Aqueous extract from Rhizoma Smilacis Glabrae alleviates immunological liver damage by selectively facilitating the dysfunction of liver- infiltrating lymphocytes

The effect of an aqueous extract from Rhizoma Smilacis Glabrae (RSG) on liver injury induced by delayed-type hypersensitivity to picryl chloride in mice has been studied. In in-vitro co-culture of non-parenchymal cells (NPC) and hepatocytes isolated from liver-injured mice, pretreatment of NPC, but not parenchymal hepatocytes, with the extract resulted in concentration- and time-dependent inhibition of NPC-induced hepatocyte damage. A significant reduction of in-vitro hepatotoxicity, as measured by inhibition of serum transaminase elevation, was also observed in NPC isolated from mice treated with RSG extract. RSG extract facilitated apoptosis in NPC from liver-injured mice but not in parenchymal hepatocytes. The results suggest that RSG extract protects against liver injury by selective induction of apoptosis in liver- infiltrating cells, mainly activated T lymphocytes. Such characteristics will help provide a novel strategy not only for treatment of liver diseases, but also for regulation of the immune response.