ABSTRACT
Acute lung injury (ALI) is a kind of lung disease mainly caused by excessive inflammatory reaction. At present, there is a lack of effective therapeutic drugs in clinic. The aim of this study was to investigate the improvement effect of Panax notoginseng saponins (PNS) on ALI and its potential mechanism. The model of wild-type C57BL/6J mice was established by intratracheal instillation of 50 μL 25 mg·mL-1 lipopolysaccharide (LPS). 24 h later, 200 and 400 mg·kg-1 PNS was given intragastric, respectively. 24 h after administration, the improvement effect of PNS on ALI mice was evaluated by lung function, wet-to-dry weight ratio (W/D), total protein, interleukin 6 (IL6) and tumor necrosis factor α (TNFα) concentration of bronchoalveolar lavage fluid (BALF), expression levels of IL6 and TNFα in lung tissues, pathological changes of lung tissues and expression of inflammatory cells in BALF. The protein expression levels of NF-κB and its upstream kinases in Raw264.7 cells and ALI mice lung tissues were further detected to evaluate the potential mechanism of PNS improving ALI mice. The experimental scheme was approved by the Animal Experiment Ethics Committee of Shanghai University of Traditional Chinese Medicine. It was found that 400 mg·kg-1 PNS could significantly improve the lung function of ALI mice, reduce the contents of W/D, BALF total protein, IL6 and TNFα, neutrophils expression in BALF and the infiltration of inflammatory cells in lung tissue. In Raw264.7 cells and ALI mice lung tissue, PNS significantly reduced the expression of NF-κB, reduced the protein expression and phosphorylation of NF-κB, promoted the expression of IκBα, and inhibited the inflammatory response. This study showed that PNS can improve ALI by inhibiting the activity of NF-κB, inhibiting the release of inflammatory factors and inflammatory cells infiltration, alleviating lung inflammation.