Objective To investigate the effect of emodin on immune suppression function of regulatory T cells in a mouse model of CT26 colon cancer. Methods Twenty-four mice were divided into the negative control group, the emodin group and the tumor group. The populations of CD8+CD3+T cells, the T cells producing IFN-γand the CD4+CD25+Tregs secreting IL-10 in different mouse tissues were detected by flow cytometry. Levels of IFN-γ, TNF- β1 and IL-10 in serum were determined by ELISA. Results Emodin could significantly increase the percent of CD8+CD3+T cells in tumor (P < 0.05) and improve the ability of IFN-γ secretion in T cells from peripheral blood and lymph nodes (P < 0.05). Emodin could reduce the levels of IFN-γ, TNF-β1 and IL-10 in the serum (P < 0.01) and inhibit IL-10 secretion in CD4+CD25+ Tregs (P < 0.01). Conclusion Emodin possesses the antitumor effect by affecting the immunosuppressive function of Tregs cells.

Purpose　The aim is to sulfonize Hunai polysaccharide fr om p leurotus tuber-rigium(Fr.)Sing. and to evaluate the antioxidative activities of the sulfated po lysaccharide (S-HNP).Methods　S-HNP was prepared by the reacti on of Hunai polysaccharide with chlorosulfonic acid-Pyridine. The antioxidative activities o f S-HNP were evaluated as follows: (1) the inhibition effects on Fe2+- Vc inducing the injury of rat liver mitochondria in vitro, (2) the protectiv e ef fect on CuSO4 -Phen-Vc-H2O2 inducing the damage of DNA, (3) the scaven ging effect on O*-2. Results　 S-HNP could protect mitochondria from lipid peroxidation induced by Fe2+-Vc, i ncluding the inhibitions of the increase of TBARS content, the swelling of mitoc hondria and the decrease of membrane fluidity, and protect DNA from the damage induced by CuSO4-Phen-Vc-H2O2， and scavenge O*-2 generated in the sel f-oxidation of pyrogallic acid. Conclusion　S-HNP exhibi ted marked antioxidative activities.