title: Soyasaponin I improved neuroprotection and regeneration in memory deficient model rats.
abstract: 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.
authors: Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Hoegi-dong, Dongdaemoon-gu, Seoul, Republic of Korea.
authors: Sung-Woon
authors: SW
authors: Hong
authors: Hwon
authors: H
authors: Heo
authors: Jeong-hwa
authors: JH
authors: Yang
authors: Maeum
authors: M
authors: Han
authors: Dong-Hyun
authors: DH
authors: Kim
authors: Yunhee Kim
authors: YK
authors: Kwon
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D006624:Hippocampus / Q000473:pathology; D007051:Ibotenic Acid; D008297:Male; D008568:Memory / Q000187:drug effects*; D008569:Memory Disorders / Q000188:drug therapy* / Q000503:physiopathology*; D017628:Microglia / Q000187:drug effects / Q000473:pathology; D009416:Nerve Regeneration / Q000187:drug effects*; D058953:Neural Stem Cells / Q000166:cytology / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D009828:Oleanolic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012503:Saponins / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use*
chemical_list: D015415:Biomarkers; D018696:Neuroprotective Agents; D012503:Saponins; D007051:Ibotenic Acid; C056684:soyasaponin I; D009828:Oleanolic Acid