Abstract: This study aimed to understand the protective effects of total alkaloids from lotus leaves (TAL) on acute liver injury induced by acetaminophen (APAP) in mice and the potential mechanisms.Mice were randomly divided into 4 groups,i.e.,the normal group,the model group,the TAL low-dosage group (30 mg/kg) and the TAL high-dosage group (100 mg/kg).Animals received TAL through gavage for 7 consecutive days.Then,except the normal group,other groups received APAP (300 mg/kg) by intraperitoneal injection to provoke acute liver injury.Serum and livers of mice were collected 12 h later and subjected to further experiments.Our results showed that as compared to the model group,TAL significantly decreased activities of ALT and AST in the serum and contents of TNF-α,IL-1β,IL-6 and MDA in the liver.In addition,TAL dose-dependently elevated hepatic levels of SOD,CAT,GSH-Px and GSH.Moreover,APAP-induced liver histopathological changes were dramatically alleviated by TAL.Mechanistically,TAL considerably boosted AMPK phosphorylation,induced nuclear translocation of Nrf2 and promoted expression of HO-1 and GCLC.In conclusion,this study revealed that TAL has the capacity of ameliorating APAP-induced acute liver injury,and the underlying mechanisms are related with the activation of hepatic AMPK/Nrf2 cascade.

Key words: total alkaloids from lotus leaves, liver injury, antioxidant, Nrf2 pathway