NF‐κB and AMPK/PI3K/Akt signaling pathways are involved in the protective effects of Platycodon grandiflorum saponins against acetaminophen‐induced acute hepatotoxicity in mice

Abstract

Acute liver injury (ALI) induced by acetaminophen (APAP) overdose is the most common cause of drug-induced liver injury. Saponins from Platycodon grandiflorum (PGSs) ameliorate alcohol-induced hepatotoxicity and enhance human lung carcinoma cell death via AMPK signaling pathway. However, whether PGS could protect from APAP-induced ALI through AMPK activation and its downstream signals is still poorly elucidated. This work investigated the protective effect and the underlying mechanisms of PGS against APAP-induced liver toxicity in mouse. PGS was administered at 15 or 30mg/kg i.g./day for 1week before a single injection of APAP (250mg/kg, i.p.) 1hr after last treatment of PGS. Serum alanine/aspartate aminotransferases, liver tumor necrosis factor-α and interleukin-1β levels, liver malondialdehyde formation, liver glutathione depletion, cytochrome P450 E1, and 4-hydroxynonenal levels were measured to demonstrate the protective efficacy of PGS against APAP-induced ALI. Liver histological observation provided further evidence on PGS's protective effects. PGS treatment altered the phosphorylation of AMPK and PI3K/Akt, as well as the downstream signals including Bcl-2 family, caspase, and NF-κB in a dose-dependent manner. In conclusion, we demonstrate that PGS exhibits a significant liver protection against APAP-induced ALI, mainly through NF-κB and AMPK/PI3K/Akt signaling pathways.