||Ginsenoside Rd, a minor ginseng saponin, has several pharmacological activities such as immunosuppressive activity, anti-inflammatory activity, immunological adjuvant, anti-cancer activity and wound-healing activity. Rd inhibits TNFα-induced NF-κB transcriptional activity with an IC50 of 12.05±0.82 μM in HepG2 cells. Rd inhibits expression of COX-2 and iNOS mRNA. Rd also inhibits Ca2+ influx. Rd inhibits CYP2D6, CYP1A2, CYP3A4, and CYP2C9, with IC50s of 58.0±4.5 μM, 78.4±5.3 μM, 81.7±2.6 μM, and 85.1±9.1 μM, respectively.
|J Ethnopharmacol. 2012 Aug 1;142(3):754-61. |
|Promotive effect of ginsenoside Rd on proliferation of neural stem cells in vivo and in vitro.[Pubmed: 22683911 ]|
|Ginseng, the root of Panax ginseng C. A. MEYER (Araliaceae), is reputedly known for its nootropic and anti-aging functions and has been widely used to treat various diseases and enhance health for thousands of years in Asia. Recent studies revealed that ginsenoside, responsible for the pharmacological effects of ginseng, can prevent memory loss and improve spatial learning in mice, but underlying mechanisms are still largely unknown. Active neurogenesis in adult hippocampus is closely related to animals' learning and memory ability. The present study aimed to investigate the possible effects of Ginsenoside Rd, one of the most effective ingredients in ginseng, on neurogenesis in vivo and in vitro.
METHODS AND RESULTS:
Adult rats and cultured neural stem cells were treated with Ginsenoside Rd at different doses, and the changes in the proliferation and differentiation of neural stem cells were examined by immunohistochemistry and immunocytochemistry.
Ginsenoside Rd significantly increased the numbers of BrdU(+) and DCX(+) cells in the hippocampal dentate gyrus but did not affect the ratio of NeuN/BrdU double-labeled cells to the total number of BrdU(+) cells. For cultured neural stem cells, Ginsenoside Rd promoted the size and number of neurospheres, increased the number of BrdU(+) and Ki67(+) cells but did not affect the differentiation of neural stem cells into neurons, astrocytes and oligodendrocytes.
These results indicate that Ginsenoside Rd can enhance the proliferation but not affect the differentiation of neural stem cells in vivo and in vitro.
|Acta Pharmacol Sin. 2015 Apr;36(4):421-8. |
|Ginsenoside Rd promotes neurogenesis in rat brain after transient focal cerebral ischemia via activation of PI3K/Akt pathway.[Pubmed: 25832422]|
|To investigate the effects of Ginsenoside Rd (Rd) on neurogenesis in rat brain after ischemia/reperfusion injury (IRI).
METHODS AND RESULTS:
Male SD rats were subjected to transient middle cerebral artery occlusion (MCAO) followed by reperfusion. The rats were injected with Rd (1, 2.5, and 5 mg·kg(-1)·d(-1), ip) from d 1 to d 3 after MCAO, and with BrdU (50 mg·kg(-1)·d(-1), ip) from d 3 to d 6, then sacrificed on 7 d. The infarct size and neurological scores were assessed. Neurogenesis in the brains was detected by BrdU, DCX, Nestin, and GFAP immunohistochemistry staining. PC12 cells subjected to OGD/reperfusion were used as an in vitro model of brain ischemia. VEGF and BDNF levels were assessed with ELISA, and Akt and ERK phosphorylation was measured using Western blotting.
Rd administration dose-dependently decreased the infarct size and neurological scores in the rats with IRI. The high dose of Rd 5 (mg·kg(-1)·d(-1)) significantly increased Akt phosphorylation in ipsilateral hemisphere, and markedly increased the number of BrdU/DCX and Nestin/GFAP double-positive cells in ischemic area, which was partially blocked by co-administration of the PI3 kinase inhibitor LY294002. Treatment with Rd (25, 50, and 100 μmol/L) during reperfusion significantly increased the expression of VEGF and BDNF in PC12 cells with IRI. Furthermore, treatment with Rd dose-dependently increased the phosphorylation of Akt and ERK, and significantly decreased PC12 cell apoptosis, which were blocked by co-application of LY294002.
Rd not only attenuates ischemia/reperfusion injury in rat brain, but also promotes neurogenesis via increasing VEGF and BDNF expression and activating the PI3K/Akt and ERK1/2 pathways.
|Expert Rev Neurother. 2013 Jun;13(6):603-13. |
|Ginsenoside Rd for acute ischemic stroke: translating from bench to bedside.[Pubmed: 23738998]|
|Numerous studies have identified pathophysiological mechanisms of acute ischemic stroke and have provided proof-of-principle evidence that strategies designed to impede the ischemic cascade, namely neuroprotection, can protect the ischemic brain. However, the translation of these therapeutic agents to the clinic has not been successful. Ginsenoside Rd, a dammarane-type steroid glycoside extracted from ginseng plants, has exhibited an encouraging neuroprotective efficacy in both laboratory and clinical studies. This article attempts to provide a synopsis of the physiochemical profile, pharmacokinetics, pharmacodynamics, clinical efficacy, safety and putative therapeutic mechanisms of Rd. Finally, the authors discuss the validity of Rd as a neuroprotective agent for acute ischemic stroke.|
|Vaccine. 2007 Jan 2;25(1):161-9. |
|Ginsenoside Rd elicits Th1 and Th2 immune responses to ovalbumin in mice.[Pubmed: 16950547]|
|Ginsenoside Rd (Rd), a saponin isolated from the roots of panax notoginseng, was evaluated for inducing Th1 or Th2 immune responses in mice against ovalbumin (OVA).
METHODS AND RESULTS:
ICR mice were immunized subcutaneously with OVA 100 microg alone or with OVA 100 microg dissolved in saline containing alum (200 microg), or Rd (10, 25 or 50 microg) on days 1 and 15.
Two weeks later (day 28), concanavalin A (Con A)-, lipopolysaccharide (LPS)- and OVA-stimulated splenocyte proliferation was determined using MTT assay, and OVA-specific antibody titers and levels of cytokines in serum were measured by ELISA and microparticle-based flow cytometric immunoassay, as well as peripheral blood T-lymphocyte subsets analyzed using flow cytometer. Rd significantly enhanced the Con A-, LPS-, and OVA-induced splenocyte proliferation in the OVA-immunized mice. OVA-specific IgG, IgG1, and IgG2b antibody titers in serum were significantly enhanced by Rd compared with OVA control group. Meanwhile, Rd also significantly promoted the production of the Th1 and Th2 cytokines in OVA-immunized mice. Further, the effects of Rd on expression of cytokine mRNA in Con A-stimulated mice splenocytes were evaluated by RT-PCR analysis. Rd significantly enhanced the interleukin-2 (IL-2), interferon-gamma (IFN-gamma), IL-4, and IL-10 mRNA expression in mice splenocyte induced by Con A.
These results suggested that Rd had immunological adjuvant activity, and elicited a Th1 and Th2 immune response by regulating production and gene expression of Th1 cytokines and Th2 cytokines.