Immunomodulatory Effect of Sasa quelpaertensis Leaves Fermentation Products in Mice

The purpose of this study was to enhance the immune-enhancing activity of mushroom strains through fermentation to promote food use of leaf extracts of S. quelpaertensis containing β-glucan. We evaluated the immunomodulatory effect of extracts from fermented S. quelpaertensis leaves (SQGL, SQHE, SQPL). S. quelpaertensis leaves fermentation products were prepared by using mushroom mycelia (Ganoderma lucidum, Hericium erinaceum, Phellinus linteus). The content of β-glucan, a major substance in S. quelpaertensis leaves fermentation products, was 3.73 ± 0.50 mg/mL in the extract (SQ) of S. quelpaertensis leaves. The fermented mushrooms, SQGL, were the highest at 5.57 ± 0.86 mg/100 mL, followed by SQHE and SQPL, and the β-glucan content of all of the glucan was >75.3%. To test the immune activity, S. quelpaertensis leaf fermentation products were administered to mice at different doses (60, 160, and 360 mg/kg) for two weeks. Th cell and macrophage populations were found to increase significantly at all three doses compared to the negative control after two weeks. SQGL and SQHE were highest at 160 mg/kg, and SQPL showed the highest Th cell proliferation at 60 mg/kg. In addition, the production of IFN-γ, IL-4, IL-10, and nitric oxide was significantly higher than that of the negative control after two weeks. In particular, an increase was seen at a low concentration of 60 mg/kg. Therefore, the S. quelpaertensis leaf fermentation product can be very useful as a functional ingredient for enhancing immunity.