Abstract
The present study aimed to investigate the effect of sinomenine hydrochloride (SIN) on cell survival/proliferation in the human hepatoma cell line Huh7, as well as determine the underlying mechanisms. Three different doses of SIN, 140, 280 and 560 µM, were tested. Cellular apoptosis and cell cycle distribution were analyzed by flow cytometry. Western blotting was used to determine protein levels of the apoptosis-associated regulators, cleaved caspase 3, B-cell lymphoma-2 (Bcl-2)-associated X protein (Bax), Bcl-2 homologous antagonist/killer (Bak) and Bcl-extra large (Bcl-xl), as well as the cell cycle-related regulators, p21 and p27. It was observed that the three doses of SIN were able to suppress Huh7 cell survival/proliferation, and efficiently induce cellular apoptosis as well as multiphase cell cycle arrest. Mechanistically, SIN treatment upregulated the levels of the pro-apoptotic regulators, cleaved caspase 3 and Bax, and downregulated the level of anti-apoptotic Bcl-xl. Additionally, SIN treatment also increased the protein levels of p21 and p27, as two regulators functioning to slow cell cycle progression. Taken together, the present studied indicated SIN to be a promising compound for the treatment of hepatocellular carcinoma, based on its apparent effect in modulating cell apoptosis and the cell cycle in Huh7 cells in vitro.