[Study on impact of ethanol extracts from Sedum sarmentosum in inhibiting STAT-3 signaling and inducing apoptosis of human hepatocellular carcinoma cell line HepG2].

ABSTRACT

OBJECTIVE: To investigate the impact of ethanol extracts from Sedum sarmentosum (ESB) on STAT-3 signaling and its probable molecular mechanism in inducing apoptosis. METHOD: MTT assay was used to detect the impact of ESB on HepG2 cell proliferation. FITC-Annexin V-FITC /PI double-labeling were used to investigate the impact on hepatoma carcinoma cell apoptosis. Western blot analysis was used to test the expression levels of cell apoptosis-related proteins Caspase-3, Caspase-9, PARP, P-STAT-3 (Tyr705) , STAT-3, Bcl-2, Mcl-1. RESULT: ESB could notably inhibit proliferation of HepG2 cells, and induce HepG2 cell apoptosis, with the dose-dependent inhibitory effect. In addition, ESB could inhibit STAT-3 signaling, down-regulate Mcl-1 and Bcl-2 expressions, and induce degradation/activation of apoptosis-related proteins Caspase-3 and Caspase-9 and PARP degradation in a dose-dependent manner. CONCLUSION: ESB inhibits HepG2 cell proliferation and induces apoptosis by inhibiting STAT-3 signaling and Mcl-1 and Bcl-2 expressions.