23-hydroxy Betulinic acid is a triterpenoid that has been found in P. chinensis and has anticancer activity. It inhibits proliferation of K562, B16, and HeLa cells (IC50s = 39.9, 78.5, and 80 μM, respectively), as well as human umbilical vein endothelial cells (HUVECs; IC50 = 94.8 μM). It halts the cell cycle at the S phase and induces apoptosis in K562 cells in a concentration-dependent manner with a loss of the mitochondrial membrane potential and an increase in Bax and cytochrome C protein levels.
