Comparison of different bile acid-phospholipid conjugates in acute hepatitis

Abstract

Introduction: The bile acid-phospholipid conjugate ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE) is a promising novel compound with profound hepatoprotective functions in vitro and in vivo. Because of high costs of LPE synthesis from hydrolysis of phosphatidylethanolamide (PE), costs for UDCA-LPE synthesis for in vivo and human use can become quite high. In this study, we evaluated whether ursodeoxycholyl phosphatidylethanolamide (udca-pe), which is more cost-effective, could replace udca-lpe in terms of protection from hepatocellular injury.

Materials and methods: Anti-apoptotic and anti-inflammatory properties of UDCA-PE and UDCA-LPE were compared in TNFα/cyclohexamide (CHX)-treated HepG2 cells as well as in a mouse model of d-galactosamine/lipopolysaccharide (Gal/LPS)-induced acute liver injury.

Results: Ursodeoxycholyl lysophosphatidylethanolamide inhibited TNFα/CHX-induced apoptosis in HepG2 cells in a dose-dependent manner and markedly ameliorated Gal/LPS-mediated fulminant hepatitis in mice. In contrast, UDCA-PE showed weaker hepatoprotective functions at low concentrations, and protection was lost at higher dosage. Analysis of hepatic gene expression showed that both conjugates significantly reduced Gal/LPS-mediated expression of chemoattractants, such as monocyte chemotactic protein 1 (MCP1) and RANTES. These inhibitory effects by UDCA-PE were transient while those by UDCA-LPE were sustained in attenuating expression of inflammatory MCP1 and RANTES expression.

Conclusions: Our data underline the superiority of UDCA-LPE compared to UDCA-PE in ameliorating acute liver inflammation. This indicates the significance of the lyso-functional group of bile acid conjugate for optimal hepatoprotection and reduction in inflammation in vivo.