Background: Natural compounds with potential antioxidant properties have been used in the form of food supplements or extracts with the intent tfor prevention and or treatment of various diseases. Many of these compounds The cytoprotective Nrf2 pathway can be activated the cytoprotective Nrf2 pathwayby many of these compounds. Besides, Ssome of themse compounds are known to impact the thyroid gland, often with potential for side-effects, but in other instances with potential utility for in the treatment of thyroid disorders.
Objective: In view of recent data regarding the multiple roles of Nrf2 in the thyroid, this review summarizes the current bibliography on natural compounds that can have an effect on thyroid gland physiology and pathophysiology, and it discusses the respective potential implication of the Nrf2 system in the respective mechanisms.
Method & Results: Literature searches for articles from 1950 to 2018 wereas performed in PubMed andor Google Scholar using relevant keywords about phytochemicals, Nrf2 and thyroid. Natural substances were categorized into phenolic compounds, sulfur-containing compounds, quinones, terpenoids, andor under the general category of plant extracts. For individual compounds in each category, respective data were summarized, as derived from in vitro (cell lines), preclinical (animal models) and clinical studies. The Mmain emerging themes were the following: phenolic compounds often showed potential to affect the production of thyroid hormones; sulfur-containing compounds impacted the pathogenesis of goiter and the proliferation of thyroid cancer cells; while quinones and terpenoids modified Nrf 2 signaling in thyroid cell lines.
Conclusion: Natural compounds that modify the activity of the Nrf2 pathway should be evaluated carefully, not only for their potential to be used as therapeutic agents for thyroid disorders, but also for their thyroidal safety when used for the prevention and treatment of non-thyroidal diseases.