Shin, Tae-Joon Hwang, Sung-Hee Choi, Sun-Hye Lee, Byung-Hwan Kang, Jiyeon Kim, Hyeon-Joong Zukin, R. Suzanne Rhim, Hyewhon Nah, Seung-Yeol 2024-01-20T15:02:57Z 2024-01-20T15:02:57Z 2021-09-05 2012-04 1226-4512 https://pubs.kist.re.kr/handle/201004/129362 Ginsenosides are low molecular weight glycosides found in ginseng that exhibit neuroprotective effects through inhibition of N-methyl-D-aspartic acid (NMDA) receptor channel activity. Ginsenosides, like other natural compounds, are metabolized by gastric juices and intestinal microorganisms to produce ginsenoside metabolites. However, little is known about how ginsenoside metabolites regulate NMDA receptor channel activity. In the present study, we investigated the effects of ginsenoside metabolites, such as compound K (CK), protopanaxadiol (PPD), and protopanaxatriol (PPT), on oocytes that heterologously express the rat NMDA receptor. NMDA receptor-mediated ion current (I-NMDA) was measured using the 2-electrode voltage clamp technique. In oocytes injected with cRNAs encoding NMDA receptor subunits, PPT, but not CK or PPD, reversibly inhibited I-NMDA in a concentration-dependent manner. The IC50 for PPT on I-NMDA was 48.1 +/- 4.6 mu M, was non-competitive with NMDA, and was independent of the membrane holding potential. These results demonstrate the possibility that PPT interacts with the NMDA receptor, although not at the NMDA binding site, and that the inhibitory effects of PPT on I-NMDA could be related to ginseng-mediated neuroprotection. English KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY PROTEIN-KINASE-C NMDA RECEPTORS GLUTAMATE RECEPTORS HIPPOCAMPAL-NEURONS XENOPUS OOCYTES INHIBITION SUBTYPES SIGNALS RG(3) Effects of Protopanaxatriol-Ginsenoside Metabolites on Rat N-Methyl-D-Aspartic Acid Receptor-Mediated Ion Currents Article 10.4196/kjpp.2012.16.2.113 1 KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY, v.16, no.2, pp.113 - 118 KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY 16 2 113 118 scie scopus kci ART001655858 000303697600005 2-s2.0-84861050601 Pharmacology & Pharmacy Physiology Pharmacology & Pharmacy Physiology Article PROTEIN-KINASE-C NMDA RECEPTORS GLUTAMATE RECEPTORS HIPPOCAMPAL-NEURONS XENOPUS OOCYTES INHIBITION SUBTYPES SIGNALS RG(3) Ginseng Ginsenoside metabolites N-methyl-D-aspartic acid receptor