Polysaccharides from Bupleurum chinense impact the recruitment and migration of neutrophils by blocking fMLP chemoattractant receptor-mediated functions

Although neutrophils play important roles in host defense, sometimes they contribute to inflammation-related tissue injuries. Thus, restriction of their recruitment to the inflammatory sites is a promising strategy in the amelioration of inflammatory disease. The previous studies reported the anti-inflammatory effects of Bupleurum chinense, but the active ingredients and possible mechanism are still unclear. Here, we isolated water-soluble polysaccharides (BCPs) from B. chinense, to evaluate its anti-inflammatory effects and possible mechanism. The present results showed that BCPs significantly impaired the in vivo neutrophil infiltration, as well as the migration capacity of dHL-60 cells in vitro. In addition, BCPs inhibits chemoattractant fMLP-induced activation and clustering of β2 integrin. BCPs impacted fMLP-induced actin polymerization and the activation of cytoskeleton regulatory molecules, Vav1 and Rac1. Together, BCPs significantly impacted recruitment and migration of neutrophils by blocking chemoattractant receptor-mediated functions, and it possesses a potential as novel anti-inflammatory drug.