The effects and mechanism of peiminine-induced apoptosis in human hepatocellular carcinoma HepG2 cells

Peiminine is a compound isolated from Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae family), which has demonstrated antitumor activities. But its precise molecular mechanism underlying antitumor activity remain elusive. In this study, peiminine-induced apoptosis towards human hepatocellular carcinoma and its molecular mechanism were investigated. MTT assay was employed to assess anticancer effects of peiminine upon Hela, HepG2, SW480 and MCF-7 cell lines. Nuclear staining and flow cytometry were carried out to detect apoptosis induced by peiminine. Mitochondrial membrane potential evaluation and Western blot analysis were performed to investigate the mechanism of peiminine-induced apoptosis. The results showed peiminine reduced the viability of HepG2 cells in a time- and dose-dependent manner and had an IC(50) of 4.58 μg/mL at 24h. Peiminine significantly increased the percentage of apoptotic cells and the mitochondrial membrane potential dose-dependently in HepG2 cells. The results of Western blotting indicated the expressions of Bcl-2, procaspase-3, procaspase-8, procaspase-9, and PARP decreased in HepG2 cells treated with peiminine, while the expressions of Bax, caspase-3, caspase-8, caspase-9, and cleaved PARP(1) increased. The result suggests that peiminine can induce apoptosis in human hepatocellular carcinoma HepG2 cells through both extrinsic and intrinsic apoptotic pathways.