Ziziphus Jujuba Extract Prevents from Brain Tissues Oxidative Damage and Learning and Memory Impairments of Juvenile Hypothyroid Rats

The effects of Ziziphus jujuba (ZJ) extract on brain tissues oxidative damage and learning and memory impairments during neonatal and juvenile growth in hypothyroid rats was examined. Materials and Methods: Thirty pregnant rats after delivery were randomly divided as following groups: (1) control, (2) PTU (propylthiouracil), (3) PTU-ZJ100mg, (4) PTUZJ150mg and (5) PTU-ZJ200mg. All dams except thecontrol group received 0.005% PTU in their drinking water during lactation. Besides PTU, dams in groups 3, 4 and 5 received 100, 150 and 200mg/kg ZJ extract respectively. After lactation period, pups continued to receive same experimental treatment for the first8 weeks of their life. Then, 10 male offspring of each group were randomly selected for Morris water maze (MMW) test. Finally, the animals were deeply anesthetized and the brain tissues were removed for biochemical measurements. Results: PTU increased the time latency in MWM test, while reduced the time spent in target quadrant. PTU reduced serum thyroxine levels and brain levels of thiol groups, catalase and superoxide dismutase (SOD) activities, and significant elevation in hippocampal MDA. Administration of 150 and 200 mg/ kg ZJ extract reduced the time latency, while increased the time spent in target quadrant compared to the PTU group in MWM test. The serum thyroxine concentrations of the animals treated by all doses of the ZJ extract were higher than that of the PTU group. Higher and mediumdoses of ZJ extract decreased the MDA concentration in hippocampal tissues, while increased thiol contents and catalase and SOD activities compared to the PTU group. Conclusion: The results of this study demonstrate that the hydroalcoholic extract of ZJ have protective effectson hypothyroidism-associated learning and memory impairment during neonatal and juvenile growth in rats. The effects might be due to the protective effects of ZJ extract against brain tissues’ oxidative damage.