Anti-proliferative effects of cucurmosin on human hepatoma HepG2 cells.

We extracted cucurmosin (CUS) from the sarcocarp of Cucrubita moschata (pumpkin). Recently, a number of studies have indicated that CUS has cytotoxic properties and induces apoptosis in a number of human tumor cells. However, the detailed mechanisms are largely unknown. The aim of this study was to confirm CUS's anticancer activity on human hepatoma HepG2 cells in vitro and in vivo, and to elucidate the mechanism of its activity. MTT was used to detect the cytotoxic effects of CUS. Flow cytometry was used to analyze cell apoptosis and the cell cycle. Transmission electron microscopy was used to observe the morphology of apoptotic cells. Western blot analysis was performed to measure the protein expression of bax, bcl-2 and procaspase-3. The established orthotopic transplantation models of human hepatoma in NOD/SCID mice were tested for anticancer activities in vivo. The results showed that CUS inhibited the proliferation of HepG2 cells in vitro and in vivo. CUS induced apoptosis and arrested the cell cycle. In addition, CUS increased the protein expression of bax, but decreased the bcl-2 and procaspase-3 expression in HepG2 cells. Our data indicate that CUS has potential anticancer activity for human hepatoma, which can be attributed in part to its inhibition of proliferation and apoptosis, induced by decreasing the bcl-2:bax ratio and caspase-3 activation.