Effect of Xiaoying Decoction on Changes of Regulatory T Cells and Th17 Cells in Experimental Autoimmune Thyroiditis Rats / 医药导报

ABSTRACT

Objective To explore the mechanism of Xiaoying decoction on experimental autoimmune thyroiditis (EAT) rats in view of regulatory T cells and Th17 cells.Methods SD rats were divided into five groups,normal control group,model control group,tripterygium glycoside group,Xiaoying decoction low and high dose groups.Except for normal control group,the other groups were established the model of EAT.Rats in the Xiaoying decoction low,and high dose groups were given Xiaoying decoction of 17.24 and 68.95 g·kg-1;rats in the tripterygium glycoside group were given tripterygium glycoside 6.25 mg·kg-1.The serum free triiodothyronine(FT3),free thyrocyte(FT4) and thyroglobulin antibody were detected by RIA method.Thyrocyte morphology was observed under optical microscope.The expression levels of Foxp3 mRNA and IL-17 mRNA were detected by real-time PCR.The changes of Treg cells and Th17 cells were analyzed by flow cytometry.Results Compared with the normal control group,FT3,FT4 and TgAb were increased in the model control group (P ＜0.01,P ＜0.01,P ＜0.05).Compared with the model control group,FT3,FT4 and TgAb were decreased in tripterygium glycoside group and Xiaoying decoction high dose group (P ＜ 0.05).The infiltration score in the normal control group,model control group,tripterygium glycoside group,Xiaoying decoction low and high dose groups were 0,4,4,3.5,2.Compared with model control group,the infiltration was improved (P ＜0.01).Foxp3 mRNA expression was decreased while IL-17 mRNA increased in the model control group as compared with the normal control group(P ＜ 0.01).In contrast,the expression of Foxp3 mRNA was increased and IL-17 mRNA expression was decreased in Xiaoying decoction low and high dose groups,tripterygium glycoside group as compared with the model control group (P ＜0.05).Compared with the normal control group,rats in the model control group had fewer Treg cells and more Th17 cells (P ＜0.01).Compared with the model control group,the percentage of Treg cells was elevated and Th17 cells was reduced in tripterygium glycoside group and Xiaoying decoction high dose groups (P ＜ 0.01).Conclusion The therapeutic mechanism of Xiaoying decoction on EAT rats may be related to changing the percentage of regulatory T cells and Th17 cells with up-regulating the expression of Foxp3 mRNA and down-regulating the expression of IL17mRNA.