Production of Minor Ginsenosides C-K and C-Y from Naturally Occurring Major Ginsenosides Using Crude ß-Glucosidase Preparation from Submerged Culture of Fomitella fraxinea.

Minor ginsenosides, such as compounds (C)-K and C-Y, possess relatively better bioactivity than those of naturally occurring major ginsenosides. Therefore, this study focused on the biotransformation of major ginsenosides into minor ginsenosides using crude ß-glucosidase preparation isolated from submerged liquid culture of Fomitella fraxinea (FFEP). FFEP was prepared by ammonium sulfate (30-80%) precipitation from submerged culture of F. fraxinea. FFEP was used to prepare minor ginsenosides from protopanaxadiol (PPD)-type ginsenoside (PPDG-F) or total ginsenoside fraction (TG-F). In addition, biotransformation of major ginsenosides into minor ginsenosides as affected by reaction time and pH were investigated by TLC and HPLC analyses, and the metabolites were also identified by UPLC/negative-ESI-Q-TOF-MS analysis. FFEP biotransformed ginsenosides Rb1 and Rc into C-K via the following pathways: Rd → F2 → C-K for Rb1 and both Rd → F2→ C-K and C-Mc1 → C-Mc → C-K for Rc, respectively, while C-Y is formed from Rb2 via C-O. FFEP can be applied to produce minor ginsenosides C-K and C-Y from PPDG-F or TG-F. To the best of our knowledge, this study is the first to report the production of C-K and C-Y from major ginsenosides by basidiomycete F. fraxinea.

Enzymatic formation of compound-K from ginsenoside Rb1 by enzyme preparation from cultured mycelia of Armillaria mellea.

BACKGROUND: Minor saponins or human intestinal bacterial metabolites, such as ginsenosides Rg3, F2, Rh2, and compound K, are more pharmacologically active than major saponins, such as ginsenosides Rb1, Rb2, and Rc. In this work, enzymatic hydrolysis of ginsenoside Rb1 was studied using enzyme preparations from cultured mycelia of mushrooms. METHODS: Mycelia of Armillaria mellea, Ganoderma lucidum, Phellinus linteus, Elfvingia applanata, and Pleurotus ostreatus were cultivated in liquid media at 25°C for 2 wk. Enzyme preparations from cultured mycelia of five mushrooms were obtained by mycelia separation from cultured broth, enzyme extraction, ammonium sulfate (30-80%) precipitation, dialysis, and freeze drying, respectively. The enzyme preparations were used for enzymatic hydrolysis of ginsenoside Rb1. RESULTS: Among the mushrooms used in this study, the enzyme preparation from cultured mycelia of A. mellea (AMMEP) was found to convert ginsenoside Rb1 into compound K with a high yield, while those from G. lucidum, P. linteus, E. applanata, and P. ostreatus produced remarkable amounts of ginsenoside Rd from ginsenoside Rb1. The enzymatic hydrolysis pathway of ginsenoside Rb1 by AMMEP was Rb1 → Rd → F2 → compound K. The optimum reaction conditions for compound K formation from ginsenoside Rb1 were as follows: reaction time 72-96 h, pH 4.0-4.5, and temperature 45-55°C. CONCLUSION: AMMEP can be used to produce the human intestinal bacterial metabolite, compound K, from ginsenoside Rb1 with a high yield and without food safety issues.

Calcium-independent CaMKII activity is involved in ginsenoside Rb1-mediated neuronal recovery after hypoxic damage.

Recent studies have indicated that Ginsenoside Rb1, one of the major components of ginseng root, may play an important role in protecting cells from damage. Here, we investigated the neuroprotective activity of Rb1 after hypoxic injury in young rats. About 50% animals were dead by exposing hypoxic condition three times in three consecutive days. Then, the pretreatment with Rb1 prior to hypoxic stimulation reduced animal death to 12%, and also significantly reduced the recovery time from hypoxia-related, compromised symptoms in survived animals. Rb1 also significantly reduced levels of lactate dehydrogenase (LDH) release from primary hippocampal neurons which were maintained at low oxygen concentration, indicating increased neuronal survival by Rb1. Ca(2+)/calmodulin-dependent kinase II (CaMKII) activity in the hippocampal tissues of hypoxia-induced rats was decreased to about 50% of the control animal. Then Rb1-treatment prior to hypoxic stimulation significantly elevated Ca(2+)-independent kinase II activity when measured 48 hr after hypoxic stimulation. Thus, the present data suggest that calcium independent CaMKII activity may be involved in the process of ginsenoside Rb1-mediated recovery of neuronal cells after hypoxic damage.

Effect of calmodulin on ginseng saponin-induced Ca2+-activated Cl- channel activation in Xenopus laevis oocytes.

We previously demonstrated the ability of ginseng saponins (active ingredients of Panax ginseng) to enhance Ca2+-activated Cl- current. The mechanism for this ginseng saponin-induced enhancement was proposed to be the release of Ca2+ from IP3-sensitive intracellular stores through the activation of PTX-insensitive Galpha(q/11) proteins and PLC pathway. Recent studies have shown that calmodulin (CaM) regulates IP3 receptor-mediated Ca2+ release in both Ca2+-dependent and -independent manner. In the present study, we have investigated the effects of CaM on ginseng saponin-induced Ca2+-activated Cl- current responses in Xenopus oocytes. Intraoocyte injection of CaM inhibited ginseng saponin-induced Ca2+-activated Cl- current enhancement, whereas co-injection of calmidazolium, a CaM antagonist, with CaM blocked CaM action. The inhibitory effect of CaM on ginseng saponin-induced Ca2+-activated Cl- current enhancement was dose- and time-dependent, with an IC50 of 14.9 +/- 3.5 microM. The inhibitory effect of CaM on saponin's activity was maximal after 6 h of intraoocyte injection of CaM, and after 48 h the activity of saponin recovered to control level. The half-recovery time was calculated to be 16.7 +/- 4.3 h. Intraoocyte injection of CaM inhibited Ca2+-induced Ca2+-activated Cl- current enhancement and also attenuated IP3-induced Ca2+-activated Cl- current enhancement. Ca2+/CaM kinase II inhibitor did not inhibit CaM-caused attenuation of ginseng saponin-induced Ca2+-activated Cl- current enhancement. These results suggest that CaM regulates ginseng saponin effect on Ca2+-activated Cl current enhancement via Ca2+-independent manner.

Effects of selected ginsenosides on phorbol ester-induced expression of cyclooxygenase-2 and activation of NF-kappaB and ERK1/2 in mouse skin.

Our previous studies have demonstrated that the methanol extract of heat-processed Panax ginseng C.A. Meyer exerts antioxidative, antiinflammatory, and anti-tumor-promoting effects. In the present study, we examined the antiinflammatory effects of several ginsenosides (Rb(1), Rc, Re, Rg(1), Rg(3)) derived from P. ginseng. Topical application of each of these ginsenosides significantly attenuated ear edema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). These ginsenosides also suppressed expression of cyclooxygenase-2 (COX-2) and activation of NF-kappaB in the TPA-treated dorsal skin of mice. Of the ginsenosides tested, Rg(3) was found to be most effective in terms of inhibiting TPA-induced ear edema, COX-2 expression, and NF-kappaB activation.

Ginsenosides regulate ligand-gated ion channels from the outside.

Treatment with ginsenosides, the major active ingredients of Panax ginseng, produces a variety of physiological effects on the central and peripheral nervous systems. Ginsenosides inhibit various types of ligand-gated ion channel but it is not clear whether they act from within or outside the cell since they are somewhat membrane-permeable. In the present study, we used the Xenopus oocyte gene expression system to determine from which side of the cell membrane the ginsenoside Rg3 (Rg3), and M4, a ginsenoside metabolite, act to regulate ligand-gated ion channel activity. Ligand-gated ion currents were measured using the two-electrode voltage clamp technique. Rg3 and M4 inhibited 5-HT3A and a3b4 nACh receptor-mediated ion currents when present outside of the cell but not when injected intracellularly. We also examined the effect of these agents on oocytes expressing the gustatory cGMP-gated ion channel, which is known to have a cGMP binding site on the intracellular side of the plasma membrane and is only activated by cytosolic cGMP. Rg3 inhibited cGMP-gated ion currents when applied extracellularly or to an outside-out patch clamp, but not when injected into the cytosol or when using an excised inside-out patch clamp. These results indicate that Rg3 and M4 regulate ligand-gated ion channel activity from the extracellular side.

Effects of ginsenosides Rg3 and Rh2 on the proliferation of prostate cancer cells.

Ginseng has an anti-cancer effect in several cancer models. This study was to characterize active constituents of ginseng and their effects on proliferation of prostate cancer cell lines, LNCaP and PC3. Cell proliferation was measured by [3H]thymidine incorporation, the intracellular calcium concentration by a dual-wavelength spectrophotometer system, effects on mitogen-activated protein (MAP) kinases by Western blotting, and cell attachment and morphologic changes were observed under a microscope. Among 11 ginsenosides tested, ginsenosides Rg3 and Rh2 inhibited the proliferation of prostate cancer cells. EC50s of Rg3 and Rh2 on PC3 cells were 8.4 microM and 5.5 microM, respectively, and 14.1 microM and 4.4 microM on LNCaP cells, respectively. Both ginsenosides induced cell detachment and modulated three modules of MAP kinases activities differently in LNCaP and PC3 cells. These results suggest that ginsenosides Rg3 and Rh2-induced cell detachment and inhibition of the proliferation of prostate cancer cells may be associated with modulation of three modules of MAP kinases.

Glucocorticoid receptor agonist compound K regulates Dectin-1-dependent inflammatory signaling through inhibition of reactive oxygen species.

AIMS: Compound K (C-K; 20-O-D-glucopyranosyl-20(S)-protopanaxadiol) is a functional ligand of the glucocorticoid receptor (GR) and regulates toll-like receptor-4-dependent inflammation. Here, the role of C-K in the regulation of zymosan-mediated inflammation was investigated in murine bone marrow-derived macrophages and the murine macrophage cell line RAW264.7. MAIN METHODS: The in vitro regulatory effects of C-K on zymosan-induced cytokine production were measured by enzyme-linked immunosorbent assay. Phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, and p47phox was determined by detection of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase cytosolic subunit by Western blotting. The generation of reactive oxygen species (ROS) was assayed using specific immunofluorescent dyes. NADPH oxidase activities were measured by luminometric analysis. The histopathology of mouse livers and spleens was evaluated immunohistochemically. Dexamethasone, a well-known GR agonist, was used to study the effects of C-K. KEY FINDINGS: Pre-treatment with C-K significantly inhibited zymosan-mediated secretion of tumor necrosis factor-alpha, interleukin (IL)-6, and IL-12 p40, and the activation of ERK1/2 and p38. C-K also markedly suppressed zymosan-mediated superoxide generation, NADPH oxidase activities, and Ser345-p47phox phosphorylation in macrophages. Blockade of Dectin-1 profoundly attenuated the inhibitory effects of C-K in zymosan-induced inflammation and ROS generation by macrophages. The in vivo administration of C-K significantly rescued cells from zymosan-induced lethal shock through inhibition of systemic inflammatory cytokine production. SIGNIFICANCE: The ability of C-K to regulate zymosan-induced inflammation through Dectin-1 suggests a novel approach for the control of excessive lethal inflammation.

The ginsenoside metabolite compound K, a novel agonist of glucocorticoid receptor, induces tolerance to endotoxin-induced lethal shock.

Compound K (C-K), a protopanaxadiol ginsenoside metabolite, was previously shown to have immunomodulatory effects. Here, we describe a novel therapeutic role for C-K in the treatment of lethal sepsis through the modulation of Toll-like receptor (TLR) 4-associated signalling via glucocorticoid receptor (GR) binding. In mononuclear phagocytes, C-K significantly repressed the activation of TLR4/lipopolysaccharide (LPS)-induced NF-kappaB and mitogen-activated protein kinases (MAPKs), as well as the secretion of pro-inflammatory cytokines. However C-K did not affect the TLR3-mediated expression of interferon-beta or the nuclear translocation of IRF-3. C-K competed with the synthetic glucocorticoid dexamethasone for binding to GR and activated glucocorticoid responsive element (GRE)-containing reporter plasmids in a dose-dependent manner. In addition, the blockade of GR with either the GR antagonist RU486 or a siRNA against GR substantially reversed the anti-inflammatory effects of C-K. Furthermore, TLR4-dependent repression of inflammatory response genes by C-K was mediated through the disruption of p65/interferon regulatory factor complexes. Importantly, pre- or post-treatment with C-K significantly rescued mice from Gram-negative bacterial LPS-induced lethal shock by lowering their systemic inflammatory cytokine levels and by reversing the lethal sequelae of sepsis. Collectively, these results demonstrate that C-K, as a functional ligand of GR, regulates distinct TLR4-mediated inflammatory responses, and suggest a novel therapy for Gram-negative septic shock.

Marked production of ginsenosides Rd, F2, Rg3, and compound K by enzymatic method.

The hydrolysis of protopanaxadiol-type saponin mixture by various glycoside hydrolases was examined. Among these enzymes, crude preparations of lactase from Aspergillus oryzae, beta-galactosidase from A. oryzae, and cellulase from Trichoderma viride were found to produce ginsenoside F(2) [3-O-(beta-D-glucopyranosyl)-20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol], compound K [20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol], and ginsenoside Rd {3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol}, respectively, from protopanaxadiol-type saponin mixture in large quantities. Moreover, the crude preparation of lactase from Penicillium sp. having a high producing activity of ginsenoside Rh(1) (6-O-beta-D-glucopyranosyl-20(S)-protopanaxatriol) from protopanaxatriol-type saponin mixture gave ginsenoside Rd as a main product, ginsenoside Rg(3) {3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20(S)-protopanaxadiol}, and compound K from protopanaxadiol-type saponin mixture. The hydrolytic pathways of ginsenosides Rb(1), Rb(2), and Rc to ginsenosides Rd, Rg(3), and F(2), and compound K by crude preparations of four glycoside hydrolases were also studied. This is the first report on the enzymatic preparation of an intestinal bacterial metabolite, ginsenoside F(2), in quantity, and a considerable amount of a minor saponin, ginsenoside Rg(3), from a protopanaxadiol-type saponin mixture.

Enzymatic preparation of ginsenosides Rg2, Rh1, and F1.

During investigation of the hydrolysis of a protopanaxatriol-type saponin mixture by various glycoside hydrolases, crude preparations of beta-galactosidase from Aspergillus oryzae and lactase from Penicillium sp. were found to produce two minor saponins, ginsenoside Rg(2) [6-O-(alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl)-20(S)-protopanaxatriol] and ginsenoside Rh(1) (6-O-beta-D-glucopyranosyl-20(S)-protopanaxatriol), respectively, in high yields. Moreover, a naringinase preparation from Penicillium decumbens readily gave an intestinal bacterial metabolite, ginsenoside F(1) (20-O-beta-D-glucopyranosyl-20(S)-protopanaxatriol), as the main product, with a small amount of 20(S)-protopanaxatriol from a protopanaxatriol-type saponin mixture. Also, a hesperidinase from Penicillium sp. selectively hydrolyzed ginsenoside Re into ginsenoside Rg(1). This is the first report on the enzymatic preparation of minor saponins, ginsenosides Rg(2) and Rh(1), and of an intestinal bacterial metabolite, ginsenoside F(1), with high efficiency from a protopanaxatriol-type saponin mixture.

Enzymatic preparation of ginsenosides Rg2, Rh1, and F1 from protopanaxatriol-type ginseng saponin mixture.

During investigations on the hydrolysis of a protopanaxatriol-type saponin mixture by various glycoside hydrolases, it was found that two minor saponins, ginsenosides Rg 2 and Rh 1, were formed in high yields by crude beta-galactosidase from Aspergillus oryzae and crude lactase from Penicillium sp., respectively. Moreover, a crude preparation of naringinase from Penicillium decumbens readily hydrolyzed a protopanaxatriol-type saponin mixture to give an intestinal bacterial metabolite, ginsenoside F 1 as the main product. A crude preparation of hesperidinase from Penicillium sp. selectively hydrolyzed ginsenoside Re into ginsenoside Rg 1. This is the first report on the enzymatic preparation of minor saponins, ginsenosides Rg 2 and Rh 1, and of an intestinal bacterial metabolite, ginsenoside F 1, with a high efficiency from a protopanaxatriol-type saponin mixture.

Diol- and triol-type ginseng saponins potentiate the apoptosis of NIH3T3 cells exposed to methyl methanesulfonate.

In this study we investigated the effect of ginseng saponins on the p53-dependent apoptosis in NIH3T3 cells exposed to methyl methanesulfonate (MMS), an alkylating agent. Trypan blue exclusion assay, cell morphology studies, and apoptotic index determined by acridine orange staining showed that the postincubation of MMS-exposed cells in medium containing diol- (PD) or triol-type (PT) ginseng saponins potentiate the apoptotic cell death. FACS analysis indicated that the increased apoptotic cell population in the saponin-postincubation group was accompanied by the accumulation of cells in G0/G1 phase. By Western blot analyses it was demonstrated that postincubation of saponins increases the expression of p53 and p21 in MMS-exposed cells but decreased that of CDK2, cyclin E and D1, and PCNA. The upregulation of p53 and p21 and downregulation of CDK2 was shown to be p53-dependent in experiments using the p53 antisense oligonucleotide. These results suggest that ginseng saponins contain components potentiating the apoptosis of MMS-exposed NIH3T3 cells via p53 and p21 activation, accompanied with by downregulation of cell cycle-related protein expression.