Selenium Nanoparticles mitigating Thyroid Dysfunction in Hexachlorobenzene-Induced Hypothyroid Rats

Abstract

Hexachlorobenzene (HCB) is a potent endocrine disruptor that targets the thyroid gland and results in thyroid dysfunction. Nano-selenium (SeNP) has attracted attention owing to its antioxidant activity. It can be used to alleviate thyroid disruption by modulating the activity of selenium-containing proteins in the thyroid gland. Our aim is to determine the ability of SeNPs to reverse the effects of the environmental toxicant HCB on thyroid function by assessing thyroid histology, thyroid function tests, lipid profile and antioxidant status. 65-day-old rats were orally administered HCB (50 mg/kg), SeNP (0.05 mg/kg), HCB (50 mg/kg) + SeNP (0.05 mg/kg) or 0.05% aqueous Tween 20 (control) for 90 days. Thyroid function, gland histology and antioxidant levels were evaluated, along with changes in the lipid profile. Experimental data were analyzed using One-way Variance (ANOVA) analysis followed by Tukey’s post-hoc test. Pearson’s correlation analysis assessed the correlation between the various parameters. Results were considered significant at p<0.05. Necrotic lesions and levels of fT3, fT4 and TSH were correlated with the detrimental changes observed due to exposure to HCB. Treatment with SeNP helped in maintaining the normalization of these changes. HCB increases LPO and decreases GSH, CAT, GPx and SOD significantly (p<0.001). A negative correlation between MDA and fT3 (r=−0.86, p= 0.003) was observed in the HCB-treated group. Similarly, GPx and TSH levels were negatively correlated (r=−0.79, p=0.05). TSH levels were negatively and strongly correlated with HDL levels in the SeNP group (r=0.91, p = 0.01). This study suggests that selenium, especially in the nanotized form, can be used to treat thyroid dysfunction caused by exposure to environmental pollutants.