Pseudoginsenoside-F11 (PF11), an ocotillol-type saponin, has been reported to have anti-inflammatory properties, but the effects of PF11 on acute lung inflammation were unknown. The present study aimed to investigate the protective effects and potential mechanisms of PF11 on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in male BALB/c mice. After being treated with PF11 (3, 10, and 30 mg/kg, intravenous) once a day for 3 consecutive days, the mice were challenged by intratracheal instillation of LPS, and then their lung tissues and bronchoalveolar lavage fluid (BALF) were collected for further analysis. The results showed that PF11 attenuated LPS-induced ALI, with alleviated histopathological damage, decreased lung wet/dry weight ratio, and reduced protein concentration and inflammatory cells number in BALF. Moreover, PF11 reversed the LPS-induced increases of mRNA expression and protein levels of interleukin-6, tumor necrosis factor-α, and interleukin-1β. Meanwhile, PF11 decreased LPS-induced myeloperoxidase activity and neutrophil infiltration in lung tissue by reducing the expression of macrophage inflammatory protein-2 and intercellular adhesion molecule-1, as well as enhanced neutrophil clearance by accelerating neutrophils apoptosis and their phagocytosis by alveolar macrophages. In conclusion, these results indicated that PF11 significantly attenuated LPS-induced ALI through suppressing neutrophil infiltration and accelerating neutrophil clearance, suggesting its potential in the treatment of ALI.
Keywords: acute lung injury; lipopolysaccharide; neutrophil; pseudoginsenoside-F11.