3-Methyladenine alleviates excessive iodine-induced cognitive impairment via suppression of autophagy in rat hippocampus.

Drinking water with high levels of iodine has been identified as the key contributor to iodine excess, but the mechanisms of neurotoxicity induced by excessive iodine remain elusive. The present study aimed to explore the role of autophagy in the neurotoxic effect induced by excessive iodine in vivo. The Morris water maze test results demonstrated that excessive iodine impaired the learning and memory capabilities of rats, which were associated with marked body weight and brain weight abnormalities. In addition, iodine treatment increased malondialdehyde accumulation, decreased superoxide dismutase activity and glutathione (GSH) level, and enhanced levels of autophagy markers in the hippocampus. Notably, inhibition of autophagy with 3-methyladenine (3-MA) could significantly alleviate excessive iodine-induced cognitive impairment. These data imply that autophagy is involved in the cognitive impairment elicited by excessive iodine as a pathway of cell death, and inhibition of autophagy via 3-MA may significantly alleviate the above damage.