RESUMO
Aim To explore the protective roles of lic-ochalcone A ( LA) on mice with cigarette smoke-medi-ated acute lung injury and the related mechanisms. Methods In vivo: Mice were exposed to cigarette smoke ( CS) to establish acute lung injury model. The bronchoalveolar lavage fluid ( BALF ) was conducted for cell counting. The mRNA and protein expression of keratinocyte-derived chemokine ( KC ) , tumor necrosis factor alpha ( TNF-α) , interleukin 1β ( IL-1β) and matrix metalloproteinases ( MMP)-9 in lungs were de-termined. The myeloperoxidase ( MPO ) , superoxide dismutase ( SOD ) activities and glutathione ( GSH ) levels in lungs were quantified. The paraffin sections of lungs were prepared and stained with HE. In vitro:Human lung epithelial cells (BEAS-2B) were exposed to cigarette smoke extract ( CSE ) , which induced cell injury. The releases of interleukin 8 (IL-8) and MMP-9 were assessed. The phosphorylation of mitogen-acti-vated protein kinases ( MAPKs, including ERK1/2, p38 and JNK ) and nuclear factor-κB ( NF-κB ) p65 protein were analyzed by Western blot. Results In vi-vo: The accumulation of inflammatory cells was lower in LA groups than that in model group. In comparison with normal control group, the mRNA and protein lev-els of KC, TNF-α, IL-1βand MMP-9 were significant-ly increased in model group. Following treatment with LA, the above indicators were significantly decreased as compared to model group. In the CS-exposed mice, the MPO activity in lungs was significantly increased, meanwhile the SOD activity and GSH level were signif-icantly decreased compared with the air-exposed ani-mals. CS-induced activity of MPO was significantly in-hibited, which were accompanied by increases in SOD and GSH levels by LA. In vitro: CSE-induced mRNA levels of IL-8 and MMP-9 were significantly inhibited by LA at 2 . 5 and 5 μmol · L-1 . The CSE-induced phosphorylation of ERK1/2 and nucleus NF-κB p65 protein expression were prevented by pretreatment with LA. Conclusions LA has protective effects on CS-ex-posed acute lung injury in mice by preventing CS-in-duced pulmonary inflammation, oxidative stress and protease rise. The exploration of the mechanisms sug-gests that LA exerts protective effects via suppressing ERK1/2/NF-κB pathways.