Antioxidant Capacity of Proteins and Hydrolysates from the Liver of Newborn Piglets, and Their Inhibitory Effects on Steatosis in vitro.

Non-alcoholic steatohepatitis is a potentially progressive hepatic disorder that can lead to end-stage liver disease and hepatocellular carcinoma. The inhibitory effects of proteins and hydrolysates from the liver of newborn piglets on hepatic steatosis in oleic acid-induced hepatocellular carcinoma (HepG2) cells were investigated in vitro. The extracted proteins from the liver of newborn piglets were hydrolysed with papain, pepsin, trypsin and Alcalase. Based on the comparison of different enzyme digestion conditions, a protein hydrolysis protocol was established to obtain hydrolysates with lipid-lowering effect. Trypsin-digested liver protein hydrolysate from newborn piglets exhibited strong antioxidant activity and good inhibitory effects against lipogenesis and cholesterol accumulation in HepG2 cells at the concentration of 150 μg/mL, with a triglyceride decrease of (43±3) % and cholesterol decrease of (31±5) %, compared with model group induced with 0.75 mM oleic acid. The addition of trypsin-digested liver protein hydrolysate from newborn piglets (300 μg/mL) decreased alanine aminotransferase and aspartate aminotransferase activities and increased superoxide dismutase activity. This study demonstrated that the trypsin-digested liver protein hydrolysate from newborn piglets has a potential preventive effect against non-alcoholic fatty liver disease in its early stage, and a potential use as the modulator of lipid overaccumulation in form of food supplements.