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PubMed1997

Iscoms containing purified Quillaja saponins upregulate both Th1-like and Th2-like immune responses.

The immune stimulating complex (iscom) is built up by antigen, cholesterol, phospholipids, and adjuvant active Quillaja saponins. Previous studies have shown that iscoms containing Quil A (a semipurified preparation of saponins) efficiently induce antibody and cell-mediated immune responses. In this study, we demonstrate that iscoms containing a mixture of two purified low toxicity Quillaja saponin fractions (ISCOPREP 703) are able to upregulate both Th1-like and Th2-like immune responses. Thus, ovalbumin (OVA) iscoms induced higher levels of antigen-specific IgG1 and IgG2a antibodies and increased the production of both IFN-gamma and IL-4 compared with OVA administered without adjuvant. In contrast, OVA formulated in Al(OH)3 elicited IgG1 and IgE antibodies and primed spleen cells producing IL-4 and IL-10, suggesting the activation of primarily Th2-like cells. These findings underline that adjuvants are able to alter the character of immune responses and may be used to generate responses with desired properties.

Animals↗

PubMed1991

Membrane-associated signal transduction modulates contractile responses to Ca2+ in saponin-skinned coronary smooth muscle.

Experiments on saponin-permeabilized bovine and porcine coronary arteries were performed to examine whether fluoride-induced contractile mechanisms are retained after permeabilization and whether they modulate muscle tension without a change in cytoplasmic Ca2+. Fluoride induced reversible contractions in skinned coronary smooth muscle and shifted the apparent Ca2(+)-sensitivity of the contractile system to lower Ca2+ values. Force development to fluoride required exogenous ATP and a minimum Ca2+ concentration (pCa less than 8) of the bathing medium. Force development occurred when the concentration of free Ca2+ available to the contractile apparatus seemed to be sufficiently controlled by a Ca2(+)-EGTA buffering system. The effects of fluoride were enhanced by Al3+ and imitated by both guanylyl-imidodiphosphate and 4 beta-phorbol-12,13-dibutyrate which suggests the involvement of both GTP-binding protein(s) and of the C-kinase pathway. Under conditions of sufficiently controlled Ca2+ buffering, saponin-skinned arteries responded to histamine or carbachol with an increase in muscle tension which was inhibited by specific receptor blocking agents (diphenhydramine, atropine), and which required the presence of both exogenous ATP and a low concentration of Ca2+ (pCa 7) which per se did not result in a contractile response. It is concluded that agents acting on different steps of membrane-associated signal transduction pathways are able to induce contractile responses of saponin-skinned vascular smooth muscle without a change in cytosolic Ca2+ concentration.

Aluminum↗

PubMed1991

Failure to induce toxicity in lambs by administering saponins from Narthecium ossifragum.

It has been suggested that saponins produced by Narthecium ossifragum (Bog asphodel) may be the direct cause of the toxicity leading to the hepatogenous photosensitivity disease alveld seen in Norwegian lambs. Lambs fed large quantities of freeze-dried N. ossifragum did not develop alveld. Chemical investigations on the freeze-dried material and fresh N. ossifragum showed no difference in their saponin content. These results indicate that alveld is not caused solely by the saponins produced by N. ossifragum.

Animals↗

PubMed1987

Comparison of the effects of a preliminary hepatic washing and of saponin on the intracellular penetration of peroxidase-labeled anti-rat albumin antibodies in hepatocytes.

The effect of a preliminary hepatic washing with saline before liver fixation either by perfusion or immersion was compared to the effect of saponin, a membrane-permeabilizing agent, in order to ascertain which procedure is best to obtain a homogeneous distribution of albumin-containing hepatocytes in the hepatic lobule. Albumin was located in the hepatocytes by peroxidase-labeled antibodies using light and electron microscopy. The efficacy of the two procedures on the intracellular penetration of labeled antibodies in liver sections was judged by preparing transverse ultrathin sections. Both procedures yielded similar results. Liver fixation by perfusion with saponin and without a preliminary washing, however, distributes albumin-containing hepatocytes more homogeneously in the hepatic lobule and enables labeled antibodies to penetrate more satisfactorily. In contrast, when the liver is fixed by immersion, the preliminary washing is the only way to obtain an even distribution of albumin-containing hepatocytes, as saponin is not effective under these conditions. In conclusion, the localization of albumin in the hepatocytes must be adapted according to the technique used to fix the liver.

Albumins↗

PubMed1996

The effect of collagenase and temperature on mitochondrial respiratory parameters in saponin-skinned cardiac fibers.

The results of a comparative study of the respiration rates of mitochondria in saponin-skinned rat cardiac fibers (SF) and in fibers treated with saponin and collagenase (SCF) suggest that only about half of the whole population of mitochondria manifest their activity in SF, in contrast to SCF, in response to extracellular substrates of oxidative phosphorylation. The apparent K(m) value for ADP with succinate as substrate, which was as high as 330 +/- 32 microM in SF in SF at 20 degrees C, decreased about 2-fold in SCF at the same temperature and in SF at 37 degrees C, and decreased further to 67 +/- 8 microM in SCF at 37 degrees C. Thus, weakening or breaking of cellular contacts by collagenase and the temperature-dependence of diffusion of substrates such as ADP, seem to be important factors that determine the respiratory activity and regulatory parameters of mitochondria in saponin-permeabilized cardiomyocytes.

Adenosine Diphosphate↗

PubMed1999

Inhibition of mouse ear edema by steroidal and triterpenoid saponins.

Certain steroids and triterpenoids isolated from diverse plant families were known to possess anti-inflammatory activity. In the course of finding new anti-inflammatory natural products, some steroidal and triterpenoid saponins were isolated and evaluated for their anti-inflammatory activity using in vivo mouse ear edema test. At the oral dose of 100 mg/kg, several steroidal saponins and triterpenoid saponins such as hederagenin glycosides showed significant inhibition of ear edema (20-37% inhibition), though less potent than indomethacin and hydrocortisone.

Animals↗

PubMed2005

In vitro inhibitory effect of triterpenoidal saponins from Platycodi Radix on pancreatic lipase.

In the process of investigating anti-obesity effect of Platycodi Radix, we found that aqueous extract of Platycodi Radix might inhibit intestinal absorption of dietary fat by inhibiting pancreatic lipase (PL) activity. In order to clarify the anti-obesity mechanism of Platycodi Radix, activity-guided isolation was performed to find active components. The total saponin fraction of Platycodi Radix appeared to have a potent inhibitory activity against the hydrolysis of triolein emulsified with phosphatidycholine by pancreatic lipase in vitro. Based on these results, further purification of active components yielded 10 known triterpenoidal saponins, among these compounds, platycodin A, C, D, and deapioplatycodin D exhibited significant inhibitory effects on PL at the concentration of 500 microg/mL with 3.3, 5.2, 34.8, and 11.67% pancreatic lipase activity vs control, respectively. Platycodin D was found to inhibit the PL activity in a dose-dependent manner. Therefore, the anti-obesity effect of Platycodi Radix might be due to the inhibition of pancreatic lipase by its saponins.

Anti-Obesity Agents↗

PubMed2004

Isolation and synthesis of shark-repelling saponins.

Saponins are complex compounds that are composed of a saccharide attached to a steroid or triterpene. They are natural surfactants, or detergents. Several important biological effects have been ascribed to saponins. They have been isolated from a great number of terrestrial plants. In the animal kingdom they are found in most sea cucumbers and starfish, whereas they are found only rarely in alcyonarians, gorgonians, sponges, and as shark-repelling compounds in fish. The present review deals with the isolation and some syntheses of the shark-repelling saponins mosesins-1 to -5 and pavoninins-1 to -6 obtained from the fish species Pardachirus.

Animals↗

PubMed1989

Hemolysis by aliphatic alcohols and saponin measured by the coil planet centrifugation method.

Using the coil planet centrifugation method, the mechanism of hemolysis by alcohols and saponin was investigated. With this technique, erythrocytes are introduced into a gradient of hemolytic agents in saline, which is prepared in a long coiled polyethylene tube. The tube is centrifuged so that the cells move from a low to a high concentration of hemolytic agent. When the cells lyse, they release hemoglobin which remains stationary, and therefore hemolytic potency can be determined spectrophotometrically by the distance the cells move before lysing. We found that alcohols caused hemolysis at a particular concentration, whereas saponin-induced hemolysis was dependent on the amount of saponin accumulated in the environment of the cell. In addition, alcohols with longer carbon chains were more potent hemolytic agents than those with shorter chains, but each additional carbon group produced less of an increase in hemolysis per mole of alcohol. This chain-length dependency is consistent with a previous study on in vivo alcohol-induced hemolysis. The coil planet centrifugation method is also adaptable to comparative studies on the mechanism of other types of hemolysis, such as immune or drug-induced lysis, and to toxicological studies.

Alcohols↗

PubMed1993

Functional characterization of mitochondrial oxidative phosphorylation in saponin-skinned human muscle fibers.

The conditions of treatment of human skeletal muscle fibers from M. vastus lateralis with saponin were optimized to achieve complete permeabilization of cell membrane at intact mitochondrial oxidative phosphorylation. After 30 min of incubation with saponin all lactate dehydrogenase, 50% of creatine kinase, 30% of adenylate kinase and less than 20% of citrate synthase was released into the permeabilization medium. These skinned fibers behave similar to isolated mitochondria from human skeletal muscle: (i) the respiration with mitochondrial substrates can be stimulated by ADP, (ii) inhibited by carboxyatractyloside and (iii) it is possible to detect fluorescence changes of mitochondrial NAD(P)H on additions of substrates, uncoupler and cyanide. From a comparison of rates of respiration per cytochrome aa3 content of isolated human skeletal muscle mitochondria and saponin-skinned muscle fibers it was possible to calculate that almost 85% of mitochondria in those fibers are accessible for the investigation of oxidative phosphorylation. As shown by the investigation of biopsy samples of two patients with undefined myopathies these fibers are a suitable object for the replacement of isolated mitochondria in the diagnosis of mitochondrial myopathies and encephalomyopathies.

Animals↗

PubMed1985

Subcellular origin of the oxalate- or inorganic phosphate-stimulated Ca2+ transport by smooth muscle microsomes: revisitation of the old problem by a new approach using saponin.

Saponin, a cell-skinning reagent which perforates the cell membrane via its specific interaction with plasmalemmal cholesterol, was used to identify the subcellular origin of ATP-dependent Ca2+ accumulation in the presence and absence of inorganic phosphate and oxalate by microsomal fractions isolated from rat vas deferens and dog aorta. The purified plasma membranes from rat gastric fundus muscle, which elicit the stimulation of ATP-dependent Ca2+ accumulation by inorganic phosphate but not by oxalate, were used as a control reference. Saponin at concentrations effective for skinning smooth muscle fibres (10-50 micrograms/ml) inhibited Ca2+ binding in the absence of ATP to a similar extent in all fractions, but the inhibition of ATP-dependent Ca2+ accumulation was more pronounced in dog aorta microsomes and rat gastric fundus muscle plasma membranes than in rat vas deferens microsomes. The resistance of phosphate- and oxalate-stimulated ATP-dependent Ca2+ accumulation to inhibition by saponin was much greater in rat vas deferens than in dog aorta microsomes. Our results suggest that phosphate- and oxalate-stimulated ATP-dependent Ca2+ accumulation also occurs in plasma membrane vesicles isolated from smooth muscle and is by no means an unique property of endoplasmic reticulum.

Animals↗

PubMed1993

Effect of sub-skinning concentrations of saponin on intracellular Ca2+ and plasma membrane fluidity in cultured cardiac cells.

To determine the underlying mechanisms of the positive inotropic effect of sub-skinning concentrations of saponin, we studied changes in the intracellular Ca2+ ([Ca2+]i) and plasma membrane fluidity after exposure to digitonin (a representative saponin) in cultured cardiac cells. [Ca2+]i was measured by use of the fluorescent calcium indicator Calcium Green-1. The membrane fluidity was evaluated by measuring the diffusion coefficient using the method of fluorescence recovery after photobleaching. 1,1'-Dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine perchlorate was used as the fluorescent probe. Digitonin at a sub-skinning concentration (0.1 to 1 microM) produced an increase in cell motion and an augmentation of [Ca2+]i. Membrane fluidity which is evaluated by the diffusion coefficient (from 0.34.10(-8) to 0.28.10(-8) cm2/s; P < 0.05), decreased in the presence of 0.2 microM digitonin while the cell maintained an augmented motion and an increased [Ca2+]i. The skinning concentration of digitonin (5 microM) produced a rapid contracture with a marked increase in [Ca2+]i. The membrane fluidity was further reduced (diffusion coefficient: 0.24.10(-8) cm2/s; P < 0.001). These results suggest that saponin at the sub-skinning concentration also causes holes in the plasma membrane by interaction with cholesterol, as was shown with the skinning concentration, and it increases [Ca2+]i, which thereby induces a positive inotropic effect.

Animals↗

PubMed1993

Synthesis and antifungal activity of medicagenic acid saponins on plant pathogens: modification of the saccharide moiety and the 23 alpha substitution.

The study of structure-antifungal activity relationships of medicagenic acid saponins was widened to include synthetic glycosides of mannose, galactose, cellobiose, and lactose as well as a 23 alpha-hydroxymethyl analog of medicagenic acid, namely, methyl 2 beta,3 beta-dihydroxy-23 alpha-hydroxymethyl-delta (12)-oleanene-28 beta-carboxylate, against Sclerotium rolfsii, Rhizoctonia solani, Trichoderma viride, Aspergillus niger, and Fusarium oxysporum. The native glucose-containing saponin was a more effective antifungal agent than the aforementioned saponins, except in the case of the cellobiose-containing derivative and F. oxysporum. A carboxyl substituent at the 23 alpha position of the sapogenin brought about higher fungistatic activity than a methyl carboxylate which, in turn, was more effective than an hydroxymethyl group at the same position.

Antifungal Agents↗

PubMed1983

Isolation of focal contact membrane using saponin.

The fragments of lower cell surface remained attached to the substrate after incubation of mouse or chick fibroblasts in 0.2% saponin solution and subsequent removal of cells under the action of shearing force. These fragments corresponded exactly to the cellular focal contacts seen by interference reflection microscopy. Ultrastructurally they were membrane fragments with typical three-layered structure. No cytoskeletal components were found in saponin-isolated focal contact membranes either by immunofluorescence or electron microscopy. Only one major cell-derived protein with an apparent molecular weight (MW) of 51 kD (chick embryo fibroblasts) or 47 kD (mouse embryo fibroblasts) remained on the substrate after saponin treatment and removal of cells.

Animals↗

PubMed1993

Determination of acidic saponins in crude drugs by high-performance liquid chromatography on octadecylsilyl porous glass.

High-performance liquid chromatographic (HPLC) analysis on octadecylsilyl porous glass was investigated for acidic saponins in ginseng, bupleurum root and senega. The acidic saponins, malonyl-ginsenosides, malonyl-saikosaponins and senegins, as well as neutral saponins in the crude drugs were separated rapidly by HPLC on this column with aqueous acetonitrile containing KH2PO4 as the mobile phase at room temperature.

Carbohydrate Sequence↗

PubMed1977

The adjuvant activity of saponin and aluminium hydroxide for promoting reagins.

Saponin and aluminium hydroxide were compared as adjuvants for promoting serum reagins in cattle using BHK cell lysate as allergen and the passive cutaneous anaphylaxis test to demonstrate the antibodies. Saponin was the better adjuvant and provoked reagins in all the injected cattle while aluminium hydroxide did so in only 2 or 5 animals. The titres were also higher in the former case. A combination of both adjuvants stimulated reagin titres marginally higher than saponin alone while BHK cell lysate without adjuvant failed to provoke demonstrable reagins.

Adjuvants, Immunologic↗

PubMed1991

Triterpenoid saponins discovered between 1987 and 1989.

Triterpenoid saponins isolated and characterized from various sources are reviewed. The recent techniques used in their isolation and structure elucidation are discussed. A compilation of the triterpenoid saponins isolated during the period from 1987 to mid-1989, together with their occurrence, available physical data and spectroscopy used for their characterization is included. The biological activities of the triterpenoid saponins are also covered.

Animals↗

PubMed1993

Clinoposaponins VI and VIII, two oleanane-triterpene saponins from Clinopodium micranthum.

From the whole plants of Clinopodium microanthum two new saponins, called clinoposaponins VI and VIII, were isolated together with five known and two artifact saponins, and their structures were elucidated by spectroscopic data and chemical evidence. Each aglycone of these saponins was genuine saikogenin-type which had an 11-ene and a five-membered ether ring, and they were 3,16-bisdesmosidic glycosides.

Carbohydrate Sequence↗