Abstract

Normal brain development requires the presence of thyroid hormones (TH). The present study aimed to declare the effect of hyperthyroidism on oxidative stress parameters in brain tissues (cortex, hypothalamus and hippocampus) and the role of folic acid supplementation in treatment. Thirty adult rats were divided into 5 groups (Group 1, Control; Group 2, Folic acid; Group 3, Hyperthyroid; Group 4, Co-treated hyperthyroid with folic acid; Group 5, Post treated hyperthyroid with folic acid). The current results showed a significant increase in the concentrations of T3 & T4 in hyperthyroid rats when compared with control group. In contrast, TSH showed a significant decrease in hyperthyroid rats when compared with the control group. Calcium was significantly increased in hyperthyroid group when compared with control group. Catalase and MDA were increased, while total protein in brain tissues was decreased in hyperthyroid rats (G3) when compared with control group. Total thiol in brain tissues showed a significant decrease in hyperthyroid group when compared with control group. Treatment with folic acid showed enhancement in oxidative stress parameters in post treated group more than co treated group.

Key words: Hyperthyroid, Oxidative stress, Folic acid, Brain rat tissues.