Objective To determina the content of cucurbitacin B in cucurbitacins .Methods The highly effective liquid phase chromatography was used,with Waters Symmetry C18(250 mm ×4.6 mm 5μm) column.The mobile phase was acetonitrile-wa-ter (51:49), the flow rate was 1 ml/min, column temperature was 25 ℃, the detection wavelength was 228 nm.Results Cucurb-itacin B regression equation:Y=1 067.3C-0.508 4 (r=0.999 9), the average recovery rate was 99.39%(n=6), RSD was 0.56%, which showed that this method had a good recovery rate .Conclusion The HPLC method for the determination of content of cucurbitacin B in cucurbitacins was simple , reproducible , accurate .

Objective To study the immunomodulatory effect of polysaccharides (CRPS25-Ⅱ) derived from Chroogomphus rutilus on mouse mononuclear macrophages, RAW264.7 cells. Methods RAW264.7 cells were resuspended and cultured, cell suspension was prepared. The blank control group and CRPS25-Ⅱ groups with different mass concentrations (1, 20, 40, 80 and 160 μg/ml) were set up. MTT assay was used to determine the cytotoxicity of CRPS25-Ⅱ on RAW264.7 cells. RT-PCR was used to detect the effects of CRPS25-Ⅱ on the secretion of immune regulatory factors IL-6 and TNF-α from RAW264.7 cells. Western blot was used to detect the effects of CRPS25-Ⅱ on the expression of p-P65 protein in NF-κB pathway of RAW264.7 cells. Results The results showed that CRPS25-Ⅱ (1−160 μg/ml) had no obvious cytotoxicity. CRPS25-Ⅱ (1−160 μg/ml) increased the secretion of cytokines, and thus promoted the mRNA expression of IL-6 and TNF-α. CRPS25-Ⅱ increased the phosphorylation of p-P65 protein and activated the NF-κB signaling pathway, and thus promoted the immune regulation of cells. CRPS25-Ⅱ (1−160 μg/ml) could increase the p-P65 protein, and the promoting effects of CRPS25-Ⅱshowed an upward trend in the concentration range of 1−40 μg/ml and gradually weakened in the concentration range of 40−160 μg/ml. Conclusion Polysaccharides derived from chroogomphus rutilus had no cytotoxicity to mouse macrophages, and could promote the secretion of inflammatory factors IL-6 and TNF-α and activate the NF-κB signaling pathway, thus playing an immunomodulatory role.