The protective effect of glycyrrhizin against injury of the liver caused by ischemia-reperfusion.

Effects of glycyrrhizin (GR) on an injury of the liver caused by ischemia-reperfusion in rats were determined. In the liver ischemia-reperfusion model, levels of serum AST, ALT and LDH, lipid peroxides in the liver tissue, and blood superoxide dismutase activity were significantly increased. On the contrary, total glutathione content in the liver tissue was decreased. When rats were given GR 100 mg/kg for 10 days, GR suppressed the elevation of the lipid peroxide level, serum AST, ALT, LDH level, and the decrease in glutathione content during the period of reperfusion. The suppressive effect of GR was similar with that of alpha-tocopherol (VE). GR showed neither 1,1-diphenyl-2-picrylhydrazyl (DPPH) nor 5,5-dimethyl-1-pyrroline-N-oxide(DMPO)-OOH radical-trapping ability, but exhibited DMPO-OH radical-trapping action, while, VE exhibited both DPPH and DMPO-OOH radical-trapping ability. These results indicate that the hydroxyl radical trapping action of GR is the likely mechanism suppressing liver injury caused by ischemia-reperfusion.