Department of Physiology, Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran.
Student Research Committee, Gonabad University of Medical Sciences, Gonabad, Iran.
Nutr Neurosci. 2023 Dec;26(12):1222-1231. doi: 10.1080/1028415X.2022.2145423. Epub 2022 Nov 21.
The present study focused on examining the impact of vitamin C (Vit C) administration on the function of memory and the status of oxidative stress (OS) in the hippocampal area of the brain using an unpredictable chronic mild stress (UCMS) model in rats. To this end, 50 male Wistar rats (11-12 weeks of age at the start of the study) were assigned to five groups of six animals, including control, UCMS, UCMS + Vit C 50 mg/Kg, UCMS + Vit C 100 mg/Kg, and UCMS + Vit C 400 mg/Kg. The animals received daily intraperitoneal injections of Vit C at a certain time (9 am) before the initiation of a stressor. UCMS, including a progression of typical stressors, was applied for four weeks. Subsequently, using the passive avoidance (PA) and Morris water maze (MWM) tests were performed to investigate learning and memory. Eventually, hippocampal tissues were evaluated in terms of OS criteria. The results revealed that the latency to enter the dark chamber ( < 0. 01 and < 0.05, PA test) and the time spent in the target quadrant ( < 0.0001, MWM test) were shorter in the UCMS group, while latency to discover the platform was longer ( < 0.05 and < 0.001, MWM test) compared to the control group. However, UCMS decreased the content of thiol ( < 0.0001), as well as the activities of catalase ( < 0.0001) and superoxide dismutase ( < 0.0001), whereas the concentration of malondialdehyde ( < 0.01) increased in the hippocampal region of the brain in comparison to the control group. Interestingly, Vit C treatment reversed the mentioned effects of UCMS. Therefore, the latency to enter the dark chamber ( < 0. 05 and < 0.01,1 and 24 h after the shock, PA test, UCMS + Vit C 400) and the time spent in the target quadrant ( < 0. 01 and < 0.05, MWM test, UCMS + Vit C 400 and UCMS + Vit C 100, respectively) were longer in the UCMS + Vit C groups. Moreover, Vit C increased the content of thiol ( < 0.05, UCMS + Vit C 400), as well as the activity of catalase ( < 0.001, UCMS + Vit C 400) and superoxide dismutase ( < 0.0001, UCMS + Vit C 400, UCMS + Vit C 100), whereas the concentration of malondialdehyde ( < 0. 05 and < 0.01, UCMS + Vit C 100, UCMS + Vit C 400) decreased in the hippocampal region of the brain in comparison to the UCMS group. Overall, these results suggest that Vit C could reverse UCMS-induced learning and memory impairment possibly through the modulation of brain OS. Memory and learning impairments were induced by unpredictable chronic mild stress (UCMS)Vitamin C could prevent cognitive impairments caused by UCMS in rats by attenuation of oxidative stress in the brain.
本研究旨在使用不可预测的慢性轻度应激（UCMS）大鼠模型，研究维生素 C（Vit C）给药对记忆功能和大脑海马区氧化应激（OS）状态的影响。为此，将 50 只雄性 Wistar 大鼠（研究开始时 11-12 周龄）分为五组，每组 6 只动物，包括对照组、UCMS 组、UCMS+Vit C 50mg/Kg 组、UCMS+Vit C 100mg/Kg 组和 UCMS+Vit C 400mg/Kg 组。动物在应激前的特定时间（上午 9 点）每天接受 Vit C 腹腔注射。UCMS 包括一系列典型的应激源，持续四周。随后，使用被动回避（PA）和 Morris 水迷宫（MWM）测试来研究学习和记忆。最终，根据 OS 标准评估海马组织。结果表明，与对照组相比，UCMS 组进入暗室的潜伏期（PA 测试，<0.01 和 <0.05）和在目标象限花费的时间（MWM 测试，<0.0001）更短，而发现平台的潜伏期（MWM 测试，<0.05 和 <0.001）更长。然而，与对照组相比，UCMS 降低了硫醇（<0.0001）的含量，以及过氧化氢酶（<0.0001）和超氧化物歧化酶（<0.0001）的活性，而丙二醛（<0.01）的浓度在海马区增加。有趣的是，Vit C 处理逆转了 UCMS 的上述作用。因此，与 UCMS 组相比，进入暗室的潜伏期（PA 测试，1 和 24 小时后受电击，<0.05 和 <0.01，UCMS+Vit C 400）和在目标象限花费的时间（MWM 测试，<0.01 和 <0.05，UCMS+Vit C 400 和 UCMS+Vit C 100）更长。此外，Vit C 增加了硫醇（<0.05，UCMS+Vit C 400）的含量，以及过氧化氢酶（<0.001，UCMS+Vit C 400）和超氧化物歧化酶（<0.0001，UCMS+Vit C 400、UCMS+Vit C 100）的活性，而丙二醛（<0.05 和 <0.01，UCMS+Vit C 100、UCMS+Vit C 400）的浓度在海马区降低。总的来说，这些结果表明，Vit C 可能通过调节大脑 OS 来逆转 UCMS 诱导的学习和记忆障碍。
