Evaluation of selenoproteins and proinflammatory cytokines in L-thyroxine-induced hyperthyroid rats: effects of selenium supplementation.

OBJECTIVE

This study investigated the effects of selenium, which is known for its antioxidant and immune-supporting properties, on serum levels of thyroid function markers, selenoproteins, and proinflammatory cytokines in a model of hyperthyroidism.

MATERIALS AND METHODS

A total of 48 Wistar albino rats were distributed into 6 groups: a control group; a hyperthyroid group (HT group); a group fed 0.5 mg/kg sodium selenite (Se 1 group); a group fed 1 mg/kg sodium selenite (Se 2 group); a hyperthyroid group fed 0.5 mg/kg sodium selenite (HT + Se 1 group); and a hyperthyroid group fed 1 mg/kg sodium selenite (HT + Se 2 group) added to standard fodder. Serum levels of interleukin (IL)-1β, IL-6, IL-18, tumour necrosis factor alpha (TNF-α), selenoprotein P (SelP), and glutathione peroxidase 1 (GPx1) were measured using ELISAs.

RESULTS

IL-Iβ, IL-6, IL-18, and TNF-α levels were increased, but selenium, GPx1, and SelP levels were decreased in the hyperthyroid group compared with those in the control group. Selenium and GPx1 levels were increased, but TNF-α levels were decreased in the HT + Se 1 group compared with those in the HT group. Selenium, SelP, and GPx1 levels were increased, but TNF-α, IL-6, and IL-18 levels were decreased in the HT + Se 2 group compared with those in the HT group.

CONCLUSION

Our results suggest that appropriate doses of selenium may be effective at preventing inflammation and providing protection against oxidative stress in hyperthyroid rats.