Porcine Splenic Hydrolysate has Antioxidant Activity in vivo and in vitro

The antioxidant capacity of porcine splenic hydrolysate (PSH) was studied in vitro and in vivo. Peptide hydrolysates were prepared, using the proteolytic enzyme $Alcalase^{(R)}$. The molecular weights of PSH were 37,666, 10,673, 6,029, and 2,918 g/mol. Rats were fed a 5% (w/v) PSH diet, instead of a casein diet, for 4 wk. The food intake, body weight gain, and liver weight of rats in the PSH group were similar to those in the control (CONT) group. There were no differences in the serum total cholesterol, triglyceride, total protein, or albumin levels between PSH and CONT groups. However, the level of in vivo hepatic lipid peroxidation in PSH group was significantly lower than that in CONT. In vivo hepatic catalase and glutathione peroxidase activities in the PSH group were significantly higher than those in the control group. The in vitro protein digestibility of PSH was lower than that of casein. The in vitro trolox equivalent antioxidant capacity of PSH was significantly higher than that of the peptide hydrolysate from casein. The in vitro radical scavenging activities of PSH were significantly higher than those of the peptide hydrolysate from casein. The present findings suggest that porcine splenic peptides improve the antioxidant status in rats by enhancing hepatic catalase and GSH-Px activities, and indicate a potential mechanism of radical scavenging activity during gastrointestinal passage.