Soybean Saponins Research Articles

The role of triterpenoid on reactive oxygen scavenging system: approach from the new chemiluminescence system (XYZ system).

We propose that the reactive oxygen species/hydrogen donor/mediator system (XYZ system) is a new chemiluminescence system for the measurement of reactive oxygen scavenging activity. By using this method, we demonstrated the role of triterpenoid on a reactive oxygen scavenging system. DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) conjugated saponin from soybean, produced a low level light emission in the presence of H202 (X) and gallic acid (Y). The soybean saponin acted as a mediator (Z) on the reactive oxygen scavenging system. When comparing the data of photon emission properties of saponin with that of cholic acids, it concludes that DDMP moiety of soybean saponin plays an important role rather than the aglycon moiety in the radical scavenging system.

Fermentation Effects of Lactic Acid Bacteria on Soybean Saponins

In order to improve undesirable tastes of soybean foods, total 211 strains of lactic acid bacteria were tested for soybean saponin-hydrolyzing activity. Twenty strains were selected by the acid production from soybean saponins used as carbohydrate sources. Decomposition rates of soyasaponin Bb using high performance liquid chromatography of selected strains were in the range of 3 to 72% and Lactobacillus casei subsp. casei strain IFO 3953 especially indicated a highest value. The optimal pH and temperature of soybean saponin hydrolase in the cell supension and the crude enzyme prepared from cells of the strain were at pH 5.0 and 50°C, respectively. It was presumed that the enzyme would be a β-glucuronidase which cleaves glucuronide bond of soybean saponins from the result of thin layer chromatography analysis.

Anabolic Effect of Soybean Saponin on Bone Components in the Femoral Tissues of Rats

The effect of soybean saponin on bone components in the femoral tissues of rats was investigated. Rats were orally administered saponin (100μg/ml/100g body weight) for 10 d. The administration caused a significant increase in calcium content, alkaline phosphatase activity, and deoxyribonucleic acid (DNA) content in the diaphyseal and metaphyseal tissues of the femur in the animals. When bone tissues were cultured for 24h in a medium containing either vehicle or saponin (10μg/ml of medium), the presence of saponin caused a significant rise in calcium content, alkaline phosphatase activity, and DNA content in the femoral-diaphyseal and metaphyseal tissues. The effect of saponin in increasing bone components was completely prevented by the presence of cycloheximide (10-6M), suggesting that the saponin effect is partly based on a newly synthesized protein component. This study demonstrates that soybean saponin has an anabolic effect on bone components in rats, suggesting its role as a nutritional factor in the prevention of osteoporosis.

Effects of Soybean Saponins on Chymotryptic Hydrolyses of Soybean Proteins

The effects of saponin fraction on chymotryptic hydrolysis of soybean acid precipitated protein and glycinin and β-conglycinin fractions were examined. Endogenous saponin affected the chymotryptic hydrolysis of soybean protein. Further addition of saponin suppressed the hydrolysis of soybean protein fraction. The effect of saponin on chymotryptic hydrolysis of glycinin was greater than on that of β-conglycinin. There were some differences in the effect of saponin on the subunits constituting the soybean globulins. Glycinin acidic polypeptides and β-conglycinin β-subunit became more resistant to chymotryptic hydrolyses by addition of saponin. Changes of CD spectra of glycinin and β-conglycinin by saponin reflected the sensitivity changes of soybean protein against chymotrypsin. Keywords: Soybean saponin; chymotrypsin hydrolysis; glycinin; β-conglycinin

Structure-Hepatoprotective Relationships Study of Soyasaponins I-IV Having Soyasapogenol B as Aglycone#

As a part of our study on the leguminous plants, we investigated the constituents of the aerial parts of Glycine soya. We isolated and identified four known saponins, soyasaponins I, II, III, and IV which have the same aglycone, soyasapogenol B. As a part of our studies concerning hepatoprotective drugs, we also examined the hepatoprotective actions of these saponins towards immunologically induced liver injury on primary cultured rat hepatocytes. The action of soyasaponin II was almost comparable with that of soyasaponin I, whereas those of soyasaponin III and IV were more effective than soyasaponins I and II. This means that the disaccharide group shows greater action than the trisaccharide group. Furthermore, the saponin having a hexosyl unit shows a slightly greater action than that of the pentosyl unit in each disaccharide group or trisaccharide group. Structure-activity relationships suggest that the sugar moiety linked at C-3 may play an important role in hepatoprotective actions of soybean saponins.

Relationship between chemical structures and biological activities of triterpenoid saponins from soybean.

Saponins can be found in more than one hundred plant families and in some marine animals. However, chemical investigation of soybean (Glycine max L. Merrill) saponins has begun only as recently as the 1970s. Here we focus on the chemical structure, the content, and biological activity of soybean saponins in current studies. Especially, we focus on 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) conjugated saponins and define the chemical structure of this as a natural precursor of group B and E saponins.

Prevention of Hydrogen Peroxide Damage by Soybean Saponins to Mouse Fibroblasts

Soybean saponin is one of several soybean glycosides. Recently, new soybean saponins which possess the DDMP (2,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one) moiety have been detected. Soyasaponin beta g of these new soybean saponins was shown to inhibit hydrogen peroxide damage to mouse fibroblast cells. Not only the new saponin but also soyasaponin I, which has lost the DDMP moiety from soyasaponin beta g, was tested and showed higher inhibition in this assay. In order to investigate the relationship between the effect and chemical structure, glycyrrhizin, which has a similar chemical structure to soyasaponin I, was also tested and exhibited the same effect as soyasaponins beta g and I. Soyasaponin Ab, a major authentic bisdesmosidic saponin that exists only in the soybean hypocotyl, was also tested and exhibited the highest inhibition of hydrogen peroxide damage among the four saponins. It was concluded that water-soluble soybean saponins protected the cells from damage by hydrogen peroxide.

Chemiluminescence of soybean saponins in the presence of active oxygen species

Natural active oxygen scavengers (Y; catalytic compounds) exhibit chemiluminescence (CL) in the presence of an X (active oxygen compounds) and a Z (receptive compounds). The CL derived from soyasaponins Ab and βg, major components of group A and DDMP saponins present at high level in the hypocotyl of soybean seeds, was compared with (−)-epigallocatechin (EGC) as the most effective Y and acetaldehyde (MeCHO) as the most effective Z in the presence of H 2O 2 as X. We have found that soyasaponin Ab and soyasaponin βg are Y equivalent to EGC and Z equivalent to MeCHO, respectively. In the presence of soyasaponin Ab as Y, CL of soyasaponin βg showed about 100-fold than that of MeCHO as Z. These results suggest that group A and DDMP saponins play an important role in the scavenging function of active oxygen.

Fourier transform infrared (FTIR) spectra of soybean saponin Ab and Bb

Fourier transform infrared (FTIR) spectra of soybean saponin Ab and Bb

Chemiluminescence of oxygen radical scavengers such as DDMP saponins in the presence of radicals and aldehyde.

Many kinds of saponins have been isolated from soybean seeds, and can be divided into two groups, group A1 and DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) saponins2 (Fig.1). Group A saponins are present only in the soybean hypocotyl, whilst DDMP saponins are widely distributed in leguminous seeds and are present in both hypocotyl and cotyledon, especially in the case of soybean. From the pharmacological or health point of view, it has been reported that soybean saponins show various properties such as hypolipidemic and antioxidative activity3, and HIV-infection-inhibitory properties4. Although both group A and DDMP saponins are present in the hypocotyl of soybean seeds at high concentration, the interrelationship concerning their physiological role is not clear.KeywordsGallic AcidSoybean SeedActive oxYgen SpeciesGlycyrrhetinic AcidEpigallocatechin GallateThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Effect of soybean saponins and gypsophila saponin on morphology of colon carcinoma cells in culture

The effect of saponins on colonic epithelial carcinoma cell (HCT-15) morphology was studied. Cells in culture were incubated with different concentrations of soybean saponins (SS) or gypsophila saponin (GS) for 24 hr. Scanning electron microscopy revealed a very rough and granular cell surface in cells treated with the lowest concentration of GS (40 ppm). Minor morphological changes were observed in the cell surface of soybean saponin-treated cells at a concentration of 1200 ppm. Examination by transmission electron microscopy indicated a dose-dependent effect of saponins on intracellular morphology of colonic epithelial carcinoma cells. Cells treated with 600 ppm or more of soybean saponins developed numerous cytoplasmic vesicles, had decreased density of cytoplasmic material and demonstrated deformations in plasma and nuclear membranes. Gypsophila saponin at a concentration of 40 ppm produced few changes in intracellular and membrane structure, whereas 80 ppm saponin induced the formation of vesicles. However, at both concentrations, changes in the density of cytoplasmic material was less extensive than in soybean saponin-treated cells. The highest concentration of gypsophila saponin used (160 ppm) completely destroyed the plasma membrane. These results indicate that soybean saponins and gypsophila saponin interact with cell membranes and induce significant dose-dependent cell morphological changes; however, they appear to act through different mechanisms.

Saponins as anticarcinogens.

Saponins, which are present in plants, have been suggested as possible anticarcinogens. They possess surface-active characteristics that are due to the amphiphilic nature of their chemical structure. The proposed mechanisms of anticarcinogenic properties of saponins include direct cytotoxicity, immune-modulatory effects, bile acid binding and normalization of carcinogen-induced cell proliferation. However, the anticarcinogenic effects of saponins from commonly consumed plant foods have not been studied. Soybeans are one of the most important sources of dietary saponins. They are the main protein supplier in many vegetarian diets. Our results showed that soybean saponins at the concentration of 150-600 ppm had a dose-dependent growth inhibitory effect on human carcinoma cells (HCT-15). Viability was also significantly reduced. Soybean saponins did not increase cell membrane permeability in a dose-dependent fashion, whereas gypsophilla saponin, a nondietary saponin, increased permeability with increasing concentrations. Electron microscopy indicated that soybean and gysophilla saponins alter cell morphology and interact with the cell membrane in different ways.

Effect of soybean saponins and gypsophilla saponin on growth and viability of colon carcinoma cells in culture

The effects of soybean saponins (SS) and gypsophilla saponin (GS) on the growth and viability of colon tumor (HCT-15) cells in culture were investigated. Cells were incubated in various concentrations of saponins for 1 hour (short term) or 48 hours (long term). Cell growth and viability were monitored at 24 and 48 hours. SS and GS inhibited cell growth and reduced cell viability in a dose-dependent manner in long-term treatment. The viability of cells was also reduced by short-term treatment with GS. The saponins differed in their effects on cell surface morphology: GS induced a rough and granular cell surface, whereas SS-treated cells displayed only minor morphological alterations. Changes in membrane permeability were assessed by measuring leakage of the cytoplasmic enzyme lactate dehydrogenase from cells. GS showed a concentration-dependent increase in lactate dehydrogenase leakage, whereas SS did not exhibit this effect. These results suggest that SS and GS have a significant growth-inhibitory effect on colon tumor cells in culture. However, it would appear that they are acting through different mechanisms.

A saponin conjugated with 2,3-dihydro-2,5-dihydroxy-6-methyl-4 H-pyran-4-one from Dolichos lablab

A new 2,3-dihydro-2,5-dihydroxy-6-methyl-4 H-pyran-4-one (DDMP)-conjugated saponin, lablab saponin I, was isolated from the hypocotyl of hyacinth bean ( Dolichos lablab). The structure was elucidated by 1H NMR and 13C NMR spectroscopy and chemical techniques as 3-O-[α- l-rhamnopyranosyl -(1 → 2)-β- d-galactopyranosyl (1 → 2)-β- d-glucuronopyranosyl (1 → )]-22-O-[2,3- dihydro-2,5-dihydroxy-6-methyl-4H- pyran-4-one(2′ → )]-3β,22β,24- trihy-droxyolean- 12-en-28-al . SOD (superoxide dismutase)-like activity depended upon the DDMP group and the aldehyde group (C-28) of the aglycone was observed in the order of lablab saponin I > glutathione > soyasaponin βg > maltol. The soybean saponin Bb, lacking the DDMP moiety was found not to exhibit the SOD-like activity.

Partition of Soybean Saponins between Butanol and Water.

The effects of the concentration of the extract and the pH of the water phase on the partition between butanol and water of a crude extract from soybean seed hypocotyls were estimated. A seventy percent ethanol extract was dispersed in butanol-water (1:1) and each layer was subjected to thin layer chromatography and high performance liquid chromatography. A low concentration of the extract showed a high purity of saponins and a low partition ratio of soyasaponin I. At about pH 3.3, soyasaponin I was contained only in the butanol layer, and the partition ratio of soyasaponin I decreased with an increase in pH.

Active Oxygen Scavenging Activity of DDMP (2,3-Dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) Saponin in Soybean Seed

DDMP saponin, which is widely distributed in leguminous seeds, scavenged oxygen radicals when assayed using the xanthine oxidase-NH2OH method, electron spin resonance (ESR), and chemiluminescence. One mg of DDMP saponin/ml scavenged superoxide at a degree equivalent to 17.1 units of superoxide dismutase/ml by the ESR spin trapping method. This scavenging activity of DDMP saponin is caused by the DDMP moiety attached to the triterpene aglycone since soybean saponin Bb, which is derived from soyasaponin βg, but which lacks this group, did not show the scavenging activity.

ChemInform Abstract: Soybean Saponin and Isoflavonoids. Structure and Antiviral Activity Against Human Immunodeficiency Virus in vitro

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Genetic and chemical polymorphisms of saponins in soybean seed

The variation in saponin composition in soybean seeds is explained by different combinations of five genes controlling the utilization of soyasapogenol

Components Responsible for the Undesirable Taste of Soybean Seeds

The components responsible for undesirable taste in soybeans have been investigated and intensities of undesirable taste were measured by electrophysiological methods. Bitterness and astringency in soybeans were shown to be caused by soybean glycosides such as saponins and isoflavones, and the soybean sapponin A group contributes most strongly to the undesirable taste. In the three electrophysiological methods to measure intensity of undesirable tastes, soybean saponins did not induce the membrane potential change of neuroblastoma cells (N-18 clone) and the electrical response of the chorda tympany nerve of rats, and only the electrical response of the glossopharyngeal nerve of the frog was induced by soybean saponins. These results showed that the mechanism of the undesirable tastes caused by soybean saponins was likely to be different from those of basic tastes (sweet, salty, sour, and bitter).

Isolation and structural elucidation of the major genuine soybean saponin.

(1992). Isolation and Structural Elucidation of the Major Genuine Soybean Saponin. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 1, pp. 142-143.