Selenium‐Enriched Submerged Fermentation of Tricholoma matsutake and Antioxidant and Hypoglycemic Activities of Its Mycelial Polysaccharide

ABSTRACT Tricholoma matsutake mycelial polysaccharides (TMP) exhibit a variety of biological activities; however, research on the biological activities of selenium‐enriched T. matsutake mycelial polysaccharides (Se‐TMP) remains limited. To compare the antioxidant and hypoglycemic activities of TMP and Se‐TMP, the optimal selenium tolerance concentration for the strains and the ideal selenium supplementation for liquid fermentation were determined first. Polysaccharide extraction was scaled up under optimized conditions. The antioxidant activities of TMP and Se‐TMP were evaluated in vitro, and both were administered by gavage to T2DM miceinduced by a high‐fat diet and streptozotocin. The results showed that the maximum selenium tolerance of T. matsutake strains was 50 μg/mL Na 2 SeO 3 on plates. The highest mycelial yield (1.04 ± 0.07 g/100 mL) occurred at 30 μg/mL Na 2 SeO 3 in liquid culture. Both TMP and Se‐TMP exhibited significant in vitro antioxidant activity. In vivo, both polysaccharides lowered blood glucose, improved glucose and lipid metabolism, reduced lipid levels, increased fasting insulin (FINS), improved HbA1c levels, enhanced hexokinase (HK) and pyruvate kinase (PK) activities, and alleviated oxidative stress. Selenium enrichment further enhanced the antioxidant and hypoglycemic effects. Thus, submerged fermentation to produce Se‐TMP improves the biological activity of TMP.