A novel Se-polysaccharide from Se-enriched G. frondosa protects against immunosuppression and low Se status in Se-deficient mice

In this study, a Se-deficient mice model was successfully developed by feeding a Se-deficient diet (0.02 mg Se/kg diet) for 4 weeks, and Se supplementation by Se-polysaccharides (Se-GFP-22) was lasted for 4 weeks. The immunomodulatory activity and Se supplementation of Se-GFP-22 from Se-enriched G. frondosa was investigated. Results showed that Se-GFP-22 remarkably enhanced glutathione peroxidase (GSH-Px) and thioredoxin reductase (TrxR) activities in liver, kidney and plasma, and serum, liver, spleen and kidney Se levels of Se-deficient mice. Se-GFP-22 increased the thymus and spleen indices, phagocytic index, co-mitogenic (ConA- or LPS-stimulated) activities on splenocytes and DTH reaction. Se-GFP-22 caused significant increments in cytokine (IL-1β, TNF-α and IFN-γ) levels and Ig G, Ig A, Ig M and Ig E levels. Se-GFP-22 exhibited superior immunomodulatory effects than GFP-22. These findings indicated that Se-GFP-22 promote the protective effects against Se deficiency-induced immunosuppression and could be a potential immunomodulatory agent and a dietary Se-supplement.