Pleurotus nebrodensis polysaccharide （PN-S） enhances the immunity of immunosuppressed mice

In the present study, the effects of Pleurotus nebrodensis polysaccharide （PN-S） on the immune functions of immunosuppressed mice were determined. The immunosuppressed mouse model was established by treating the mice with cyclophosphamide （40 mg/kg/2d, CY） through intraperitoneal injection. The results showed that PN-S administration significantly reversed the CY-induced weight loss, increased the thymic and splenic indices, and promoted proliferation of T lymphocyte, B lymphocyte, and macrophages. PN-S also enhanced the activity of natural killer cells and increased the immunoglobulin M （IgM） and immunoglobulin G （IgG） levels in the serum. In addition, PN-S treatment significantly increased the phagocytic activity of mouse peritoneal macrophages. PN-S also increased the levels of interleukin-6 （IL-6）, tumor necrosis factor-a （TNF-a, interferon-？, （INF-7）, and nitric oxide （NOS） in splenocytes, qRT-PCR results also indicated that PN-S increased the mRNA expression of IL-6, TNF-a, INF-y, and nitric oxide synth