Matrine Inhibits Infiltration of the Inflammatory Gr1hi Monocyte Subset in Injured Mouse Liver through Inhibition of Monocyte Chemoattractant Protein-1

Matrine (Mat) is a major alkaloid extracted from Sophora flavescens Ait, an herb which is used in the traditional Chinese medicine for treatment of inflammation, cancer, and other diseases. The present study examined the impact of Mat on the CCl4-induced hepatic infiltration of Gr1hi monocytes to explore the possible mechanisms underlying its anti-inflammatory and antifibrotic effects. The results indicated that Mat protected mice from acute liver injury induced by single intraperitoneal injection of CCl4 and attenuated liver fibrosis induced by repeated CCl4 injection. Meanwhile, the infiltrations of Gr1hi monocytes in both acute and chronic injured livers were all inhibited, and the enhanced hepatic expression of MCP-1 was suppressed. Cellular experiments demonstrated that Mat directly inhibited MCP-1 production in both nonparenchymal cells and hepatic stellate cells derived from CCl4-injured livers. Transwell chemotaxis assays showed that Mat significantly inhibited the chemotactic activity of MCP-1. These results suggest that the anti-inflammatory and antifibrotic effects of Mat could be contributed, at least in part, to its prevention of Gr1hi monocyte infiltration into the injured livers and inhibition of MCP-1 production and activity. These findings extend our understanding of the mechanisms underlying the anti-inflammatory and antifibrotic effects of Mat.