Bovine lactoferrin intake prevents hepatic injury in a mouse model of non-alcoholic steatohepatitis induced by choline and methionine deficiency

Lactoferrin, a multifunctional protein found in breast milk, is important for the regulation of immune function. Non-alcoholic steatohepatitis (NASH), which is characterized by hepatitis and fibrosis, has no established drug treatment. In this study, we aimed to investigate the effects of lactoferrin on hepatocyte inflammation in a mouse model of NASH induced with a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD). As a method, C57BL/6JJmsSlc mice were fed CDAHFD for 14 days and simultaneously intake lactoferrin (3.3 g/kg or 6.6 g/kg) of water. Then, plasma levels aspartate aminotransferase (ALT) and alanine aminotransferase (AST) were measured and gene expression levels of inflammatory cytokines in the liver were examined. Plasma levels of ALT and AST significantly increased in the NASH model, indicating hepatocyte inflammation, and lactoferrin intake suppressed their elevation in a dose-dependent manner. Histological analysis revealed that lactoferrin alleviated the fatty liver-associated tissue damage. Additionally, lactoferrin suppressed the gene expression of the pro-inflammatory cytokines tumor necrosis factor (TNF-α), interleukin (IL)-1β, and IL-6 and the macrophage migration factor (MCP)-1, suggesting inhibition of macrophage activation. Lactoferrin also significantly reduced the expression of apoptosis-related genes (caspase 3 and p53), indicating its anti-apoptotic effects. Furthermore, lactoferrin alleviated oxidative stress by suppressing inducible nitric oxide synthase expression. These findings suggest that lactoferrin prevented liver injury in the mouse model of NASH induced by CDAHFD feeding by inhibiting macrophage-mediated inflammation and alleviating oxidative stress caused by fat accumulation.