Recently, high-fat diet (HFD) induced steatosis was thought

to be associated with the depletion of hepatic regulatory T cells (Tregs) and the adoptive transfer of Tregs decreased inflammation in HFD-fed mice. Glycyrrhizin (GL), a natural triterpene in clinical treatment of patients with chronic liver disease, Roxadustat in vitro can significantly reduce free fatty acid (FFA)/ HFD induced hepatic lipotoxicity. Methods: For induction of NASH, mice were fed with a methionin–choline-deficient (MCD) diet for 8 weeks. Control mice received a standard diet containing 10% fat. All diets were γ-irradiated. Development of liver injury was followed by intraperitoneal administration of GL or vehicle control (saline) two times a week for the last 4 weeks on the diet in MCD mice. The analysis of hepatic and splenic CD4+T cells phenotypes and the preparation of splenic CD4+T,

CD4+CD25+ and CD4+CD25-T cells were done by flow cytometry. The detection of PPAR-γ was done by Western blot and T-cell cytokines were measured by ELISA. T-cell proliferation assay was tested by the MTT method and cell apoptosis was analyzed using the Annexin V-FITC Apoptosis Detection Kit. Purified splenic CD4+CD25+T cells from MCD-fed mice or GL treated MCD-fed mice were collected and co-cultured with splenic CD4+CD25-T cells from control mice. Furthermore, specific inhibitor of PPAR-γ (GW9662) or agonist of PPAR-γ was also added along with GL treatment to observe whether the effects of GL Ivacaftor datasheet were dependent on PPAR-γ signaling or not. Results: GL alleviated MCD-induced liver injury by decreasing ALT and AST levels in serum to normalization

nearly in time and dose dependent manners. GL also reduced hepatic inflammatory cell infiltrations, hepatic lipid overloading and the NAFLD activity in MCD-fed mice. GL altered the proportion of hepatic and splenic CD4+T cells and cytokines secretion in MCD-fed mice, which showed the prevalence MCE of Tregs and decreased proportion of Th17 cells. GL promoted the apoptosis of hepatic and splenic Th1 and Th17 cells but relatively inhibited which of Tregs. GL enhanced the level of PPARγ, which correlated with the enhanced proportion of serum CD4+CD25+T cells. In vitro experiment, PPARγ signaling participated in the GL-induced proliferation of splenic nTregs. GL enhanced the inhibitory effect of splenic nTregs on Teffs (CD4+CD25-T cells), which was dependent on PPAR-γ. Furthermore, GL promoted the production of iTregs and altered the proliferation, apoptosis and cytokines secretion of iTregs Conclusion: These results provide evidence that GL, which has excellent anti-inflammatory characteristics, amelioration of hepatic injury and definite lipidlowering properties, and may be capable of alleviating the progression of NASH. The therapeutic effects of GL partly contribute to the induction of Tregs and the enhanced modulatory functions of Tregs, and furthermore, PPAR-γ signaling may be involved in the modulatory mechanism of GL. Key Word(s): 1. Glycyrrhizin; 2.