OBJECTIVE To study the effects of the non steroidal estrogen antagonist idoxifene on hepatocyte apoptosis induced by oxidative stress METHODS After hepatocytes were incubated with or without FeNTA(100 mmol·L -1 )in the presence or absence of idoxifene(10 -9 ,10 -8 ,10 -7 mol·L -1 ),apoptotic hepatocytes were examined by flow cytometry The protein levels of Bcl 2 family, activity of caspase 3 and activator protein 1(AP 1) were detected by western blot, enzyme linked immunosorbent assay and electrophoretic mobility shift assay respectively RESULTS Idoxifene inhibited oxidative stress induced hepatocyte apoptosis The protein levels of Bcl 2 and Bcl X L in hepatocytes cultured with FeNTA plus idoxifene were 3 01 and 1 68 times of those in hepatocytes cultured with FeNTA alone respectively Idoxifene reduced the activity of caspase 3 by 36 92% and significantly inhibited AP 1 activity in hepatocytes undergoing oxidative stress The activated AP 1 mainly consists of c jun and c fos The activated AP 1 mailnly consists of c jum and c fos CONCLUSION Idoxifene could inhibit oxidative stress induced hepatocyte apoptosis through maintaining the protein levels of Bcl 2 and Bcl X L and suppressing the activity of caspase 3 and AP 1