Objective To observe the effect of electroacupuncture(EA)intervention on spleen T-helper 17(Th 17)and regulatory T(Treg)cell levels in mice with ulcerative colitis(UC)

so as to reveal its mechanisms underlying improvement of UC.Methods Kunming mice were randomized into control

UC model and EA groups

with 8mice in each group.The UC model was established by giving the mice with 3% Dextran Sulfate Sodium(DSS)for 5days.EA(15Hz/25 Hz

0.1-0.2mA)was applied at"Guanyuan"(CV 4)and bilateral"Zusanli"(ST 36

used alternatively)for 10 min

once a day for 5days.The animals' disease activity index[DAI

=(body weight index score+stool score+bleeding score)/3;0-4points]were calculated.The pathological changes of colon tissues were observed by light microscopy after H.E.stain

and spleen Treg(CD4+CD25+Foxp3+Treg)and Th 17(CD3+CD8+IL-17+Th 17)lymphocyte levels were determined by flow cytometry.Results Compared to the control group

the DAI score and the ratio of Th 17/CD8+T cells were significantly increased

while the ratio of Treg/CD4+T cells obviously decreased in the model group(P<0.05).After EA intervention

the increased DAI score and the ratio of Th 17/CD8+T cells and the decreased Treg/CD4+T cells were reversed(P<0.05)

and the inflammatory cell infiltration degree of the colon tissue was attenuated.Conclusion EA intervention can improve the UC rats' symptoms of activity state

bloody or viscidity stool and colonic inflammation

probably by regulating the balance between the spleenic Treg and Th 17 lymphocytes.