Protective effect of whey protein hydrolysates against oxidative stress in d-galactose-induced ageing rats

The protective effect of whey protein hydrolysate (WPH) against oxidation was studied in d-galactose-induced ageing rats. The rats were divided into a normal group, a d-galactose model group, low-, middle-, and high-dose WPH groups, and an ascorbic acid group. The three WPH groups and the ascorbic acid group also received d-galactose treatment. Administration of WPH significantly increased body weight gain, spleen index and high-density lipoprotein content (P < 0.05) and decreased the triglyceride and low-density lipoprotein contents (P < 0.05) compared with the ageing model group. WPH had a protective effect against d-galactose-induced ageing in rats as shown by the increased activities of superoxide dismutase, catalase and glutathione peroxidase and decrease in the malonaldehyde contents (P < 0.05) in the serum, spleen, liver, and lungs. The protective effect of WPH on d-galactose-induced ageing in rats can be attributed to enhanced antioxidant defences and the elevation of antioxidase activity.