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Biomedical subjects

R Kasai

Publications and source records attributed to R Kasai.

At least 37 records · Page 2Linked to original sources
PubMed2000

Suppressive effects of vietnamese ginseng saponin and its major component majonoside-R2 on psychological stress-induced enhancement of lipid peroxidation in the mouse brain.

We investigated the in vivo effects of Vietnamese ginseng saponin (VG saponin) and its major component majonoside-R2 (MR2) on psychological stress-induced enhancement of lipid peroxidation in the mouse brain. Psychological stress exposure using a communication box system for 4 h significantly increased the content of thiobarbituric acid reactive substance (TBARS), an index of lipid peroxidation activity, in the brain. Pretreatment with VG saponin (15-25 mg/kg, PO) and MR2 (1-10 mg/kg, IP) significantly attenuated the psychological stress-induced increase in TBARS content in the brain. The aglycone of MR2 (MR2-aglycone: 1.2 mg/kg, IP), at the equivalent dose of MR2 (i.e., 3 mg/kg, IP), also produced the suppressive effect on the increase in the TBARS content. The in vivo suppressive effect of MR2 was dose dependently attenuated by flumazenil (3 and 10 mg/kg, IP), a benzodiazepine receptor antagonist, and pregnenolone sulfate (10 mg/kg, IP), a neurosteroidal negative allosteric modulator of GABA(A) receptors. These findings suggest that VG saponin and its major component MR2 have preventive effects on the psychological stress-induced brain cell membrane damage, and that the effect of MR2 is partly due to enhancement of GABA(A)-ergic systems in the brain.

Animals↗
PubMed2000

Antiyeast steroidal saponins from Yucca schidigera (Mohave yucca), a new anti-food-deteriorating agent.

A saponin fraction from the stems of Yucca schidigera (Mohave yucca) exhibited potent growth-inhibitory activities against certain food-deteriorating yeasts, film-forming yeasts, and dermatophytic yeasts and fungi. From this fraction, a number of new anti-yeast monodesmosidic spirostanol saponins, named schidigera-saponins A1 (1), A2 (2), A3 (3), B1 (4), C1 (5),C2 (6); 25(R and S) schidigera-saponins D1 (7), D2 (8), E1 (12), F1 (13); and 25(S) schidigera-saponins D3 (9), D4 (10), D5 (11), and F2 (14) were isolated, together with several related known saponins, and the structures were elucidated by spectroscopic methods (see Chart 1). The relationship between the antiyeast activities and the structures of these saponins is described.

Animals↗
PubMed2000

Triterpenoidal saponins from Cornulaca monacantha.

From the aerial parts of Cornulaca monacantha, three new triterpenoidal saponins have been isolated and their genuine structures were identified as 3-O-[beta-xylopyranosyl-(1-->3)-beta- glucuronopyranosyl]-30-methylphytolaccagenate (2), 3-O-[beta-xylopyranosyl- (1-->3)-beta-glucuronopyranosyl]-30-methylphytolaccagenate 28-O-beta-gluco-pyranoside (3) and 3-O-[beta-xylopyranosyl-(1-->3)-beta- glucurono-pyranosyl]-30-methylserjanate 28-O-beta glucopyranoside (4) together with nine known saponins of oleanolic acid (5-9), hederagenin (1, 10, 11) and 30-methyl phytolaccagenate (12).

Egypt↗
PubMed1999

Cancer chemopreventive activity of majonoside-R2 from Vietnamese ginseng, Panax vietnamensis.

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Panax plants were screened. Consequently, the ocotillol-type saponin, majonoside-R2 (MR2), was obtained from the rhizome and root of Panax vietnamensis (Vietnamese ginseng) as an active constituent. MR2 exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse hepatic tumor using N-nitrosodiethylamine (DEN) as an initiator and phenobarbital (PB) as a promoter. Further, MR2 exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin induced by nitric oxide (NO) donor/12-O-tetradecanoylphorbol-13-acetate (TPA) or peroxynitrite/TPA.

Alkylating Agents↗
PubMed1999

Expression of the c-fos gene induced by parathyroid hormone in the bones of SAMP6 mice, a murine model for senile osteoporosis.

SAMP6 mice are a murine model for senile osteoporosis, characterized by low peak bone mass seen at 4 or 5 months of age. Parathyroid hormone (PTH)-induced c-fos expression was examined in the bones, bone-marrow cells and kidney tissues of 2-month-old male SAMP6 mice. SAMP2 mice, which have a higher peak bone mass, were used as controls. The expression of c-fos in the bone peaked at 30 min after 60 microg/kg of human PTH(1-34) administration. After peaking, the expression fell quickly in SAMP2 mice. This decrease in expression was delayed in SAMP6 mice and the expression was higher at 1 h than in SAMP2 mice. The phenomenon observed in the bone appears to be tissue specific as it was not seen in the bone-marrow cells or kidney tissue. Immunohistochemical studies showed that c-Fos protein was localized to the nuclei of some of the osteocytes and a few of the osteoblasts in the cortical bone, and that osteocytes expressing c-Fos protein increased after PTH treatment. These results suggest that osteocytes might contribute to the maintenance of higher levels of c-fos expression in the bones of SAMP6 mice and may be related to cortical osteopenia in these mice by modulating bone remodeling and/or modeling.

Animals↗
PubMed1998

Oleanane saponins from Polyscias fruticosa.

From the leaves and roots of Polyscias fruticosa, eight new oleanolic acid saponins named polysciosides A to H were isolated together with three known saponins. The structures of the saponins were established by means of spectral data, particularly NMR, which included COSY, HSQC, HMBC, HOHAHA and ROESY techniques.

Carbohydrate Sequence↗
PubMed1998

Anti-tumor-promoting activity of majonoside-R2 from Vietnamese ginseng, Panax vietnamensis Ha et Grushv. (I).

Seven saponins (1-7) isolated from the rhizomes and roots of Panax vietnamensis were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), in Raji cells as a primary screening test for anti-tumor-promoters (cancer chemopreventive agents). The ocotillol-type saponin, majonoside-R2 (2), which is the major and characteristic constituent of this plant, exhibited a significant inhibitory effect on EBV-EA activation. Furthermore, the cell cycle analysis of 2 on Raji cells was also examined and strong inhibition was observed on the effect of the cell cycle induced by TPA. Compound 2 showed potent anti-tumor-promoting activity in two-stage carcinogenesis tests of mouse skin using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA or fumonisin B1 as a promoter. Consequently, these results suggest that majonoside-R2 (2) could be a valuable chemopreventive agent against chemical carcinogenesis.

Animals↗
PubMed1998

In vitro antioxidant activity of Vietnamese ginseng saponin and its components.

To elucidate the antioxidant action of Vietnamese ginseng saponin against free radial-mediated cellular damage, we examined the effect of Vietnamese ginseng saponin on lipid peroxidation in the mouse brain, liver, and liver microsomes by using two in vitro free radical generating systems (iron ferrous+ascorbic acid and iron ferrous+hydrogen peroxide). Free radical-mediated lipid peroxidation was determined by measuring the endogenous and stimulated accumulation of thiobarbituric acid reactive substance (TBA-RS). Vietnamese ginseng saponin (0.05-0.5 mg/ml), as well as vitamin E, significantly inhibited the formation of TBA-RS in tissue homogenates. Panax ginseng saponin, at the same concentration range as Vietnamese ginseng saponin, also had inhibitory action on free radical-mediated lipid peroxidation. However, majonoside-R2, ginsenoside-Rg1 and ginsenoside-Rb1, the main saponin components of Vietnamese ginseng saponin fraction, had no effect on lipid peroxidation. These results suggest that Vietnamese ginseng exerts a protective action against free radical-induced tissue injury and that this effect is attributable to minor components rather than the main saponin components tested.

Animals↗
PubMed1998

A-W glass ceramic as a bone substitute in cemented hip arthroplasty: 15 hips followed 2-10 years.

We retrospectively reviewed hip arthroplasties in 13 patients (15 hips), in whom we had used apatite-wollastonite (A-W) glass ceramic together with auto- or allograft for augmentation of severe bone deficiency. 11 cemented sockets and 4 stem revisions were included and followed for 2-9.6 years. There were no radiolucent lines between A-W glass ceramic and surrounding bone, and remodeling of the bone graft containing A-W glass ceramic was observed. No migration of cemented sockets was seen except in 1 case, which was revised. In this case, direct bonding between bone and A-W glass ceramic granules was present histologically. In 4 stem revisions, 5 mm subsidence occurred in 1 case. However, the stem became stable and remodeling of the grafted bone occurred. An artificial bone material, such as A-W glass ceramic, can be used under high-load conditions, because of its good mechanical properties.

Adult↗
PubMed1997

Cucurbitane-type compounds from Hemsleya carnosiflora antagonize ecdysteroid action in the Drosophila melanogaster BII cell line.

The ecdysteroid agonist and antagonist activities of 3 cucurbitanes, 2 cucurbitane glycosides and 2 cucurbitacins isolated from Hemsleya carnosiflora (Cucurbitaceae) have been determined in the Drosophila melanogaster BII bioassay. Carnosiflogenins A and C and carnosiflosides II and VI possess antagonistic activity. Carnosiflogenin A was also found to induce the formation of spindle-shaped cells with high frequency in both the agonist and antagonist assays. At 10(-3) M, carnosiflogenins B and C were cytotoxic, 23,24-Dihydrocucurbitacin F and 25-acetoxy-23,24-dihydrocucurbitacin F are also antagonistic at high concentrations. The concentration dependencies of the antagonistic activities of these two cucurbitacins, carnosiflosides II and VI and carnosiflogenin C are presented. The biological and ecological significance of these results are discussed in relationship to the concentrations present in the rhizomes of H. carnosiflora.

Animals↗
PubMed1997

Synovial fluids from patients with osteoarthritis and rheumatoid arthritis contain high levels of parathyroid hormone-related peptide.

High levels of immunoreactive and biologically active parathyroid hormone-related peptide (PTHrP) were detected in synovial fluids from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). The levels of PTHrP immunoreactivity in synovial fluids, measured by a two-site immunoradiometric assay (IRMA) which detects hPTHrP(1-72) or longer peptides and a radioimmunoassay (RIA) specific to the carboxy-terminal portion of hPTHrP, were 3.2 +/- 0.3 pmol of hPTHrP(1-86)/l and 61 +/- 7.0 pmol of hPTHrP(109-141)/l in OA patients (mean +/- SE, n = 23), and 4.8 +/- 0.8 pmol of hPTHrP(1-86)/l and 164 +/- 30 pmol of hPTHrP(109-141)/l in RA patients (n = 26). Synovial fluid PTHrP levels distributed above the normal plasma reference ranges in each assay (0.7-2.6 pmol of hPTHrP(1-86)/l; 16-60.6 pmol of hPTHrP(109-141)/l). After concentration using sequential cation-exchange and reverse-phase chromatography, synovial fluid exhibited the activity that stimulated cyclic adenosine monophosphate (cAMP) accumulation in osteoblastic ROS 17/2.8 cells expressing PTH/PTHrP receptors. The cAMP accumulation activity in synovial fluid was sensitive to coincubation with excess hPTHrP(3-40), a PTH/PTHrP receptor antagonist, and was completely neutralized by preincubation with a monoclonal antibody specific to hPTHrP but not PTH. Immunohistochemical analysis of RA synovium revealed that PTHrP was localized in fibroblast-like cells in the synovial pannus invading articular cartilage. Our data show that PTHrP is produced locally by the diseased synovial tissue and released into synovial fluid at high concentrations, allowing us to hypothesize that PTHrP plays a novel role as a paracrine/autocrine factor in the pathology of OA and RA.

Aged↗
PubMed1996

1 alpha,25-dihydroxyvitamin D3 inhibits cell growth and chondrogenesis of a clonal mouse EC cell line, ATDC5.

Here we report the effects of 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] in vitro on the growth and chondrogenesis of a chondroprogenitor-like clonal mouse EC cell line, 10(-10) to 10(-7) M ATDC5. 1,25(OH)2D3 inhibited [3H]thymidine incorporation in undifferentiated chondroprogenitor-like ATDC5 cells in time- and dose-dependent manners. 1,25(OH)2D3 suppressed cartilage-nodule formation and the accumulation of cartilage-specific proteoglycan in ATDC5 cells in a dose-dependent manner. The 1,25(OH)2D3-induced inhibition of cartilage-nodule formation was reversible and direct, unrelated to the antiproliferative action of the hormone on the undifferentiated ATDC5 cells. ATDC5 cells even in the precartilaginous stage expressed 4.4 kb vitamin D receptor (VDR) mRNA as assessed by northern blot analysis. The equilibrium saturation binding experiment revealed the presence of a single class of saturable and high-affinity binding sites for 1,25(OH)2D3 in the cytosols. These results provide evidence for the hypothesis that both recruitment and chondrogenesis of chondroprogenitors are negatively regulated by 1,25(OH)2D3 via a VDR-mediated process in vivo.

Animals↗
PubMed1996

Furanoid diterpene glucosides from Tinospora rumphii.

The stems of Tinospora rumphii yielded clerodane type furanoid diterpene glucosides: the new rumphioside I, the known borapetosides C and F and three other compounds. Their structures were established on the basis of various spectroscopic techniques. The three compounds have physical and spectral data identical to those of the reported compounds borapetosides E, D and B, respectively. However, the positions of the lactone rings of the first two compounds and the configuration of the bond attaching the glucose moiety to C-6 of the third differ from the reported ones.

Diterpenes↗
PubMed1996

Steroidal saponins from fruits of Tribulus terrestris.

Further studies on the constituents of the fruits of Tribulus terrestris led to the isolation of five new steroidal saponins (terrestrosin A-E), (25R,S)-5 alpha-spirostan-3 beta-ol-3 -O-beta-D-galactopyranosyl(1-2)-beta-D- glucopyranosyl(1-4)-beta-D-galactopyranoside, (25R,S)-5 alpha-spirostan-3 beta-ol-3-O-beta-D-glucopyranosyl(1-4)-[alpha-L- rhamnopyranosyl(1-2)]-beta-D-galactopyranoside, (25R,S)-5 alpha-spirostan-12-on-3 beta-ol-3-O-beta-D-galactopyranosyl (1-2)-beta-D-glucopyranosyl(1-4)-beta-D-galactopyranoside, hecogenin 3-O-beta-D-galactopyranosyl)1-2)-[beta-D- xylopyranosyl(1-3)]-beta-D-glucopyranosyl(1-4)-beta-D-galactopyranoside and (25R,S)-5 alpha-spirostane-2 alpha, 3 beta-diol-3- O-beta-D-galactopyranosyl(1-2)-beta-D-glucopyranosyl(1-4)-beta-D- galactopyranoside, together with five known steroidal saponins, desgalactotigonin, F-gitonin, desglucolanatigonin, gitonin and tigogenin 3-O-beta-D- xylopyranosyl)1-2)-[beta-D-xylopyranosyl)1-3)]-beta-D-glucopyranosyl)1-4 )- [alpha-L-rhamnopyranosyl(1-2)]-beta-D-galactopyranoside. The structures of the new saponins were elucidated on the basis of spectroscopic analyses, including two-dimensional NMR techniques, and chemical reactions.

Chromatography, High Pressure Liquid↗
PubMed1996

Taste-modifying triterpene glycosides from Staurogyne merguensis.

Five new oleanane-type triterpene glycosides named strogins 1-5 were isolated from leaves of Staurogyne merguensis. Their structures were determined on the basis of chemical and spectral evidence. After strogins 1, 2 and 4 were held in mouth, water elicited a sweet taste. On the other hand, strogins 3 and 5 had no activity. The structure-activity relationship is discussed.

Glycosides↗
PubMed1996

Triterpenoid saponins from Bellis sylvestris. 2. Structures of partially deacylated saponins.

Four saponins have been isolated from the herbal parts of Bellis sylvestris and the same, together with three further compounds, from the underground parts. The structures were elucidated by electrospray ionization mass spectrometry, including tandem mass spectrometry, and by 1D and 2D homonuclear and heteronuclear NMR spectroscopy. Two of the compounds are new saponins with the structures 3-O-beta-D-glucopyranosyl-2 beta, 3 beta, 23-trihydroxyolean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl (1-->3)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D- glucopyranoside and 3-O-beta-D-glucopyranosyl-2 beta, 3 beta,16 alpha, 23-tetrahydroxyolean-12-en- 28-oic acid 28-O-alpha-L-rhamnopyranosyl (1-->3)-beta-D-xylopyranosyl(1-->4)-alpha-L- rhamnopyranosyl(1-->2)-[(E)-2-butenoic acid (1-->3)]-beta-D-fucopyranoside. Taxonomically these data provide significant evidence of a link between the Bellis genus and Bellium bellidioides.

Carbohydrate Sequence↗