摘要BACKGROUND: Paraquat (PQ)-induced acute lung injury (ALI) and pulmonary fi brosis are common diseases with high mortality but without eff ective antidotes in emergency medicine. Our previous study has proved that arctigenin suppressed pulmonary fibrosis induced by PQ. We wondered whether arctigenin could also have a protective eff ect on PQ-induced ALI.METHODS: A PQ-induced A549 cell injury model was used, and the effect of arctigenin was determined by a cell counting kit-8 (CCK-8) cell viability assay. In addition, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labelling (TUNEL) staining assays and mitochondrial membrane potential assays were performed to evaluate the level of cell apoptosis. The generation of reactive oxygen species (ROS) was refl ected by dihydroethidium (DHE) staining and a 2',7'-dichlorodihy drofluorescein diacetate (DCFH-DA) assay. Moreover, immunoblotting studies were used to assess the expression of mitogen-activated protein kinases (MAPKs) and p38 MAPK. RESULTS: Arctigenin attenuated PQ-induced inhibition of A549 cell viability in a dose-dependent manner. Arctigenin also significantly reduced PQ-induced A549 cell apoptosis, as refl ected by the TUNEL assay and mitochondrial membrane potential assay, which may result from suppressed ROS/p38 MAPK signaling because we found that arctigenin dramatically suppressed ROS generation and p38 MAPK phosphorylation. CONCLUSION: Arctigenin could attenuate PQ-induced lung epithelial A549 cell injury in vitro by suppressing ROS/p38 MAPK-mediated cell apoptosis, and arctigenin might be considered a potential candidate drug for PQ-induced ALI.