Liensinine alleviates sepsis-induced acute liver injury by inhibiting the NF-κB and MAPK pathways in an Nrf2-dependent manner

Sepsis remains a serious public health issue that needs to be addressed globally. Severe liver injury caused by sepsis increases the risk of death in patients with sepsis. Liensinine (Lie) is one of the primary active components in Plumula nelumbinis and has anti-inflammatory and antioxidant effects. Nevertheless, the effects of Lie on septic liver injury are unclear. This research investigated the protective effect of Lie (10, 20 and 40 mg/kg) on liver damage via intraperitoneal administration of LPS (10 mg/kg) to C57BL/6 mice. Lie was given through intraperitoneal injection once a day for five days. Mice were treated with LPS intraperitoneally for 6 h at 1 h after Lie administration on the last day. The results suggested that Lie could decrease AST and ALT levels in serum, ameliorate histopathological changes and inhibit cell apoptosis in mice with LPS-induced septic liver injury. In addition, Lie inhibited increases in the mRNA levels of TNF-α, IL-1β, iNOS and IL-6. Lie also increased the mRNA level of IL-10. Lie reduced the content of MDA, a marker of lipid peroxidation, and increased the activity of the antioxidant enzymes GSH-Px, CAT and SOD. Our results also showed that Lie could suppress the LPS-activated MAPK and NF-κB pathways and trigger the Nrf2 signaling pathway both in vitro and in vivo. Additionally, an Nrf2 inhibitor (ML385) weakened the suppressive effect of Lie on the MAPK and NF-κB pathways. Our results demonstrated that the suppressive effect of Lie on the MAPK and NF-κB pathways was partially reliant on activation of the Nrf2 pathway. In summary, these results indicate that Lie can improve inflammation and oxidative stress by activating Nrf2, which is a prospective therapeutic drug for alleviating septic liver injury.