Scutellariae radix suppresses LPS-induced liver endothelial cell activation and inhibits hepatic stellate cell migration

Liver fibrosis is the result of long-term liver damage and the wound-healing process, in which the hepatic stellate cell (HSC) plays a crucial role during fibrogenesis. The liver sinusoidal endothelial cell (LSEC) is a liver-resident scavenger, contributing to sinusoidal remodeling, HSC activation and liver fibrosis. Lipopolysaccharide (LPS) causes an inflammatory reaction associated with portal circulation and LSECs signaling. Scutellariae radix, the root of Scutellaria baicalensis Georgi, is a Chinese herb widely used for liver diseases. However, its effect on LSEC activation and HSC migration in liver fibrosis has not been investigated yet. LPS-induced rat LSEC (rLSEC) activation was used as a model to screen and explore the active components of Scutellariae radix. The anti-fibrotic effect of Scutellariae radix on rLSEC activation and rHSC migration was further investigated. LPS-induced rLSEC mRNA expression, including VEGF, VEGFR, MCP-1, and TGF-β1, were examined by real-time PCR analyses. MCP-1 protein levels were measured by an ELISA kit. rLSEC conditioned medium on rHSC migration was measured by wound-healing assay and transwell chemoattraction assay. Results showed LPS-induced rLSEC activation with upregulated MCP-1 mRNA and protein expressions, and that rLSEC-condition medium enhanced rHSC migration. Both baicalein and wogonin from the active subfraction significantly reduced MCP-1 expression, but only baicalein markedly inhibited rHSC migration in rLSEC conditioned medium. This study demonstrated that Scutellariae radix attenuates LPS-induced rLSEC activation and HSC migration with downregulation of MCP-1 expression. The results provide supporting evidence that Scutellariae radix may be beneficial for the amelioration of liver fibrosis.