Preparation of corn (Zea mays) peptides and their protective effect against alcohol-induced acute hepatic injury in NH mice.

CPS [corn (Zea mays) peptides] were prepared from corn gluten meal by proteolysis with alcalase, an alkaline protease. The molecular-mass distribution of CPS is from 200 to 1000 Da as determined by MS. The amino acid composition of CPS was also analysed by HPLC. CPS contains almost no free amino acids. The protective effect of CPS against acute hepatic injuries induced by alcohol was verified in NH mice that were fed with different dosages of CPS for 30 days and subsequently given an acute dose of alcohol orally. As a result, CPS reduced both hepatic malondialdehyde and triacylglycerol levels, along with enhanced hepatic GSH (glutathione) levels, relative to the control. Hepatic histological changes were also observed. The result indicates that CPS is capable of attenuating ethanol-induced hepatic injury. The effect of CPS on removing superoxide anion in vitro was also studied as an additional proof that CPS is capable of abating hepatic superoxidant stress.