There is a controversial data about the prooxidant-antioxidant balance in hypothyroidism. We investigated the effect of α-lipoic acid (ALA) on oxidative stress parameters in liver and brain of propylthiouracil (PTU)-induced hypothyroid rats.
PTU (500 mg/L) was given to rats in drinking water for 10 weeks. ALA (% 0.2 in diet) alone and together with thyroxine (T4; 20 µg/kg body weight, s.c) were given to hypothyroid rats in the last 5 weeks of experimental period. Liver and brain reactive oxygen species, malondialdehyde, protein carbonyl, ferric reducing antioxidant power and glutathione levels, superoxide dismutase and glutathione peroxidase activities were determined. Histopathological examinations were also performed.
Prooxidant parameters were increased in the brain but not liver in hypothyroid rats. ALA treatment alone lowered enhanced brain oxidative stress in hypothyroid rats. In addition, ALA was also found to be ameliorates changes due to oxidative stress arising from T4 replacement therapy.
Our results indicate that ALA alone and together with T4 may be useful in reducing oxidative stress in thyroid dysfunctions.