Induction of Apoptosis in the HepG2 Cells by HY53, a Novel Natural Compound Isolated from Bauhinia forficata

In the search for a novel cytotoxic substance from medicinal plants, HY53 (C∧17H∧32O₂N₂; molecular weight 296) was isolated from the leaves of Pata de Vaca (Bauhinia forficata). The growth of the HepG2 cells was inhibited in a dose-dependent manner when treated with 0.07 to 0.40 mM HY53 for 24 h (IC∧50: 0.13 mM). Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HepG2 cells exposed to 0.27 mM HY53, whereas a flow cytometric analysis of the HepG2 cells using propidium iodide showed that the apoptotic cell population increased gradually from 8% at 0 mM to 23% at 0.14 mM and 45% at 0.40 mM after being exposed to each concentration of HY53 for 24 h.