Polyphenols from citrus fruits induce structural and immunohistochemical changes in thyroids of old-aged male Wistar rats
2017
Authors:
Miler, MarkoAjdžanović, Vladimir
Jarić, Ivana
Živanović, Jasmina
Kardum, Nevena
Milenković, Dragan
Milošević, Verica
Šošić-Jurjević, Branka
Contributors
Santisteban, PilarŽarković, Miloš
Document Type:
Conference object (Published version)
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© Copyright 2017 European Thyroid Association Published by S. Karger AG, Basel
Metadata
Show full item recordAbstract:
Polyphenols are class of plant secondary metabolites that exert various beneficial effects. Namely, citrus polyphenols, naringenin (NAR) and hesperetin (HES) are potent antioxidants that may contribute to maintenance of health at old age by improving redox and metabolic status. However, polyphenols also interfere with thyroid peroxidase (TPO) activity and might affect thyroid structure and hormone production. Keeping in mind impaired thyroid function at older age, in this study we tested weather NAR or HES administration could induce structural and immunohistochemical changes in male 24-monthold Wistar rats. NAR or HES were administrated orally (15 mg/kg) during 4 weeks, while control groups received vehicle, sunflower oil. Stereological analyses (absolute and relative volume of epithelium, colloid and interstitium) and qualitative immunohistochemical examination of TPO and vascular endothelial growth factor (VEGF) proteins were performed. Results showed that thyroid structure of both flavanone-treated groups was characterized by lower (p < 0.05) absolute and relative volume of luminal colloid, accompanied by elevated (p < 0.05) relative volume of interstitium in comparison with the controls. These changes were more prominent after NAR even no hypertrophy or absolute thyroid volume change was detected. TPO expression was localized in the cytoplasm and on the apical membrane of the active follicles, showing stronger immunostaining in both flavanone treated group in comparison with the controls. VEGF immunohistochemical expression was localized in the thyrocytes’s cytoplasm of thyrocytes and C cells, being stronger in flavanone-treated animals. In conclusion, both citrus flavanones induced structural alteration of thyroid tissue. Depleted colloid and stronger apical TPO immunostaining in the thyrocytes indicate higher thyroid hormone secretion and production. In line with this, interstitium volume increment, and higher VEGF expression in thyroid parenchyma might be due to a better blood supply and the expansion of microcirculation around active follicles in the thyroid of old-aged males.
Source:
40th Annual Meeting of the European Thyroid Association Programme; 2017 Sep 9-12; Belgrade, Serbia (European Thyroid Journal; Vol. 6; No. 1), 2017, 42-Funding / projects:
- The effects of select plant extracts, phytoestrogens, steroid and peptide hormones on the rat neuroendocrine system (RS-MESTD-Basic Research (BR or ON)-173009)
URI
https://www.karger.com/Article/Abstract/477987https://radar.ibiss.bg.ac.rs/handle/123456789/3501