Noboru Shoji

Gingerol, a novel cardiotonic agent, activates the Ca2+-pumping ATPase in skeletal and cardiac sarcoplasmic reticulum

Gingerol, isolated as a potent cardiotonic agent from the rhizome of ginger, stimulated the Ca2+-pumping activity of fragmented sarcoplasmic reticulum (SR) prepared from rabbit skeletal and dog cardiac muscles. The extravesicular Ca2+ concentrations of the heavy fraction of the fragmented SR (HSR) were measured directly with a Ca2+ electrode to examine the effect of gingerol on the SR. Gingerol (3-30 microM) accelerated the Ca2+-pumping rate of skeletal and cardiac SR in a concentration-dependent manner. The rate of 45Ca2+ uptake of HSR was also increased markedly by 30 microM gingerol without affecting the 45Ca2+ efflux from HSR. Furthermore, gingerol activated Ca2+-ATPase activities of skeletal and cardiac SR (EC50, 4 microM). The activation of SR Ca2+-ATPase activity by gingerol (30 microM) was completely reversed by 100-fold dilution with the fresh saline solution. Kinetic analysis of activating effects of gingerol suggests that the activation of SR Ca2+-ATPase is uncompetitive and competitive with respect to Mg . ATP at concentrations of 0.2-0.5 mM and above 1 mM, respectively. Kinetic analysis also suggests that the activation by gingerol is mixed-type with respect to free Ca2+ and this enzyme is activated probably due to the acceleration of enzyme-substrate complex breakdown. Gingerol had no significant effect on sarcolemmal Ca2+-ATPase, myosin Ca2+-ATPase, actin-activated myosin ATPase and cAMP-phosphodiesterase activities, indicating that the effect of gingerol is rather specific to SR Ca2+-ATPase activity. Gingerol may provide a valuable chemical tool for studies aimed at clarifying the regulatory mechanisms of SR Ca2+-pumping systems and the causal relationship between the Ca2+-pumping activity of SR and muscle contractility.

Triterpenoid glycosides from Anagallis arvensis

From the herb of Anagallis arvensis, we have isolated four novel oleanane glycosides, anagallosaponins VI-IX, and two artifact saponins, apoanagallosaponins III and IV, formed from anagallosaponins III and IV. The structures were elucidated by chemical and spectral methods, 2D NMR techniques being particularly helpful. The structures of anagallosaponins VI and VII were characterized as priverogenin B 3-O-beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-alpha-L-arabinopyranoside and 3-O-(beta-D-glucopyranosyl (1-->4)-[beta-D-xylopyranosyl (1-->2)]beta-D-glucopyranosyl (1-->4)-alpha-L-arabinopyranoside), respectively. The structures of anagallosaponins VIII and IX were characterized as 23-hydroxypriverogenin B 22-acetate 3-O-(beta-D-xylopyranosyl (1-->2)-O-beta-D-glucopyranosyl (1-->4)[beta-D-glucopyranosyl (1-->2)]-alpha-L-arabinopyranoside), 3-O-(beta-D-glucopyranosyl (1-->4)-[beta-D-xylopyranosyl (1-->2)]beta-D-glucopyranosyl (1-->4)[beta-D-glucopyranosyl (1-->2)]- alpha-L-arabinopyranoside), respectively. The structures of apoanagallosaponins III and IV were characterized as camelliagenin A 16-acetate 3-O-beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-alpha-L-arabnopyranoside, 3-O-(beta-D-xylopyranosyl (1-->2)-O-beta-D-glucopyranosyl (1-->4)[beta-D-glucopyranosyl (1-->2)]-alpha-L-arabinopyranoside), respectively.

Baccharane glycosides from seeds of Impatiens balsamina

From the seeds of Impatiens balsamina have been isolated four rare baccharane glycosides, hosenkosides L-O. The structures of all isolates were secured by the use of 2D NMR techniques (1H-1H COSY, HMQC, HMBC, ROESY) and chemical derivatization. Hosenkosides L and M are hosenkol A 3-O-sambubiosyl-28-O-glucoside and 3-O-sambubiosyl-26-O-glucosyl-28-O-glucoside, respectively. Hosenkoside N is hosenkol C 3-O-glucosyl-28-O-glucoside. Hosenkoside O is hosenkol D 3-O-sophorosyl-28-O-glucoside.

Hosenkosides A, B, C, D, and E, novel baccharane glycosides from the seeds of Impatiens balsamina

Abstract From the seeds of Impatiens balsamina has been isolated five novel baccharane glycosides, hosenkosides A-E. The structures of all isolates were secured by the use of 2D NMR techniques (1H-1H COSY, HMQC, HMBC, ROESY, TOCSY), CD spectroscopy and chemical derivatization.

Mechanism of inhibition of IgE-dependent histamine release from rat mast cells by xestobergsterol A from the Okinawan marine spongeXestospongia bergquistia

Histamine release from rat peritoneal mast cells induced by anti-IgE was essentially complete within 4–5 min. Xestobergsterol A and B, which are constituents of the Okinawan marine spongeXestospongia bergquistia Fromont, dose-dependently inhibited anti-IgE-induced histamine release from rat mast cells. The IC50 values of xestobergsterol A and B for histamine release in mast cells activated by anti-IgE were 0.07 and 0.11 μM, respectively. Anti-IgE stimulated PI-PLC activity in a mast cell membrane preparation. Xestobergsterol A dose-dependently inhibited the generation of IP3 and membrane-bound PI-PLC activity. Moreover, xestobergsterol A inhibited Ca2+-mobilization from intracellular Ca2+-stores as well as histamine release in mast cells activated by anti-IgE. On the other hand, xestobergsterol B did not inhibit the membrane-bound and cytosolic PI-PLC activity, IP3 generation or the initial rise in [Ca2+]i in mast cells activated by anti-IgE. These results suggest that the mechanism of inhibition by xestobergsterol A of the initial rise in [Ca2+]i, of the generation of IP3, and of histamine release induced by anti-IgE, was through the inhibition of PI-PLC activity.

Diterpene, 16-phyllocladanol enhances Th1 polarization induced by LPS-primed DC, but not TNF-α-primed DC

16-Phyllocladanol is diterpene isolated form the heartwood of Cryptomeria japonica. We demonstrate that the effect of 16-phyllocladanol on the phenotypic and functional maturation of human monocytes-derived DC in vitro. Human monocytes were exposed to 16-phyllocladanol alone, or in combination with LPS and thereafter co-cultured with naïve T cells. The expression levels of CD83 and HLA-DR on LPS-primed DC were enhanced by 16-phyllocladanol. 16-Phyllocladanol dose-dependently augmented the T cell stimulatory capacity in an allo MLR to LPS-primed DC and the production of IL-12p70 by LPS-primed DC. The cytokine production by 16-phyllocladanol-primed DC was not inhibited by anti-TLR2 and 4 mAbs. IFN-gamma secretion from naïve T cells co-cultured with DC differentiated with LPS was also augmented by 16-phyllocladanol. These results suggest that the enhancement of Th1 cells polarization to LPS-primed DC induced by 16-phyllocladanol via the activation of IL-12p70 and independent on TLR2 or TLR4.

Polyacetylenediols regulate the function of human monocyte-derived dendritic cells.

Callyspongidiol and 14,15-dihydrosiphonodiol are Polyacetylenediols isolated from marine sponges and are pharmacologically active substances. Dendritic cells (DC) play an important role in the initiation and regulation of immune response. DC have a key influence in the differentiation of naïve T cells into Th1, Th2 or Th17 effector cells. We demonstrated that callyspongidiol and 14,15-dihydrosiphonodiol activate human DC as documented by phenotypic and functional maturation, and altered cytokine production. Up regulation of cell surface expression of CD1a, CD80, CD83, CD86, HLA-DR and CCR7 was observed following DC treatment with callyspongidiol and 14,15-dihydrosiphonodiol. The production of IL-10 by callyspongidiol-primed DC after stimulation with CD40-L was higher than that of LPS- or 14,15-dihydrosiphonodiol-primed DC. Naïve T cells co-cultured with allogeneic 14,15-dihydrosiphonodiol-primed DC at 1:5 DC/T cell ratio turned into typical Th1 cells depending on IL-12 secretion and independent on TLR2 or TLR4. In contrast, callyspongidiol-primed DC co-cultured with naïve T cells secreted IL-4 and IL-10, but had little effect on IFN-gamma. Callyspongidiol-primed DC induced the development of Th2 cells via the inhibition of IL-12p70 and the enhancement of IL-10. Polyacetylenediols-primed DC expressed the chemokine receptor CCR7 and had a high migration to CCL19. These results suggested that some Polyacetylenediols modulate human DC function in a fashion that favors Th1/Th2 cell polarization or IL-10 producing T cells, and might have implication in tumor or in autoimmune diseases.

Uncarinic Acid C Isolated from Uncaria rhynchophylla Induces Differentiation of Th1-Promoting Dendritic Cells Through TLR4 Signaling

Uncarinic acid C (URC) is triterpene isolated from Uncaria rhynchophylla and is a pharmacologically active substance. The induction of dendritic cells (DC) is critical for the induction of Ag-specific T lymphocyte responses and may be essential for the development of human vaccines relying on T cell immunity. DC might be a potential target for URC. We demonstrate that URC activates human DC as documented by phenotypic and functional maturation, and altered cytokine production. The expression of CD1a, CD38, CD40, CD54, CD80, CD83, CD86, HLA-DR and CCR7 on URC-primed DC was enhanced. The production of IL-12p70 by URC-primed DC was higher than that of lipopolysaccharide (LPS)-primed DC. The production of IL-12p70 by URC-primed DC was inhibited by the anti-Toll-like receptor 4 (TLR4) monoclonal antibody (mAb), but partially abolished by anti-TLR2 mAb. mRNA coding for TLR2 and TLR4 was expressed in URC-primed DC. URC-primed DC induced the NF-κB transcription factor. Naïve T cells co-cultured with URC-primed DC turned into typical Th1 cells that produced large quantities of IFN-γ depending on IL-12 secretion. URC enhanced the T cell stimulatory capacity in an allo MLR. In the cytotoxic T-lymphocyte assay (CTL) assay, DNA fragmentation assay and 51Cr release on URC-primed DC were more augmented than that of TNF-α-primed DC. DC matured with URC had an intermediate migratory capacity towards CCL19 and CCL21. These results suggest that URC modulates DC function in a fashion that favors Th1 polarization via the activation of IL-12p70 dependent on TLR4 signaling, and may be used on DC-based vaccine for cancer immunotherapy.

Triterpene esters from Uncaria rhynchophylla drive potent IL-12-dependent Th1 polarization

Dendritic cells (DC) are key antigen-presenting cells that link innate and adaptive immunity and ultimately activate antigen-specific T cells. In the current study, we demonstrated that two triterpene esters, uncarinic acid C (1) and uncarinic acid D (2), which are isolated from the hooks of Uncaria rhynchophylla, activate phenotypic and cytokine production alterations in DC. We also show that 1 and 2 modulate human DC function in a fashion that favors Th1 cell polarization. The effect of 1 (E configuration at the 2′ position) was approximately 20 times more potent than that of 2 (Z configuration at 2′). These results indicated that the configuration of the 2′ double bond greatly effects activity. Thus, 1 and 2 may prove useful as DC-based vaccines for cancer immunotherapy.

Cryptomerione induces Th1 cell polarization via influencing IL-10 production by cholera toxin-primed dendritic cells.

Dendritic cells play an important role in the initiation and regulation of immune response. Dendritic cells have a key influence in the differentiation of naïve T cells into Th1, Th2 or Th17 effector cells. Cryptomerione is terpene isolated from the heartwood of Cryptomeria japonica. In this study, we investigated the effects of Cryptomerione on the phenotypic and functional maturation of human monocyte-derived dendritic cells in vitro. Human monocytes were exposed to either Cryptomerione alone, or in combination with lipopolysaccaride (LPS) or cholera toxin (CT) and thereafter co-cultured with naïve T cells. We found no enhanced CD1a, CD80, CD83, CD86 and HLA-DR expression on Cryptomerione-primed dendritic cells. However, Cryptomerione augmented T cell stimulatory capacity in an allogeneic mixed lymphocyte reaction to CT-primed dendritic cells and influenced the production of interleukin (IL)-10 and IL-12p70 by CT-primed dendritic cells, but not LPS-primed dendritic cells. Cryptomerione also inhibited Th2 cell polarization induced by CT-primed dendritic cells, but enhanced IFN-gamma secretion by naïve T cells co-cultured with CT-primed dendritic cells. Cytokine production by CT-primed dendritic cells alone, or in combination with Cryptomerione was also influenced following treatment with anti-IL-10 mAb and anti-OX40L mAb. Thus, the potential mechanisms underlying the enhancement of Th1 polarization in CT-primed dendritic cells induced by Cryptomerione appeared to depend on IL-10 secretion and OX40L. These results suggest that Cryptomerione modulates human dendritic cells function in a fashion that favors Th1/Th2 cell polarization.