Ryoo, Nayeon Rahman, Md Ataur Hwang, Hongik Ko, Sung Kwon Nah, Seung-Yeol Kim, Hyoung-Chun Rhim, Hyewhon 2024-01-19T17:33:09Z 2024-01-19T17:33:09Z 2022-01-10 2020-05 1226-8453 https://pubs.kist.re.kr/handle/201004/118653 Background: Ginsenoside Rk1, a saponin component isolated from heat-processed Panax ginseng Meyer, has been implicated in the regulation of antitumor and anti-inflammatory activities. Although our previous studies have demonstrated that ginsenoside Rg3 significantly attenuated the activation of NMDA receptors (NMDARs) in hippocampal neurons, the effects of ginsenosides Rg5 and Rk1, which are derived from heat-mediated dehydration of ginsenoside Rg3, on neuronal NMDARs have not yet been elucidated. Methods: We examined the regulation of NMDARs by ginsenosides Rg5 and Rk1 in cultured rat hippocampal neurons using fura-2-based calcium imaging and whole-cell patch-clamp recordings. Results: The results from our investigation showed that ginsenosides Rg3 and Rg5 inhibited NMDARs with similar potencies. However, ginsenoside Rkl inhibited NMDARs most effectively among the five compounds (Rg3, Rg5, Rk1, Rg5/Rk1 mixture, and protopanaxadiol) tested in cultured hippocampal neurons. Its inhibition is independent of the NMDA- and glycine-binding sites, and its action seems to involve in an interaction with the polyamine-binding site of the NMDAR channel complex. Conclusion: Taken together, our results suggest that ginsenoside Rk1 might be a novel component contributable to the development of ginseng-based therapeutic treatments for neurodegenerative diseases. (C) 2019 The Korean Society of Ginseng. Publishing services by Elsevier B.V. English 고려인삼학회 Ginsenoside Rk1 is a novel inhibitor of NMDA receptors in cultured rat hippocampal neurons Article 10.1016/j.jgr.2019.04.002 1 Journal of Ginseng Research, v.44, no.3, pp.490 - 495 Journal of Ginseng Research 44 3 490 495 Y scie scopus kci ART002587133 000529068000013 2-s2.0-85065447424 Plant Sciences Chemistry, Medicinal Integrative & Complementary Medicine Plant Sciences Pharmacology & Pharmacy Integrative & Complementary Medicine Article BRAIN-INJURY RG1 CELLS SITE NEUROGENESIS RB-1 RB1 Ginsenoside Rk1 Hippocampal neurons Intracellular Ca2+ NMDA receptors Whole-cell patch-clamp