Ameliorative effect of Trametes orientalis polysaccharide against immunosuppression and oxidative stress in cyclophosphamide-treated mice

The present study evaluated the ameliorative effects of Trametes orientalis polysaccharide (TOP-2) against cyclophosphamide (CP) induced toxicity in mice. Intraperitoneal administration of TOP-2 not only effectively increased the thymus, spleen, heart, liver, and kidney indices, but also significantly enhanced the phagocytic activities of macrophages and splenocyte proliferation, dose-dependently. The lowered nitric oxide level of macrophages after CP treatment was elevated by TOP-2 administration. Impaired splenic natural killer cells and cytotoxic T lymphocytes activities were remarkably enhanced by TOP-2. Furthermore, the levels of interleukin-2, interferon-γ, Immunoglobulin A, immunoglobulin G, and immunoglobulin M were notably reduced by CP, while TOP-2 abolished these effects. TOP-2 could also effectively increase the total antioxidant capacity, superoxidase dismutase, catalase and glutathione peroxidase activities, and inhibit the increase in malondialdehyde level. These results indicate that TOP-2 may be of therapeutic value in ameliorating the immunosuppression and oxidative stress caused by CP treatment, through its immunomodulatory and antioxidant potential.