Attenuating Oxidative Stress by Paeonol Protected against Acetaminophen-Induced Hepatotoxicity in Mice

Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. The purpose of this study was to investigate whether paeonol protected against APAP-induced hepatotoxicity. Mice treated with paeonol (25, 50, 100 mg/kg) received 400 mg/kg acetaminophen intraperitoneally (i.p.) and hepatotoxicity was assessed. Pretreatment with paeonol for 6 and 24 h ameliorated APAP-induced hepatic necrosis and significantly reduced the serum alanine aminotransferase (ALT) and aspartate transaminase (AST) levels in a dose-dependent manner. Post-treatment with 100 mg/kg paeonol ameliorated APAP-induced hepatic necrosis and reduced AST and ALT levels in the serum after APAP administration for 24 h. Western blot revealed that paeonol inhibited APAP-induced phosphorylated JNK protein expression but not p38 and Erk1/2. Moreover, paeonol showed anti-oxidant activities with reducing hepatic MDA contents and increasing hepatic SOD, GSH-PX and GSH levels. Paeonol dose-dependently prevented against H2O2 or APAP-induced LDH releasing and ROS production in primary mouse hepatocytes. In addition, the mRNA levels of pro-inflammatory genes such as TNF-alpha, MCP-1, IL-1 beta and IL-6 in the liver were dose-dependently reduced by paeonol pre-treatment. Pre-treatment with paeonol significantly inhibited IKK alpha/beta, I kappa B alpha and p65 phosphorylation which contributed to ameliorating APAP-induced hepatic inflammation. Collectively, the present study demonstrates paeonol has a protective ability against APAP-induced hepatotoxicity and might be an effective candidate compound against drug-induced acute liver failure.