The Effects of Seed Extract of Carrot on Memory, Nerve Conduction Velocity, and Serum Thyroxin in Rats

BACKGROUND: Thyroid hormones are essential to maintain the tissue's metabolism throughout the life. Thyroid hormones exert their effects on physiology and almost all body functions. Carrot is a rich source of iodine and carotenoids that can interfere in the synthesis of thyroid hormones. MATERIALS AND METHODS: The present study was designed to investigate the effects of carrot consumption on T4 levels and its effect on memory, nerve conduction velocity (NCV), animal weight, and finally, on water and food intake in Wistar rats. In this study, 24 male rats were used and divided into three groups: Control, Ca 200 mg/kg, and Ca 400 mg/kg. RESULTS: The results indicated that carrot consumption at Ca 200 mg/kg treated group increased the level of serum T4 and induced hyperthyroidism. Animal weight in both treated groups did not change compared to the control group (P > 0.05). Water and food consumption, and the level of T4 in Ca 200 mg/kg group increased when compared to the control group (P < 0.05). NCV in both treated groups was not significantly different in comparison with the control group (P > 0.05). Spatial memory and passive avoidance memory in both treated groups significantly decreased compared to the control group (P < 0.05). CONCLUSION: Carrot consumption, via increases the synthesis of thyroid hormones, creates hyperthyroidism, but due to induced moderate hyperthyroidism did not impact on weight. Moderate hyperthyroidism induced appetite and memory impairment. Then increased food intake or effect of hyperthyroidism on metabolism increased water intake.