Dhf-18, A New Synthetic Flavonoid, Induced A Mitochondrial-Mediated Apoptosis Of Hepatocarcinoma Cells In Vivo And In Vitro

A new synthetic flavonoid DHF-18, synthesized with a piperazine substitution, has been recently found to show potent anti-tumor activities both in vivo and in vitro. In this study, we demonstrated that DHF-18 significantly inhibited tumor growth in mice inoculated with Heps hepatoma cells without evident toxicity. After the treatment of 40 mg/kg DHF-18, the inhibitory rate of tumor weight was 53.69%. To investigate whether apoptosis induction contributed to the anti-tumor effects of DHF-18, DAPI (diamidino-phenylindole) staining and Annexin V/PI (Propidium iodide) double staining were performed in our tests. The data showed that DHF-18 could induce the apoptosis cell death in HepG2 cells. Moreover, the apparent increase of intracellular reactive oxygen species levels and the reduction of mitochondria Delta Psi m were both observed in HepG2 cells after DHF-18 treatment. Meanwhile, the transposition of apoptotic inducing factor (AIF) from mitochondria to nuclei, the release of cytochrome c from mitochondria and the activation of caspase-3, -9 were also detected, indicating that DHF-18 may induce apoptosis through a mitochondrial-mediated pathway. Additionally. DHF-18 decreased the expression of Bcl-2 protein, whereas the levels of Bax and Bak were found to increase after DHF-18 treatment. Moreover, the activation of caspase-8, the increase of TNF-R1 (Tumor necrosis factor receptor) and Bid were found. Taken together, our results suggested that DHF-18 may induce HeG2 cells apoptosis through a mitochondrial-dependent and independent pathway. (c) 2010 Published by Elsevier B.V.