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T Namba

Publications and source records attributed to T Namba.

At least 91 records · Page 5Linked to original sources
PubMed1997

Aldose reductase inhibitory constituents of the root of Salvia miltiorhiza Bunge.

The constituents of the MeOH extract of Salvia miltiorhiza BUNGE, which showed strong aldose reductase (AR) inhibitory activity, were examined, and two new abietane-type diterpenoids, danshenol A (1) and danshenol B (2), were isolated together with six known ones: dihydrotanshimme I (3), cryptotanshinone (4), tanshinone I (5), tanshinone IIA (6), (-)-danshexinkun A (7), and sugiol (8). Among them, 4, 5, and 8 were weak AR inhibitors with IC50 from 4.80 to > 10.0 microM, while 1, 2, 3, 6, and 7 were strong inhibitors (IC50 from 0.10 to 1.75 microM). Danshenol A (1), the strongest inhibitor, had IC50 of 0.10 microM which is comparable to that of epalrestat in clinical use. Moreover, from a consideration of IC50, and yield of each compound, it was concluded that tanshinone IIA (6) is the major active constituent of the MeOH extract and danshenol A (I) and (-)danshexinkun A(7) are the minor ones.

Aldehyde Reductase↗
PubMed1997

Hepatoprotective principles of Swertia japonica Makino on D-galactosamine/lipopolysaccharide-induced liver injury in mice.

The n-BuOH extract of Swertia japonica showed a significant hepatoprotective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. The activity-guided fractionation led to the isolation of a new tetrahydroxanthone derivative, tetrahydroswertianolin (1), as well as two known iridoids, gentiopicroside (2) and sweroside (3). Their structures were elucidated by spectroscopic methods and chemical reactions. Of the three compounds, 2 and 3 possessed mild hepatoprotective activity at a dose range of 25-50 mg/kg, whereas, 1 exhibited potent activity in a dose-dependent manner. The hepatoprotective effect of tetrahydroswertianolin (1) was stronger than that of glycyrrhizin which was used as a positive control.

Animals↗
PubMed1997

Surgical results of abdominal aortic aneurysm repair in patients with chronic renal dysfunction.

The purpose of this study was to determine the influence of preoperative renal dysfunction on the outcome of patients undergoing elective, infrarenal abdominal aortic aneurysm (AAA) repair. Patients undergoing AAA repair from 1984 to 1996 (n = 250) were divided into 2 groups, according to their preoperative serum creatinine levels: > or = 1.5 mg/dl (group A, n = 33) and < 1.5 mg/dl (group B, n = 217). There was no apparent difference in the incidences of preoperative risk factors, excluding ischemic heart disease, between the groups. The mortality rates of the 2 groups did not differ (9.9% vs 3.2% in groups A and B, respectively, p = 0.13), but the morbidity rate of group A (30.3%) was significantly higher than that of group B (12.9%, p = 0.0095). The 5-year cumulative survival rate of group A patients was 60%, which was significantly lower (p < 0.0001) than that of group B patients (84%). Five group A patients underwent simultaneous renal artery reconstruction, which relieved postoperative renal deterioration in 4, although 2 of them developed chronic renal failure requiring hemodialysis over 5 years after the operation. These findings suggest that morbidity and long-term survival in patients with renal dysfunction can be severe after AAA repair and that simultaneous renal artery reconstruction may delay renal function decline.

Aged↗
PubMed1997

[Ameliorating effects of dan-shen and its major ingredient calcium/magnesium lithospermate B on cognitive deficiencies in senescence-accelerated mouse].

Effect of the long-term treatment with a Dan-Shen (Salviae miltiorrhizae radix) methanol extract (DME) or its major ingredient lithospermate B (LSB) on memory and learning in scenescence-accelerated mouse (SAM) was investigated by means of Morris's water maze task. DME or LSB treatment significantly decreased the escape latency in the P8 strain of SAM (SAMP8), which strain spontaneously develops learning deficits. These results suggest that DME and LSB treatment improved spacial learning. Neurochemical investigations indicated that both drugs did not affect the cholinergic system, but enhanced functions of the glutamate-PKC system in hippocampus, since the increases in [3H]MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,b]-cyclohepten-5,10-imine maleate) binding in cortex and [3H]PDBu (phorbol 12,13-dibutyrate) binding in hippocampus were observed in DME and LSB treatments. Our previous studies indicate the decrease in PDBu binding and NMDA receptor-mediated functions in SAMP8 brain. Thus, it is suggested that 1) Methanol extract of Dan-Shen is effective for prevention of spacial learning deficit caused with aging, 2) lithospermate B is one of the active ingredients, 3) SAMP8 is useful model animal to investigate drugs for anti-aging or anti-dementia.

Aging↗
PubMed1997

Dantrolene sodium reduces the enhanced leakage of creatine kinase caused by ethanol, cocaine, and electrical stimulation in isolated fast and slow muscles of rat.

Binge drinking of alcohol, cocaine overdose, or overexertion can lead to rhabdomyolysis characterized by elevated creatine kinase (CK) and myoglobin in the serum, myoglobinuria, and muscle tenderness. Our previous studies showed that ethanol, cocaine, and electrical stimulation enhanced the leakage of CK from isolated soleus and extensor digitorum longus (EDL) muscles of rat. Dantrolene sodium was reported to reduce the muscle damage and elevated serum CK levels in exercised rats. The present study was aimed at testing whether dantrolene can reduce the enhanced leakage of CK from isolated rat soleus and EDL muscles caused by ethanol, cocaine, and electrical stimulation. After 4-hr incubation in oxygenated physiological solution at 37 degrees C, the mean leakage of CK was 1.56 units/mg of muscle in soleus and 0.89 units/mg in EDL. Ethanol at 0.2% increased the leakage of CK by 47% (p < 0.05) in soleus and by 26% in EDL. Cocaine at 1 mM increased the leakage of CK by 55% (p < 0.05) in soleus and by 27% in EDL. Electrical stimulation at 1 Hz for 4 hr increased the mean leakage of CK by 100% (p < 0.05) in soleus and 127% (p < 0.05) in EDL. Dantrolene sodium reduced the enhanced leakage of CK caused by ethanol, cocaine, and electrical stimulation significantly in soleus and slightly in EDL. Dantrolene may involve myoplasmic free Ca2+ in these beneficial effects as in malignant hyperthermia, and may be useful in the treatment of rhabdomyolysis associated with acute alcoholic myopathy, cocaine overdose, and overexertion.

Animals↗
PubMed1996

Mapping of the genes encoding mouse prostaglandin D, E, and F and prostacyclin receptors.

Prostaglandins and prostacyclin are metabolites of arachidonic acid and exert a variety of actions to maintain local homeostasis in the body. Their actions are mediated by cell surface receptors specific to the respective ligands. Using a panel of interspecific back-cross mice, we have mapped the prostaglandin D receptor gene (Ptgdr), prostaglandin E receptor subtype EP(1) gene (Ptgerepl), prostaglandin F receptor gene (Ptgfr), and prostacyclin receptor gene (Ptgir). Ptgdr mapped to proximal Chr 14, Ptgfr mapped to distal Chr 3, Ptgerepl mapped to middle Chr 8, and Ptgir mapped to proximal Chr 7.

Animals↗
PubMed1996

Prophylactic treatment of cytomegalovirus infection with traditional herbs.

Hot water extracts of four traditional herbs, Geum japonicum, Syzygium aromaticum, Terminalia chebula and Rhus javanica, which have been shown to have anti-herpes simplex virus (HSV) activity in vivo, were examined for anti-cytomegalovirus (CMV) activity in vitro and in vivo in this study. They inhibited replication of human CMV and murine CMV (MCMV) in vitro. These anti-CMV activities in vivo were examined in an MCMV infection model using immunosuppressed mice. Mice were subcutaneously treated with various doses of cyclosporine, and immunosuppression and MCMV infection were monitored by suppression of antibody production and virus yield in the lung, respectively. Each herbal extract was orally administered to mice treated with 50 mg/kg of cyclosporine from a day before intraperitoneal infection, and the efficacy of herbs was evaluated by the reduction in the virus yield in the lung. Among them Geum japonicum, Syzygium aromaticum, and Terminalia chebula significantly suppressed MCMV yields in lungs of treated mice compared with water treatment. Efficacy of oral treatment with 750 mg/kg per day of Geum japonicum extract was similar to that of the intraperitoneal administration of 2 mg/kg per day of ganciclovir in increasing the body weight of infected mice and reducing the virus yield in the lungs. These herbs may be beneficial for the prophylaxis of CMV diseases in immunocompromised patients.

Animals↗
PubMed1996

Hepatoprotective effects of emodin from Ventilago leiocarpa.

A major component of ethyl acetate (EtOAc) and chloroform (CHCl3) fractions of Ventilago leiocarpa Bunge (Rhamnaceae), emodin, was isolated and exhibited hepatoprotective effects on carbon tetrachloride (CCl4) as well as D-galactosamine (D-GalN)-induced liver damage. The histopathological examination also clearly showed that emodin reduced lymphocyte cells, Kupffer cells, ballooning degeneration, cell necrosis and hyaline degeneration on CCl4 and D-galactosamine-induced tests.

Acetates↗
PubMed1996

Syringin 4-O-beta-glucoside, a new phenylpropanoid glycoside, and costunolide, a nitric oxide synthase inhibitor, from the stem bark of Magnolia sieboldii.

Syringin 4-O-beta-glucoside (1), a new phenylpropanoid glycoside, and costunolide (2) were isolated from the stem bark of Magnolia sieboldii. The structures were determined by spectroscopic and chemical methods. Costunolide (2) exhibited strong nitric oxide synthase inhibitory activity in the endotoxin-activated murine macrophage, J774.1.

Animals↗
PubMed1996

Effects on cultured neonatal mouse calvaria of the flavonoids isolated from Boerhaavia repens.

A MeOH extract from the whole plant of Boerhaavia repens was found to inhibit bone resorption induced by parathyroid hormone (PTH) in tissue culture. Systematic separation of the MeOH extract afforded one new and two known flavonoid glycosides, namely, eupalitin 3-O-beta-D-galactopyranosyl-(1-->2)-beta-D-glucopyranoside (1), eupalitin 3-O-beta-D-galactopyranoside (2), and 6-methoxykaempferol 3-O-beta-D-(1-->6)-robinoside (3). The structure of the new compound 1 was determined using spectroscopic techniques. The inhibitory activity of these substances toward bone resorption induced by PTH was evaluated, and compounds 1 and 2 were found to exhibit significant activity.

Animals↗
PubMed1996

Relationship among homocyst(e)ine, vitamin B-12 and cardiac disease in the elderly: association between vitamin B-12 deficiency and decreased left ventricular ejection fraction.

We evaluated the association of moderate hyperhomocyst(e)inemia and vitamin B-12 status with coronary artery disease (CAD) and left ventricular ejection fraction in 367 elderly patients undergoing coronary angiography. The extent of CAD was scored, left ventricular ejection fraction was assessed and vitamins B-12 and folate and the metabolites homocyst(e)ine, methylmalonic acid and 2-methylcitric acid were measured. There was no significant trend in change in homocyst(e)ine as the extent of CAD increased. There was an association between vitamin B-12 deficiency, i.e., vitamin B-12 < 221 pmol/l and homocyst(e)ine > 16 nmol/ml and low left ventricular ejection fraction (P = 0.014). Of 105 samples, selected for vitamin B-12 < 221 pmol/l or high normal vitamin B-12 and folate levels, metabolites including methylmalonic acid revealed a specific diagnosis of vitamin B-12 deficiency in 18 patients. The trend among these vitamin B-12-deficient patients and low left ventricular ejection fraction was significant (P = 0.028). In vitro studies on rat heart revealed that nitrous oxide in the presence of 200 microM/l methionine reduced contractility of the heart. In conclusion, vitamin B-12-deficient patients had significantly lower left ventricular ejection fractions than nonvitamin B-12-deficient patients. Whether low left ventricular ejection fraction results in malabsorption of vitamin B-12 and vitamin B-12 deficiency, or conversely, whether vitamin B-12 and its marker, elevated homocyst(e)ine, depress left ventricular function warrants further evaluation.

Aged↗
PubMed1996

Inhibition of agrin-mediated acetylcholine receptor clustering by utrophin C-terminal peptides.

BACKGROUND: Agrin is an extracellular matrix protein that is required for neuromuscular synaptogenesis and is particularly important in the clustering of acetylcholine receptors at post-synaptic sites. Little is known about the signal transduction pathway of agrin-mediated receptor clustering, although cytoskeletal elements and a dystrophin associated glycoprotein complex (DGC) have been implicated. Because agrin binds to alpha-dystroglycan, a member of the DGC, and the DGC is linked to actin through utrophin at postsynaptic sites, it has been suggested that binding of utrophin to the DGC plays a central role in agrin mediated receptor clustering. RESULTS: To test this hypothesis, we expressed at high levels the DGC binding domains of utrophin in cultured myotubes using recombinant Semliki Forest Virus. Myotubes expressing the utrophin and dystrophin DGC binding domain formed significantly fewer acetylcholine receptor clusters in response to agrin than myotubes expressing other proteins. CONCLUSIONS: These results suggest involvement of the DGC and utrophin in the signal transduction pathway of agrin-mediated acetylcholine receptor cluster formation or stabilization.

Agrin↗
PubMed1996

Processing of nux vomica. VII. Antinociceptive effects of crude alkaloids from the processed and unprocessed seeds of Strychnos nux-vomica in mice.

We examined the antinociceptive effects of the crude alkaloid fractions (CAF) of nux vomica (the dried seeds of Strychnos nux-vomica L.) and the influences of various processing methods upon their antinociception in three analgesic tests in mice. In the tail-pressure test, the CAF (0.01--1 micrograms/kg, i.p.) of nux vomica that was unprocessed or treated with sand-, licorice-, oil- or vinegar and sand-processing showed clear antinociception. The CAF (1 microgram/kg, i.p.) of vinegar-processed nux vomica showed antinociception, without effects at lower doses of 0.01 and 0.1 microgram/kg and those treated with urine- or urine and sand-processing were without effects at doses of 0.01--1 microgram/kg. Morphine (2 mg/kg, s.c.) showed short-lasting antinociception, without effects at a dose of 1 microgram/kg. In the hot-plate test, the CAF (100 microgram/kg, i.p.) of nux vomica having undergone sand-processing produced a significant antinociception, without effects at lower doses of 0.01 and 1 microgram/kg. The CAF (0.01--100 microgram/kg, i.p.) of nux vomica that was unprocessed or treated with oil- or vinegar and sand-processing and morphine (1 and 100 micrograms/kg, s.c.) were without effects. In the acetic acid-induced writhing test, the CAF (1 microgram/kg, i.p.) of nux vomica that was treated with sand-processing significantly inhibited the writhing behavior, while those of nux vomica that was unprocessed or treated with oil- or vinegar and sand-processing and morphine were without effects at a dose of 1 microgram/kg. The present results demonstrate the antinociceptive effects of the CAF of nux vomica and suggest that sand-processing is good for the analgesic potency of nux vomica. It is also suggested that the CAF of nux vomica has distinct antinociceptive potency, even after treatment with licorice-, oil-, vinegar and sand-processing.

Acetic Acid↗
PubMed1996

A purgative action of barbaloin is induced by Eubacterium sp. strain BAR, a human intestinal anaerobe, capable of transforming barbaloin to aloe-emodin anthrone.

Orally administered barbaloin (100 mg/kg) did not induce any diarrhea in male Wistar rats, in spite of severe diarrhea with sennoside B (40 mg/kg). Also, in gnotobiote rats mono-associated with Peptostreptococcus intermedius, a human intestinal anaerobe capable of reducing sennidins to rhein anthrone, barbaloin did not induce diarrhea; the faecal water content (71.9%) 8 h after the administration of barbaloin was not increased, compared with that (73.9%) just before the treatment. However, severe diarrhea was induced with barbaloin in gnotobiote rats mono-associated with Eubacterium sp. strain BAR, another human intestinal anaerobe capable of transforming barbaloin to aloe-emodin anthrone; the faecal water content was significantly increased to 85.5% 8 h after the administration, from 73.2% before the treatment. At this time, barbaloin was transformed to aloe-emodin anthrone in the feces from the gnotobiote rats mono-associated with the strain BAR, but not in feces from the conventional rats or the gnotobiote rats mono-associated with P. intermedius. These facts indicate that barbaloin is inactive as a laxative itself but is activated to aloe-emodin anthrone, a genuine purgative component, by Eubacterium sp. strain BAR.

Animals↗
PubMed1996

Four di-O-caffeoyl quinic acid derivatives from propolis. Potent hepatoprotective activity in experimental liver injury models.

The water extract of propolis (PWE) showed a strong hepatoprotective activity against CCl4-toxicity in rats and D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. The PWE also showed a significant hepatoprotective activity against CCl4-induced liver cell injury in cultured rat hepatocytes. The in vitro hepatoprotective activity guided fractionation and chemical analysis led to the isolation of four dicaffeoyl quinic acid derivatives from the PWE. The structure of these isolates was determined to be methyl 3,4-di-O-caffeoyl quinate (1), 3,4-di-O-caffeoyl quinic acid (2), methyl 4,5-di-O-caffeoyl quinate (3), and 3,5-di-O-caffeoyl quinic acid (4) by spectroscopic methods. These compounds were more potent hepatoprotective agents than glycyrrhizin at a concentration of 10 micrograms/ml and 1 was the most potent among the four compounds in the cultured hepatocytes. Quinic acid (5) alone did not show hepatoprotective effects in cultured rat hepatocytes against CCl4-toxicity. On the other hand, chlorogenic acid (6) or caffeic acid alone was found to be less potent than the dicaffeoyl quinic acid derivatives.

Animals↗
PubMed1996

18S ribosomal RNA gene sequences of three Panax species and the corresponding ginseng drugs.

Total DNA was extracted from the fresh underground parts of three Panax separate species. The 18S rRNA regions of extracted DNA were amplified by the polymerase chain reaction (PCR) and their sequences were determined. In each species, the sequences were found to be of 1809 base pairs (bps) but with different gene sequences. Different base substitutions were observed at nucleotide positions 497, 499, 501 and 712. The same procedure was performed on commercial samples of Ginseng Radix, Panacis Japonici Rhizoma and American Ginseng. Each sequence completely corresponded with that of each original plant, namely P. ginseng, P. japonicus and P. quinquefolius, respectively. This is the first time that 18S rRNA gene sequencing on Panax species was carried out. Previously, Ginseng drugs have been identified mainly by their external and internal structure. Thus this method will be useful in identifying Ginseng drugs at the gene level.

Base Sequence↗
PubMed1996

Antioxidative effects of phenylethanoids from Cistanche deserticola.

The acetone-H2O (9:1) extract from the stem of Cistanche deserticola showed a strong free radical scavenging activity. Nine major phenylethanoid compounds were isolated from this extract. They were identified by NMR as acteoside, isoacteoside, 2'-acetylacteoside, tubuloside B, echinacoside, tubuloside A, syringalide A 3'-alpha-rhamnopyranoside, cistanoside A and cistanoside F. All of these compounds showed stronger free radical scavenging activities than alpha-tocopherol on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine/xanthine oxidase (XOD) generated superoxide anion radical (O2-.). Among the nine compounds, isoacteoside and tubuloside B, whose caffeoyl moiety is at 6'-position of the glucose, showed an inhibitory effect on XOD. We further studied the effects of these phenylethanoids on the lipid peroxidation in rat liver microsomes induced by enzymatic and non-enzymatic methods. As expected, each of them exhibited significant inhibition on both ascorbic acid/Fe2+ and ADP/NADPH/Fe3+ induced lipid peroxidation in rat liver microsomes, which were more potent than alpha-tocopherol of caffeic acid. The antioxidative effect was found to be potentiated by an increase in the number of phenolic hydroxyl groups in the molecule.

Animals↗