ABSTRACT
The medicinal mushroom Cordyceps militaris has been reported to possess anticancer and immunomodulatory effects. We investigated the immunostimulatory effects of culture supernatant of C. militaris (WIB-801CE) by examining its in vitro enhancing effects on cell proliferation and cytokine releases in splenocytes and its in vivo effects on cyclophosphamide-induced immunosuppressed mice. WIB-801CE enhanced normal and methotrexate-induced cell proliferation. WIB-801CE significantly ameliorated interleukin (IL)-2, interferon-γ, and tumor necrosis factor-α secretion in methotrexate-induced splenocytes. Oral administration of WIB-801CE effectively increased the cyclophosphamide-suppressed splenocyte proliferation and natural killer cytotoxic activity. WIB-801CE effectively recovered cyclophosphamide-induced decreases in IL-2, interferon-γ, tumor necrosis factor-α, and IL-10 level. The collective data implicate WIB-801CE as a therapeutic candidate in ameliorating the immunosuppression through immunostimulatory properties.
Subject(s)
Cordyceps/chemistry , Cyclophosphamide/pharmacology , Deoxyadenosines/chemistry , Drugs, Chinese Herbal/pharmacology , Fibrinolytic Agents/pharmacology , Plant Extracts/pharmacology , Animals , Cell Proliferation , Immunosuppression Therapy , Male , Mice , Mice, Inbred C57BLABSTRACT
Cancer cells usually obtain energy from a high rate of glycolysis rather than oxidative phosphorylation under normoxia as well as hypoxia. Under these circumstances, pyruvate, the end-product of glycolysis, accumulates in cancer cells. We have previously reported that pyruvate activates endothelial cells and induces angiogenesis. Here, we examined the angiogenic activity of pyruvate in tumor cells. Plasminogen activator inhibitor-1 (PAI-1), the gene most upregulated by pyruvate, showed a pro-angiogenic activity, which was abolished by a PAI-1 neutralizing antibody. Moreover, stabilization of hypoxia-inducible factor-1α (HIF-1α) by pyruvate was required for induction of PAI-1 transcription through direct binding to hypoxia response element-2 (HRE-2) on the promoter. These results suggest that pyruvate can activate the angiogenic activity of cancer cells under normoxia and that PAI-1 may act as a pro-angiogenic factor in pyruvate-induced angiogenesis.