• Journal of Ginseng Research
• /
• v.42 no.1
• /
• pp.75-80
• /
• 2018

Background: The aim of the present study was to evaluate the potential protective effects of six ginsenosides (Rb1, Rb2, Rc, Rd, Rg1, and Rg3) isolated from Panax ginseng against tacrolimus (FK506)-induced apoptosis in renal proximal tubular LLC-PK1 cells. Methods: LLC-PK1 cells were treated with FK506 and ginsenosides, and cell viability was measured. Protein expressions of mitogen-activated protein kinases, caspase-3, and kidney injury molecule-1 (KIM-1) were evaluated by Western blotting analyses. The number of apoptotic cells was measured using an image-based cytometric assay. Results: Reduction in cell viability by $60{\mu}M$ FK506 was ameliorated significantly by cotreatment with ginsenosides Rg1 and Rb1. The phosphorylation of p38, extracellular signal-regulated kinases, and KIM-1, and cleavage of caspase-3, increased markedly in LLC-PK1 cells treated with FK506 and significantly decreased after cotreatment with ginsenoside Rb1. The number of apoptotic cells decreased by 6.0% after cotreatment with ginsenoside Rb1 ($10{\mu}M$ and $50{\mu}M$). Conclusion: The antiapoptotic effects of ginsenoside Rb1 on FK506-induced apoptosis were mediated by the inhibition of mitogen-activated protein kinases and caspase activation.

• Journal of Ginseng Research
• /
• v.44 no.4
• /
• pp.603-610
• /
• 2020

Background: Depression is a common neuropsychiatric disease that shows astrocyte pathology. Ginsenoside Rf (G-Rf) is a saponin found in Panax ginseng which has been used to treat neuropsychiatric diseases. We aimed to investigate antidepressant properties of G-Rf when introduced into the L-alphaaminoadipic acid (L-AAA)-infused mice model which is representative of a major depressive disorder that features diminished astrocytes in the brain. Methods: L-AAA was infused into the prefrontal cortex (PFC) of mice to induce decrease of astrocytes. Mice were orally administered G-Rf (20 mg/kg) as well as vehicle only or imipramine (20 mg/kg) as controls. Depression-like behavior of mice was evaluated using forced swimming test (FST) and tail suspension test (TST). We observed recovery of astroglial impairment and increased proliferative cells in the PFC and its accompanied change in the hippocampus by Western blot and immunohistochemistry to assess the effect of G-Rf. Results: After injection of L-AAA into the PFC, mice showed increased immobility time in FST and TST and loss of astrocytes without significant neuronal change in the PFC. G-Rf-treated mice displayed significantly more decreased immobility time in FST and TST than did vehicle-treated mice, and their immobility time almost recovered to those of the sham mice and imipramine-treated mice. G-Rf upregulated glial fibrillary acidic protein (GFAP) expression and Ki-67 expression in the PFC reduced by L-AAA and also alleviated astroglial change in the hippocampus. Conclusion: G-Rf markedly reversed depression-like behavioral changes and exhibited protective effect against the astrocyte ablation in the PFC induced by L-AAA. These protective properties suggest that G-Rf might be a therapeutic agent for major depressive disorders.

• Journal of Ginseng Research
• /
• v.29 no.4
• /
• pp.159-166
• /
• 2005

Ginsenosides, a group of Panax ginseng saponins, exert the lowering effects of plasma cholesterol levels in animals. We had reported earlier that ginsenoside Rb2 upregulate low-density lipoprotein receptor (LDLR) expression via a mechanism that is dependent of the activation of sterol response element binding protein 2 (SREBP-2) expression. This study was conducted to determine the effects of ginsenoside Rb2 on the expression of the hepatic LDLR expression at cellular levels using HepG2 cells, and to evaluate whether the sterol response element binding protein 1 (SREBP-l) was involved in the regulation of LDLR expression. Incubation of HepG2 cells in serum-free medium supplemented with cholesterol $(10{\mu}g/ml)$ for 8 hours decreased the mRNAs of LDLR mRNA by $12\%$ and SREBP-l mRNA by $35\%$. Ginsenoside Rb2 antagonized the repressive effects of cholesterol and increased both LDLR and SREBP-l mRNA expression to 1.5- and 2-fold, respectively. Furthermore, Western blot and confocal microscopic analyses with SREBP-l polyclonal antibody revealed that ginsenoside Rb2 enhanced the maturation of the SREBP-1 from the inactive precursor form in ER membrane to the active transcription factor form in nucleus. These results suggest that ginsenoside Rb2 upregulates LDLR expression via a mechanism that is dependent of the activation of not only SREBP-2 expression, but also SREBP-1 expression and maturation, and also indicate that the pharmacological value of ginsenoside Rb2 may be distinguished from that of lovastatin which is reported that it upregulate LDLR through SREBP-2 only, not through SREBP-1.

• Journal of Ginseng Research
• /
• v.44 no.2
• /
• pp.300-307
• /
• 2020

Background: Emerging evidence suggests that endothelial-to-mesenchymal transition (EndMT) in endothelial dysfunction due to persistent inflammation is a key component and emerging concept in the pathogenesis of vascular diseases. Ginsenoside Rg3 (Rg3), an active compound from red ginseng, has been known to be important for vascular homeostasis. However, the effect of Rg3 on inflammation-induced EndMT has never been reported. Here, we hypothesize that Rg3 might reverse the inflammation-induced EndMT and serve as a novel therapeutic strategy for vascular diseases. Methods: EndMT was examined under an inflammatory condition mediated by the NOD1 agonist, γ-d-glutamyl-meso-diaminopimelic acid (iE-DAP), treatment in human umbilical vein endothelial cells. The expression of EndMT markers was determined by Western blot analysis, real-time polymerase chain reaction, and immunocytochemistry. The underlying mechanisms of Rg3-mediated EndMT regulation were investigated by modulating the microRNA expression. Results: The NOD1 agonist, iE-DAP, led to a fibroblast-like morphology change with a decrease in the expression of endothelial markers and an increase in the expression of the mesenchymal marker, namely EndMT. On the other hand, Rg3 markedly attenuated the iE-DAP-induced EndMT and preserved the endothelial phenotype. Mechanically, miR-139 was downregulated in cells with iE-DAP-induced EndMT and partly reversed in response to Rg3 via the regulation of NF-κB signaling, suggesting that the Rg3-miR-139-5p-NF-κB axis is a key mediator in iE-DAP-induced EndMT. Conclusion: These results suggest, for the first time, that Rg3 can be used to inhibit inflammation-induced EndMT and may be a novel therapeutic option against EndMT-associated vascular diseases.

• Journal of Ginseng Research
• /
• v.44 no.2
• /
• pp.274-281
• /
• 2020

Background: Ultraviolet (UV) goes through the epidermis and promotes release of inflammatory cytokines in keratinocytes. Granulocyte-macrophage colony-stimulating factor (GM-CSF), one of the keratinocyte-derived cytokines, regulates proliferation and differentiation of melanocytes. Extracellular signal-regulated kinase (ERK1/2) and protein kinase C (PKC) signaling pathways regulate expression of GM-CSF. Based on these results, we found that ginsenoside Rh3 prevented GM-CSF production and release in UV-B-exposed SP-1 keratinocytes and that this inhibitory effect resulted from the reduction of PKCδ and ERK phosphorylation. Methods: We investigated the mechanism by which ginsenoside Rh3 from Panax ginseng inhibited GM-CSF release from UV-B-irradiated keratinocytes. Results: Treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) or UV-B induced release of GM-CSF in the SP-1 keratinocytes. To elucidate whether the change in GM-CSF expression could be related to PKC signaling, the cells were pretreated with H7, an inhibitor of PKC, and irradiated with UV-B. GM-CSF was decreased by H7 in a dose-dependent manner. When we analyzed which ginsenosides repressed GM-CSF expression among 15 ginsenosides, ginsenoside Rh3 showed the largest decline to 40% of GM-CSF expression in enzyme-linked immunosorbent assay. Western blot analysis showed that TPA enhanced the phosphorylation of PKCδ and ERK in the keratinocytes. When we examined the effect of ginsenoside Rh3, we identified that ginsenoside Rh3 inhibited the TPA-induced phosphorylation levels of PKCδ and ERK. Conclusion: In summary, we found that ginsenoside Rh3 impeded UV-B-induced GM-CSF production through repression of PKCδ and ERK phosphorylation in SP-1 keratinocytes.

• Journal of Ginseng Research
• /
• v.45 no.5
• /
• pp.610-616
• /
• 2021

Background: Thymic stromal lymphopoietin (TSLP) acts as a master switch for inflammatory responses. Ginsenoside Rg3 (Rg3) which is an active ingredient of Panax ginseng Meyer (Araliaceae) is known to possess various therapeutic effects. However, a modulatory effect of Rg3 on TSLP expression in the inflammatory responses remains poorly understood. Methods: We investigated antiinflammatory effects of Rg3 on an in vitro model using HMC-1 cells stimulated by PMA plus calcium ionophore (PMACI), as well as an in vivo model using PMA-induced mouse ear edema. TSLP and vascular endothelial growth factor (VEGF) levels were detected using enzyme-linked immunosorbent assay or real-time PCR analysis. Murine double minute 2 (MDM2) and hypoxia-inducible factor 1α (HIF1α) expression levels were detected using Western blot analysis. Results: Rg3 treatment restrained the production and mRNA expression levels of TSLP and VEGF in activated HMC-1 cells. Rg3 down-regulated the MDM2 expression level increased by PMACI stimulation. The HIF1α expression level was also reduced by Rg3 in activated HMC-1 cells. In addition, Rg3-administered mice showed the decreased redness and ear thickness in PMA-irritated ear edema. Rg3 inhibited the TSLP and VEGF levels in the serum and ear tissue homogenate. Moreover, the MDM2 and HIF1α expression levels in the ear tissue homogenate were suppressed by Rg3. Conclusion: Taken together, the current study identifies new mechanistic evidence about MDM2/HIF1α pathway in the antiinflammatory effect of Rg3, providing a new effective therapeutic strategy for the treatment of skin inflammatory diseases.

• Journal of Ginseng Research
• /
• v.43 no.3
• /
• pp.394-401
• /
• 2019

Background: Ginsenoside Rb1, a triterpene saponin, is derived from the Panax ginseng root and has potent antiinflammatory activity. In this study, we determined if Rb1 can increase macrophage phagocytosis and elucidated the underlying mechanisms. Methods: To measure macrophage phagocytosis, mouse peritoneal macrophages or RAW 264.7 cells were cultured with fluorescein isothiocyanate-conjugated Escherichia coli, and the phagocytic index was determined by flow cytometry. Western blot analyses were performed. Results: Ginsenoside Rb1 increased macrophage phagocytosis and phosphorylation of p38 mitogenactivated protein kinase (MAPK), but inhibition of p38 MAPK activity with SB203580 decreased the phagocytic ability of macrophages. Rb1 also increased Akt phosphorylation, which was suppressed by LY294002, a phosphoinositide 3-kinase inhibitor. Rb1-induced Akt phosphorylation was inhibited by SB203580, (5Z)-7-oxozeaenol, and small-interfering RNA (siRNA)-mediated knockdown of $p38{\alpha}$ MAPK in macrophages. However, Rb1-induced p38 MAPK phosphorylation was not blocked by LY294002 or siRNA-mediated knockdown of Akt. The inhibition of Akt activation with siRNA or LY294002 also inhibited the Rb1-induced increase in phagocytosis. Rb1 increased macrophage phagocytosis of IgG-opsonized beads but not unopsonized beads. The phosphorylation of p21 activated kinase 1/2 and actin polymerization induced by IgG-opsonized beads and Rb1 were inhibited by SB203580 and LY294002. Intraperitoneal injection of Rb1 increased phosphorylation of p38 MAPK and Akt and the phagocytosis of bacteria in bronchoalveolar cells. Conclusion: These results suggest that ginsenoside Rb1 enhances the phagocytic capacity of macrophages for bacteria via activation of the p38/Akt pathway. Rb1 may be a useful pharmacological adjuvant for the treatment of bacterial infections in clinically relevant conditions.

• Journal of Ginseng Research
• /
• v.43 no.1
• /
• pp.154-160
• /
• 2019

Background: Compound K (CK) is an active metabolite of ginseng saponin, ginsenoside Rb1, that has been shown to have ameliorative properties in various diseases. However, its role in inflammation and the underlying mechanisms are poorly understood. In this report, the antiinflammatory role of CK was investigated in macrophage-like cells. Methods: The CK-mediated antiinflammatory mechanism was explored in RAW264.7 and HEK293 cells that were activated by lipopolysaccharide (LPS) or exhibited overexpression of known activation proteins. The mRNA levels of inflammatory genes and the activation levels of target proteins were identified by quantitative and semiquantitative reverse transcription polymerase chain reaction and Western blot analysis. Results: CK significantly inhibited the mRNA expression of inducible nitric oxide synthase and tumor necrosis factor-${\alpha}$ and morphological changes in LPS-activated RAW264.7 cells under noncytotoxic concentrations. CK downregulated the phosphorylation of AKT1, but not AKT2, in LPS-activated RAW264.7 cells. Similarly, CK reduced the AKT1 overexpression-induced expression of aldehyde oxidase 1, interleukin-$1{\beta}$, interferon-${\beta}$, and tumor necrosis factor-${\alpha}$ in a dose-dependent manner. Conclusion: Our results suggest that CK plays an antiinflammatory role during macrophage-mediated inflammatory actions by specifically targeting the AKT1-mediated signaling pathway.

• Journal of Ginseng Research
• /
• v.43 no.3
• /
• pp.488-495
• /
• 2019

Background: Timosaponin AIII (TA3) is a steroidal saponin extracted from Anemarrhena asphodeloides. Here, we investigated the anticancer effects of TA3 in MG63 human osteosarcoma cells. TA3 attenuates migration and invasion of MG63 cells via regulations of two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, which are involved with cancer metastasis in various cancer cells. TA3 reduced enzymatic activities and transcriptional expressions of MMP-2 and MMP-9 in MG63 cells. TA3 also inhibited Src, focal adhesion kinase, extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), p38, ${\beta}-catenin$, and cAMP response element binding signaling, which regulate migration and invasion of cells. TA3 induced apoptosis of MG63 cells via regulations of caspase-3, caspase-7, and poly(ADP-ribose) polymerase (PARP). Then, we tested several ginsenosides to be used in combination with TA3 for the synergistic anticancer effects. We found that ginsenosides Rb1 and Rc have synergistic effects on TA3-induced apoptosis in MG63 cells. Methods: We investigated the anticancer effects of TA3 and synergistic effects of various ginseng saponins on TA3-induced apoptosis in MG63 cells. To test antimetastatic effects, we performed wound healing migration assay, Boyden chamber invasion assays, gelatin zymography assay, and Western blot analysis. Annexin V/PI staining apoptosis assay was performed to determine the apoptotic effect of TA3 and ginsenosides. Results: TA3 attenuated migration and invasion of MG63 cells and induced apoptosis of MG63 cells. Ginsenosides Rb1 and Rc showed the synergistic effects on TA3-induced apoptosis in MG63 cells. Conclusions: The results strongly suggest that the combination of TA3 and the two ginsenosides Rb1 and Rc may be a strong candidate for the effective antiosteosarcoma agent.

• Journal of Ginseng Research
• /
• v.43 no.4
• /
• pp.618-624
• /
• 2019

Background: Ginsenoside Re (Re) is one of the major components of Panax ginseng Meyer. Ginsenoside $Rk_3$ ($Rk_3$) is a secondary metabolite of Re. The aim of this study was to investigate and compare the effects and underlying mechanisms of Re and $Rk_3$ on cyclophosphamide-induced myelosuppression. Methods: The mice myelosuppression model was established by intraperitoneal (i.p.) injection of cyclophosphamide. Peripheral blood cells, bone marrow nucleated cells, and colony yield of hematopoietic progenitor cells in vitro were counted. The levels of erythropoietin, thrombopoietin, and granulocyte macrophage colony-stimulating factor in plasma were measured by enzyme-linked immunosorbent assay. Bone marrow cell cycle was performed by flow cytometry. The expression of apoptotic protein bcl-2, bax, and caspase-3 was detected by Western blotting. Results: Both Re and $Rk_3$ could improve peripheral blood cells, bone marrow nucleated cell counts, thymus index, and spleen index. Furthermore, they could enhance the yield of colonies cultured in vitro and make the levels of granulocyte macrophage colony-stimulating factor, erythropoietin, and thrombopoietin normal, reduce the ratio of $G_0/G_1$ phase cells, and increase the proliferation index. Finally, Re and $Rk_3$ could upregulate the expression of bcl-2, whereas they could downregulate the expression of bax and caspase-3. Conclusion: Re and $Rk_3$ could improve the hematopoietic function of myelosuppressed mice. The effect of $Rk_3$ was superior to that of Re at any dose. Regulating the levels of cytokines, promoting cells enter the normal cell cycle, regulating the balance of bcl-2/bax, and inhibiting the expression of caspase-3 may be the effects of Re and $Rk_3$ on myelosuppression.