Glycyrrhizin attenuates HMGB1-induced hepatocyte apoptosis by inhibiting the p38-dependent mitochondrial pathway

Figure 3 Glycyrrhizin attenuates high-mobility group box 1-induced hepatocyte apoptosis. A: Huh-BAT cells were pretreated with glycyrrhizin (GL) (0, 0.1, 0.5, 1.0 and 2.0 mmol/L) for 12 h. Cells were then treated with 10 μg/mL of high-mobility group box 1 (HMGB1) for 6 h. Apoptosis was quantified by 4',6-diamidino-2-phenylindole staining and fluorescence microscopy. Data are expressed as the mean ± SD of three individual experiments. ^aP < 0.05, vs GL 0 mmo/L; B: Huh-BAT cells were pretreated with GL (2.0 mmol/L) for 12 h prior to adding HMGB1 (0-10 μg/mL). Mitochondrial and cytosolic extracts were isolated after 6 h of HMGB1 treatment, and equivalent amounts of cytosolic protein were immunoblotted with an anti-cytochrome c antibody. Immunoblot analysis using an anti-actin antibody was performed as a control for protein loading; C: Huh-BAT cells were pretreated with GL (2.0 mmol/L) for 12 h prior to being incubated with HMGB1. Cells were then lysed at the indicated time points, and immunoblot analysis was performed using antibodies specific for the phosphorylated forms of p38 and actin.