**Novel Mechanism Supporting Therapeutic Effects of Glycyrrhizin in Acute or Chronic Hepatitis Glycyrrhizin in Acute or Chronic Hepatitis**

**Novel Mechanism Supporting Therapeutic Effects of** 

Noriyuki Kuroda and Tetsuji Sato Noriyuki Kuroda and Tetsuji Sato Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/67078

#### **Abstract**

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134 Biological Activities and Action Mechanisms of Licorice Ingredients

7(4) (2014) 1116–29.

Glycyrrhizin (GL) isolated from the roots of licorice plant (*Glycyrrhiza glabra* L.) has been traditionally used for treating peptic ulcer, hepatitis, and pulmonary bronchitis. In addi‐ tion to the protective effects of GL against liver injury or cancer proliferation by the mem‐ brane stabilization or via progesterone‐receptor membrane component 1 (PGRMC1), the present chapter reports its new therapeutic mechanism through high‐mobility group protein 1 (HMGB1) to which GL directly binds. In this study, we evaluated inflamma‐ tion‐promoting activity of HMGB1 and blockade of extracellular release of HMGB1 by GL in lipopolysaccharide (LPS)/d‐galactosamine (GalN)‐triggered mouse liver injury. In this experimental hepatitis model, apoptotic response of hepatocytes through the binding of HMGB1 protein to Glutathione transferase omega 1 (*Gsto1*), an apoptosis‐associated gene, promoter region is caused, serum AST and ALT activities significantly increased, and GL‐treatment prevented the apoptosis and inflammatory infiltrates induced with LPS/GalN‐injection by disturbing the binding of HMGB1 protein to *Gsto1* promoter sequence. Analysis with chromatin immunoprecipitation (ChIP)‐assay revealed inhibit‐ ing the binding of HMGB1 protein to *Gsto1* by the binding of GL to HMGB1.

**Keywords:** glycyrrhizin, liver injury, PAMPs, DAMPs, HMGB1
