The protective potential of metformin against acetaminophen-induced hepatotoxicity in BALB/C mice

Context: Acetaminophen overdose is regarded to a common cause of acute liver failure. The hepatotoxicity leads to mitochondrial oxidative stress and subsequent necrotic hepatocellular death. Objective: This study examines the protective effect of metformin on acetaminophen-induced oxidative stress, inflammation and subsequent hepatotoxicity in mice. Materials and methods: Male BALB/c mice were orally administered to acetaminophen (250 mg/kg/d) for a 7-day period. The mice received metformin (100 and 200mg/kg/d, p.o.) for 21 days. To evaluate acetaminophen-induced oxidative stress, liver tissue level of malodialdehyde (MDA), end product of membrane lipid peroxidation, and activities of superoxide dismutase (SOD) and glutathione (GSH) were measured. Histological analysis and measurement of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were performed. Moreover, tissue concentrations of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), along with, C-reactive protein (CRP) were assessed. Results: Acetaminophen caused focal hepatocyte necrosis, inflammation and fatty degeneration, as well as increased tissue levels of AST, ALT, ALP and MDA, and also decreased GSH and SOD activities. Moreover, IL-6, TNF-a and CRP levels were increased following acetaminophen hepatotoxicity. Metformin (200mg/kg/d) significantly normalized MDA, SOD and GSH levels (p<0.001), and exerted a hepatoprotective effect by significant decreasing ALT, AST and ALP concentrations (p<0.001). The tissue levels of IL-6, TNF-alpha and CRP were markedly decreased by 21-day treatment with metformin (200mg/kg/d) (p<0.001). Discussion: The results suggest metformin protects hepatocytes against acute acetaminophen toxicity. Metformin is indicated to diminish oxidative stress, proinflammatory cytokines, and hepatocyte necrosis.