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Y Tezuka

Publications and source records attributed to Y Tezuka.

At least 73 records · Page 4Linked to original sources
PubMed1999

The effect of low molecular weight chitosan on bone resorption in vitro and in vivo.

We studied the effect of low molecular weight chitosan (LMWC) on the formation of osteoclast-like multinucleated cells (OCLs) in the co-culture of mouse osteoblastic cells and bone marrow cells in the presence of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3]. LMWC at 440 microg/ml inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive OCLs induced by 1alpha,25(OH)2D3. We prepared OCLs in the co-culture of osteoblastic cells and bone marrow cells. The effect of LMWC on pit formation by OCLs was examined using dentin slices, and LMWC inhibited pit formation at 440 microg/ml. Oral administration of the LMWC to ovariectomized rats prevented a decrease in bone mineral density (BMD) of the lumbar vertebra without affecting the body and uterus weights. These results suggested that LMWC prevented a decrease in BMD in vivo by inhibiting osteoclastic bone resorption.

Animals↗
PubMed1999

Prolyl endopeptidase inhibitors from the underground part of Rhodiola sacra S. H. Fu.

Prolyl endopeptidase (PEP, EC 3.4.21.26) is an enzyme which plays a role in the metabolism of proline-containing neuropeptides, e.g., vasopressin, substance P and thyrotropin-releasing hormone (TRH), which have been suggested to be involved in learning and memory processes. In our systematic screening for PEP inhibitors from traditional Chinese medicines, we found that MeOH extract from the underground part of Rhodiola sacra S. H. Fu shows significant inhibitory activity against PEP from Flavobacterium meningosepticum. Examination of the constituents of the extract resulted in the isolation of nineteen known compounds, identified as hydroquinone (1), 4-hydroxybenzoic acid (2), caffeic acid (3), 4-hydroxycinnamic acid (4), suberic acid (5), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 2-phenylethyl beta-D-glucopyranoside (9), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), 2-phenylethyl alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside (11), sacranoside A (12), beta-D-glucopyranosyl 4-hydroxybenzoate (13), rhodiocyanoside A (14), rhodiooctanoside (15), sarmentosin (16), heterodendrin (17), arbutin (18) and 4-O-(beta-D-glucopyranosyl)-gallic acid (19). Among these, 1, 2, 5, 8-10, 13, 16, 18 and 19 have been isolated for the first time from R. sacra, among which 5, 9, 10, 13, 16, 18 and 19 have been isolated from Rhodiola plants for the first time. On the PEP inhibition, seven compounds (6-8, 10, 12, 18, 19) showed inhibition with an 1C50 of 27.8, 487, 1.47, 0.437, 348, 391 and 215 microM, respectively. The kinetic study of these inhibitors indicated that they are noncompetitive inhibitors, except for 6 which is a competitive inhibitor.

Drugs, Chinese Herbal↗
PubMed1999

The effect of kampo formulae on bone resorption in vitro and in vivo. II. Detailed study of berberine.

We previously isolated berberine from aqueous extracts of tsu-kan-gan, a Kampo formula used for the treatment of osteoporosis. Berberine caused an inhibitory effect on parathyroid hormone (PTH)-stimulated bone resorption in neonatal mouse bone. In this report we describe the inhibitory effect of berberine on the formation of osteoclast-like multinucleated cells (OCLs) in the co-culture of mouse osteoblastic cells and bone marrow cells in the presence of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3], PTH and interleukin-1alpha (IL-1alpha). Berberine dose-dependently inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive OCLs induced by 1alpha25(OH)2D3, PTH and IL-1alpha. We prepared OCLs in the co-culture of osteoblastic cells and bone marrow cells. The effect of berberine on pit formation by OCLs was examined using dentin slices. As OCLs are terminally differentiated multinucleated cells, the survival of OCLs affects the bone-resorbing activity of OCLs. This prompted us to count the number of TRAP-positive OCLs on the slices. Berberine dose-dependently inhibited pit formation and caused a decrease in the number of TRAP-positive OCLs. Calcitonin (CT) inhibited pit formation without affecting the number of OCLs. Berberine accelerated the cell death in OCLs cultivated on a culture plate, but CT did not affect the cell death of OCLs. This suggests that the decrease in the number of OCLs on dentin slices may be due to apoptotic cell death in OCLs. In fact, Hoechst 33258 staining revealed that the treatment of OCLs with berberine resulted in condensed nuclei and a decrease in cell size. Oral administration of the berberine (30 and 50 mg/kg/d) to ovariectomized rats prevented a decrease in bone mineral density (BMD) of the lumbar vertebra without affecting the weight of the uterus and plasma concentration of estradiol. These results suggested that berberine prevented a decrease in BMD in vivo by inhibiting osteoclastic bone resorption.

Animals↗
PubMed1998

Cytotoxic cycloartane-type triterpenes from Combretum quadrangulare.

Seven novel cycloartane-type triterpenes were isolated from Combretum quadrangulare, and their structures were elucidated on the basis of spectral analysis. All these compounds were tested for their cytotoxicity against murine colon 26-L5 carcinoma cells. Methyl quadrangularate B (2) and methyl quadrangularate D (4) exhibited potent cytotoxicity having ED50 values 9.54 and 5.42 microM, respectively.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Selectins induced by interleukin-1beta on the human liver endothelial cells act as ligands for sialyl Lewis X-expressing human colon cancer cell metastasis.

We have previously reported that colon cancer cells metastasized to the liver expressed an increased amount of sialyl Lewis X (SLeX) antigen compared to their corresponding primary lesions. It is now well known that SLeX antigen and sialyl Lewis A (SLeA) antigen are ligands for the selectins expressed on the endothelial cells. Therefore, it is assumed that SLeX-rich colon cancer cells could be easily adhered to the endothelial cells that express selectins. In this report we have tried to induce selectin expression on the human liver sinusoidal endothelial cells and have examined the adhesion of SLeX-high or -low expressing colon cancer cells to the interleukin-1beta (IL-1beta)-treated liver specimens using Stamper-Woodruff assay. These human colon cancer cells are termed KM12HX or KM12LX cells, respectively. A significantly increased number of KM12HX cells adhered to the IL-1beta-treated liver specimens compared to KM12LX cells. The adhesion of KM12HX cells was inhibited by the pretreatment of tumor cells with anti-SLeX antibody or by the pretreatment of liver specimens with anti-selectin antibodies. Selectin expression on the liver sinusoidal endothelial cells and endothelial cells of blood vessels after IL-1beta treatment was confirmed by immunohistochemically using anti-selectin monoclonal antibodies (MAbs). These findings strongly suggest that SLeX-expressing cancer cells could adhere to the sinusoidal endothelial cells via an SLeX-selectin interaction system and this could be a first step for colon cancer cells that metastasize to the liver. The mechanism by which these selectins can be induced in vivo is the next problem to be considered.

Cells, Cultured↗
PubMed1998

Spectrometer for polarized soft X-ray Raman scattering.

An experimental system for polarized soft X-ray Raman scattering spectroscopy has been constructed. The soft X-ray spectrometer is based on the Rowland circle geometry with a holographic spherical grating. Three types of gratings are used to cover the energy range from 18 eV to 1200 eV. According to a ray-trace simulation, the resolution is expected to be 200 meV at 700 eV by using a 10 micro m slit width. The polarized and depolarized soft X-ray Raman scattering spectra can be measured by rotating the soft X-ray spectrometer around the axis of the incident beam. Preliminary measurements of polarized and depolarized spectra were accomplished at undulator beamline BL-2C of the Photon Factory.

Journal Article↗
PubMed1998

Calyxin H, Epicalyxin H, and Blepharocalyxins A and B, Novel Diarylheptanoids from the Seeds of Alpinia blepharocalyx

Four unprecedented diarylheptanoids-calyxin H (1) and epicalyxin H (2), possessing a diarylheptanoid unit and a chalcone moiety, and blepharocalyxins A (3) and B (4), possessing two diarylheptanoid units and a chalcone moiety-were isolated from the seeds of Alpiniablepharocalyx. The structures of 1-4, including absolute stereochemistry, were elucidated by spectroscopic means and after a consideration of their biogenesis.

Journal Article↗
PubMed1998

Effects of methylenechloride-soluble fraction of Japanese angelica root extract, ligustilide and butylidenephthalide, on pentobarbital sleep in group-housed and socially isolated mice.

We previously showed that the extract of Japanese angelica root (JAR-E) reversed the decrease in pentobarbital (PB) sleep induced by isolation stress and yohimbine and methoxamine, stimulants of central noradrenergic systems, in mice. Here, we tested the effects of several fractions from JAR-E and ligustilide and butylidenephthalide, phthalide components of JAR-E, on PB sleep in isolated mice to elucidate the mechanism of the action of JAR-E. Methanol-soluble (Met-S) and -insoluble (Met-IS) fractions were obtained from JAR-E. Methylenechloride-soluble (MC-S) and -insoluble fractions (MC-IS) were prepared from Met-S. MC-S (11.4-76 mg/kg, p.o.) reversed the isolation stress-induced decrease in PB sleep, but neither Met-IS (0.8-2.4 g/kg, p.o.) nor MC-IS (0.7-2 g/kg, p.o.) had the same effect. The i.p. administration of MC-S exhibited a similar activity to that observed after the p.o. administration of the same fraction. Ligustilide (5-20 mg/kg, i.p.) and butylidenephthalide (10-30 mg/kg, i.p.) reversed PB sleep decrease in isolated mice. Both components (20 mg/kg, i.p.) attenuated the suppressive effects of yohimbine (30 nmol, i.c.v.), methoxamine (200 nmol, i.c.v.) and a benzodiazepine inverse agonist FG7142 (10 mg/kg, i.p.) on PB sleep in group-housed mice. These results suggest the contribution of ligustilide and butylidenephthalide to the effect of JAR-E on PB sleep in isolated mice, and implicate central noradrenergic and/or GABA(A) systems in the effects of these components.

4-Butyrolactone↗
PubMed1998

Anti-HIV-1 and anti-HIV-1-protease substances from Ganoderma lucidum.

A new highly oxygenated triterpene named ganoderic acid alpha has been isolated from a methanol extract of the fruiting bodies of Ganoderma lucidum together with twelve known compounds. The structures of the isolated compounds were determined by spectroscopic means including 2D-NMR. Ganoderiol F and ganodermanontriol were found to be active as anti-HIV-1 agents with an inhibitory concentration of 7.8 micrograms ml-1 for both, and ganoderic acid B, ganoderiol B, ganoderic acid C1, 3 beta-5 alpha-dihydroxy-6 beta-methoxyergosta-7,22-diene, ganoderic acid alpha, ganoderic acid H and ganoderiol A were moderately active inhibitors against HIV-1 PR with a 50% inhibitory concentration of 0.17-0.23 mM.

Anti-HIV Agents↗
PubMed1998

4-Hydroxybenzoic acid: a hypoglycemic constituent of aqueous extract of Pandanus odorus root.

Hypoglycemic activity-guided fraction led to the isolation of the known compound, 4-hydroxybenzoic acid, from Pandanus odorus Ridl. (Thai name: Toei-hom, Pandanaceae). This compound showed a hypoglycemic effect in normal rats after the oral administration of 5 mg/kg. Additionally, the compound increased serum insulin levels and liver glycogen content in normal rats.

Animals↗
PubMed1998

Chemical constituents of Brazilian propolis and their cytotoxic activities.

The EtOAc-soluble fraction of the MeOH extract of propolis afforded a new prenylated chromane derivative, 3-hydroxy-2, 2-dimethyl-8-prenylchromane-6-propenoic acid (1), along with 22 known compounds, 2-23. Of the known compounds, 4, 7, 12-19, and 22 were isolated for the first time from propolis, and the absolute configuration of 23 was established as (2S,3R). Investigation suggested that Baccharis spp. are a significant source of tropical Brazilian propolis, in addition to Clusia minor, Clusia major, and Araucaria heterophylla. All the compounds were tested for their cytotoxicity toward human HT-1080 fibrosarcoma and murine colon 26-L5 carcinoma cells. Among these compounds, 9 and 19-21 showed potent cytotoxicity, having ED50 values equal to or less than 10 microg/mL.

Animals↗
PubMed1998

(+)-Verussurine, a new steroidal alkaloid from the roots and rhizomes of veratrum nigrum var. ussuriense and structure revision of (+)-verabenzoamine1

Two minor steroidal alkaloids, 1 and 2, have been isolated from the roots and rhizomes of Veratrum nigrum var. ussuriense. Their structures have been determined by the use of spectral data as 7-O-acetyl-15-O-(2-methylbutyroyl)-3-O-veratroylgermine (1) and 15-O-(2-methylbutyroyl)-3-O-veratroylgermine (2). By spectral data comparison with verabenzoamine, the structure of the latter compound has been revised from the previously reported 7-O-acetyl-15-O-(2-methylbutyroyl)-3-O-veratroylgermine (1) to 15-O-(2-methylbutyroyl)-3-O-veratroylgermine (2). Accordingly, alkaloid 1 [7-O-acetyl-15-O-(2-methylbutyroyl)-3-O-veratroylgermine] must be new, and it was given the trivial name verussurine.

Journal Article↗
PubMed1998

Two new steroidal alkaloids, 20-isoveratramine and verapatuline, from the roots and rhizomes of veratrum patulum

Roots and rhizomes of Veratrum patulum L. (Liliaceae), used as a source of the Chinese crude drug "Li-lu", have yielded two new steroidal alkaloids, 20-isoveratramine (1) and verapatuline (2), along with three known alkaloids, veratramine (3), veratrosine (4), and jervine (5). Structures of new alkaloids 1 and 2 were determined to be a C-20 epimer of 3 and N-(methoxycarbonyl)jervine, respectively, by the use of spectral data including 2D NMR.

Journal Article↗
PubMed1998

Hepatoprotective activity of phenylethanoids from Cistanche deserticola.

Four phenylethanoids isolated from the stems of Cistanche deserticola, acteoside (1), 2'-acetylacteoside (2), isoacteoside (3) and tubuloside B (4), significantly suppressed NADPH/CCl4-induced lipid peroxidation in rat liver microsomes. Addition of them to primary cultured rat hepatocytes efficiently prevented cell damage induced by exposure to CCl4 or D-galactosamine (D-GalN). Acteoside (1) further showed pronounced anti-hepatotoxic activity against CCl4 in vivo.

Animals↗
PubMed1998

Tribulusamide A and B, new hepatoprotective lignanamides from the fruits of Tribulus terrestris: indications of cytoprotective activity in murine hepatocyte culture.

Tribulusamides A (1) and B (2), new lignanamides embracing two cinnamic amide parts joined in a cis configuration, were isolated from the fruits of Tribulus terrestris, together with four known compounds, N-trans-feruloyltyramine (3), terrestriamide (4), N-trans-coumaroyltyramine (5), and beta-sitosterol. The structures were elucidated by 2D-NMR spectroscopy. Addition of compounds 1-5, especially 1 and 2, to primary cultured mouse hepatocytes significantly prevented cell death induced by D-galactosamine (D-GalN)/tumor necrosis factor alpha (TNF-alpha).

Animals↗
PubMed1998

The effect of Kampo formulae on bone resorption in vitro and in vivo. I. Active constituents of Tsu-kan-gan.

Four water extracts of Kampo formulae (Yi-kkan-sen, Dai-ho-in-gan, Ni-chi-gan, Tsu-kan-gan) were screened for their inhibitory activities on bone resorption induced by parathyroid hormone (PTH) in organ culture using neonatal mouse parietal bones. Among the Kampo formulae, Tsu-kan-gan (TKG) showed the most potent inhibitory activity. We further fractionated the TKG water extract by monitoring the inhibitory activity on bone resorption stimulated by PTH in vitro. The MeOH fraction of the water extract inhibited PTH-stimulated bone resorption, and its inhibitory activity was more potent than those of other fractions. The MeOH fraction was then subjected to Sephadex LH-20 column chromatography to give fractions I, II and III, which were examined for bone resorption activity. Fraction I inhibited PTH-stimulated bone resorption, and its inhibitory activity was more potent than those of the other fractions. Upon oral administration of the three fractions (100 mg/kg/d) to ovariectomized (OVX) mice, fractions I and III prevented the decrease of bone mineral density (BMD) of the lumbar vertebra. Eleven compounds isolated from the MeOH fraction were examined for their inhibitory effect on PTH-stimulated bone resorption. Among them, berberine (1), syringin (3), limonin (4) and mangiferin (10) showed a significant inhibitory effect on bone resorption. In the formation assay of osteoclast-like cells, these compounds decreased the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs). The inhibitory effect of TKG on bone resorption may be at least partly due to the inhibitory action of these compounds.

Animals↗
PubMed1998

Inhibitory effect of diarylheptanoids on nitric oxide production in activated murine macrophages.

Thirteen novel diarylheptanoids bearing a chalcone or a flavanone moiety (1-13), a new curcumin derivative, 1,2-dihydrobis(de-O-methyl)curcumin (14), and two known flavonoids (15 and 16) isolated from the seeds of Alpinia blepharocalyx K. Schum. were tested for their inhibitory effects on nitric oxide (NO) production in lipopolysaccaride (LPS)-activated murine macrophages J774.1 in vitro. All the tested compounds inhibited NO production in a concentration-dependent manner (IC50=36-568 microM). Among the compounds examined, blepharocalyxin B (13) was the most potent inhibitor of NO production (IC50=36 microM). Analysis of the structure activity relationship among these novel diarylheptanoids led to the conclusion that the position of attachment of a chalcone or a flavanone to a diarylheptanoid does not affect their inhibitory potency although their presence in association causes a substantial enhancement of the inhibitory activity. Moreover, a conjugated double bond in a chalcone moiety potentiated the inhibitory activity. On the other hand, hexamethoxydeoxycalyxin A (17) and pentamethoxycalyxin B (18), a methylated product of calyxin A (1) and an epimeric mixture of calyxin B, showed greatly reduced activity suggesting that phenolic hydroxyl groups are involved in the inhibitory activity.

Animals↗