Hepatoprotective effect of allicin against acetaminophen-induced liver injury: Role of inflammasome pathway, apoptosis, and liver regeneration

Acetaminophen (APAP) overdose leads to liver injury. NLRP3 inflammasome is a key player in APAP-induced inflammation. Also, apoptosis and liver regeneration play an important role in liver injury. Therefore, we assessed allicin's protective effect on APAP-induced hepatotoxicity and studied its effect on NLRP3 inflammasome and apoptosis. Mice in the APAP group were injected by APAP (250 mg/kg, intraperitoneal). The allicin-treated group received allicin orally (10 mg/kg/d) during 7 days before APAP injection. Serum and hepatic tissues were separated 24 hours after APAP injection. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, alkaline phosphatase (ALP), and hepatic malondialdehyde (MDA) were assessed using the colorimetric method. Hepatic NLRP3 inflammasome, caspase-1, and interleukin-1 beta (IL-1 beta) were estimated using enzyme-linked immunosorbent assay. Hepatic Bcl-2 and Ki-67 were investigated by immunohistochemistry. APAP significantly increased AST, ALT, and ALP, whereas allicin significantly decreased their levels. Also, APAP significantly decreased albumin and allicin significantly improved it. APAP produced changes in liver morphology, including inflammation and massive coagulative necrosis. Allicin protected the liver from APAP-induced necrosis, apoptosis, and hepatocellular degeneration via increasing Bcl-2 and Ki-67 levels. APAP significantly increased the hepatic MDA, whereas allicin significantly prevented this increase. APAP markedly activated the NLRP3 inflammasome pathway and consequently increased the production of caspase-1 and IL-1 beta. Interestingly, we found that allicin significantly inhibited NLRP3 inflammasome activation, which resulted in decreased caspase-1 and IL-1 beta levels. Allicin has a hepatoprotective effect against APAP-induced liver injury via the decline of oxidative stress and inhibition of the inflammasome pathway and apoptosis. Therefore, allicin might be a novel tool to halt the progression of APAP-stimulated hepatotoxicity.