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Biomedical subjects

S Kadota

Publications and source records attributed to S Kadota.

At least 109 records · Page 6Linked to original sources
PubMed1995

Bellidifolin stimulates glucose uptake in rat 1 fibroblasts and ameliorates hyperglycemia in streptozotocin (STZ)-induced diabetic rats.

Bellidifolin, isolated from Swertia japonica, was found to be a potent hypoglycemic agent in STZ-induced diabetic rats by both oral and intraperitoneal administration. Bellidifolin significantly lowered the loaded glucose level in normal as well as diabetic rats. Bellidifolin also lowered blood triglyceride levels significantly. It stimulated glucose uptake activity in Rat 1 fibroblasts expressing human insulin receptors.

Animals↗
PubMed1995

Potent inhibitors of tyrosinase activity and melanin biosynthesis from Rheum officinale.

Thirty-three crude drug extracts were screened for their tyrosinase inhibitory activity. Among them, the acetone extract of the rhizomes of Rheum officinale Baillon showed the strongest inhibitory activity. Tyrosinase inhibitory activity-guided fractionation and chemical analysis led to the isolation of two potent compounds, 3,4',5-trihydroxystilbene-4'-O-beta-D-(2"-O-galloyl)glucopyr anoside (1) and 3,4',5-trihydroxystilbene-4'-O-beta-D-(6"-O-galloyl)glucopyr anoside (2). These compounds showed a competitive inhibition against tyrosinase and also inhibited the melanin biosynthesis.

Enzyme Inhibitors↗
PubMed1995

Five new C-methyl flavonoids, the potent aldose reductase inhibitors from Matteuccia orientalis Trev.

Five new compounds, matteuorien, matteuorienin, and matteuorienate A (7), B (8), and C (9) were isolated together with five known compounds from the MeOH extract of the rhizome of Matteuccia orientalis Trev. The structures of these compounds were determined by the use of spectroscopic methods including two dimensional (2D)-NMR experiments and chemical methods, except for the configuration at the C-3"' of matteuorienate A (7), B (8), and C (9). Among them, matteuorienate A, B, and C showed very strong aldose reductase inhibitory activity. A structure-activity relationship study showed that a carboxyl group played an important part in aldose reductase inhibitory activity in these three compounds.

Aldehyde Reductase↗
PubMed1995

Inhibitory effects of Egyptian folk medicines on human immunodeficiency virus (HIV) reverse transcriptase.

Extracts of 41 medicinal plants used in Egyptian folk medicine were screened for their inhibitory effects on human immunodeficiency virus-1 reverse transcriptase. The extracts of fruits of Phyllanthus emblica, Quercus pedunculata, Rumex cyprius, Terminalia bellerica, Terminalia chebula and Terminalia horrida showed significant inhibitory activity with IC50 < or = 50 micrograms/ml. Through a bioassay guided-fractionation of the methanol extract of the fruit of P. emblica, putranjivain A (1) was isolated as a potent inhibitory substance with IC50 = 3.9 microM, together with 1,6-di-O-galloyl-beta-D-glucose (2), 1-O-galloyl-beta-D-glucose (3), kaempferol-3-O-beta-D-glucoside (4), quercetin-3-O-beta-D-glucoside (5) and digallic acid (6). The inhibitory mode of action by 1, 2 and 6 was non-competitive with respect to the substrate but competitive with respect to a template-primer. Furthermore, the stereochemistry of 1 was established in this paper by nuclear magnetic resonance spectroscopy.

Carbohydrate Conformation↗
PubMed1995

[Study on baths with crude drug. II.: the effects of coptidis rhizoma extracts as skin permeation enhancer].

Skin permeation and its enhancing activity of Coptidis Rhizoma (Coptis japonica Makino) were studied in regard to its application as a bath agent. As a result, methanol extracts and three alkaloids (berberine, coptisine, and palmatine isolated from Coptidis Rhizoma) enhanced effectively the skin permeation of 5-fluorouracil, which is taken as a hydrophilic permeant. Furthermore, it was observed that diffusion coefficient is almost constant on the skin permeation of 5-fluorouracil and was also observed that these three kinds of alkaloids did not penetrate through the skin, but adsorbed into the skin. These results suggest that these three protoberberine type alkaloids increase the concentration of polar drugs in the skin and enhance the skin permeation similarly to surfactants.

Animals↗
PubMed1994

Bellidifolin: a potent hypoglycemic agent in streptozotocin (STZ)-induced diabetic rats from Swertia japonica.

Hypoglycemic activity-guided fractionation led to the isolation of five known xanthones and two triterpenoids from the ethyl acetate soluble fraction of Swertia japonica and their identification was based on spectroscopic methods. One of the triterpenes, thysanolactone, was first isolated from this plant. Among the xanthones, bellidifolin showed a potent and dose-dependent hypoglycemic activity in STZ-induced diabetic rats both in i.p. and p.o. administration. A comparative hypoglycemic activity of the other three xanthones together with bellidifolin was also studied.

Animals↗
PubMed1994

Enzymatic sulfation of glycosides and their corresponding aglycones by arylsulfate sulfotransferase from a human intestinal bacterium.

A novel type of arylsulfate sulfotransferase (ASST) from a predominant human intestinal bacterium catalyzes the stoichiometric transfer of a sulfate group from phenolic sulfate esters to phenols. We clarified that polyphenols were better substrates of this enzyme than the corresponding glycosides. Additionally, a coumarin derivative, esculetin, was sulfated by ASST at the 6-position to give 6-monosulfate. Therefore, ASST is more useful for the preparation of sulfated polyphenols at their specific hydroxyl groups and would play an important role in the metabolism of phenolic compounds in vegetable food and traditional medicines.

Arylsulfotransferase↗
PubMed1994

Matteuorienate A and B, two new and potent aldose reductase inhibitors from Matteuccia orientalis (Hook.) Trev.

Matteuorienate A and B, two new C-methyl flavanone derivatives, were isolated from the Matteuccia orientalis (Hook.) Trev. (Aspidiaceae), and their structures were determined by the use of spectroscopic methods including 2D-NMR (1H-1H COSY, 1H-13C COSY and 1H-13C long-range COSY) experiments and chemical methods. Both the compounds were found to be very strong inhibitors of aldose reductase among the natural products.

Aldehyde Reductase↗
PubMed1993

Antiviral traditional medicines against herpes simplex virus (HSV-1), poliovirus, and measles virus in vitro and their therapeutic efficacies for HSV-1 infection in mice.

One hundred forty-two kinds of traditional medicines, which have been historically used in China, Indonesia, and Japan, were examined for the antiviral activity of their hot water (HW) extracts against herpes simplex virus type 1 (HSV-1), poliovirus type 1, and measles virus by plaque reduction assay. Thirty-two, 55, and 30 HW-extracts of them showed anti-HSV-1, antipoliovirus, and anti-measles virus activities, respectively. Among the 32 HW-extracts with anti-HSV-1 activity, 3 HW-extracts had anti-HSV-1 activity alone and the others showed anti-HSV-1 activity with anti-poliovirus and/or anti-measles virus activities. The 32 HW-extracts were further examined for their therapeutic efficacies of HSV-1 infection in mice. The mice were infected cutaneously with HSV-1 and HW-extracts were orally administered three times daily. Twelve HW-extracts, currently used for the treatment of various diseases other than viral infection, were found to be significantly effective in limiting the development of skin lesions and/or in prolonging the mean survival times of HSV-1-infected mice. These results suggested that 12 of 142 HW-extracts that exhibited therapeutic efficacy in an animal infection model were possible candidates for anti-HSV-1 traditional medicine.

Animals↗
PubMed1993

Inhibitory effect of the water extract of spikes of Miscanthus sinensis on IgE formation in mice.

The effects of four different plant extracts of the spikes of Miscanthus sinensis, Phragmites communis, and Imperata cylindrica var. major, and of the spikelets of Coix lachryma-jobi on IgE antibody formation were investigated in mice. The IgE antibody titer was tested by the passive cutaneous anaphylaxis (PCA) method in rats. Of these, the water extract of M. sinensis showed an appreciable inhibitory effect on IgE formation. Furthermore, an undialyzable fraction of the water extract with a relative molecular mass of more than 50,000 d, designated as MSIS, showed the most potent inhibitory activity on IgE formation. MSIS was also a potent inhibitor of IgE formation when given intraperitoneally or intranasally to mice the day before injection of dinitrophenyl (DNP)-ovalbumin (OVA) antigen in both the primary and secondary immune responses. Moreover, MSIS clearly suppressed on-going IgE antibody formation in both primary and secondary immune responses.

Animals↗
PubMed1993

Two new 2-arylbenzofuran derivatives from hypoglycemic activity-bearing fractions of Morus insignis.

Ethyl acetate- and n-butanol-soluble fractions of the leaves of Morus insignis showed a significant hypoglycemic activity on streptozotocin (STZ)-induced hyperglycemic rats. From these hypoglycemic activity-showing fractions, two new compounds, mulberrofuran U (2) and moracin M-3-O-beta-D-glucopyranoside (3) were isolated, along with six known compounds [beta-sitosterol, beta-sitosterol-3-O-beta-glucopyranoside, ursolic acid, moracin M (1), kaempferol-3-O-beta-glucopyranoside and quercetin-3-O-beta-glucopyranoside] and the structures of the new compounds were determined by spectroscopic and chemical methods.

Animals↗
PubMed1993

2'-Hydroxymatteucinol, a new C-methyl flavanone derivative from Matteccia orientalis; potent hypoglycemic activity in streptozotocin (STZ)-induced diabetic rat.

The CHCl3 extract of Matteccia orientalis showed very strong hypoglycemic activity in streptozotocin (STZ)-induced diabetic rats. A new C-methyl flavanone derivative, 2'-hydroxymatteucinol (3) was isolated from the hypoglycemic activity bearing fraction, along with two known compounds, demethoxymatteucinol (1) and matteucinol (2). The structures of these isolated compounds were elucidated by spectroscopic methods. One of the compounds isolated from CHCl3 extract, 2'-hydroxymatteucinol (3), showed dose-dependent hypoglycemic activity, and a blood sugar lowering effect was observed even at the dose of 10 mg/kg (p.o.) in STZ-induced diabetic rats.

Animals↗
PubMed1993

Two new quinochalcone yellow pigments from Carthamus tinctorius and Ca2+ antagonistic activity of tinctormine.

Two new quinochalcone C-glycosides, hydroxysafflor yellow A (1a) and tinctormine (2a), were isolated from Carthamus tinctorius L. (Compositae) together with carthamin, safflor yellow B and safflomin C. The structures of 1a and 2a have been determined by spectroscopic methods including heteronuclear multiple-bond multiple-quantum coherence and linked scan FAB-MS. The latter compound (2a) was demonstrated to have potent Ca2+ antagonistic action.

Animals↗
PubMed1993

Isolation and structure of woodorien, a new glucoside having antiviral activity, from Woodwardia orientalis.

Hot aqueous and methanol extracts of the rhizomes of Woodwardia orientalis were tested for their in vitro antiviral activity against herpes simplex virus type 1 (HSV-1), poliovirus type 1, and measles virus by plaque reduction assay. The aqueous extract of W. orientalis reduced the plaque forming ability of HSV-1 and poliovirus more strongly than did the methanol extract. By bioassay-directed fractionation of the aqueous extract, a new glucoside, woodorien (1), along with five known compounds were isolated from an EtOAc-soluble fraction that had antiviral activity. The structures of these compounds were determined by the use of two dimensional (2D) NMR techniques (1H-1H correlation spectroscopy (COSY), 1H-13C COSY and heteronuclear multiple-bond multiple-quantum coherence (HMBC)). Woodorien (1) was the most potent inhibitor against HSV-1 among the isolated compounds.

Animals↗
PubMed1993

Palbinone, a novel terpenoid from Paeonia albiflora; potent inhibitory activity on 3 alpha-hydroxysteroid dehydrogenase.

Palbinone, a novel terpenoid isolated from the roots of Paeonia albiflora, showed a strong inhibitory activity on the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH)-linked 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) of rat liver cytosol. The structures of palbinone and a known compound, paeonilactone-B isolated from the active fraction of this plant were determined by the use of 2D NMR techniques (1H-1H COSY, 1H-13C COSY, 1H-13C long-range COSY, and HMBC).

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1992

Woodfruticosin (woodfordin C), a new inhibitor of DNA topoisomerase II. Experimental antitumor activity.

Woodfruticosin (woodfordin C) (WFC), a new inhibitor of DNA topoisomerase II (topo-II), was isolated from methanol extract of Woodfordia fruticosa Kurz (Lythraceae) and studied for in vitro and in vivo antitumor activities in comparison with Adriamycin (ADR) and etoposide (ETP), well known inhibitors of topo-II. The inhibitory activity against DNA topo-II shown by WFC was much stronger than that shown by ETP or ADR. WFC inhibited strongly intracellular DNA synthesis but not RNA and protein synthesis. On the other hand, WFC had a weaker growth inhibitory activity against various human tumor cells than ETP or ADR, but it showed remarkable activity against PC-1 cells and moderate activity against MKN45 and KB cells. Furthermore, WFC had in vivo growth inhibitory activity against s.c. inoculated colon38. These results indicate that the mechanism by which WFC exhibits antitumor activity may be through inhibition of topo-II.

Animals↗