Department of Biology, School of Basic Sciences, Bu-Ali Sina University, Hamadan, Iran.
Neurobiol Learn Mem. 2010 May;93(4):472-8. doi: 10.1016/j.nlm.2010.01.004. Epub 2010 Jan 18.
Learning and memory deficits occur in diabetes mellitus. Although the pathogenesis of cognitive impairment in diabetes has not been fully elucidated, factors such as metabolic impairments, vascular complications and oxidative stress are thought to play possible roles. Here we investigated the effect of chronic treatment with vitamin C (50mg/kg, p.o), vitamin E (100mg/kg, p.o) and both together on passive avoidance learning (PAL) and memory in male Wistar control and diabetic rats. Treatments were begun at the onset of hyperglycemia. Passive avoidance learning was assessed 30 days later. Retention was tested 24h after training. At the end, animals were weighed and blood samples were drawn for plasma glucose measurement. Diabetes caused impairment in acquisition and retrieval processes of PAL and memory. The combination of vitamin C and E improved learning and memory in controls and reversed learning and memory deficits in diabetic rats. Combined treatment also affected the body weight and plasma glucose level of diabetic treated animals compared to untreated diabetic animals. Hypoglycemic effects and antioxidant properties of the vitamins may be involved in the nootropic effect of such treatment. These results show that combined treatment with vitamins C and E improved PAL and memory of control rats. In addition, combined vitamins administration to rats for 30 days from onset of diabetes alleviated the negative influence of diabetes on learning and memory. Therefore, combined vitamins treatment may provide a new potential alternative for prevention of impaired cognitive functions associated with diabetes and may warrant further clinical study.
学习和记忆障碍发生在糖尿病患者中。尽管糖尿病患者认知障碍的发病机制尚未完全阐明，但代谢损伤、血管并发症和氧化应激等因素被认为可能发挥作用。在这里，我们研究了慢性给予维生素 C（50mg/kg，口服）、维生素 E（100mg/kg，口服）和两者联合治疗对雄性 Wistar 对照和糖尿病大鼠的被动回避学习（PAL）和记忆的影响。治疗在高血糖发生时开始。30 天后评估被动回避学习。训练后 24 小时进行保留测试。最后，称重动物并抽取血液样本测量血浆葡萄糖。糖尿病导致 PAL 和记忆的获取和检索过程受损。维生素 C 和 E 的联合治疗改善了对照组的学习和记忆，并逆转了糖尿病大鼠的学习和记忆缺陷。与未治疗的糖尿病动物相比，联合治疗还影响了糖尿病治疗动物的体重和血浆葡萄糖水平。维生素的降血糖作用和抗氧化特性可能参与了这种治疗的益智作用。这些结果表明，联合给予维生素 C 和 E 可改善对照大鼠的 PAL 和记忆。此外，糖尿病发病后 30 天给予大鼠联合维生素治疗可减轻糖尿病对学习和记忆的负面影响。因此，联合维生素治疗可能为预防与糖尿病相关的认知功能障碍提供新的潜在选择，并值得进一步临床研究。
