Ginsenoside Rg1 Alleviates Hepatic Ischemia-Reperfusion Injury in Mice via Activating ERα-Regulating YAP Expression

OBJECTIVE: To verify whether ginsenoside Rg1 alleviates liver hepatic ischemia-reperfusion injury (IRI) in mice by upregulating the expression of Yes-associated protein (YAP) through estrogen receptor alpha pathway. METHODS: The whole hepatic IRI model and the local (70%) hepatic IRI model were established, respectively. The whole hepatic IRI model was used to observe the survival curve of mice, and the mouse models with 70% hepatic IRI were used to explore the mechanism of liver injury about Rg1 in hepatic IRI. Wild-type C57BL/6 mice were randomly divided into some groups: (1) the whole hepatic IRI model group: the survival rate of mice was observed at 0, 30, 60, 90, and 120 min after ischemia and Rg1 intervention (90 min after ischemia), with 10 mice in each group, and (2) the 70% hepatic IRI model group: sham operation group, I/R model group, verteporfin (VP) group, doxycycline (Doxy) group, 17β-estradiol (E2) group, clomiphene (Clom) group, and Rg1 group with 6 mice in each group. The level of serum alanine aminotransferase (ALT) was measured by enzyme labeling instrument, the degree of liver injury was analyzed after hematoxylin-eosin (HE) staining, and the function of mitochondria was detected in fresh liver tissue, including mitochondrial membrane potential with JC-1 (5,5′,6,6′-tetrachloro1,1′,3,3′-tetramethylbenzimidazolylcarbocyanine iodide), adenosine triphosphate (ATP), and mitochondrial reactive oxygen species (ROS), and the expression of YAP and estrogen receptor alpha (ERα) genes and proteins were detected by real‐time reverse‐transcriptase polymerase chain reaction (RT-PCR) and Western blot. RESULTS: The whole hepatic IRI model showed that the survival rate of mice decreased with the prolongation of ischemia time. IRI model mice showed mitochondrial damage, JC-1 red/green fluorescence value and ATP significantly decreased, and ROS production increased; in comparison, in the Doxy and E2 intervention group, JC-1 red/green fluorescence value and ATP production increased and ROS downregulated, indicating that mitochondrial function returned to normal. The level of serum ALT showed that the liver enzyme increased with the time of reperfusion and decreased gradually after 6 hours. The results of Western blot and PCR showed that the expression of YAP and ERα showed the same trend. The IRI model mice were observed after 90 minutes of ischemia and 6 hours of reperfusion. Compared with the corresponding sham group, the expression of YAP in the liver tissue of the Doxy group, E2 group, and Rg1 intervention group increased, and the expression of ERα in the E2 group and Rg1 group increased. HE staining showed that a large number of inflammatory cell infiltration could be seen in the liver tissue of the model group, but it decreased in the Doxy and E2 intervention groups. CONCLUSION: Ginsenoside Rg1 exerts an estrogenic effect by activating ERα, upregulating the expression of YAP, reducing liver oxidative stress injury, and inhibiting mitochondrial injury to protect the liver from ischemia-reperfusion injury in mice.