This study investigated the in vitro and in vivo antiproliferative activity of
esculetin against
hepatocellular carcinoma, and clarified its potential molecular mechanisms. Cell viability was determined by the
MTT (tetrazolium) colorimetric assay. In vivo antitumor activity of
esculetin was evaluated in a
hepatocellular carcinoma mouse model. Seventy-five C57BL/6J mice were implanted with Hepa1-6 cells and randomized into five groups (n=15 each) given daily
intraperitoneal injections of vehicle (physiological saline),
esculetin (200, 400, or 700 mg·kg-1·day-1), or
5-Fu (200 mg·kg-1·day-1) for 15 days.
Esculetin significantly decreased
tumor growth in mice bearing Hepa1-6 cells.
Tumor weight was decreased by 20.33, 40.37, and 55.42% with increasing doses of
esculetin.
Esculetin significantly inhibited proliferation of HCC cells in a concentration- and time-dependent manner and with an IC50 value of 2.24 mM. It blocked the cell cycle at S phase and induced apoptosis in SMMC-7721 cells with significant elevation of
caspase-3 and
caspase-9 activity, but did not affect
caspase-8 activity. Moreover,
esculetin treatment resulted in the collapse of mitochondrial membrane potential in vitro and in vivo accompanied by increased Bax expression and decreased Bcl-2 expression at both transcriptional and translational levels. Thus,
esculetin exerted in vitro and in vivo antiproliferative activity in
hepatocellular carcinoma, and its mechanisms involved initiation of a mitochondrial-mediated, caspase-dependent apoptosis pathway.