ABSTRACT
Naringin (Nar) has been reported to exert potential hepatoprotective effects against acetaminophen (APAP)-induced injury. Mitochondrial dysfunction plays an important role in APAP-induced liver injury. However, the protective mechanism of Nar against mitochondrial damage has not been elucidated. Therefore, the aim of this study was to investigate the hepatoprotective effects of Nar against APAP and the possible mechanisms of actions. Primary rat hepatocytes and HepG2 cells were utilized to establish an in vitro model of APAP-induced hepatotoxicity. The effect of APAP and Nar on cell viability was evaluated by a CCK8 assay and detection of the concentrations of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase. The cellular concentrations of biomarkers of oxidative stress were measured by ELISA. The mRNA expression levels of APAP-related phase II enzymes were determined by real-time PCR. The protein levels of Nrf2, phospho (p)-AMPK/AMPK, and biomarkers of mitochondrial dynamics were determined by western blot analysis. The mitochondrial membrane potential (MMP) was measured by high-content analysis and confocal microscopy. JC-1 staining was performed to evaluate mitochondrial depolarization. Nar pretreatment notably prevented the marked APAP-induced hepatocyte injury, increases in oxidative stress marker expression, reductions in the expression of phase II enzymes, significant loss of MMP, mitochondrial depolarization, and mitochondrial fission in vitro. In conclusion, Nar alleviated APAP-induced hepatocyte and mitochondrial injury by activating the AMPK/Nrf2 pathway to reduce oxidative stress in vitro. Applying Nar for the treatment of APAP-induced liver injury might be promising.
ABSTRACT
The role of the high mobility group box 1 (HMGB-1) in acute hepatic failure and the ef- fect of artificial liver support system treatment on HMGB-1 level were investigated. Pig models of acute hepatic failure were induced by D-galactosamine and randomly divided into two groups with or without artificial liver support system treatment. Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels were detected by the enzyme linked immunosorbent assay (ELISA), the expression of HMGB-1 by Western blot, and serum levels of HMGB-1, liver function and hepatic pathology were observed after artificial liver support system treatment. The levels of TNF-α and IL-1β were increased and reached the peak at 24th h in the acute hepatic failure group, then quickly decreased. The serum level of HMGB-1 was increased at 24th h in the acute hepatic failure group and reached the peak at 48th h, then kept a stable high level. Significant liver injury appeared at 24th h and was continuously getting worse in the pig models of acute hepatic failure. In contrast, the liver injury was significantly alleviated and serum level of HMGB-1 was significantly decreased in the group treated with artificial liver support system (P＜0.05). It was suggested that HMGB-1 may participate in the inflammatory response and liver injury in the late stage of the acute liver failure. Artificial liver support system treatment can reduce serum HMGB-1 level and relieve liver pathological damage.