Anti-hepatocellular carcinoma activity of tormentic acid derived from suspension cells of Eriobotrya japonica (Thunb.) Lindl.

Tormentic acid (TA), which is the main pentacyclic triterpene secondary metabolite formed by Eriobotrya japonica (Thunb.) Lindl., was purified by preparative HPLC and characterized by UPLC-MS. The inhibitory activity of the purified material towards hepatocellular carcinoma cells (HepG2, Bel-7405, Sk-hep-1) was evaluated based on proliferation, tumorigenesis, transformation, invasion and migration, as well as its ability to induce apoptosis in these cells. At concentrations of 22.5 μg/mL or more, TA led to considerable decreases in cell viability, colony formation and cell migration. TA treatment also induced apoptosis in the three hepatocellular carcinoma cell lines evaluated in this study. These effects were related to changes in the expression levels of Caspase3 and poly ADP-ribose polymerase, therefore highlighting the potent anti-cancer activity of TA towards all three of these cell lines.