Diammonium glycyrrhizinate, a component of traditional Chinese medicine Gan-Cao, prevents murine T-cell-mediated fulminant hepatitis in IL-10- and IL-6-dependent manners

Diammonium glycyrrhizinate (DG), a traditional Chinese medicine (TCM), is extracted and purified from liquorices (Radix glycyrrhizae). The liquorices exert an important function in the treatment of hepatitis because of its anti-inflammatory effects based upon the clinical practice, but the underlying mechanism is unclear. In this study, we investigated the mechanisms of DG in protecting mice from ConA-induced hepatitis. The results showed that intraperitoneal administration of DG protected mice against ConA-induced elevation of serum ALT levels and apoptosis of hepatocytes; at the same time, the absolute amount of hepatic NKT cells and T cells was significantly decreased, indicating that DG can inhibit the recruitment of lymphocytes into the liver. In addition, the production of IL-6 and IL-10 was improved by DG pretreatment, suggesting that DG may possibly protect the liver from injury via two pathways: direct protection of hepatocytes from apoptosis through an IL-6-dependent way and indirect inhibition of T-cell-mediated inflammation through an IL-10-dependent way. (c) 2007 Elsevier B.V. All rights reserved.