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Biomedical subjects

S Kadota

Publications and source records attributed to S Kadota.

At least 73 records · Page 4Linked to original sources
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

Hypoglycemic effect of the water extract of Piper sarmentosum in rats.

The hypoglycemic effect of the water extract of the whole plant of Piper sarmentosum Roxb. (Piperaceae, Thai name: Chaplu) was examined in normal and streptozotocin-diabetic rats. In an oral glucose tolerance test, a single oral administration of the water extract at doses of 0.125 and 0.25 g/kg significantly lowered the plasma glucose level in the normal rats. A reference drug, glibenclamide, at a dose of 5 mg/kg (per os, p.o.) also showed a significant hypoglycemic effect in the normal rats. In contrast, a single oral administration of the water extract at these doses and glibenclamide did not significantly lower the plasma glucose level in the diabetic rats. However, the repeated oral administration of the water extract at a dose of 0.125 g/kg for 7 days produced a significant hypoglycemic effect in the diabetic rats. Glibenclamide (5 mg/kg, p.o.) also caused significant hypoglycemia in the diabetic rats. These results demonstrated that the water extract of whole plant of Piper sarmentosum has a hypoglycemic effect in rats.

Animals↗
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

A new antiplatelet diarylheptanoid from Alpinia blepharocalyx.

A new diarylheptanoid, 1,7-bis(4-hydroxyphenyl)-3-hydroxy-1,3-heptadien-5-one (1), along with seven other known compounds, were isolated from the seeds of Alpinia blepharocalyx. Of these, compounds 1 and 3 showed strong inhibition of collagen-induced, arachidonic acid-induced, and adenosine diphosphate-induced platelet aggregation of human whole blood. Compound 3 also strongly inhibited ristocetin-induced platelet aggregation. Structures of these compounds were elucidated by spectroscopic and chemical means.

China↗
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

Effect of spikelets of Miscanthus sinensis on IgE-mediated biphasic cutaneous reaction in mice.

The effect of spikelets of Miscanthus sinensis Andersson (M. sinensis) on IgE-mediated biphasic cutaneous reactions was investigated in BALB/c mice. Mice were passively sensitized by an intravenous (i.v.) injection of monoclonal antidinitrophenol IgE antibody (anti-DNP IgE mAb), or actively by an intraperitoneal (i.p.) injection of DNP-derivatized ovalbumin (DNP-OVA) plus aluminium hydroxide gel (Alum) as an adjuvant. Skin reactions were elicited by an epicutaneous challenge of dinitrofluorobenzene (DNFB) and occurred biphasically with peak responses at 1 and 24 h in both animal models. The administrations of a nondialysable water extract of M. sinensis within 2 h before or after DNFB challenge via oral or i.p. route significantly inhibited the biphasic cutaneous reactions in passively and actively sensitized mice. The inhibitory effect was much stronger than those of a glucocorticoid, prednisolone, and histamine release inhibitor, amlexanox, as positive controls. The active component(s) was predominantly located in the glycoprotein fraction by gel chromatography. In the ears of DNFB-challenged mice, this fraction suppressed the accumulation of inflammatory cells, including mast cells and neutrophils/macrophages. In addition, the biphasic ear swelling was also improved by an administration of the glycoprotein fraction 24 h before active sensitization. These findings indicate that the glycoprotein fraction of M. sinensis was able to inhibit not only the IgE-mediated allergic inflammatory reaction but also the IgE formation. Thus, this fraction may be a useful antiallergic therapy.

Animals↗
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

Anti-metastatic and immunomodulating properties of the water extract from Celosia argentea seeds.

We have investigated the anti-metastatic effect of Celosia argentea seed extracts (CAE), which have traditionally been used as a therapeutic drug for eye and hepatic diseases in China and Japan. Intraperitoneal (i.p.) administration of CAE for 7 d before tumor inoculation significantly inhibited liver metastasis caused by intraportal injection of colon 26-L5 carcinoma cells in a dose-dependent manner. CAE also showed concentration dependent mitogenic activity on BALB/c whole splenocytes, whereas incubation of the non-adherent fraction of splenocytes with CAE did not induce this activity. CAE has the ability to induce interleukin (IL)-12 production from macrophages in vitro. Following i.p. administration of CAE the maximal levels of IL-12 and interferon (IFN)-gamma production in serum were achieved at 2-3 and 6 h, respectively. Experiments using macrophage- or NK cell-deficient mice revealed that CAE-induced IL-12 in serum was not mediated by macrophages and that IFN-gamma production was mainly dependent on natural killer (NK) cells. Since CAE was inactive when the contributions of macrophages were removed in our system, its inhibitory mechanism is likely to be mainly associated with the activation of macrophages to an anti-metastatic state rather than NK cells. CAE administration resulted in increased production of IL-2, IFN-gamma and decreased production of a Th2 cytokine (IL-4) from splenocytes stimulated by PMA and A23187. Thus, the anti-metastatic effect by CAE is based on its immunomodulating properties including induction of cytokines such as IL-12, IL-2 and IFN-gamma leading to a Th1 dominant immune state and activating macrophages to the tumoricidal state. This may provide a basis for the inhibition of cancer metastasis.

2-Chloroadenosine↗
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↗
PubMed1998

Synthesis of a biologically active fluorescent derivative of GM1, a main Ginseng saponin metabolite formed by intestinal bacteria.

A fluorescent derivative of GM1 [20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol], a main Ginseng saponin metabolite formed by intestinal bacteria, was obtained from the condensation of its trisnor-aldehyde derivative with dansyl hydrazine. The dansylated GM1 fluoresced strongly and showed almost the same properties as its parent compound in lipophilicity and biological activities, so this fluorescent compound might provide an insight into the mechanism of pharmacological activities of GM1.

Antineoplastic Agents↗
PubMed1998

Antiosteoporotic activity of the stems of Sambucus sieboldiana.

We previously found that a methanolic extract of the stems of Sambucus sieboldiana inhibited bone resorption in organ culture. In this study, we further fractionated the methanol extract guided by the activity towards bone resorption stimulated by parathyroid hormone (PTH) in vitro. The ethyl acetate fraction (EtOAc Fr.) of the methanolic extract inhibited PTH-stimulated bone resorption of neonatal mouse bones, and the inhibitory activity was more potent than those of other fractions. Oral administration of the EtOAc Fr. (50 and 100 mg/kg/d) to ovariectomized (OVX) rat prevented the decrease in bone mineral density (BMD) of the lumbar (L2-4) vertebra, indicating that the EtOAc Fr. is effective in vivo. Furthermore, the EtOAc Fr. (50, 100 and 150 mg/kg/d) decreased the serum calcium level elevated in low calcium dietary rats. The phenolic constituents of the EtOAc fraction were examined for their inhibitory effect on bone resorption stimulated by PTH in neonatal mouse bone. Among them, vanillic acid, vanillin and coniferyl alcohol showed significant inhibitory effects on bone resorption. Of the compounds examined, vanillic acid was found to have a significant inhibitory effect on the decrease of BMD in OVX mice. Therefore, the EtOAc Fr. of S. sieboldiana showed a suppressive effect on bone resorption in vitro and in vivo. In addition, the inhibitory effects of the EtOAc Fr. on bone resorption may be at least partly due to the inhibitory action of vanillic acid.

Acetates↗
PubMed1998

Comparative study of seventeen Salvia plants: aldose reductase inhibitory activity of water and MeOH extracts and liquid chromatography-mass spectrometry (LC-MS) analysis of water extracts.

The dry root and rhizome of Salvia miltiorhiza (Lamiaceae) are used as a crude drug Danshen, while those of S. deserta (Xinjiang-Danshen) are mixed in Danshen at Xinjiang province when the former is in short supply. The water and MeOH extracts of S. deserta showed strong aldose reductase (AR) inhibitory activity, and their active constituents were determined to be polar compounds different from "tanshinones" of S. miltiorhiza, i.e., lithospermic acid B (1), salvianolic acid K (2), salviaflaside (3), and rosmarinic acid (4) (IC50, 2.63-3.91 microM). We also examined the AR inhibitory activity of water and MeOH extracts of seventeen Salvia plants, including ten species of Danshen resources (S. bowleyana, S. deserta, S. miltiorhiza, S. miltiorhiza var. miltiorhiza f. alba, S. paramiltiorhiza, S. paramiltiorhiza f. purpureo-rubra, S. przewalskii, S. przewalskii var. mandarinorum, S. sinica f. purpurea, S. trijuga), and their water extracts were also analyzed by liquid chromatography-mass spectrometry (LC-MS). The results indicated that there were four types with regard to the AR inhibitory activity and three types with regard to the amount of 1. Ten species used as Danshen resources showed good correlation between the AR inhibitory activity and the morphological classification. However, the intensities of their AR inhibitory activity varied, and they contained 1 in varying amounts. These facts suggested that the ten species were not the same, and thus their use as a Danshen resource should be based on their activity and/or active constituents.

Aldehyde Reductase↗
PubMed1998

[Development of antiviral therapeutic agents from traditional medicines].

Traditional medicines contain various metabolites derived from nucleic acid, protein, and lipid metabolism. Some of these specific metabolites may recognize the differences between viral and host metabolism resulting in anti-viral activity; hence traditional medicines may be useful sources for new antiviral agents. Traditional medicines can be cheaply obtained and have been orally administered as hot-water extracts. Therefore, they may be used for the prophylactic and therapeutic treatment of viral infection by drinking them, such as coffee or tea. Here we describe how the antiviral activity of traditional medicines was screened in vitro and how their therapeutic antiviral activities were verified in vivo, to obtain traditional antiviral medicines that can be clinically used. Therefore, we have selected 12 herbal extracts, from more than 250 herbal medicines, that exhibit therapeutic activities against cutaneous herpes simplex virus (HSV) type 1 (HSV-1) infection in mice. Four of the 12 augmented the therapeutic efficacy of acyclovir (ACV) in mice and showed potent anti-HSV activity against infection with ACV-resistant HSV-1 mutants in mice. These herbal extracts selectively inhibited viral DNA synthesis and showed a different mode of anti-HSV-1 action from that of ACV. They were also effective against both recurrent HSV and cytomegalovirus infections, without toxicity. Such prophylactic and therapeutic antiviral activities of the traditional medicines were verified by the purification of major active compounds. We could show new indications of traditional medicines as antiviral agents. Thus, the drinking of the extracts, in a daily tea or coffee, may be used for prophylaxis and therapy of diseases caused by herpes virus infection and improve the quality of life.

Animals↗
PubMed1998

[Studies on flavonoids from Fenugreek (Trigonella foenumgraecum L.)].

OBJECTIVE: To study the flavonoids in fenugreek (Trigonella foenumgraecum) produced in China. METHOD: The flavonoids were isolated with silica gel, polyamide and Sephadex LH-20 chromatography, and their structures were identified by physical, chemical properties and spectral analysis. RESULT: Five flavonoid compounds were isolated from fenugreek seeds and identified as vitexin, tricin, naringenin, quercetin and tricin-7-O-beta-D-glucopyranoside. CONCLUSION: Three flavonoids, tricin, naringenin and tricin-7-O-beta-D-glucopyranoside, were isolated from fenugreek as well as from the plants of Trigonella for the first time.

Apigenin↗
PubMed1998

Purification and characterization of eugeniin as an anti-herpesvirus compound from Geum japonicum and Syzygium aromaticum.

The hot-water extract of Geum japonicum has been shown to exhibit prophylactic and therapeutic anti-herpes simplex virus (HSV) activity in murine infection models. Eugeniin was purified as an anti-HSV compound from the extract and also was isolated from another herbal extract (Syzygium aromaticum) that had exhibited anti-HSV activity in mice. Thus the anti-HSV action of eugeniin was characterized. The effective concentration (5.0 microg/ml) for 50% plaque reduction of eugeniin for wild HSV type 1 (HSV-1) on Vero cells was 13.9-fold lower than its 50% cytotoxic concentration determined by a yield-reduction assay. Eugeniin also inhibited the growth of acyclovir-phosphonoacetic acid-resistant HSV-1, thymidine kinase-deficient HSV-1 and wild HSV type 2. Eugeniin as well as phosphonoacetic acid inhibited viral DNA and late viral protein syntheses in their infected Vero cells, but not cellular protein synthesis at its inhibitory concentrations. Purified HSV-1 DNA polymerase activity was inhibited by eugeniin noncompetitively with respect to dTTP. Its apparent Ki value for euginiin was 8.2- and 5. 8-fold lower than the Ki values of purified human DNA polymerases alpha and beta, respectively. Thus one of the major target sites of inhibitory action of eugeniin is viral DNA synthesis; the inhibitory action for viral DNA polymerase activity was novel compared with anti-HSV nucleoside analogs.

Animals↗