Are silymarin and N‐acetylcysteine able to prevent liver damage mediated by multiple factors? Findings against ethanol plus LPS‐induced liver injury in mice

Abstract This study investigated the effect of N‐acetylcysteine (NAC) and silymarin (SIL) in the liver of mice exposed to ethanol and lipopolysaccharides (LPS). Mice were divided into four groups ( n = 6): naive, vehicle, NAC (200 mg/kg), and SIL (200 mg/kg). Treatments were given orally (po) once daily for 10 days. Liver injury was induced by administration of ethanol (30%, po) for 10 days, once daily, followed by a single administration of LPS (2 mg/kg, ip) 24 h before euthanasia. After the treatment period, animals were euthanized, and liver and blood samples were collected. NAC, but not SIL, prevented the increase in oxalacetic glutamic transaminase (OGT) and pyruvic glutamic transaminase (PGT) serum levels. NAC and SIL did not restore levels of reduced glutathione or hepatic malonaldehyde. The treatments with NAC or SIL showed no difference in the activity of glutathione S‐transferase, superoxide dismutase, and catalase compared to vehicle group. Myeloperoxidase and N‐acetylglucosaminidase activities are increased, as well as the IL‐6 and IL‐10 levels in the liver. The treatment with NAC, but not SIL, reduced the N‐acetylglucosamines activity and the IL‐6 and IL‐10 amount in the liver. Histological findings revealed microsteatosis in the vehicle group, which was not prevented by SIL but was partially reduced in animals receiving NAC. Unlike other liver injury models, NAC (200 mg/kg) or SIL (200 mg/kg) did not positively affect antioxidant patterns in liver tissue of animals exposed to ethanol plus LPS, but NAC treatment displays anti‐inflammatory properties in this model.