1.04 µM). Betulinic acid is used to study its potential cardiovascular role in the modulation of endothelium-dependent relaxation. Betulinic acid displays anti-HIV and antitumor activity.