N-acetylcysteine antagonises arsenic trioxide in inducing apoptosis in a human hepatocarcinoma cell line

Objectives To study the antagonising effect of antioxidant N-acetylcysteine (NAC) on arsenic trioxide (AT)-induced human hepatocarcinoma cell apoptosis and its possible mechanisms.?Methods MTT, DNA ladder and hematoxylin-eosin (HE) staining methods were used to study the effects of AT on the human hepatocarcinoma cell line BEL-7402 in inducing apoptosis and producing injuries in the cells,as well as the antagonistic action of NAC in vitro.?Results (1) AT in effective doses inhibited the proliferation of human hepatocarcinoma cells and induced apoptosis. (2) NAC could antagonise the apoptosis and cell injuries induced by AT.?Conclusions The effect of AT on cancer cells is related to the intracellular GSH level. AT might inactivate many functional proteins by binding with their -SH radicles, inhibiting the abnormal growth of human hepatocarcinoma cells and inducing their apoptosis.