The Effect of Simvastatin on Thyroid Function in Experimental Autoimmune Thyroiditis Induced in Rats


  • Yaqeen Talib Mohammed Department of Pharmacology and Toxicology, College of Pharmacy, University of Mustansiriyah, Baghdad, Iraq.
  • Nadia Hameed Mohameed Department of Microbiology and Immunology, College of Medicine, University of Mustansiriyah, Baghdad, Iraq.
  • Inaam Samih Arif Department of Pharmacology and Toxicology, College of Pharmacy, University of Mustansiriyah, Baghdad, Iraq.



Autoimmune thyroiditis or Hashimoto’s thyroiditis (HT): is the most common autoimmune thyroid disease. is characterized by marked lymphocytic infiltration and the presence of serum autoantibodies against Thyroid peroxidase (TPO) and Thyroglobulin (TG). HT is a prevalent cause of hypothyroidism in areas of the world where dietary iodine is sufficient. Genetic predisposition and cellular and humoral immunity play a role in thyroid autoimmune pathogenesis. Antithyroid antibodies are produced by interaction between APC, T cells, and B cells to fix complement. Thyroid tissue is more severely damaged by complement-dependent antibody-mediated cytotoxicity. Statins, the powerful inhibitors of HMG-CoA reductase have pleotropic effects including anti-inflammatory and immunomodulatory effects. In this current study, Experimental autoimmune thyroiditis was induced in twenty-four female Wistar rat. Simvastatin was given at a dose of 4mg/kg for 30 days. Thyroid autoantibodies and Thyroid hormones were measured by ELISA technique Results showed that Simvastatin reduced autoantibodies against TPO and TG. It also lowered serum level of TSH and increased serum level of T4. Due to the undesirable side effects associated with the current treatment options used in Autoimmune thyroiditis. Simvastatin might be a promising approach in the treatment of this disease.


Önalan E, Dönder E. Neutrophil and platelet to lymphocyte ratio in patients with hypothyroid hashimoto’s thyroiditis. Acta Biomedica. 2020;91(2):310–4.

Leung AKC, Leung AAC. Evaluation and management of the child with hypothyroidism. Vol. 15, World Journal of Pediatrics. Institute of Pediatrics of Zhejiang University; 2019. p. 124–34.

Zabczyńska M, Kozłowska K, Pocheć E. Glycosylation in the thyroid gland: Vital aspects of glycoprotein function in thyrocyte physiology and thyroid disorders. Vol. 19, International Journal of Molecular Sciences. MDPI AG; 2018.

Hu S, Rayman MP. Multiple Nutritional Factors and the Risk of Hashimoto’s Thyroiditis. Vol. 27, Thyroid. Mary Ann Liebert Inc.; 2017. p. 597–610.

Ferrari SM, Fallahi P, Antonelli A, Benvenga S. Environmental issues in thyroid diseases. Vol. 8, Frontiers in Endocrinology. Frontiers Research Foundation; 2017.

Zhang P, Lu Q. Genetic and epigenetic influences on the loss of tolerance in autoimmunity. Vol. 15, Cellular and Molecular Immunology. Chinese Soc Immunology; 2018. p. 575–85.

Frommer L, Kahaly GJ. Type 1 Diabetes and Autoimmune Thyroid Disease—The Genetic Link. Vol. 12, Frontiers in Endocrinology. Frontiers Media S.A.; 2021.

Weetman AP. An update on the pathogenesis of Hashimoto’s thyroiditis. J Endocrinol Invest [Internet]. 2021;44:883–90.

Ajjan RA, Weetman AP. The Pathogenesis of Hashimoto’s Thyroiditis: Further Developments in our Understanding. Hormone and Metabolic Research. 2015 Apr 16;47(10):702–10.

Ahmadi M, Amiri S, Pecic S, Machaj F, Rosik J, Łos MJ, et al. Pleiotropic effects of statins: A focus on cancer. Vol. 1866, Biochimica et Biophysica Acta - Molecular Basis of Disease. Elsevier B.V.; 2020.

Göbel A, Rauner M, Hofbauer LC, Rachner TD. Cholesterol and beyond - The role of the mevalonate pathway in cancer biology. Vol. 1873, Biochimica et Biophysica Acta - Reviews on Cancer. Elsevier B.V.; 2020.

Mollazadeh H, Tavana E, Fanni G, Bo S, Banach M, Pirro M, et al. Effects of statins on mitochondrial pathways. Vol. 12, Journal of Cachexia, Sarcopenia and Muscle. John Wiley and Sons Inc; 2021. p. 237–51.

Sorathia N, George’ S, Al-Rubaye H, Zal B. Citation. European Cardiology Review [Internet]. 2019;14(2):123–32. Available from:

Martinez Quintero B, Yazbeck C, Sweeney LB. Thyroiditis: Evaluation and Treatment [Internet]. 2021. Available from:

Liberman AC, Budziñski ML, Sokn C, Gobbini RP, Steininger A, Arzt E. Regulatory and mechanistic actions of glucocorticoids on T and inflammatory cells. Vol. 9, Frontiers in Endocrinology. Frontiers Media S.A.; 2018.

Gilbert R, Al-Janabi A, Tomkins-Netzer O, Lightman S. Statins as anti-inflammatory agents: A potential therapeutic role in sight-

threatening non-infectious uveitis. Porto Biomed J. 2017 Mar;2(2):33–9.

Li Y, Zuo X, Hua C, Zhao Y, Pei X, Tian M. Effects of Selenium Supplement on B Lymphocyte Activity in Experimental Autoimmune Thyroiditis Rats. 2021.

Song XH, Zan RZ, Yu CH, Wang F. Effects of modified Haizao Yuhu Decoction in experimental autoimmune thyroiditis rats. J Ethnopharmacol. 2011 May 17;135(2):321–4.

Crespo MJ. Simvastatin, atorvastatin, and pravastatin equally improve the hemodynamic status of diabetic rats. World J Diabetes. 2015;6(10):1168.

Koirala KP, Sharma V. Treatment of acute painful thyroiditis with low dose prednisolone: A study on patients from Western Nepal. Journal of Clinical and Diagnostic Research. 2015 Sep 1;9(9).

Li H, Min J, Mao X, Wang X, Yang Y, Chen Y. Edaravone ameliorates experimental autoimmune thyroiditis in rats through HO-1-dependent STAT3/PI3K/AKT pathway. Am J Transl Res. 2018;10(7):2037–46.

Yilmaz H, Cakmak M, Ceydilek B, Demir C, Aktas A. Role of interlekin-35 as a biomarker in patients with newly diagnosed hashimoto’s thyroiditis. Endocr Regul. 2016 Apr 1;50(2):55–61.

Shahbaz SK, Sadeghi M, Koushki K, Penson PE, Sahebkar A. Regulatory T cells: Possible mediators for the anti-inflammatory action of statins. Vol. 149, Pharmacological Research. Academic Press; 2019.

Li Y, Zuo X, Hua C, Zhao Y, Pei X, Tian M. Effects of Selenium Supplement on B Lymphocyte Activity in Experimental Autoimmune Thyroiditis Rats. Int J Endocrinol. 2021;2021.

Gullu S, Emral R, Bastemir M, Parkes AB, Lazarus JH. In vivo and in vitro effects of statins on lymphocytes in patients with Hashimoto’s thyroiditis. Eur J Endocrinol. 2005 Jul;153(1):41–8.

Wang Y, Li Q, Yuan Z, Ma S, Shao S, Wu Y, et al. Statin Use and Benefits of Thyroid Function: A Retrospective Cohort Study. Front Endocrinol (Lausanne). 2021 Mar 2;12.

Kobayashi R, Hasegawa M, Kawaguchi C, Ishikawa N, Tomiwa K, Shima M, et al. Thyroid function in patients with selenium deficiency exhibits high free T4 to T3 ratio. Clinical Pediatric Endocrinology. 2021;30(1):19–26.