Antifatigue, Antioxidant and Immunoregulatory Effects of Peptides Hydrolyzed from Manchurian Walnut (Juglans mandshurica Maxim.) on Mice

Abstract

Abstract:: The Manchurian walnut (Juglans mandshurica Maxim.) is rich in proteins, whereas this resource has not been used efficiently. The antifatigue, antioxidative and immunoregulatory effects of Manchurian walnut hydrolysate peptides (MWHPs) were evaluated in this study. MWHPs with a degree of hydrolysis of 32.23% were ultrafiltered and divided into three fractions, namely, high (> 10 kDa), medium (3–10 kDa), and low molecular weight (< 3 kDa), and then fed to mice continuously at doses of 200, 400 or 800 mg/(kg·d). The antifatigue, antioxidative, and immunoregulatory effects of the peptides were tested on the second and fourth weeks of MWHP administration. Results showed that low-molecular-weight MWHPs exerted significant antifatigue (prolonging swimming time, elevating liver glycogen contents, and reducing lactic acid contents), antioxidative (enhancing superoxide dismutase (SOD), GSH-Px, and catalase (CAT) activities and reducing malondialdehyde (MDA) content), and immunoregulatory (raising the immune-organ index and promoting T-lymphocyte proliferation and sIgA secretion in the intestinal tract) effects. This research indicates that MWHPs have potential applications in health care and may be developed as a base for new functional foods.Supported by National High Technology Research and Development Program (No. 2013AA102206-2) Keywords:: Manchurian walnut, Hydrolysate peptide, Antifatigue property, Antioxidant activity, Immune modulation