Beneficial effects of histidine and carnosine on ethanol-induced chronic liver injury

Alleviative effects of histidine and carnosine in mice against ethanol-induced oxidative and inflammatory was examined. After chronic alcoholic liver injury was induced, histidine and carnosine at 0.5, 1, 2 g/L were added to the drinking water for 3 weeks. Results showed that the post-intake of histidine or carnosine markedly decreased alanine aminotransferase and aspartate aminotransferase activities (P < 0.05). Ethanol treatment increased malondialdehyde (MDA) level, decreased glutathione (GSH) content and catalase and glutathione peroxidase (GPX) activities, and increased cytochrome P450 2E1 (CYP2E1) activity in liver (P < 0.05). The post-intake of histidine and carnosine significantly decreased MDA formations, increased GSH content, enhanced catalase and GPX activities, and suppressed CYP2E1 activity (P < 0.05), in which the effects on catalase and CYP2E1 activities were dose-dependent (P < 0.05). Ethanol treatment elevated hepatic levels of c-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) (P < 0.05), the post-intake of histidine and carnosine significantly and dose-dependently diminished the release of CRP, IL-6, and TNF-α (P < 0.05). Ethanol treatment caused down-regulation in both catalase and GPX mRNA expression, and up-regulated both IL-6 and TNF-α mRNA expression (P < 0.05). Histidine and carnosine post-treatments significantly and dose-dependently upregulated catalase mRNA, and down-regulated mRNA expression of IL-6 and TNF-α (P < 0.05). Based on the observed anti-oxidative and anti-inflammatory effects, the supplement of histidine or carnosine might be helpful for the treatment of chronic alcoholic liver injury.