Biomedical subjects

S Kadota

Publications and source records attributed to S Kadota.

At least 37 records · Page 2Linked to original sources

PubMed2001

Triterpenoid saponins from leaves and stems of Panax quinquefolium L.

In the chemical investigation on the saponin composition of leaves and stems of Panax quinquefolium L., two new minor dammarane saponins, quinquenoside L1 (1) and L2 (2) have been isolated. By means of physico-chemical evidences and spectral analysis their structures were established as 3-O-[beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-dammara-23,25-diene-3beta, 12beta, 20(S)-triol (1) and 3-O-[beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-(24Z)-dammar-24-ene-3beta, 12beta, 20(S), 26-tetraol (2).

Carbohydrate Sequence↗

PubMed2001

Antiproliferative activity of diarylheptanoids from the seeds of Alpinia blepharocalyx.

The 95% EtOH extract of the seeds of Alpinia blepharocalyx (Zingiberaceae) showed significant antiproliferative activity towards human HT-1080 fibrosarcoma and murine colon 26-L5 carcinoma cells. Chemical investigation of the extract led to the isolation of forty-four new (1-44) and one known (45) diarylheptanoids, eleven phenolic compounds (46-56) together with beta-sitosterol glucoside (57). Almost all the isolated compounds showed significant antiproliferative activity in a concentration-dependent manner. Among the compounds, epicalyxin F (17) exhibited the most potent activity against the proliferation of colon 26-L5 carcinoma cells with an ED50 value of 0.89 microM, while calyxin B (2) exhibited the most potent activity against human HT-1080 fibrosarcoma cells with an ED50 value of 0.69 microM. Moreover, calyxins B (2) and K (11), epicalyxins F (17), I (20) and K (22), 6-hydroxycalyxin F (25), blepharocalyxin B (27) and mixtures of 7 and epicalyxin G (18) and of calyxin J (10) and epicalyxin J (21) possessed more potent activity than a clinically used anticancer drug, 5-fluorouracil, towards HT-1080 fibrosarcoma cells. Analysis of the structure activity relationship suggested that the position of the attachment of a chalcone or a flavanone moiety does not affect the activity, although their presence in association causes a substantial enhancement of the antiproliferative activity. Moreover, the conjugated double bond of the chalcone moiety and the phenolic hydroxyl group potentiate the antiproliferative activity of the compounds.

Animals↗

PubMed2001

Prolyl endopeptidase inhibitors from the underground part of Rhodiola sachalinensis.

The methanolic extract of the underground part of Rhodiola sachalinensis was found to show inhibitory activity on prolyl endopeptidase (PEP, EC. 3.4.21.26), an enzyme that plays a role in the metabolism of proline-containing neuropeptidase which is recognized to be involved in learning and memory. From the MeOH extract, five new monoterpenoids named sachalinols A (24), B (25) and C (26) and sachalinosides A (23) and B (27) were isolated, together with twenty-two known compounds, gallic acid (1), trans-p-hydroxycinnamic acid (2), p-tyrosol (3), salidroside (4), 6n-O-galloylsalidroside (5), benzyl beta-D-glucopyranoside (6), 2-phenylethyl beta-D-glucopyranoside (7), trans-cinnamyl beta-D-glucopyranoside (8), rosarin (9), rhodiocyanoside A (10), lotaustralin (11), octyl beta-D-glucopyranoside (12), 1,2,3,6-tetra-O-galloyl-beta-D-glucose (13), 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (14), kaempferol (15), kaempferol 3-O-beta-D-xylofuranosyl(1-->2)-beta-D-glucopyranoside (16), kaempferol 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranoside (17), rhodionin (18), rhodiosin (19), (-)-epigallocatechin (20), 3-O-galloylepigallocatechin-(4-->8)-epigallocatechin 3-O-gallate (21) and rosiridin (22). Among these, nineteen compounds other than 3, 4 and 9 have been isolated for the first time from R. sachalinensis, and six (6, 8, 13, 16, 17, 20) are isolated from Rhodiola plants for the first time. Among them, six compounds (13, 14, 18, 19, 21, 22) showed noncompetitive inhibition against Flavobacterium PEP, with an IC50 of 0.025, 0.17, 22, 41, 0.44 and 84 microM, respectively.

Binding, Competitive↗

PubMed2001

Effect of mirabilitum in formularization: change of prolyl endopeptidase inhibitory activity and of constituents using the preparation method of Tokaku-joki-to.

To clarify the effect of Mirabilitum in formularization, change of prolyl endopeptidase inhibitory activity and of constituents using the preparation method of a Kampo formula Tokaku-joki-to ([Japanese characters: see text], Persia and Rhubarb combination) was examined by the liquid chromatography-mass spectroscopy (LC-MS) method. Mirabilitum under boiling condition caused qualitative and quantitative change of the constituents through hydrolysis which caused a change of its activity. This was considered to be the main reason the classical Chinese medical book "Shang han lun ([Japanese characters: see text])" specified that Mirabilitum should be added at a later stage of decoction.

Chromatography, High Pressure Liquid↗

PubMed2001

Biological characterization of eugeniin as an anti-herpes simplex virus type 1 compound in vitro and in vivo.

Eugeniin exhibits antiviral activity against acyclovir and phosphonoacetic acid (PAA)-resistant herpes simplex virus type 1 (HSV-1) as well as the wild-type HSV-1 in vitro. In this study, we characterized the biological activity of eugeniin in cutaneously HSV-1-infected mice and its interaction with HSV-1 DNA polymerase. The oral and intraperitoneal administrations of eugeniin at 0.3 mg/kg showed similar therapeutic efficacy in retarding the development of skin lesions of HSV-1-infected mice. The two routes of administration at 6 or 50 mg/kg significantly prolonged the mean survival times and/or reduced mortality without toxicity. The oral administration of eugeniin at 50 mg/kg reduced virus yields in the skin and brain of infected mice. Thus, the therapeutic efficacy of oral administration at the various doses of eugeniin was similar to that of intraperitoneal administration, suggesting that the oral bioavailability of eugeniin was high with respect to absorption. Furthermore, the anti-HSV-1 activity of eugeniin was characterized by isobolograms analyzing its combined effects with acyclovir or PAA in HSV-1-infected Vero cells. Eugeniin enhanced the anti-HSV-1 activity of acyclovir but was suggested to be antagonistic with PAA. The interaction of eugeniin and PAA on the activity of partially purified HSV-1 DNA polymerase suggested that eugeniin interacted with the polymerase in the vicinity of PAA-binding site. Thus, eugeniin showed different anti-HSV-1 action from acyclovir and PAA and therapeutic anti-HSV-1 activity in mice.

Acyclovir↗

PubMed2000

Inhibition of nitric oxide by phenylethanoids in activated macrophages.

Nitric oxide (NO) is one of the pro-inflammatory molecules. Some phenylethanoids have been previously shown to possess anti-inflammatory effects. Seven phenylethanoids from the stems of Cistanche deserticola, viz. isoacteoside, tubuloside B, acteoside, 2'-O-acetylacteoside, echinacoside, cistanoside A and tubuloside A, were tested for their effect on NO radical generation by activated murine macrophages. At the concentration of 100-200 microM, all the phenylethanoids reduced (6.3-62.3%) nitrite accumulation in lipopolysaccharide (0.1 microgram/ml)-stimulated J774.1 cells. At 200 microM, they inhibited by 32.2-72.4% nitrite accumulation induced by lipopolysaccharide (0.1 microgram/ml)/interferon-gamma (100 U/ml) in mouse peritoneal exudate macrophages. However, these compounds did not affect the expression of inducible nitric oxide (iNOS) mRNA, the iNOS protein level, or the iNOS activity in lipopolysaccharide-stimulated J774.1 cells. Instead, they showed a clear scavenging effect (6.9-43.9%) at the low concentrations of 2-10 microM of about 12 microM nitrite generated from an NO donor, 1-propanamine-3-hydroxy-2-nitroso-1-propylhydrazino (PAPA NONOate). These results indicate that the phenylethanoids have NO radical-scavenging activity, which possibly contributes to their anti-inflammatory effects.

Animals↗

PubMed2000

Inhibitory effects of an aqueous extract of Apocynum venetum leaves and its constituents on Cu(2+)-induced oxidative modification of low density lipoprotein.

An aqueous extract of Apocynum venetum leaves and its constituents inhibited thiobarbituric acid reactive substances (TBARS) and conjugated-diene formation in the Cu(2+)-induced oxidation of low density lipoprotein (LDL) in vitro. The TBARS formation was most strongly inhibited by chlorogenic acid with an IC(50) value of 1.9 microM, but other constituents were in a range of 2.3-23.3 microM. On the other hand, the lag time in the conjugated-diene formation was dose-dependently prolonged by addition of the aqueous extract. Catechin prolonged the lag time more than 300 min and other constituents such as chlorogenic acid, epicatechin, epigallocatechin, hyperoside and isoquercitrin led to no conjugated-diene formation within 700 min under the experimental conditions.

Cholesterol, LDL↗

PubMed2000

Saponins from Lonicera bournei.

The lupane-triterpene glycosides, bourneioside A and bourneioside B, and two known saponins were isolated from Lonicera bournei Hemsl. The structures of bourneioside A and B were elucidated as 3-O-beta-D-glucopyranosyl-23-hydroxy-lup-20(29)-en-28-oic acid-28-O-beta-D-glucopyranosyl ester and 3-O-beta-D-glucopyranosyl-23-hydroxy-lup-20(29)-en-28-oic acid-28-O-[beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl] ester, respectively, on the basis of spectral data and chemical evidence.

Glucosides↗

PubMed2000

Distribution, metabolism and excretion of butylidenephthalide of Ligustici chuanxiong rhizoma in hairless mouse after dermal application.

The absorption, distribution and excretion of butylidenephthalide after dermal application to hairless mouse have been examined with [8-14C]butylidenephthalide. By the investigation of the whole body autoradiogram and liquid scintillation analysis, it was indicated that the transdermally applied butylidenephthalide quickly permeate into peripheral circulation system without accumulation in the skin and then distribute into lung, liver, bile and kidney. The total radioactivity, however, was decreased due to excretion into urine, and in the case of i.v.-administration, 80% of the administered butylidenephthalide was excreted into urine within 24 h, while only 5% was excreted into feces within 24 h. Then, the metabolite in urine was determined to be a cysteine conjugate by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method. Thus, it has been concluded that after dermal application butylidenephthalide quickly permeates through skin into peripheral circulation system; distributes to lung, liver, bile and kidney; and then excreted into urine as a cysteine adduct.

Administration, Cutaneous↗

PubMed2000

Effects of aqueous extracts of Apocynum venetum leaves on spontaneously hypertensive, renal hypertensive and NaCl-fed-hypertensive rats.

Effects of aqueous extracts of Apocynum venetum leaves (Luobuma extracts) on the blood pressure were evaluated in hypertensive animal models, such as spontaneously hypertensive rats (SHR), renal hypertensive rats and NaCl-induced hypertensive rats. In SHR, administration of Luobuma (heat-processed and unprocessed leaves) extracts at a dose of 70 mg/rat per day significantly decreased the systolic blood pressure value, but their decreasing effects were weaker than that of captopril. The urine volume, and the urinary Na(+), K(+) and protein excretions were not significantly different between Luobuma-treated and untreated groups. In 3/4 nephrectomized rats, the Luobuma extracts significantly decreased the systolic blood pressure value, accompanied by significant increases of the urine volume and the urinary Na(+) and K(+) excretions. Furthermore, they decreased the blood urea nitrogen (BUN) level. In NaCl-induced hypertensive rats, the Luobuma extract decreased the systolic blood pressure value. However, it did not change the urinary excretions of Na(+), K(+) and protein. The BUN level was lower than that of control rats, but the serum total cholesterol (TC) level did not changed. From these findings, the Luobuma extracts have an anti-hypertensive effect, possibly due to amelioration of the kidney functions in the three experimental animal models.

Animals↗

PubMed2000

Cytotoxic, hepatoprotective and free radical scavenging effects of propolis from Brazil, Peru, the Netherlands and China.

Propolis is a resinous hive product collected by honeybees from various plant sources. The composition of the propolis depends upon the time, vegetation and the area of collection. Thus, quality evaluation of the propolis is important, before use in food and beverages. For this propose three different biological activities were carried out, i.e. 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, cytotoxicity and hepatoprotective activity, of MeOH and water extracts of nine different propolis from Brazil, Peru, the Netherlands and China. The results showed that water extracts of six Brazilian and a Chinese propolis possessed stronger DPPH free radical scavenging activity than the corresponding MeOH extract, whereas in the case of Netherlands and Peruvian propolis MeOH extract exhibited stronger DPPH free radical scavenging activity. The MeOH extracts of all propolis possessed stronger cytotoxicity than the corresponding water extract towards murine colon 26-L5 carcinoma and human HT-1080 fibrosarcoma cells. The result of hepatoprotective activity of Brazilian propolis on D-galactosamine (D-GalN)/tumor necrosis factor-alpha (TNF-alpha)-induced cell death in primary cultured mouse hepatocytes were found in accordance with the grade set up by beekeepers in Brazil.

Animals↗

PubMed2000

Two novel cytotoxic benzofuran derivatives from Brazilian propolis.

Two novel benzofuran derivatives, propolis-benzofurans A (1) and B (2), were isolated from the MeOH extract of Brazilian propolis, together with two known isoprenylated compounds (E)-3-[2, 3-dihydro-2-(1-methylethenyl)-7-prenyl-5-benzofuranyl]-2-propen oic acid and (E)-3-¿4-hydroxy-3-[(E)-4-(2, 3-dihydrocinnamoyloxy)-3-methyl-2-butenyl]-5-prenylphenyl¿-2 -propenoi c acid. The structures of these compounds were elucidated on the basis of spectral analysis. Both the new compounds exhibited mild cytotoxicity toward highly liver-metastatic murine colon 26-L5 carcinoma and human HT-1080 fibrosarcoma cells.

Animals↗

PubMed2000

Kinmoonosides A-C, three new cytotoxic saponins from the fruits of Acacia concinna, a medicinal plant collected in myanmar.

Three genuine saponins, named kinmoonosides A-C (1-3), have been isolated, together with a new monoterpenoid (4), from a methanolic extract of the fruits of Acacia concinna. The structures of kinmoonosides A-C were elucidated on the basis of spectral analysis as 3-O-¿alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl¿-21-O-¿(6R, 2E)-2-hydroxymethyl-6-methyl-6-O-[4-O-(2'E)-6'-hydroxyl-2'-hydroxymet hyl-6'-methyl-2',7'-octadienoyl-beta-D-quinovopyranosyl]-2, 7-octadienoyl¿acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (1); 3-O-¿alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl¿-21-O-¿(6S, 2E)-2-hydroxymethyl-6-methyl-6-O-[4-O-(2'E)-6'-hydroxyl-2'-hydroxymet hyl-6'-methyl-2',7'-octadienoyl-beta-D-quinobopyranosyl]-2, 7-octadienoyl¿acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (2); and 3-O-¿alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl¿-21-O-[(2E)-6-hydroxyl-2-hydroxymethyl-6-methyl- 2,7-octadienoyl]acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (3), respectively. The new monoterpenoid 4 was determined as 4-O-[(2E)-6-hydroxyl-2-hydroxymethyl-6-methyl-2, 7-octadienoyl]-D-quinovopyranose. Compounds 1-3 showed significant cytotoxicity against human HT-1080 fibrosarcoma cells.

Antineoplastic Agents, Phytogenic↗

PubMed2000

Thirteen novel cycloartane-type triterpenes from Combretum quadrangulare.

Thirteen novel cycloartane-type triterpenes were isolated from Combretum quadrangulare, a Vietnamese medicinal plant. The structures of the novel triterpenes were determined by spectroscopic methods as well as by chemical transformations. Among those compounds, quadrangularic acids F (1), G (2), and H (4) and 24-epiquadrangularic acid G (3) are the first examples of cycloartane-type triterpenes bearing carboxylic acid groups at both C-4 and C-20. Furthermore, norquadrangularic acid A (13) is the first example of a trinorcycloartane-type triterpene isolated from the genus Combretum.

Plants, Medicinal↗

PubMed2000

Quadranosides I-V, new triterpene glucosides from the seeds of Combretum quadrangulare.

Five new triterpene glucosides, quadranosides I-V (1-5), have been isolated from a MeOH extract of the seeds of Combretum quadrangulare, together with 13 known compounds. The structures of compounds 1-5 were elucidated on the basis of spectroscopic analysis. Among the new triterpene glucosides, three compounds (1, 2, 5) showed significant hepatoprotective effects against D-galactosamine (D-GalN)/tumor necrosis factor-alpha (TNF-alpha)-induced cell death in primary cultured mouse hepatocytes.

Africa↗

PubMed2000

Hepatoprotective effect of Apocynum venetum and its active constituents.

The leaves of Apocynum venetum L. are used as a tea material in north China and Japan. A water extract (500 mg/kg/day, one week administration) of the leaves of A. venetum showed protective effects against carbon tetrachloride (CCl4, 30 microliters/mouse) or D-galactosamine (D-GalN, 700 mg/kg)/lipopolysaccharide (LPS, 20 micrograms/kg)-induced liver injury in mice. Tumor necrosis factor-alpha (TNF-alpha) secreted from LPS-stimulated macrophages is the most crucial mediator in the D-GalN/LPS-induced liver injury model. The extract had no significant inhibition on the increase of serum TNF-alpha (1169 +/- 132 pg/ml vs. 1595 +/- 314 pg/ml of control), but exhibited a complete inhibition at the concentration of 100 micrograms/ml on TNF-alpha (100 ng/ml)-induced cell death in D-GalN (0.5 mM)-sensitized mouse hepatocytes. Further activity-guided fractionation resulted in the isolation of fifteen flavonoids viz. (-)-epicatechin (1), (-)-epigallocatechin (2), isoquercetin (3), hyperin (4), (+)-catechin (5), (+)-gallocatechin (6), kaempferol-6'-O-acetate (7), isoquercetin-6'-O-acetate (8), catechin-[8,7-e]-4 alpha-(3,4-dihydroxpyhenyl)-dihydro-2(3H)-pyranone (9), apocynin B (10), apocynin A (11), cinchonain Ia (12), apocynin C (13), apocynin D (14) and quercetin (15). All the compounds showed inhibitory effects on TNF-alpha-induced cell death with different intensities. The flavonol glycosides 3, 4, 7 and 8 and the phenylpropanoid-substituted flavan-3-ols 11 and 12 showed potent inhibitory effects on TNF-alpha-induced cell death with IC50 values of 37.5, 14.5, 31.2, 55.1, 71.9 and 41.2 microM, respectively. In contrast, the clinically used 5 and its analogues 1, 2 and 6 showed apparent activity only at 80 microM. These flavonoids appeared to be the hepatoprotective principles of the leaves of A. venetum. The hepatoprotective effects exhibited by the extract and its constituents suggest a validation of the leaves as a tea material.

Animals↗

PubMed2000

Highly selective antibacterial activity of novel alkyl quinolone alkaloids from a Chinese herbal medicine, Gosyuyu (Wu-Chu-Yu), against Helicobacter pylori in vitro.

To elucidate the antibacterial activity of Gosyuyu, the crude extract from the fruit of Evodia rutaecarpa, a Chinese herbal medicine, has been fractionated chromatographically, and each fraction was assayed for antibacterial activity against Helicobacterpylori (H. pylori) in vitro. As the result, a single spot having marked antibacterial activity against H. pylori was obtained and the chemical structure was analyzed. The isolated compound was revealed to be a novel alkyl quinolone alkaloid based on the solubility, IR spectra, NMR analysis and mass spectrometric data after purification by TLC of silica. We compared the antimicrobial activity of this compound with that of other antimicrobial agents and examined susceptibility of various intestinal pathogens. As the result, the new quinolone compounds obtained from Gosyuyu extracts were found to be a mixture of two quinolone alkaloids, 1-methyl-2-[(Z)-8-tridecenyl]-4-(1H)-quinolone and 1-methyl-2-[(Z)-7-tridecenyl]-4-(1H)-quinolone (MW: 339), reported previously. The minimum inhibitory concentration (MIC) of these compounds against reference strains and clinically isolated H. pylori strains were less than 0.05 microg/ml, which was similar to the MIC of amoxicillin and clarithromycin that are used worldwide for the eradication of H. pylori, clinically. Furthermore, it was noted that the antimicrobial activity of these compounds was highly selective against H. pylori and almost non-active against other intestinal pathogens. The above results showed that these alkyl methyl quinolone (AM quinolones) alkaloids were useful for the eradication of H. pylori without affecting other intestinal flora.

Alkaloids↗

PubMed2000

Pharmacokinetics of ginsenoside deglycosylated by intestinal bacteria and its transformation to biologically active fatty acid esters.

Ginsenosides are deglycosylated by intestinal bacteria to active forms after oral administration. The present study demonstrated the pharmacodynamics of 20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol (M1), an intestinal bacterial metabolite of ginsenosides, and the in vitro and in vivo antitumor activities of M1-metabolites in comparison with M1 using C57BL/6 mice and Wistar rats. M1 was selectively accumulated into the liver soon after its intravenous administration to mice, and mostly excreted as bile; however, some M1 was transformed to fatty acid ester (EM1) in the liver. EM1 was isolated from rats in a recovery dose of approximately 24 mol%. Structural analysis indicated that EM1 comprised a family of fatty acid mono-esters of M1. Because EM1 was not excreted as bile as M1 was, it was accumulated in the liver longer than M1. Although the cytotoxicity of M1 against B16-F10 melanoma cells was attenuated by fatty acid esterification, EM1 inhibited tumor growth more than M1 in vivo. These results suggest that the fatty acid M1 esters may be the real active principles of ginsenosides in the body.

Animals↗