Mechanism of Xiaoying Daotan decoction in treating Hashimoto’s thyroiditis based on the Notch/Treg/Th17 pathway

Herbal medicine for Hashimoto's thyroiditis: A systematic review and network meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Conventional treatments for Hashimoto's thyroiditis (HT) are limited. Herbal medicines (HM) are considered a potential intervention for the treatment of HT.

AIM OF THE STUDY

This study aimed to investigate the efficacy and safety of HM for HT.

MATERIALS AND METHODS

A Bayesian network meta-analysis was conducted for patients with HT in randomized controlled trials identified in PubMed, Cochrane Library, Web of Science, EMBASE, Chinese Clinical Trial Registry (Chi CTR), China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (the VIP), China Chinese Biomedical Database (CBM), and Wanfang Database were searched from their inception to Oct 1, 2022. Outcomes included the primary outcome (TPOAb), secondary outcomes (TSH, TGAb, FT3, FT4, and traditional Chinese medicine symptom scores), and adverse events. This study was registered in PROSPERO (CRD42022363640).

RESULTS

Sixteen trials were reviewed and 16 HM formulae were compared. Compared with non-drug therapy (NDT), all therapies, except for Tiaoqi-Qingjie Therapy, reduced the primary outcome of TPOAb with different levels of effectiveness, ranging from 0.01 (95%CI 0.00, 0.02) to 0.92 (95%CI 0.56, 1.53). Ranking probability analysis indicated that Yiqi Huayu Recipe, Liqi Xiaoying decoction, and Shugan Sanjie therapy reduced thyroid antibody levels the most, including TPOAb (100.0%, 90.9%, and 90.3%, respectively) and TGAb (98.3%, 94.4%, and 87.3%, respectively). All HMs displayed a significant effect on the TCM Symptom score and possibly benefitted the treatment of HT, ranging from 6.62 (95% CI 2.06, 21.24) to 94.50 (95% CI 15.97, 559.14). No serious adverse events were reported.

CONCLUSIONS

Herbal medicines may be effective in the treatment of HT, especially in reducing thyroid antibody levels and improving clinical symptoms without affecting thyroid function. However, these results should be considered preliminary and further verified using high-quality evidence.

Clinical efficacy and molecular mechanism of Chinese medicine in the treatment of autoimmune thyroiditis

ETHNOPHARMACOLOGICAL RELEVANCE

Autoimmune Thyroiditis (AIT) is a common refractory autoimmune disease of the endocrine system that may eventually lead to complete loss of thyroid function, with subsequent severe effects on the metabolism. Because of the deficiency in current clinical management of AIT, the need for alternative therapies is highlighted. With its multi-component and multi-target characteristics, Chinese medicine has good potential as an alternative therapy for AIT.

AIM OF THE STUDY

The aim of this study was to systematically summarize the clinical efficacy and safety evaluation of TCM and its active ingredients in the treatment and regulation of AIT. Additionally, we provide an in-depth discussion of the relevant mechanisms and molecular targets to understand the protective effects of traditional Chinese medicine on AIT and explore new ideas for clinical treatment.

MATERIALS AND METHODS

The literature related to "Hashimoto", "autoimmune thyroiditis", "traditional Chinese medicine," and "Chinese herbal medicine" was systematically summarized and reviewed from Web of Science Core Collection, PubMed, CNKI, and other databases. Domestic and international literature were analyzed, compared, and reviewed.

RESULTS

An increasing number of studies have demonstrated that herbal medicines can intervene in immunomodulation, with pharmacological effects such as antibody lowering, anti-inflammatory, anti-apoptotic thyroid follicular cells, regulation of intestinal flora, and regulation of estrogen and progesterone levels. The signaling pathways and molecular targets of the immunomodulatory effects of Chinese herbal medicine for AIT may include Fas/FasL, Caspase, BCL-2, and TLRs/MyD88/NF-κB et al. CONCLUSIONS: The use of Chinese herbs in the treatment and management of AIT is clinically experienced, satisfactory, and safe. Future studies may evaluate the influence of herbal medicines on the occurrence and development of AIT by modulating the interaction between immune factors and conventional signaling pathways.

Selenium regulates T cell differentiation in experimental autoimmune thyroiditis in mice

Selenium (Se) is an essential trace element that plays an important role in thyroid physiology. Se supplementation can reduce levels of autoimmune thyroid antibodies, which may be beneficial in Hashimoto's thyroiditis (HT). However, the long-term benefits of Se supplementation for HT patients are controversial and there is no clear clinical evidence to support it, so further basic and clinical research is needed. The effect of Se on immune cells, especially T cells, in autoimmune thyroiditis (AIT) has not been elucidated. Here, we replicated a mouse model of experimental autoimmune thyroiditis (EAT) on a high-iodine diet and treated it with Se supplementation. At week 8 of the experiment, Se supplementation reduced the destruction of thyroid follicles and the infiltration rate of lymphocytes in EAT mice, and reversed the disturbance of peripheral blood thyroxine and thyroid autoantibody levels. Further examination revealed that Se had broad effects on T-cell subsets. Its effects include reducing the production of pro-inflammatory cytokines by Th1 cells, inhibiting the differentiation and production of cytokines by Th2 and Th17 cells, and upregulating the differentiation and production of cytokines by Treg cells. These changes help alleviate thyroid follicle damage during EAT. In conclusion, selenium supplementation has the potential to improve the prognosis of AIT by altering the subset differentiation and/or function of CD4+ T cells.

Leptin receptor antagonist attenuates experimental autoimmune thyroiditis in mice by regulating Treg/Th17 cell differentiation

Leptin has been found to be involved in the development and progression of many autoimmune diseases. As an organ-specific autoimmune disease, the pathogenesis of Hashimoto's thyroiditis has not been fully elucidated. It has been reported that serum leptin level is increased in Hashimoto's thyroiditis, but other studies have not shown any difference. We replicated a mouse model of experimental autoimmune thyroiditis (EAT) with a high-iodine diet and found that injection of the leptin receptor antagonist Allo-aca reduced thyroid follicle destruction and inflammatory cell infiltration in EAT mice, and thyroxine and thyroid autoimmune antibody levels. Further investigation revealed that Allo-aca promotes the differentiation of Treg cells and inhibits the differentiation of Th17 cells. We believe that Allo-aca can alter the differentiation of Treg/Th17 cells by inhibiting the leptin signaling pathway, thereby alleviating thyroid injury in EAT mice. Interfering with the leptin signaling pathway may be a novel new approach to treat treating and ameliorating Hashimoto's thyroiditis.