Ginsenoside Rh2 Ameliorates Scopolamine-Induced Learning Deficit in Mice

Abstract

To understand memory-enhancing effect of red ginseng biotransformed by Bifidobacterium longum H-1 (RGB), which more potently improved scopolamine-induced learning deficit than red ginseng in the preliminary experiment, its main constituents, ginsenosides Rb1, Rg3 and Rh2, were isolated and their memory-enhancing effects investigated in scopolamine-treated mice by using passive avoidance and Y-maze tests. Among them, ginsenoside Rh2 most potently reversed memory impairment caused by scopolamine. Ginsenoside Rh2 also significantly shortened the escape latencies prolonged by scopolamine in the Morris water maze test (pϽ Ͻ0.001) and increased the swimming time shorten by scopolamine within the platform quadrant (pϽ Ͻ0.05). The ginsenoside Rh2 (3 m mM) reversed scopolamine (10 m mM)-induced suppression of long-term potentiation. It recovered field excitatory post synaptic potential (fEPSP) amplitude potentiation to 152.3؎8.7% of the control (pϽ Ͻ0.05). Based on these findings, RGB and its main constituent, ginsenoside Rh2, might improve learning deficits. Also the memoryenhancing effects of RGB may be dependent on the content of ginsenoside Rh2.Key words red ginseng; ginsenoside Rh2; memory; scopolamine; long-term potentiation Biol. Pharm. Bull. 32(10) 1710-1715 (2009) © 2009 Pharmaceutical Society of Japan * To whom correspondence should be addressed. e-mail: dhkim@khu.ac.kr

20(<i>S</i>)-Ginsenoside Rh2 Induces Apoptosis in Human Leukaemia Reh Cells through Mitochondrial Signaling Pathways

“…[8][9][10] 20(S)-Ginsenoside Rh2 (GRh2), with a dammarane skeleton, belongs to the protopanaxadiol family and has drawn attention in chemopreventive research. [11][12][13] Recently, researchers have found that 20(S)-GRh2 exhibits anticancer effects and could inhibit growth of several cancer cell lines and induce apoptosis in mammalian tumor cells. [14][15][16] However, the details of the signal transduction cascade involved in 20(S)-GRh2-induced death in Reh cells remaine unclear.…”

Ginsenoside Rh2 Improves Learning and Memory in Mice

“…25 Further, ginsenoside Rh 2 ameliorates Scopolamineinduced learning deficit in mice. 26 Because there is little evidence in the literature for improvement in memory and learning by ginsenoside Rh 2 , the present study provided reasonable mechanism for ginsenoside Rh 2 -mediated regulation of memory and learning in mice.…”

Traditional Korean East Asian Medicines and Herbal Formulations for Cognitive Impairment

“…The nootropic signaling pathway has also been assessed in normal rats, and the Rg1-induced signaling pathway is similar to memory formation that occurs in mammals, suggesting that Rg1 may potentially increase intellectual capacity in normal people [24]. Ginsenoside Rh2 recovers the scopolamine-induced reduction in long-term potentiation (LTP) in the hippocampal CA1 area [25]. Rb1 enhances the stimulatory effect of neurite outgrowth [26], promotes neurotransmitter release by modulating phosphorylation of synapsins through a cAMP-dependent protein kinase pathway [27], upregulates cell genesis in the dentate gyrus (DG) and CA3 hippocampal subregions [28].…”

“…Related to the memory deficit-protecting effects of ginsenosides, ginsenoside Rg3 and ginsenoside Rg5/Rk1 mixture (1:1, w/w), isolated from heat-processed ginseng, show a memory enhancing effect in scopolamine-treated mice [32]. Ginsenoside Rg3 isolated from red ginseng and its metabolite ginsenoside Rh2, as well as ginsenoside Rg1, also protected against scopolamine-induced memory deficit in mice [25,33]. However, when ginsenoside Rg5 was incubated with human feces, it was metabolized to ginsenoside Rh3 [32].…”

“…C. officinale has been shown to improve memory in scopolamine-injected mice [101]. Several formulations containing C. officinale have been showed to improve memory impairment in cerebral ischemia [102,103], Aβ (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) -injected mice [104] and Tg-APPswe/PS1dE9, transgenic mice of AD [105].…”