OBJECTIVETo investigate the effect of paraquat (PQ) on reactive oxygen species (ROS) and neutrophil apoptosis and its possible signal transduction pathways.

METHODSCultured neutrophils were treated with different concentrations of PQ for 6-24 h. The apoptosis rate of neutrophils and ROS content were determined by flow cytometry. The exoressions of nuclear factor kappa B (NF-κB) and Caspase 3 were detected by Western blot. These parameters were checked again after NF-κB and Caspase 3 antagonist were applied.

RESULTSPQ could boost ROS generation and depress neutrophil apoptosis significantly. At the same time PQ could enhance the expression of NF-κB and inhibit the expression of Caspase 3. These effects could be reversed by ROS inhibitor diphenyleneiodonium (DPI) and NF-κB inhibitor pyrrolidinedithiocarbamate (PDTC).

CONCLUSIONPQ is a potent inducer of ROS and can inhibit neutrophil apoptosis by activating NF-κB and surpressing Caspase 3 activity.