Flavonoid rutin increases thyroid iodide uptake in rats

PLoS One. 2013 Sep 4;8(9):e73908. doi: 10.1371/journal.pone.0073908. eCollection 2013.

Abstract

Thyroid iodide uptake through the sodium-iodide symporter (NIS) is not only an essential step for thyroid hormones biosynthesis, but also fundamental for the diagnosis and treatment of different thyroid diseases. However, part of patients with thyroid cancer is refractory to radioiodine therapy, due to reduced ability to uptake iodide, which greatly reduces the chances of survival. Therefore, compounds able to increase thyroid iodide uptake are of great interest. It has been shown that some flavonoids are able to increase iodide uptake and NIS expression in vitro, however, data in vivo are lacking. Flavonoids are polyhydroxyphenolic compounds, found in vegetables present in human diet, and have been shown not only to modulate NIS, but also thyroperoxidase (TPO), the key enzyme in thyroid hormones biosynthesis, besides having antiproliferative effect in thyroid cancer cell lines. Therefore, we aimed to evaluate the effect of some flavonoids on thyroid iodide uptake in Wistar rats in vivo. Among the flavonoids tested, rutin was the only one able to increase thyroid iodide uptake, so we decided to evaluate the effect of this flavonoid on some aspects of thyroid hormones synthesis and metabolism. Rutin led to a slight reduction of serum T4 and T3 without changes in serum thyrotropin (TSH), and significantly increased hypothalamic, pituitary and brown adipose tissue type 2 deiodinase and decreased liver type 1 deiodinase activities. Moreover, rutin treatment increased thyroid iodide uptake probably due to the increment of NIS expression, which might be secondary to increased response to TSH, since TSH receptor expression was increased. Thus, rutin might be useful as an adjuvant in radioiodine therapy, since this flavonoid increased thyroid iodide uptake without greatly affecting thyroid function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport / drug effects
  • Iodides / metabolism*
  • Male
  • Rats
  • Rats, Wistar
  • Rutin / pharmacology*
  • Symporters / metabolism
  • Thyroid Gland / drug effects*
  • Thyroid Gland / metabolism*
  • Thyroid Gland / physiology
  • Thyroid Hormones / blood
  • Thyrotropin / blood

Substances

  • Iodides
  • Symporters
  • Thyroid Hormones
  • sodium-iodide symporter
  • Rutin
  • Thyrotropin

Grant support

This work was supported by grants from Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Programa de Apoio a Núcleos de Excelência (PRONEX/FAPERJ), Instituto de Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação do Câncer. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.