Anti-tumor and immunomodulating activities of proteoglycans from mycelium of Phellinus nigricans and culture medium.

Two proteoglycans, PNW1 and PNM1, were isolated from the mycelium of Phellinus nigricans through submerged fermentation and culture medium, respectively. PNW1 and PNM1 with similar average molecular weight (33 kDa and 29 kDa) were composed of glucose, galactose, mannose, arabinose and fucose in the molar ratios of 3.26:8.77:6.44:1:1.35 and 20.06:8.72:6.94:1:0.76. At the dose of 100, 200, and 400 mg/kg, PNW1 and PNM1 exhibited anti-tumor activity against mice-transplanted Sarcoma 180 in vivo. However, no direct cytotoxic activity against Sarcoma 180 could be determined. Significant increase in the relative spleen and thymus weight and expression of tumor necrosis factor-alpha (TNF-alpha) in serum was observed, decreasing the tumor weight significantly. PNW1 and PNM1 could stimulate lymphocytes proliferation and increase production of nitric oxide (NO) and TNF-alpha in macrophages. The results indicate that both lymphocyte and macrophages were activated by preparations of proteoglycans from mycelium and culture medium of P. nigricans. The anti-tumor effect of the proteoglycans is not directly tumoricidal but rather immunostimulating.