Abstract:

The antioxidant activity and immunoregulatory activity of oligopeptides from wheat residue left after solid-state
fermentation for alcohol production were studied in vivo. Totally 112 healthy Kunming mice (4 weeks old) were randomly
divided into 14 groups. The mice in the normal control group and experimental groups 1–6 were fed a normal diet and
gavaged with normal saline and oligopeptides (penta and hepta peptides each at different doses (4, 8, and 12 mg)),
respectively, while those in the high-fat control group and experimental groups 7–12 were fed a high-fat diet and orally
administrated with normal saline and the oligopeptides (each at different doses (2, 4, and 8 mg)), respectively. After
continuous intragastric administration for 28 days, the levels of malondialdehyde (MDA) in serum and liver, and the
activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in liver were determined in
the mice in the normal control group and experimental groups 1–6, and the populations of T-lymphocytes such as CD3+, CD4+ and
CD8+ in spleen were determined by flow cytometry. Also, the tissue homogenates of duodenum, jejunum and ileum of the mice
in the normal control group, high-fat control group and experimental groups 7–12 were determined for the levels of MDA and the
activities of SOD, CAT and GSH-Px. The results showed that MDA contents in liver, duodenum, jejunum and ileum of the highfat
diet-fed mice declined significantly (P < 0.05) in response to administration of the oligopeptides, and SOD, CAT and GSH-Px
activities increased significantly (P < 0.05). CD4+/CD8+ ratio also significantly increased (P < 0.05). These experimental findings
suggest that the oligopeptides from fermented wheat residue have antioxidant capacity and can enhance immune function, as
well as can inhibit oxidative damage caused by high-fat diets in the intestine of mice.

Key words: wheat residue left after alcohol fermentation, oligopeptide, high-fat diet, antioxidant activity, immunoregulatory activity, mice