Monotropein alleviates septic acute liver injury by restricting oxidative stress, inflammation, and apoptosis via the AKT (Ser473)/GSK3β (Ser9)/Fyn/NRF2 pathway

Sepsis-associated acute liver injury (ALI) is a deadly condition resulting from a systemic inflammatory response to liver cell damage and malfunction. Monotropein (MON) belongs to the iris group of compounds extracted from the natural product Mollen dae officinalis radix, which has strong anti-inflammatory and antioxidant pharmacological effects. The purpose of this study was to elucidate the underlying mechanism of MON in the treatment of sepsis ALI. In this study, an in vivo caecal ligation puncture (CLP)-induced ALI model and in vitro LPS-stimulated AML12 cells and RAW264.7 cells model were established. Additionally, a variety of experimental techniques, including CCK8, H&E staining, DHE probe labelling, biochemical, QPCR, and Western blotting and blocking tests, were used to explore the role of MON in ALI. The results showed that MON improved liver morphological abnormalities, oedema, histopathological injury, and elevated ALT and AST, providing a protective effect against ALI. MON reduced CYP2E1 expression, alleviated oxidative stress (downregulation of MDA levels and upregulation of GSH, CAT, and T-AOC levels) and ROS accumulation with the involvement of the NRF2-Keap-1 pathway. MON inhibited inflammation via the TLR4/NF-kappa B/NLRP3 inflammasome pathway. In addition, it activated the Akt (Ser473)/GSK3 beta (Ser9)/Fyn pathway and accelerated NRF2 nuclear accumulation; MK-2206 blockade reversed the NRF2 nuclear accumulation and anti-inflammatory function of MON. MON also restricted the mitochondrial apoptosis pathway, a process specifically blocked by MK-2206. In summary, we concluded that MON alleviated septic ALI by restricting oxidative stress, inflammation, and apoptosis via the AKT (Ser473)/GSK3 beta (Ser9)/Fyn/NRF2 pathway.