Development of an Enzyme-Linked Immunosorbent Assay and Immunoaffinity Column Chromatography for Saikosaponin d Using an Anti-Saikosaponin d Monoclonal Antibody.

This work developed a novel immunochemical approach for the quality control of saikosaponin d using an enzyme-linked immunosorbent assay. Splenocytes from mice immunized with the saikosaponin d-bovine serum albumin conjugate were fused with the hypoxanthine-aminopterin-thymidine-sensitive mouse myeloma SP2/0 cell line, and a hybridoma secreting monoclonal antibody against saikosaponin d was successfully obtained. The prepared anti-saikosaponin d monoclonal antibody 1E7F3 has a novel characteristic, showing weak reactivity with compounds that are structurally related to saikosaponin d. Using monoclonal antibody 1E7F3, a specific and reliable enzyme-linked immunosorbent assay was developed to detect saikosaponin d. The system shows a full measurement range from 156.25 to 5000.00 ng × mL(-1). Both intra-assay and inter-assay repeatability and precision were achieved, with relative standard deviations lower than 10.00%. The recovery rates ranged from 92.36% to 101.00%, meeting the requirements for biological samples. There was a good correlation between the enzyme-linked immunosorbent assay and high-performance liquid chromatography analyses of saikosaponin d, and the saikosaponin d levels in formulated Chinese medicines were successfully determined. Furthermore, immunoaffinity column chromatography was established using this anti-saikosaponin d monoclonal antibody, and the elution profile of saikosaponin d was detected by a Bio-Rad QuadTec UV/Vis detector at 203 nm. The results demonstrate that we generated a reliable and more efficient assay system for measuring saikosaponin d and provide a potential approach for purifying and separating saikosaponin d.

Triterpene acids from rose hip powder inhibit self-antigen- and LPS-induced cytokine production and CD4⁺ T-cell proliferation in human mononuclear cell cultures.

A triterpene acid mixture consisting of oleanolic, ursolic and betulinic acid isolated from a standardized rose hip powder (Rosa canina L.) has been shown to inhibit interleukin (IL)-6 release from Mono Mac 6 cells. The present study examined the effects of the triterpene acid mixture on the cytokine production and proliferation of CD4⁺ T cells and CD19⁺ B cells induced by a self-antigen, human thyroglobulin and by lipopolysaccharide in cultures of normal mononuclear cells. The triterpene acid mixture inhibited the production of tumor necrosis factor-α and IL-6 with estimated IC50 values in the range 35-56 µg/mL, the Th1 cytokines interferon-γ and IL-2 (IC50 values 10-20 µg/mL) and the antiinflammatory cytokine IL-10 (IC50 values 18-21 µg/mL). Moreover, the mixture also inhibited CD4⁺ T-cell and CD19⁺ B-cell proliferation (IC50 value 22 and 12 µg/mL, respectively). Together, these data demonstrate that oleanolic, ursolic and betulinic acid are active immunomodulatory constituents of the standardized rose hip powder. However, since the estimated IC50 values are in the µg/mL range, it is questionable whether the content of the triterpene acids in the standardized rose hip powder, alone, can explain the reported clinical effects.

[Synthesis and immunotropic activity of 2-alkylaminomethylene-19beta,28-epoxyolean-3-ones].

2-Alkylaminomethylene-19beta,28-epoxyolean-3-ones were obtained by interaction of 2-hydroxymethylene-19beta,28-epoxyolean-3-one with aliphatic amines. Some of the resulting substances exhibit immunotropic activity.

Generation and characterisation of monoclonal antibodies to oleanolic acid.

Monoclonal antibodies to oleanolic acid, a pentacyclic triterpene, were generated using the hybridoma fusion method described by Kohler and Milstein . Protein conjugates of the target molecule for immunisation were prepared either by directly linking the isoprenoid to different protein carriers via the carboxylic function or after introduction of a succinic spacer between the protein carrier and position 3 of the target molecule. Antibodies of three different cell lines were further analysed by competitive ELISA and were shown to be directed either against both rings A and B or to ring E of the pentacyclic system. Thus these antibodies can be used in the specific detection of oleanolic acid itself or of a broad range of oleanolic acid derivatives sharing a specific structural moiety. Therefore these antibodies may be interesting tools for the screening of putative terpenoid-containing plants.

Development of an assay system for saikosaponin a using anti-saikosaponin a monoclonal antibodies.

For immunization, saikosaponin a (SSa) was conjugated with bovine serum albumin (BSA). The hapten number in an antigen conjugate was determined to be eleven by matrix-assisted laser adsorption/ionization time-of-flight mass spectrometry (MALDI-TOF Mass). Hybridomas secreting monoclonal antibodies (MAb) against SSa were produced by fusing splenocytes immunized with SSa-BSA conjugate and a hypoxanthine-aminopterin-thymidine-sensitive (HAT) mouse myeloma cell line, P3-X63-Ag8-653. A high specific MAb against SSa was selected from hybridomas using enzyme-linked immunosorbent assay (ELISA) analysis. Weak cross-reactivities occurred with saikosaponin c, b(2) and d, which are stereochemical and/or functional isomers of SSa, but no cross-reactivities were observed with other related steroidal glycosides. The full range of the assay extends 26 ng/ml to 1.5 microg/ml of SSa. Good correlation of SSa concentrations in a crude extract of Bupleuri radix between ELISA and HPLC methods was obtained after hydrolysis of acyl saikosaponins by treatment with a mild alkaline solution. The newly established ELISA has been applied for the quantitative assay of SSa in the Bupleuri radix and the Kampo medicines (TCM) prescribed with Bupleuri radix.

Relationship between adjuvant activity and amphipathic structure of soyasaponins.

A correlation between adjuvant activity and amphipathic structure of saponin was first demonstrated on an experimental basis using structurally consecutive analogues. To clarify the physicochemical factors regulating the adjuvanticity of saponin, we compared the profile of the antibody response against chicken ovalbumin (OVA) in mice and hydrophile-lipophile balance (HLB) of eight purified soyasaponins. Soyasaponins bearing sugar chain(s) showed adjuvanticity stimulating anti-OVA total-IgG and IgG1 antibody responses, while their corresponding aglycones soyasapogenols A and B, did not. Among bisdesmosidic soyasaponins, soyasaponin A(1) (HLB: 26.9) with a long sugar side chain induced stronger total-IgG and IgG1 antibody responses than soyasaponin A(2) (HLB: 21.4). For monodesmosidic soyasaponins, the ranking in terms of antibody response was soyasaponin I (which has the highest HLB value (13.6) among the monodesmosidic soyasaponins) > soyasaponin II (HLB: 12.2) > soyasaponin III (HLB: 10.0). The adjuvant activity increased with the HLB value. The length, the number, and the composition of sugar side chains affecting the HLB value would give the overall conformation of each saponin molecule, and the amphipathic structure may define the fundamental adjuvanticity of saponins.

In vitro anticomplementary activity of hederagenin saponins isolated from roots of Dipsacus asper.

Anticomplementary activity of hederagenin and related saponins isolated from Dipsacus asper was investigated in vitro. HN saponin F (3) was most potent with IC50 value of 3.7x10(-5) M followed by 3-O-beta-D-glucopyranosyl-(1->3)-alpha-L-rhamnopyranosyl-(1->2)-beta-L-+ ++arabi nopyranosyl hederagenin 28-O-beta-D-glucopyranosyl-(1->6)-beta-D-glucopyrano side (8), 3-O-beta-L-arabinopyranosyl hederagenin 28-O-beta-D-glucopyranosyl-(1->6)-beta-D-glucopyranoside (5), dipsacus saponin A (4), and hederagenin (1) on the classical pathway (CP) of complement system, while the saponins 3-5 did not show the inhibition of hemolysis and rather increase the hemolysis on the alternative pathway (AP). However, all of C-3 monodesmosides [prosapogenin CP (2), dipsacus saponin B (6), and dipsacus saponin C (7)] evoked hemolysis directly on the erythrocytes.