ABSTRACT
OBJECTIVE: To investigate the anti-tumor mechanisms of a new oleanolic acid derivative (the test substance, 3β- hydroxyolea-12-en-28-oic acid-3, 5, 6-trimethylpyrazin-2-methyl ester) on the human hepatocellular carcinoma SMMC-7721 cells. METHODS: MTT assay and morphology observation were used to determine the effects of the new oleanolic acid derivative on human hepatocellular carcinoma SMMC-7721 cells. Cell membrane integrity was assessed with AV/PI uptake by fluorescence microscope. The loss of mitochondrial membrane potential (Δψm) was detected by using JC-1 assay. Western blotting was used to detect the apoptosisrelated proteins Bcl-2, Bax, caspase-9 and caspase-3. RESULTS: The new oleanolic acid derivative reduced the cell viability of SMMC-7721 cells in dose-and time-dependent manner. After treatment of the new oleanolic acid derivative on cells for 48 h, cell nucleus pycnosis, cell lysis and the generation apoptosis body and so on were observed, the cell membrane integrity was damaged, the mitochondrial membrane potential (Δψm) was decreased, the protein levels of Bax, pro-caspase-9, cleaved caspase-9, pro-caspase-3 and cleaved caspase-3 were upregulated, and the protein level of Bcl-2 was downregulated. CONCLUSION: The growth inhibition and proapoptotic effects of this new oleanolic acid derivative on human SMMC-7721 cells associate with its damage on mitochondrial function.