[Effects of lipopolysaccharides of Bacterium prodigiosum on tumor growth and immunosuppression in mice].

OBJECTIVE: To observe the effects of lipopolysaccharides of Bacterium prodigiosum (BP-LPS) in inhibiting tumor growth and improving immunosuppression in mice. METHODS: In mice bearing S180 tumor and a mouse model of immunosuppression induced by cyclophosphamide (CTX), the tumor growth, indexes of the immune organs and peripheral white blood cell count were measured after intraperitoneal injection of BP-LPS. RESULTS: Injections of BP-LPS (40 U/kg) for 8 consecutive days resulted in a significant inhibition of the tumor growth in mice bearing S180 tumor (P<0.01), with a dose-dependent increase of the spleen indexes but no obvious changes in the thymus indexes. Intraperitoneal injections of BP-LPS for 7 days inhibited the reduction of peripheral white blood cells and spleen indexes in immunosuppressive mice, but did not produce any significant changes in normal mice. CONCLUSION: BP-LPS can inhibit the tumor growth in tumor-bearing mice and enhance the immune functions of immunosuppressive mice.

[Effect of Flammulina velutipes polysaccharides on production of cytokines by murine immunocytes and serum levels of cytokines in tumor-bearing mice].

OBJECTIVE: To study the effect of Flammulina velutipes polysaccharides (FVP) on the production of tumor necrosis factor alpha (TNF-alpha), interferon-gamma (INF-gamma) and interleukin 2 (IL-2) by murine immunocytes. METHODS: The cell's metabolic activity was determined with methylthiazolyl tetrazolium (MTT) colorimetry assay and the amounts of TNF-alpha, INF-gamma and IL-2 were measured by ELISA. RESULTS: FVP (200, 100, 50 microg/mL) could promote the metabolic activity of murine splenocytes and peritoneal exudate cells (PEC) and increase the amounts of TNF-alpha, INF-gamma and IL-2 in the supernatants of splenocyte cultures, and the amount of TNF-alpha in PEC cultures, with the most marked increase on TNF-alpha level. FVP (100, 50, 25 mg/kg) could raise the serum levels of TNF-alpha and INF-gamma in S180 tumor-bearing mice. CONCLUSION: FVP may regulate murine immune function through promoting the production of TNF-alpha, INF-gamma and IL-2.