Abstract: The protective effect of Meretrix meretrix oligopeptide (MMO) on CCl4-induced acute liver injury in mice was examined. MMO, with the potential to repair damaged liver, was enzymatically extracted and purified by ultrafiltration and Sephadex G-25 column chromatography, and its amino acid sequence was determined to be Gln-Leu-Asn-Trp-Asp. Then, an acute liver injury model was established by intraperitoneal injection of CCl4 into mice. The liver index of mice was measured, the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (γ-GT) and superoxide dismutase (SOD) were determined, and serum triglyceride (TG) and malondialdehyde (MDA) levels were measured. Liver tissue samples from mice were stained with hematoxylin-eosin (HE) to observe the effect of MMO on liver histopathology. Immunohistochemical staining was used to detect the protein expression of TNF-α and NF-κB in hepatic tissue. The results showed that the MMO group exhibited a decrease in liver index, a reduction in serum ALT, AST and γ-GT activities (by up to 47.16%), an elevation in serum SOD activity, and a decline in serum TG and MDA levels (by up to 31.88% and 28.83%) compared with the model group, all these changes being statistically significant. Mouse liver tissue stained with HE revealed a notable improvement in liver histology. The protein expression of TNF-α and NF-κB in hepatic tissue was significantly decreased by administration of MMO. Therefore, MMO can effectively protect against acute liver injury induced by CCl4 in mice.

Key words: Meretrix meretrix oligopeptides, carbon tetrachloride, acute liver injury