The protective effect of glycyrrhizin on hepatic ischemia-reperfusion injury in rats and possible related signal pathway

To investigate the protective effect of glycyrrhizin (GL) on hepatic ischemia-reperfusion injury (HIRI). Forty SD rats were randomly divided into sham group, HIRI group, GL 100 mg/kg group, and GL 200 mg/kg group. The pathological alterations of liver tissue in each group were observed. The levels of alanine transaminase (ALT), aspartate aminotransferase (AST), endothelin-1 (ET-l), nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) were detected. Western blot was used to detect the expression levels of cytoplasmic protein caspase-3, Bax, Bcl-2, heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear protein Nrf2. Compared with the HIRI group, the levels of AST, ALT, ET-1, TNF-α, IL-1β, and IL-6 in GL groups were lower, serum NO content was higher, MDA content was lower, SOD and GSH-Px activities were significantly increased, apoptosis index was lower (P<0.05), which was more obvious in high-dose GL (200 mg/kg) group. The LC3-II/LC3-I ratio and Beclin-1 protein expression levels in the GL group were significantly lower than the HIRI group, but the expression levels of cytoplasmic protein HO-1 and nuclear protein Nrf2 were significantly higher than those of the HIRI group, which was more obvious in the high-dose GL group (P<0.05). GL has a protective effect on the liver of HIRI rats, and its mechanism may be related to activation of the Nrf2/HO-1 signaling pathway, inhibition of oxidative stress, inflammation, autophagy, and apoptosis.