Peptides from Antarctic krill (Euphausia superba) ameliorate acute liver injury in mice induced by carbon tetrachloride via activating the Nrf2/HO-1 pathway

This study aimed to evaluate the hepatoprotective effects of peptides from Antarctic krill (AKP) on carbon tetrachloride (CCl4)-induced acute liver injury (ALI) in mice and the underlying molecular mechanisms. ICR mice were pretreated with AKP (500 mg kg-1, i.g.) and silybin (30 mg kg-1, i.g.) for 15 days before CCl4 (0.25 mL per kg BW, i.p.) injection. To assess hepatocellular damage and molecular indices, the serum and liver tissue were evaluated at harvest. The results showed that AKP pretreatment remarkably attenuated CCl4-induced liver injury, which was identified by the decrease in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), alleviation of hepatocyte necrosis, and inhibition of the levels of the pro-inflammatory factors TNF-α and IL-1β compared to those for silymarin. AKP pretreatment also enhanced the redox balance by reducing the concentrations of MDA and 8-iso-PG and increasing the activities of SOD, GSH and GSH-PX in the liver of mice. In addition, AKP upregulated oxidative stress-related mRNA expressions of Nrf2, Keap1, HO-1, and NQO1 and further activated the protein expression on the Nrf2/HO-1 singling pathway. In summary, AKP might be a promising hepatoprotective nutraceutical against ALI and its underlying mechanisms are associated with activation of the Nrf2/HO-1 pathway.