Interaction between iodine and glucosinolates in rutabaga sprouts and selected biomarkers of thyroid function in male rats

J Trace Elem Med Biol. 2018 Mar:46:110-116. doi: 10.1016/j.jtemb.2017.12.002. Epub 2017 Dec 15.

Abstract

Rutabaga sprouts belong to the Brassicaceae family and may exert a negative influence on thyroid function, because they are a rich in glucosinolates. These sprouts are also valuable source of iodine (6.5 ± 0.6 μg/100 g of fresh weight). Sprouts were tested in a long-term experiment with young male rats as an element of their diet, combined with two models of hypothyroidism, the first - deficit of iodine and the second - sulfadimethoxine ingestion as a pharmacological agent caused inhibition of thyroid peroxidase. Evaluations were performed for the serum TSH and thyroid hormones together with analyzes of thyroid histopathology, cytosolic glutathione peroxidase (GPX1), thioredoxin reductase in the thyroid, plasma GPX3 and CAT, erythrocyte GPX1. Rutabaga sprouts' intake by healthy rats did not cause any harmful effect on their health, including thyroid function. For animals with hypothyroidism, rutabaga sprouts enhanced the adverse effect of iodine deficiency or ingestion of sulfadimethoxine on the organism. According to the results obtained for young male rats thyroid function, the interpretation of data for human exposure to rutabaga sprouts has to be avoided. Furthermore, unless new scientific data confirms a lack of the negative effect of brassica sprouts on thyroid function in human, they should not be excluded from the group of goitrogenic products.

Keywords: Brassica vegetables; Goitrogens; Hypothyroidism; Iodine deficiency; Rutabaga sprouts; Thyroid gland.

MeSH terms

  • Animals
  • Biomarkers / analysis
  • Brassica napus / chemistry*
  • Diet
  • Glucosinolates / metabolism*
  • Hypothyroidism / etiology
  • Hypothyroidism / pathology
  • Hypothyroidism / physiopathology
  • Iodide Peroxidase / antagonists & inhibitors
  • Iodine / analysis
  • Iodine / metabolism*
  • Male
  • Rats, Inbred F344
  • Seedlings / chemistry*
  • Sulfadimethoxine
  • Thyroid Gland / pathology
  • Thyroid Gland / physiopathology*
  • Thyroid Hormones / metabolism

Substances

  • Biomarkers
  • Glucosinolates
  • Thyroid Hormones
  • Sulfadimethoxine
  • Iodine
  • Iodide Peroxidase