title: Impact of flavonoids on thyroid function.
abstract: Flavonoids are polyphenolic compounds of natural occurrence produced by plants that are largely consumed both for therapeutic purposes and as food. Experimental data have shown that many flavonoids could inhibit thyroperoxidase activity, decreasing thyroid hormones levels thus increasing TSH and causing goiter. In humans, infants fed with soy formula have been shown to develop goiter. However, in post-menopausal women soy intake did not affect thyroid function. In thyroid tumor cell line, flavonoids were shown to inhibit cell growth, but they can also decrease radioiodine uptake, that could reduce the efficacy of radioiodine therapy. Flavonoids could also affect the availability of thyroid hormones to target tissues, by inhibiting deiodinase activity or displacing T4 from transthyretin. Thus, flavonoids have been shown to interfere with many aspects of the thyroid hormones synthesis and availability in in vivo and in vitro models. In the present article, we review and synthesize the literature on the effects of flavonoids on thyroid and discuss the possible relevance of these effects for humans.
authors: Laboratório de Fisiologia Endócrina Doris Rosenthal, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, Brazil.
authors: Maria Carolina
authors: MC
authors: de Souza Dos Santos
authors: Carlos Frederico Lima
authors: CF
authors: Gonçalves
authors: Mário
authors: M
authors: Vaisman
authors: Andrea Claudia Freitas
authors: AC
authors: Ferreira
authors: Denise Pires
authors: DP
authors: de Carvalho
mesh_terms: D000818:Animals; D005419:Flavonoids / Q000009:adverse effects / Q000494:pharmacology*; D006801:Humans; D007453:Iodide Peroxidase / Q000037:antagonists & inhibitors; D013961:Thyroid Gland / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D013963:Thyroid Hormones / Q000378:metabolism
chemical_list: D005419:Flavonoids; D013963:Thyroid Hormones; D007453:Iodide Peroxidase