Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Hoegi-dong, Dongdaemoon-gu, Seoul, Republic of Korea.
PLoS One. 2013 Dec 4;8(12):e81556. doi: 10.1371/journal.pone.0081556. eCollection 2013.
Soy (Glycine Max Merr, family Leguminosae) has been reported to possess anti-cancer, anti-lipidemic, estrogen-like, and memory-enhancing effects. We investigated the memory-enhancing effects and the underlying mechanisms of soyasaponin I (soya-I), a major constituent of soy. Impaired learning and memory were induced by injecting ibotenic acid into the entorhinal cortex of adult rat brains. The effects of soya-I were evaluated by measuring behavioral tasks and neuronal regeneration of memory-deficient rats. Oral administration of soya-I exhibited significant memory-enhancing effects in the passive avoidance, Y-maze, and Morris water maze tests. Soya-Ι also increased BrdU incorporation into the dentate gyrus and the number of cell types (GAD67, ChAT, and VGluT1) in the hippocampal region of memory-deficient rats, whereas the number of reactive microglia (OX42) decreased. The mechanism underlying memory improvement was assessed by detecting the differentiation and proliferation of neural precursor cells (NPCs) prepared from the embryonic hippocampus (E16) of timed-pregnant Sprague-Dawley rats using immunocytochemical staining and immunoblotting analysis. Addition of soya-Ι in the cultured NPCs significantly elevated the markers for cell proliferation (Ki-67) and neuronal differentiation (NeuN, TUJ1, and MAP2). Finally, soya-I increased neurite lengthening and the number of neurites during the differentiation of NPCs. Soya-Ι may improve hippocampal learning and memory impairment by promoting proliferation and differentiation of NPCs in the hippocampus through facilitation of neuronal regeneration and minimization of neuro-inflammation.
大豆（Glycine Max Merr，豆科）已被报道具有抗癌、抗血脂、类雌激素和增强记忆的作用。我们研究了大豆皂甙 I（soya-I）的增强记忆作用及其潜在机制，它是大豆的主要成分之一。通过向成年大鼠大脑的内嗅皮层注射鹅膏蕈氨酸来诱导学习和记忆受损。通过测量记忆缺陷大鼠的行为任务和神经元再生来评估 soya-I 的作用。大豆皂甙 I 的口服给药在被动回避、Y 迷宫和 Morris 水迷宫测试中表现出显著的记忆增强作用。Soya-Ι还增加了 BrdU 在内侧齿状回的掺入以及海马区记忆缺陷大鼠的细胞类型（GAD67、ChAT 和 VGluT1）的数量，而反应性小胶质细胞（OX42）的数量减少。通过检测从定时怀孕的 Sprague-Dawley 大鼠胚胎海马（E16）制备的神经前体细胞（NPC）的分化和增殖，评估记忆改善的机制，使用免疫细胞化学染色和免疫印迹分析。在培养的 NPC 中添加 soya-Ι 可显著提高细胞增殖标志物（Ki-67）和神经元分化标志物（NeuN、TUJ1 和 MAP2）。最后，soya-I 增加了 NPC 分化过程中神经突的伸长和数量。Soya-I 通过促进神经元再生和最小化神经炎症来改善海马体的学习和记忆损伤，从而促进海马体中 NPC 的增殖和分化。
