Roots Of Bupleurum Falcatum Research Articles

Pharmacologically Active Saikosaponin in Bupleurum falcatum Detected by Competitive ELISA and Eastern Blotting Using Monoclonal Antibodies

This study showed the effective microanalytic methods for detection of saikosaponin by a competitive enzyme-linked immunosorbent assay (ELISA) using anti-saikosaponin a (SSa) monoclonal antibody (MAb). The results showed that the competitive ELISA had higher sensitivity than high performance liquid chromatography (HPLC) for the detection of saikosaponin. ELISA showed a highly significant difference in SSa concentrations between the roots of Bupleurum falcatum with different origins. In addition, a difference in SSa concentrations was observed between cytologically different cultivars originating from Japan (2n = 26) and Korea (2n = 20). It also showed excellent performance in quantitative analysis of SSa in the small samples from regenerated plantlets and calli. In addition, Eastern blotting using anti-SSa MAb 3G10 multispecific to saikosaponins was applied to analyze the distribution of saikosaponins in Bupleurum falcatum roots and leaves. The localized distribution of saikosaponins in whole leaves and cork layer of the roots in B. falcatum was successfully demonstrated by this novel immunoassay.

Upregulation of Isoprenoid Pathway Genes During Enhanced Saikosaponin Biosynthesis in the Hairy Roots of Bupleurum falcatum

Upregulation of Isoprenoid Pathway Genes During Enhanced Saikosaponin Biosynthesis in the Hairy Roots of Bupleurum falcatum

The presence of natural human antibodies reactive against pharmacologically active pectic polysaccharides from herbal medicines

Direct ELISA was performed using normal human sera and human colostrum, to analyse the presence of antibodies which react with pharmacologically active pectic polysaccharides isolated from plants used in traditional Japanese herbal (Kampo) medicine. All sera and colostrum were shown to contain IgM, IgG, IgA and secretory IgA class antibodies which react with the active pectic polysaccharides to different degrees. The reacting IgG antibody in normal human serum recognized the ramified regions (rhamnogalacturonan core with carbohydrate side-chains) of the pharmacologically active pectic polysaccharides as the active sites for complement-activating activity. Correlation analysis indicated that a significant and positive correlation was observed between reactivity with the reacting antibody of IgG class and the degree of complement-activating activity of the active polysaccharides. The reacting IgG class antibody, which was purified from normal human serum by affinity chromatography on bupleuran 2IIc (a pharmacologically active pectic polysaccharide from the roots of Bupleurum falcatum)-immobilized Sepharose, showed cross-reactivity not only with some other pharmacologically active pectic polysaccharides from other medicinal herbs but also with autoantigens such as single-strand DNA, myosin and tublin from mammals.

A possible signal transduction pathway for cyclin D2 expression by a pectic polysaccharide from the roots of Bupleurum falcatum L. in murine B cell

Bupleuran 2IIc, a pectic polysaccharide isolated from the roots of Bupleurum falcatum L., was previously characterized as a T-cell-independent B cell mitogen. This study focuses on elucidating the mechanism by which bupleuran 2IIc induces cyclin D2 production for inducing mitogenesis in murine B cells. Bupleuran 2IIc was digested with endo-α-(1→4)- d-polygalacturonase and the resulting bupleuran 2IIc/PG-1 (“ramified” region) strongly stimulated cyclin D2 expression. When murine B cells were stimulated with bupleuran 2IIc/PG-1, phosphorylation of tyrosine residues of a number of proteins was observed. Cyclin D2 expression by bupleuran 2IIc/PG-1 was inhibited by the tyrosine kinase inhibitors, genistein and herbimycin A, and the Src family tyrosine kinase inhibitor, PP2, suggesting a possible role for tyrosine kinases. The stimulation by bupleuran 2IIc/PG-1 of cyclin D2 expression was significantly decreased by inhibitors, PI 3-kinase (LY294002 and Wortmannin), PLCγ (U73122), PKC (H-7), receptor-operated calcium entry inhibitor (SK&F 96365), and calcineurin (FK506). Both PD98059 and U0126, highly selective inhibitors of MEK1 and MEK1/2, respectively, did not strongly suppress the expression of cyclin D2 after stimulation by bupleuran 2IIc/PG-1. The results suggest that (1) bupleuran 2IIc/PG-1 is the active site for induction of cyclin D2 by bupleuran 2IIc, (2) the expression of the cyclin D2 gene by bupleuran 2IIc/PG-1 may be mediated via the activation of PI 3-kinase and PLCγ followed by activation of PKC and calcium mobilization, and (3) the ERK1/2 cascade is not a central signaling pathway for bupleuran 2IIc/PG-1-induced cyclin D2 expression.

Induction of cell cycle regulatory proteins by murine B cell proliferating pectic polysaccharide from the roots of Bupleurum falcatum L

Bupleuran 2IIc, a pectic polysaccharide isolated from the roots of Bupleurum falcatum L., was characterized as a T-cell-independent B cell mitogen, that activates, proliferates and differentiates B cells in vivo and in vitro (Immunology 97 (1999) 540). Studies were focused on elucidating the mechanism by which bupleuran 2IIc causes proliferation of B cells and expression of cell cycle regulatory proteins. B cells showed slower rates of entry into the S and G2/M phases of the cell cycle when stimulated with bupleuran 2IIc versus anti-IgM. However, the Stimulation Index continued up to two times longer with bupleuran 2IIc over anti-IgM. Although both bupleuran 2IIc and anti-IgM induced similar expressions of cell cycle regulatory proteins, cyclins D2, A, and B1, in B cells, those cells stimulated with bupleuran 2IIc appeared to sustain expressions of these protein for longer periods of time. Stimulation of B cells with bupleuran 2IIc induced phosphorylation of retinoblastoma protein, pRB, an important gene product regulating the restriction point, R, which is responsible for the transition from the G0/G1 to the S phases of the cell cycle. The results of this study demonstrate that both bupleuran 2IIc and anti-IgM interact with B cells, thus, leading to expressions of cell cycle regulatory proteins. However, the respective modes of binding and proximity of interactions with the B cell membrane may differ.

Effects of a pectic polysaccharide from a medicinal herb, the roots of Bupleurum falcatum L. on interleukin 6 production of murine B cells and B cell lines

The effect of T-cell-independent B cell mitogen, a pectic polysaccharide, bupleuran 2IIc, from a medicinal herb, the roots of Bupleurum falcatum L. on interleukin 6 (IL-6) production of murine B cells and B cell lines was investigated in order to clarify the mechanism of enhanced immunoglobulin (Ig) secretion from B cells. Bupleuran 2IIc enhanced IgM secretion from highly purified murine normal B cells. When normal B cells from murine spleen were cultured with bupleuran 2IIc in the presence of anti-IL-6 neutralizing antibody, the enhanced IgM secretion by bupleuran 2IIc was reduced. When B cells were stimulated with bupleuran 2IIc, their IL-6 secretion and the transcription of IL-6 mRNA were enhanced. The enhanced IL-6 secretion by bupleuran 2IIc was also observed in B cell line, Y16 cell. When bupleuran 2IIc was digested with endo-α-(1→4)-d-polygalacturonase, the resulting enzyme resistant carbohydrate portion, “ramified” region (PG-1) composed of rhamnogalacturonan core containing neutral sugar side chains showed potent IL-6 secretion-enhancing activity. These results suggest that the “ramified” region of bupleuran 2IIc stimulates the secretion of IL-6 as the active site, and the resulting IL-6 may partially contribute the enhancement of IgM secretion as an autocrine and/or paracrine mechanism.

B-cell proliferation activity of pectic polysaccharide from a medicinal herb, the roots of Bupleurum falcatum L. and its structural requirement.

Pectic polysaccharide fraction (BR-2) containing pharmacologically active pectic polysaccharide, bupleuran 2IIc, which was prepared from a medicinal herb, the roots of Bupleurum falcatum L., was administered orally to C3H/HeJ mice for 7 consecutive days. Proliferative responses of spleen cells were enhanced in the presence of the purified pectic polysaccharide, bupleuran 2IIc, but another B-cell mitogen, lipopolysaccharide (LPS) did not give a similar effect. In vitro studies using spleen cells showed that bupleuran 2IIc also stimulated lymphocytes, depleted of adherent cells or T cells. Bupleuran 2IIc treatment increased subpopulation of CD25+ and surface immunoglobulin M-positive (sIgM+) lymphocytes. Non-specific immunoglobulin secretion of spleen cells treated with bupleuran 2IIc was increased according to the culture time, and coexistence of interleukin-6 (IL-6) enhanced the secretion more than that of bupleuran 2IIc alone. These results suggest that bupleuran 2IIc proliferates B cells in the absence of macrophages, and the resulting activated B cells are then induced into antibody-forming cells in the presence of IL-6. Among the structural region of bupleuran 2IIc, ramified region (PG-1), which consists of rhamnogalacturonan core rich in neutral sugar chain, showed the potent mitogenic activity suggesting it to be an active site. Mitogenic activity of bupleuran 2IIc was reduced in the presence of antipolysaccharide antibody (antibupleuran 2IIc/PG-1-IgG), which recognizes the ramified region of bupleuran 2IIc as the antigenic epitope. Mitogenic activity of bupleuran 2IIc was also reduced by the addition of beta-d-GlcpA-(1-->6)-beta-d-Galp-(1-->6)-d-Galp or beta-d-GlcpA-(1-->6)-d-Galp, which are a part of the epitopes of antibupleuran 2IIc/PG-1-IgG. These results suggest that the epitopes in bupleuran 2IIc act as active sites of the polysaccharide during mitogenic activity.

Inhibitory effect of bupleuri radix saponins on adhesion of some solid tumor cells and relation to hemolytic action: screening of 232 herbal drugs for anti-cell adhesion.

Anti-cell adhesive activity and hemolytic action of herbal drugs were investigated. Among 232 herbal drugs tested, six showed a remarkable anti-cell adhesive activity, and the extract from the roots of Bupleurum falcatum (Umbelliferae), the semen of Psorala corylifolia (Leguminosae), and the semen of Areca catechu (Palmae) showed an anti-cell adhesive action at non-cytotoxic concentrations. Saikosaponins-a, d and e, isolated from the roots of Bupleurum falcatum, exhibited a potent anti-cell adhesive activity and a strong hemolytic action. In a structure-activity relationship for both activities, it seems that a sugar moiety and an ether linkage between C-13 and C-28 are required for good bioactivities. In addition, saikosaponin d with a beta-hydroxy group at C-16 was more potent than saikosaponin a possessing an alpha-hydroxy group. Taken together, it is suggested that the mechanism for anti-cell adhesive activity of saikosaponin may resemble that for their hemolytic action.

Detection and Tissue Distribution of Anti-Ulcer Pectic Polysaccharides fromBupleurum falcatumby a Polyclonal Antibody

Anti-sera against the "ramified" region (PG-1) of an anti-ulcer polysaccharide (bupleuran 2IIc), which was purified from the roots of Bupleurum falcatum L, were obtained by immunization of rabbits, and a polyclonal anti-bupleuran 2IIc/PG-1-antibody of the IgG class was purified by Protein G and "ramified" region (PG-1) immobilized affinity chromatographies. The antigenic specificity of anti-bupleuran 2IIc/PG-1-IgG was examined by a two-site sandwich ELISA which was developed as an improved method for microanalysis of bupleuran 2IIc using a biotinylated antibody. Another pectin from B. falcatum and anti-complementary pectins from Angelica acutilaba and Glycyrrhiza uralensis also showed significant reactivity to anti-bupleuran 2IIc/PG-1-IgG, although these reactivities were lower than that of bupleuran 2IIc. Other polysaccharides tested such as apple pectin, araban, yeast mannan, pullulan, etc., had negligible reactivity. The KDO-containing region and oligogalacturonides, which were obtained by endo-alpha-(1-->4)-polygalacturonase digestion of bupleuran 2IIc, were also not significantly recognized by anti-bupleuran 2IIc/PG-1-IgG. When bupleuran 2IIc was administered to the mice i.v., the polysaccharide disappeared from the circulation within 24 h and was mainly detected in the liver by the two-site sandwich ELISA. However the clearance of bupleuran 2IIc from the circulation was delayed by pretreatment with iota-carrageenan. When the crude polysaccharide fraction (BR-2), containing mainly bupleurans 2IIb and 2IIc from B.falcatum, was administrated orally to the mice, the polysaccharides were detected in the liver and Peyer's patch.

Saponins from the root of Bupleurum falcatum

Three new saponins and nine known saponins were isolated from the dried roots of Bupleurum falcatum. On the basis of chemical and spectral analyses, the structures of new compounds, named 4″- O-acetylsaikosaponin d and hydroxysaikosaponins a and c, were established. In aqueous acidic conditions, saikosaponins a and d were converted into not only known compounds, saikosaponins b 1 and b 2, but also hydroxysaikosaponins a and d, respectively. Furthermore, quantitative analysis of the decoction of Bupleuri Radix itself by HPLC exhibited that it contained saikosaponins a, c and d, and hydroxysaikosaponins a, c and d.

Structure and pharmacological activity of pectic polysaccharides from the roots of Bupleurum falcatum L

Several pharmacological activities have been observed in pectic polysaccharides which were isolated from Chinese herbs containing Kampo medicines. We found two different bioactive pectic polysaccharides, bupleuran 2IIb and 2IIc, from the roots of Bupleurum falcatum. These bioactive pectic polysaccharides were comprised of an alpha (1-->4) linked galacturonan region, a ramified region that consists of a rhamnogalacturonan core substituted neutral sugar chains as the side chains and a rhamnogalacturonan II (RG II)-like region containing unique sugars such as 3-deoxy-manno-2-octulosonic acid (KDO). In order to understand the pharmacological activity of pectic polysaccharides on the molecular level, we have elucidated the essential carbohydrate structure for the expression of each pharmacological activity and their mode of actions. The ramified region in bupleuran 2IIb induced Fc receptor up-regulation in macrophages by a mechanism dependent on an increase of intracellular Ca2+, followed by the enhancement of immune complex clearance, whereas bupleuran 2IIc, which mainly consists of a partially branched galacturonan region, showed potent anti-ulcer activity. The major mechanism of its mucosal protection was suggested to be due to anti-secretory activity on acid and pepsin, its ability to provide a protective coating and radical scavenging effect. The future problems were also discussed in order to develop pectic polysaccharides as medicines.

Production of medicinal plants by soilless culture system. I. Studies of morphological characteristics and saikosaponins content in Bupleurum falcatum cultivated by Ebb & Flood system

We studied that the morphological and histological characteristics, and the content (%DW) of saikosaponins on the root of Bupleurum falcatum cultivated in an Ebb & Flood system (E & F), a kind of soilless culture system, by both the direct sowing and the transplanting methods, and that effects of pinching on the root growth and the content (%DW) of saikosaponins in each part of root. Yield of root and content (%DW) of saikosaponins in each part of root, 8-months-old, cultivated in E & F by both methods were at the same level as that cultivated for the same period in soil condition by generally standard procedures. Morphological characteristics of the root cultivated by the direct sowing method were the same appearance as that by soil condition, but by the transplanting method main root branched off in all direction and the lateral root were more developed than by the direct sowing method. By pinching lignification in xylem on the main root were inhibited, but the dried weight of total root part and content (%DW) of saikosaponins in each part of the root were not shown to be significantly changed.

Characterization of the Immunoregulatory Action of Saikosaponin-d

The immunoregulatory action of saikosaponin-d (SSd), which was isolated from the root of Bupleurum falcatum L. and has a steroid-like structure, was examined on splenic T lymphocytes of C57BL/6 mice. SSd displayed a definite action in vitro to bidirectionally control the growth response of T lymphocytes stimulated by concanavalin A, anti-CD3 monoclonal antibody, and calcium ionophore A23187 plus phorbol 12-myristate 13-acetate. Low concentrations (I-3 μg/ml) of SSd upregulated the responses to suboptimum stimuli of agonists, particularly during the relatively late stage of the responses, whereas it downregulated the responses to supraoptimal stimuli. Under appropriate experimental conditions, SSd promoted interleukin-2 (IL-2) production and IL-2 receptor expression. It also accelerated c-fos gene transcription, but it did not modulate the level of tyrosine phosphorylation of cellular proteins. We concluded from these results that SSd uniquely modulates T lymphocyte function and that at least one target of the action of SSd is located at or before the step of c-fos gene transcription and after T-cell receptor/CD3-mediated protein tyrosine kinase activation.

Structural studies of endopolygalacturonase-resistant fragments of an antiulcer pectin from the roots of Bupleurum falcatum L.

The endoα-(1 → 4)-polygalacturonase-resistant fractions (PG-1, PG-2, and PG-3) from an antiulcer pectin (Bupleuran 2IIc), isolated from the roots of Bupleurum falcatum, L., were further analysed by lithium degradation. The results indicated that PG-1 contained a small proportion of long, branched arabinosyl chains and a large proportion of short, neutral oligosaccharide chains. GLC-MS analysis showed that, after methylation the short, neutral oligosaccharide fraction consisted of at least 22 kinds of di- to tetra-saccharide alditols, such as Gal-(1 → 4)-Rha-ol (a major component), Ara-(1 → 4)-Rha-ol, Glc-(1 → 4)-Rha-ol, Ara → Ara →a Ara-ol, and Ara → Ara → Ara → Ara-ol (minor components) in addition to heteroglycosyl alditols. After deesterification, PG-2 and PG-3 were digested with endo-α-(1 → 4)-polygalacturonase again, and the enzyme-resistant intermediate size fraction (PG-2′) was purified. Component sugar analysis indicated that PG-2′ contained 2-Me-Fuc, 2-Me-Xyl, apiose (Api), aceric acid (AceA), 3-deoxy- d- lyxo-heptulosaric acid (Dha), and 3-deoxy- d- manno-2-octulosonic acid (Kdo) in addition to Rha, Fuc, Ara, Xyl, Man, Gal, Glc, GalA, and GlcA. Lithium degradation of PG-2′ gave mainly a pentosyl → 6-deoxyhexosyl → 6-deoxyhexosyl → pentitol fragment, with some neutral di- and tri-saccharide alditols, including a pentosysl → deoxyhexitol. Methylation analysis of these degradation products indicated that they contained terminal Rha, Ara f, Fuc, Xyl, and Gal, 4-linked Rha, 3-linked Fuc, 3-linked Ara, and 3′-linked Api. Bupleuran 2IIc was eluted as essentially a single peak on gel filtration on Sepharose CL-6B. The neutral sugar content of the successive fractions increased with increasing molecular weight, but each fraction also contained, in addition to Rha, Ara, and Gal, 2-Me-Fuc, 2-Me-Xyl, and Api.

Role of polymorphonuclear leucocytes and oxygen-derived free radicals in the formation of gastric lesions induced by HCl/ethanol, and a possible mechanism of protection by anti-ulcer polysaccharide.

This study examined the role of oxygen-derived free radicals in the pathogenesis of gastric mucosal lesions induced by HCl/ethanol. Superoxide dismutase, and catalase, and their combination reduced gastric lesion formation in mice. Gastric lesions were also reduced in mice treated with cyclophosphamide or anti-neutrophils, but not in mice treated with allopurinol or desulphated-carrageenan. Cobra venom factor did not reduce lesion formation. These results suggested that oxygen-free radicals may contribute to the formation of gastric mucosal lesions induced by HCl/ethanol, and that oxygen radicals were generated from neutrophils but not from xanthine oxidase. Anti-ulcer pectic polysaccharide, bupleuran 2IIc, which was recently isolated from the roots of Bupleurum falcatum L., showed potent inhibition of HCl/ethanol-induced gastric lesions in mice. Bupleuran 2IIc seemed to scavenge hydroxyl radical effectively. It was suggested that this anti-ulcer polysaccharide may provide protection to the gastric mucosa by scavenging oxygen-free radicals.

Purification of Anti-Ulcer Polysaccharides from the Roots ofBupleurum falcatum

A water-soluble crude polysaccharide fraction (BR-1) prepared from the root of Bupleurum falcatum L. (Japanese name = Saiko) prevented HCl/ethanol induced ulcerogenesis in mice significantly. BR-1 was fractionated into four polysaccharide fractions (BR-2, BR-3, BR-4, and BR-5) by the addition of cetyltrimethylammonium bromide, and the strongly acidic polysaccharide fraction BR-2 showed the most potent inhibition of gastric lesion formation. When BR-2 was further fractionated by anion-exchange chromatography, the most potent anti-ulcer activity was observed in the pectin-like polysaccharide, bupleuran 2IIc. Bupleuran 2IIc was homogeneous as determined by electrophoresis and gel filtration. Bupleuran 2IIc was composed mainly of galacturonic acid with small proportions of arabinose, rhamnose, and galactose, and its average relative molecular mass was estimated to be 63,000 d. BR-2 lost most of its activity after treatment with periodate or digestion with endo-polygalacturonase indicating that the polygalacturonan region and/or the molecular mass may contribute to activity.

Partial structure of an anti-ulcer pectic polysaccharide from the roots of Bupleurum falcatum L.

Methylation analysis of a pectic polysaccharide (Bupleuran 2IIc) with anti-ulcer activity, isolated from the roots of Bupleurum falcatum L., revealed (1→4)-linked α-Ga1A together with small proportions of 2,4- and 3,4-linked GalA, and variously linked neutral sugars. Digestion of Bupleuran 2IIc with endo-α-(1→4)-polygalacturonase gave mainly galacturono-oligosaccharides (PG-4) and small proportions of enzyme-resistant regions (PG-1-3). PG-1 contained the sequence →4)-GalA-(1→2)-Rha(1→4)-GalA-(1→, and partial acid ydrolysis gave GalA-(1→4)-Rha, GlcA-(1→4)-Rha, and several di- and oligosaccharides consisting variously of Xyl, Glc, Gal, and Man. PG-2 and PG-3 each contained Rha, Fuc, Ara, Xyl, Man, Gal, Glc, GalA, GlcA, 2-Me-Fuc, 2-Me-Xyl, apiose (Api), aceric acid (AceA), and 3-deoxy- d- manno-2-octulosonic acid (Kdo). PG-4 contained (1→4)-linked α-galacturono-di-to-penta-saccharides and GalA. The galacturono-tetra- and -penta-saccharides had one and three methyl-esterified GalA units, respectively, and some of the galacturono-oligosaccharides contained 2,4- or 2,3-linked GalA.

Effects of a Polysaccharide Fraction from the Roots of Bupleurum falcatum L. on Experimental Gastric Ulcer Models in Rats and Mice

Effects of an acidic polysaccharide fraction, BR-2, from the roots of Bupleurum falcatum L., on HCl-ethanol, ethanol and water immersion stress-induced gastric lesions in mice and pylorus-ligated ulcers in rats have been studied. Oral administration of BR-2 at doses of 50 to 200 mg kg-1 inhibited the formation of the gastric lesions induced by necrotizing agents such as HCl-ethanol and ethanol, in a dose dependent manner. This protective effect was observed after oral, intraperitoneal, and subcutaneous administration of BR-2 (25-100 mg kg-1). BR-2 also inhibited the formation of gastric ulcers which were induced by water immersion stress or pylorus-ligation. Prostaglandin E2 in gastric juice from rats and in gastric mucosa from mice was not influenced by oral administration of BR-2. The protective action of BR-2 against HCl-ethanol-induced gastric lesions was not abolished by pretreatment with indomethacin (20 mg kg-1, i.p.). The amount of alcian blue binding to mucosa also increased after administration of BR-2 (100 mg kg-1, p.o.); however, the amount of hexosamine and N-acetylneuraminic acid in mucosa did not change significantly.

Polyacetylenes from roots of Bupleurum falcatum

Three new polyacetylenes, saikodiynes AC were isolated from an ethereal extract of roots of Bupleurum falcatum, along with a known compound, 2Z-9Z-pentadecadiene-4,6-diyn-1-ol. The chemical structures were elucidated by spectral and chemical methods.

Isolation of new saponins from the root of Bupleurum falcatum L.

Two new malonylated oleanane-type triterpene oligoglycosides, named malonylsaikosaponins a (1) and d (2), were isolated from Bupleuri Radix, the root of Bupleurum falcatum L. Their structures were elucidated on the basis of the chemical and spectroscopic studies. Quantitative analysis of various Bupleuri Radixes by HPLC suggested that these malonylsaikosaponins are genuine saponins of this crude drug.