Vitamin E attenuates the Zinc Oxide Nanoparticles-Induced Thyroid Gland Toxicity in Rats: A Histological, Immunohistochemical and Biochemical study.

Background: One of the most important nanoparticles used in various fields of life is Zinc Oxide nanoparticles. They have toxic effects on various organs including the thyroid gland. The present study was designed to analyze the protective role of vitamin E against ZnO NPs induced thyroid gland toxicity in rats.Material & Methods: twenty-eight male albino rats were divided into 4 groups (control, ZnO NPs treated group, recovery group and vitamin E-treated group). Blood samples collected for hormone analysis (T3, T4, TSH), and to measure MDA and GSH. Thyroid gland was removed and prepared for histological examination (hematoxylin and eosin, Mallory's Triochrome) and immunohistochemical study (TNF alpha and P53). Statistical study was done for the resultant data. Results: ZnO NPs treated group showed loss of normal architecture of thyroid follicles. Inflammatory cells infiltration in thyroid follicles, areas of pyknosis and hemorrhage were also seen. Mallory’s trichrome stained sections showed thick collagen bundles in between thyroid follicles. Immunohistochemical stained sections showed strong positive TNF-α and P53 reactions. Biochemical studies showed disturbance of thyroid hormones and Oxidant/antioxidant ratio in ZnO NPs treated group. All these results didn’t improve significantly in recovery group, but they improved significantly in vitamin E treated group.Conclusions: Vitamin E could ameliorate the thyroid damage induced by ZnO NPs