Immunomodulatory effects of selenium‐enriched peptides from soybean in cyclophosphamide‐induced immunosuppressed mice

In this study, selenium‐enriched soybean peptides (<3 kDa, named Se‐SPep) was isolated and purified from the selenium‐enriched soybean protein (Se‐SPro) hydrolysate by ultrafiltration. The in‐vivo immunomodulatory effects of Se‐SPep were investigated in cyclophosphamide‐induced immunosuppressed mice. Se‐SPep treatment could alleviate the atrophy of immune organs and weight loss observed in immunosuppressive mice. Besides, Se‐SPep administration could dramatically improve total protein, albumin, white blood cell, immunoglobulin (Ig) M, IgG, and IgA levels in blood. Moreover, Se‐SPep strongly stimulated interleukin‐2 (IL‐2), interferon‐gamma (IFN‐γ), nitric oxide (NO), and cyclic guanosine monophosphate productions by up‐regulating mRNA expressions of IL‐2, IFN‐γ, and inducible NO synthase in spleen tissue. Furthermore, Se‐SPep exhibits more effective immunomodulatory activity compared to Se‐SPro and SPep. In conclusion, Se‐SPep could effectively enhance the immune capacity of immunosuppressive mice. These findings confirm Se‐SPep is an effective immunomodulator with potential application in functional foods or dietary supplements.