Collagen peptides from Acaudina molpadioides prevent CCl 4 ‐induced liver injury via Keap1/Nrf2‐ARE, PI3K/AKT, and MAPKs pathways

Abstract Collagen peptide from Acaudina molpadioides (AMP) showed antioxidative activity in H 2 O 2 ‐induced RAW264.7 cells in our pervious study. In this study, it was observed that AMP could effectively improve the morphology and function of liver in CCl 4 ‐induced mice. After 200 mg/kg AMP treatment, the content of MDA in liver decreased by 62.3%, and the level of antioxidant enzymes (SOD, GSH‐Px, and CAT) increased by more than 65%. Western blot results disclosed that AMP (200 mg/kg) upregulated the Nrf2 level by 73.8% and downregulated Keap1 by 41.0% in CCl 4 ‐induced mice liver. The levels of p‐ERK, p‐JNK, and p‐p38 in 200 mg/kg AMP treatment groups decreased by 57.3%, 40.9%, and 40.6%, but the levels of p‐PI3K and p‐AKT increased by 162.6% and 60.3%, respectively. Furthermore, the trends of Nrf2, Keap1, p‐ERK, p‐JNK, p‐p38, p‐PI3K, and p‐AKT levels in H 2 O 2 ‐induced RAW264.7 cells after AMP treatment were similar to the results in CCl 4 ‐induced mice liver. These findings provided evidence that AMP exerted antioxidant activity via Keap1/Nrf2‐ARE, PI3K/AKT, and MAPKs pathways in vivo and in vitro. Therefore, the collagen peptide from A. molpadioides might represent a novel functional food to prevent acute liver injury via attenuation of oxidative stress.