Jasurolignoside from Ilex pubescens exerts a therapeutic effect on acute lung injury in vitro and in vivo by binding to TLR4

Acute lung injury (ALI) is a fatal disease caused by a severe viral infection that triggers an uncontrolled inflammatory response. Our study explored the ability of jasurolignoside (JO), a naturally occurring substance, to bind to TLR4 and treat ALI. The inflammatory effects of JO were examined in vitro through Western blotting, ELISA, immunofluorescence staining, and co-immunoprecipitation. The present investigation employed an animal model of acute lung injury induced by lipopolysaccharide (LPS) to examine the therapeutic potential and underlying mechanism of JO in vivo. JO was found to alleviate inflammatory syndromes in infected cells and tissues by regulating the NLRP3 inflammasome and the NF-κB/MAPK pathway. The results of molecular docking simulations confirmed that JO binds to the active sites of TLR4, which was confirmed by a cellular thermal shift assay. Direct binding studies demonstrated that JO directly interacted with TLR4 with a KD value of 35.1 μM, as determined by surface plasmon resonance. Furthermore, JO inhibited the secretion of TNF-α, IL-1β, and IL-6 and decreased the infiltration of leukocytes, neutrophils, lymphocytes, and macrophages in mice with ALI. Additionally, JO was shown to improve lung function and prevent mortality caused by ALI. Immunohistochemical staining results indicated that JO was able to suppress TLR4 expression in the lung tissue of mice with ALI. In conclusion, our study indicated that JO can bind to TLR4 and effectively treat ALI, suggesting that it is a highly promising therapeutic agent for clinical application.