Abstract: Objective:To observe the effects of RuanJianXiaoYing Granule on the expressions of specific transcription factors and cytokines of Treg and Th17 in the Hashimoto thyroiditis(HT) rats with liver depression and spleen deficiency, and to investigate the therapeutic effect of RuanJianXiaoYing Granule on HT and its immunological mechanism. Methods:A total of 48 SD rats were randomly divided into normal group (12 rats) and modeling group (36 rats).The HT model was established by subcutaneous injection of excessive iodine drinking water and thyroglobulin,and then combined with chronic restraint stress, excessive fatigue and dietary disorders to prepare the rat models with liver depression and spleen deficiency.After modeling,the rats were randomly divided into model group(n=12),Tripterygium wilfordii group(n=12), and RuanJianXiaoYing group(n=12),and the rats were treated for 8 weeks. In addition to the dead rats and unqualified specimens during the experiment,the test results of 10 rats in each group were retained.The general situation of the rats in various groups was observed; the abdominal aortic blood and thyroid gland tissue of the rats in various groups were collected after the last administration;the levels of thyroglobulin antibody(TGAb), thyroid peroxidase antibody(TPOAb),free triiodothyronine(FT3), free thyroxine(FT4), thyrotropin-releasing hormone(TRH) and thyrotropin(TSH) in serum and the levels of IL-17, IL-23 and IL-10 were detected by ELISA method;the pathomorphology of thyroid gland tissue of the rats in various groups were detected by HE staining; the expression levels of Foxp3 and RORγt proteins in thyroid gland tissue of the rats in various groups were detected by Western blotting method. Results:Compared with normal group,the levels of serum TGAb and TPOAb of the rats in model group, Tripterygium wilfordii group and RuanJianXiaoYing~group were increased (P< 0.05);the levels of FT3, FT4 and TRH were decreased(P<0.05),the levels of TSH were increased(P<0.05);the expression levels of Foxp3 protein in thyroid gland tissue were decreased(P<0.05), and the expression levels of RORγt protein were increased (P<0.05);the levels of serum IL-10 were decreased(P<0.05),and the levels of serum IL-17 and IL-23 were increased(P<0.05).Compared with model group, the levels of TGAb and TPOAb of the rats in Tripterygium wilfordii group and RuanJianXiaoYing group were decreased(P<0.05);the levels of FT3, FT4 and TRH were increased (P< 0.05), and the levels of TSH were decreased (P< 0.05);the expression levels of Foxp3 protein in thyroid gland tissue were increased(P<0.05), and the expression levels of RORγt protein were decreased (P< 0.05);the levels of serum IL-10 were increased(P< 0.05), and the levels of IL -17 and IL-23 were decreased (P< 0.05).Compared with Tripterygium wilfordii group, the levels of TGAb, TPOAb,FT3,FT4,and TRH of the rats in RuanJianXiaoYing group were increased (P< 0.05),and the levels of TSH of the rats in RuanJianXiaoYing group was decreased(P<0.05);the expression level of Foxp3 protein in thyroid gland tissue of the rats was increased, and the expression level of RORγt protein in thyroid gland tissue was decreased,but there no were significant differences(P>0.05);the level of serum IL-10 was increased(P<0.05),and the levels of serum IL-17 and IL-23 were decreased(P<0.05). The follicular cavity of thyroid gland in normal group had regular morphology, complete structure and no lymphocyte infiltration. In model group, the follicular cavity of thyroid gland was enlarged,the follicular structure was destroyed, and a large number of lymphocyte infiltration was observed in and around the follicular cavity. In Tripterygium wilfordii group, the follicular cavity of thyroid gland was enlarged, part of the follicular structure was destroyed, and there was a small amount of lymphocyte infiltration in and around the follicular cavity, which was less than that in model group.The morphological changes of thyroid gland in RuanJianXiaoYing group were similar to those in Tripterygium wilfordii group. Conclusion:RuanJianXiaoYing Granule has the therapeutic effect in the HT rats with liver depression and spleen deficiency by regulating the expressions of the specific transcription factors Foxp3 and RORγt protein and related cytokines of Treg and Th17.

Key words: RuanJianXiaoYing Granule, Hashimoto's thyroiditis, liver depression and spleen deficiency, Treg/Th17 balance, duplex fork transcription factor P3, retinoic acid related nuclear orphan receptor γt