New steroidal saponins from the rhizomes of Anemarrhena asphodeloides Bunge (Liliaceae)

Transcriptomic investigation of the biochemical function of 7-dehydrocholesterol reductase 1 from the traditional Chinese medicinal plant Anemarrhena asphodeloides Bunge

Anemarrhena asphodeloides Bunge (Liliaceae) is an important Traditional Chinese Medicine herb, which contains up to 6 % total steroidal saponins (timosaponins) and has multiple pharmacological properties. However, the timosaponin biosynthetic pathway has not been extensively investigated. Here we conducted de novo transcriptome sequencing and analysis of A. asphodeloides Bunge and screened for candidate genes involved in the timosaponin biosynthetic pathway. Targeted metabolite analysis showed that timosaponins primarily accumulated in rhizomes, while phytosterols (including cholesterol) were distributed throughout various organs. Most of the identified candidate genes of the timosaponin biosynthetic pathway were also highly expressed in the rhizome, consistent with the results of metabolic analysis. Based on the transcriptome results, two candidate 7-dehydrocholesterol reductase genes were cloned and heterologously expressed in the yeast Saccharomyces cerevisiae. The purified and identified products supported that Aa7DR1 possessed Δ⁷-reduction activity in yeast and therefore may be involved in the timosaponins biosynthetic pathway in A. asphodeloides Bunge. Phylogenetic analysis showed Aa7DR1 belongs to monocotyledonous Δ⁷ reductase of phytosterol biosynthesis. These data expand our understanding of timosaponin biosynthesis.

Analysis of Chemical Variations between Crude and Salt-Processed Anemarrhenae rhizoma Using Ultra-High-Performance Liquid Chromatography-Mass Spectrometry Methods

The present study was designed to systematically investigate the chemical profile differences between crude Anemarrhenae rhizoma (CAR) and salt-processed Anemarrhenae rhizoma (SAR). Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS), coupled with multivariate statistical analysis was used for the discrimination of chemical profiles and the identification of the differentiation of the chemical constitutions of CAR and SAR. In addition, seven main constituents of CAR and SAR were simultaneously determined by ultra-high-performance liquid chromatography-quadrupole mass spectrometry (UHPLC-MS) for analyzing the content variations. A total of 24 components were found to be the main contributors to the significant difference between CAR and SAR. The structures of the marker compounds were identified based on their chromatographic behaviors, intact precursor ions, and characteristic MS fragmentation patterns. The potential structural transformation mechanism of furostanol saponins during salt processing was explored. The results may provide a scientific foundation for deeply elucidating the processing mechanism of Anemarrhenae rhizoma.

Four New Glycosides from the Rhizoma of Anemarrhena asphodeloides

Four new compounds, aneglycoside A-C (1-3) and timosaponin U (4), were isolated from the rhizomes of Anemarrhena asphodeloides. Their structures were determined through extensive spectroscopic analysis, chemical characteristics, and high-resolution mass spectrometry (HRMS). All the isolations were evaluated for cytotoxicity against HepG2, Hela, and SGC7901 human cancer lines. Compounds 1, 2, and 4 showed weak antiproliferative activities on HepG2, Hela, and SGC7901 cells.

New steroids from Anemarrhena asphodeloides rhizome and their α-glucosidase inhibitory activity

Two new steroids were isolated from acid hydrolysis residue of the rhizomes of Anemarrhena asphodeloides. Their structures were identified on the basis of several spectroscopic analysis approaches including 1D, 2D-NMR techniques, and MS data, and by the comparison of spectral data of the known compounds. The biological activities of these two isolated compounds were explored on α-glucosidase. Compound 1 displayed 4.7 folds inhibitory activity against α-glucosidase compared with the positive control acarbose.

Steroidal Saponins from the Rhizomes of Anemarrhena asphodeloides

Four new steroid saponins 1-4 were isolated from the rhizomes of Anemarrhena asphodeloides (Asparagaceae), as well as four known saponins: anemarsaponin B (5) timosaponin D (6), timosaponin E1 (7) anemarsaponin B II (8). Their structures were established through UV and NMR as well as MS data. All the compounds were evaluated for cytotoxicity against HepG2 and SGC7901 human cancer lines. Compounds 3 and 7 displayed medium antiproliferative activities on HepG2 and SGC7901 cells, with IC50 values of 43.90 and 57.90 μM, respectively.

Separation of chemical constituents from three plant medicines by counter-current chromatography using a three-phase solvent system at a novel ratio

A solvent system of n-hexane, methyl acetate, acetonitrile, and water at a novel volume ratio of 4:3:4:4 forms three layers, i.e. upper phase (UP), middle phase (MP), and lower phase (LP), with a volume ratio of 1:1.20:1.42 at room temperature (25°C). All three two-phases from this three-phase solvent system were successfully used to separate some chemical constituents from three plant medicines with counter-current chromatography (CCC). Eight coumarins (B1-B8) were obtained from petroleum ether extract of fresh roots of Angelica dahurica (Baizhi) with a stationary phase of UP and a mobile phase of LP. Six diarylheptanoids (L1-L6) were obtained from petroleum ether extract of dried rhizomes of Alpinia officinarum (Liangjiang) with a stationary phase of UP and a mobile phase of MP. Three chemical constituents (Z1-Z3) were obtained from ethyl acetate extract of fresh rhizomes of Anemarrhena asphodeloides (Zhimu) with a stationary phase of MP and a mobile phase of LP. Preparative HPLC was used for further purification if necessary. Seventeen chemical constituents were identified as oxypeucedanin hydrate (B1), byakangelicin (B2), byakangelicol (B3), bergapten (B4), oxypeucedanin (B5), imperatorin (B6), phellopterin (B7), isoimperatorin (B8), 5-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-phenyl-3-heptanone (L1), 7-(4-hydroxy-3-methoxyphenyl)-1-phenyl-4E-en-3-heptanone (L2), 5-hydroxy-1,7-diphenyl-3-heptanone (L3), 1,7-diphenyl-4E-en-3-heptanone (L4), 5-hydroxy-1,7-diphenyl-4E,6E-dien-3-heptanone (L5), isomers of 1,7-diphenyl-3,5-heptandione and 5-hydroxy-1,7-diphenyl-4E-en-3-heptanone (L6), mangiferin (Z1), timosaponin A-III (Z2), and 2,6,4'-trihydroxy-4-methoxy-benzophenone (Z3) by means of MS, (1)H and (13)C NMR studies. Five compounds of B3, L3, L5, L6, and Z3 were isolated by CCC for the first time.

Folding fan mode counter-current chromatography offers fast blind screening for drug discovery. Case study: finding anti-enterovirus 71 agents from Anemarrhena asphodeloides

A new application of counter-current chromatography (CCC) in drug discovery, called folding fan mode (FFM), is designed to eliminate the extensive and time-consuming calculation of the partition coefficients of some preset compounds in conventional CCC separation. Careful reading of reports in the literature reveals that, when two-phase solvent systems are listed in a polarity-increasing sequence, the isolates also show a similar trend in polarity. The relationship between the two-phase solvent system and the isolates is like that between the folds and the picture of a folding fan. We can directly select a two-phase solvent system to separate fractions having similar polarity, just as opening a fan reveals a picture. The solvent ratio of two-phase solvent systems can be adjusted according to the polarity and weight ratio of active fractions rather than the partition coefficients. Without preset compounds, FFM-CCC not only requires no measurement of partition coefficients, but also achieves true blind screening. This paper reports the method's first success in drug discovery: six anti-EV71 saponins were found from the mixture (9.13 g) of ethanol extract and water extract of Anemarrhena asphodeloides after a total of four CCC separations, using hexan/ethyl acetate/methanol/butanol/water as the model solvent system. Among these saponins, timosaponin B-II displayed a comparable IC50 (4.3 ± 2.1 μM) and a 40-fold higher selective index (SI=92.9) than the positive control (IC50=361.7 ± 104.6 μM, SI=2.4), ribavirin. The structure-activity relationship (SAR) of these compounds was also studied.

The Rhizome Mixture of Anemarrhena asphodeloides and Coptidis chinensis Ameliorates Acute and Chronic Colitis in Mice by Inhibiting the Binding of Lipopolysaccharide to TLR4 and IRAK1 Phosphorylation

In the previous study, the mixture of the rhizome of Anemarrhena asphodeloides (AA, family Liliaceae) and the rhizome of Coptidis chinensis (CC, family Ranunculaceae) (AC-mix) improved TNBS- or oxazolone-induced colitis in mice. Therefore, to investigate its anticolitic mechanism, we measured its effect in acute and chronic DSS-induced colitic mice and investigated its anti-inflammatory mechanism in peritoneal macrophages. AC-mix potently suppressed DSS-induced body weight loss, colon shortening, myeloperoxidase activity, and TNF-α, IL-1β, and IL-6 expressions in acute or chronic DSS-stimulated colitic mice. Among AC-mix ingredients, AA, CC, and their main constituents mangiferin and berberine potently inhibited the expression of proinflammatory cytokines TNF-α and IL-1β, as well as the activation of NF-κB in LPS-stimulated peritoneal macrophages. AA and mangiferin potently inhibited IRAK phosphorylation, but CC and berberine potently inhibited the binding of LPS to TLR4 on macrophages, as well as the phosphorylation of IRAK1. AC-mix potently inhibited IRAK phosphorylation and LPS binding to TLR4 on macrophages. Based on these findings, AC-mix may ameliorate colitis by the synergistic inhibition of IRAK phosphorylation and LPS binding to TLR4 on macrophages.

(-)-Nyasol, isolated from Anemarrhena asphodeloides suppresses neuroinflammatory response through the inhibition of I-κBα degradation in LPS-stimulated BV-2 microglial cells

Microglial activation has been associated with neurodegenerative diseases by inducing the neuroinflammatory mediators such as nitric oxide (NO), TNF-α and IL-1β. (-)-Nyasol, a norlignan isolated from a medicinal plant Anemarrhena asphodeloides, showed anti-inflammatory potential in lipopolysaccharide (LPS)-activated BV-2 microglial cells. (-)-Nyasol inhibited the production of NO and prostaglandin E2 (PGE2) and also the expression of inducible nitric oxide synthase and cyclooxygenase-2, which are responsible for the respective production of NO and PGE2. It also suppressed the mRNA levels of TNF-α and IL-1β in activated microglial cells. These effects of (-)-nyasol were correlated with the inactivation of p38 MAPK and the suppression of LPS-induced I-κBα degradation. Taken together, these results suggest that (-)-nyasol can be a modulator in neuroinflammatory conditions induced by microglial activation.

Detection, characterization and identification of major constituents in Zhimu-Baihe herb-pair extract by fast high-performance liquid chromatography and time-of-flight mass spectrometry through dynamic adjustment of fragmentor voltage

This work describes a novel methodology for unequivocal identification of chemical constituents in Zhimu-Baihe herb-pair (ZMBHHP). Compounds were removed from ZMBHHP by ultrasonic extraction with 70% ethanol, and then analyzed by fast high-performance liquid chromatography (HPLC) coupled with time-of-flight mass spectrometry (TOFMS). The accurate-mass capability of the TOF analyzer allowed reliable confirmation of the identity of the detected compounds, normally with mass errors below 3 ppm in routine analysis. This mass accuracy was sufficient to verify the elemental compositions of the chemical constituents in ZMBHHP. With dynamic adjustment of fragmentor voltage in TOFMS, an efficient ion transmission was achieved to obtain the best sensitivity and abundant fragmentation. By accurate mass measurements for each molecular ion and subsequent fragment ions, a reliable identification and differentiation of 24 saponins, 3 xanthones, 1 anthraquinone and 2 alkaloids was described here, including four groups of isomers. It is concluded that this fast and sensitive HPLC/ESI-TOFMS technique is powerful in qualitative analysis of complex herbal medicines in terms of sensitivity, selectivity, resolving power, time savings and lower solvent consumption. Furthermore, the data gathered in this study may be helpful for understanding the synergistic nature of this herb pair in traditional Chinese medicine (TCM) and further pharmacokinetic studies of ZMBHHP.

Steroidal saponins from Yucca gloriosa L. rhizomes: LC-MS profiling, isolation and quantitative determination

The occurrence of steroidal saponins in the rhizomes of Yucca gloriosa has been detected by LC-MS. On the basis of the LC-MS analysis, five steroidal glycosides, including three spirostane, one furostane and one cholestane glycosides, along with seven known compounds have been isolated and characterized by ESI-MS and by the extensive use of 1D- and 2D-NMR experiments. Quantitative analysis of the steroidal glycosides in Y. gloriosa rhizomes was performed by an LC-MS method validated according to European Medicines Agency (EMEA) guidelines. The dried BuOH extract obtained from rhizomes contains more than 25% w/w of glycosides, thus Y. gloriosa rhizomes can be considered a rich source of steroidal glycosides.

Timosaponin AIII is preferentially cytotoxic to tumor cells through inhibition of mTOR and induction of ER stress

The aqueous extract of Anemarrhena asphodeloides (BN108) induces apoptosis in various cancer cell lines but is significantly less cytotoxic in non-transformed cells. Chemical fractionation of BN108 showed that its cytotoxicity is associated with timosaponins, steroidal saponins of coprostane type. Timosaponin BII (TBII) is a major saponin in BN108, but it shows little cytotoxicity. A much less abundant TAIII induces cell death in tumor cells but not in normal cells, reproducing the selectivity of the total extract BN108. Glycosidase treatment, by removing the extra sugar moiety in TBII, converts it to TAIII and confers cytotoxic activity. Analysis of the mechanisms of death induced by TAIII revealed activation of two distinct pro-apoptotic pathways: first, inhibition of mTORC1 manifested in much reduced phosphorylation of mTORC1 targets; second, induction of endoplasmic reticulum stress culminating in phosphorylation of eIF2α and activation of caspase 4. These pro-apoptotic pathways are activated by TAIII selectively in tumor cells but not in normal cells. Both pathways play a causative role in TAIII cytotoxicity, as restoration of either mTOR activity or relief of ER stress alone offer only partial protection from TAIII. Inhibition of mTORC1 and induction of ER stress apparently contribute to the induction of the previously reported autophagic response in TAIII-treated cells. TAIII induced autophagy plays a protective role in TAIII induced death signaling, and failure to mount autophagic response is associated with heightened sensitivity to TAIII induced apoptosis. The multiple death-promoting and apparently tumor-selective responses to TAIII, its ability to inhibit mTORC1, and the possibility of further enhancing its cytotoxicity by pharmacological inhibition of autophagy, make TAIII an attractive candidate for development as a cancer therapeutic agent.

Chromatographic behaviour of steroidal saponins studied by high-performance liquid chromatography-mass spectrometry

The chromatographic behaviour of steroidal saponins found in Anemarrhena asphodeloides, Asparagus officinalis, Convallaria majalis, Digitalis purpurea and Ruscus aculeatus was studied by HPLC-MS using a C-18 reversed-phase column and aqueous acetonitrile or aqueous methanol mobile phase gradients, with or without the addition of 1% acetic acid. The behaviour was compared to that of triterpene saponins found in Aesculus hippocastanum, Centella asiatica, Panax notoginseng and Potentilla tormentilla. Inclusion of methanol in the mobile phase under acidic conditions was found to cause furostanol saponins hydroxylated at C-22 to chromatograph as broad peaks, whereas the peak shapes of the spirostanol saponins and triterpene saponins studied remained acceptable. In aqueous methanol mobile phases without the addition of acid, furostanol saponins chromatographed with good peak shape, but each C-22 hydroxylated furostanol saponin was accompanied by a second chromatographic peak identified as its C-22 methyl ether. Methanolic extracts analysed in non-acidified aqueous acetonitrile mobile phases also resolved pairs of C-22 hydroxy and C-22 methoxy furostanol saponins. The C-22 methyl ether of deglucoruscoside was found to convert to deglucoruscoside during chromatography in acidified aqueous acetonitrile, or by dissolving in water. Poor chromatography of furostanol saponins in acidified aqueous methanol is due to the interconversion of the C-22 hydroxy and C-22 methoxy forms. It is recommended that initial analysis of saponins by HPLC-MS using a C-18 stationary phase is performed using acidified aqueous acetonitrile mobile phase gradients. The existence of naturally-occurring furostanol saponins methoxylated at C-22 can be investigated with aqueous acetonitrile mobile phases and avoiding methanol in the extraction solvent.

Furostanol oligoglycosides from Asparagus cochinchinensis

Three new furostanol oligoglycosides, named aspacochioside A (1), B (2) and C (3), together with the known compound 3-O-[(alpha-L-rhamnopyranosyl-(1 --> 4))(beta-D-glucopyranosyl)]-26-O[beta-D-glucopyranosyl]-(25S)-5beta-spirostane-3beta-ol were isolated from the roots of Asparagus cochinchinensis. Their structures were elucidated by spectroscopic techniques (IR, HR-ESIMS, ESIMS/MS, ID and 2D NMR) and chemical methods as 3-O-[(alpha-L-rhamnopyranosyl-(1 --> 4))(beta-D-glucopyranosyl)]-26-O-[beta-D-glucopyranosyl]-(25S)-5beta-furostane-3beta,22alpha,26-triol (1), 3-O-[(alpha-L-rhamnopyranosyl-(1 --> 4))(beta-D-glucopyranosyl)]-26-O-[beta-D-glucopyranosyl]-22alpha-methoxy-(25S)-5beta-furostane-3beta,26-diol (2), and 3-O-[(alpha-L-rhamnopyranosyl-(1 --> 4))(beta-D-glucopyranosyl)]-26-O-[beta-D-glucopyranosyl]-(25S)-5beta-furost-20(22)-en-3beta,26-diol (3).

Isolation and anti-oomycete activity of nyasol from Anemarrhena asphodeloides rhizomes

The methanol extract of Anemarrhena asphodeloides rhizomes exhibited strong antifungal activity against the plant pathogenic fungi Magnaphothe grisea, Rhizoctonia solani, and the plant pathogenic oomycete Phytophthora capsici. The antifungal substance isolated from the rhizomes of A. asphodeloides was identified to be nyasol, (Z)-1,3-bis(4-hydroxyphenyl)-1,4-pentadiene by NMR and mass spectral analysis. Nyasol effectively inhibited the mycelial growth of Colletotrichum orbiculare, P. capsici, Pythium ultimum, R. solani, and Cladosporium cucumerinum in a range of 1-50 mug/ml, but did not affect the growth of bacteria and yeast. In a greenhouse test, treatment with the antifungal compound nyasol was significantly effective in suppressing the Phytophthora blight on pepper plants.

Effect of five flavonoid compounds isolated from leaves of Diospyros kaki on stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophils

BACKGROUND

The crude drug "kaki-yô" is a traditional medicine used in Japan as a hypotensive drug.

METHODS

The effect of five flavonoid compounds isolated from the leaves of Diospyros kaki was investigated on the stimulus-induced superoxide generation and phosphorylation of tyrosine residues of protein in human neutrophils. The five compounds examined were kaempferol 3-O-beta-D-galactopyranoside (TR), kaempferol 3-O-beta-D-glucopyranoside (AS), isorhamnetin 3-O-beta-D-glucopyranoside (IS), quercetin 3-O-beta-D-galactopyranoside (HY), quercetin 3-O-beta-D-glucopyranosyl-(6-->1)-alpha-L-rhamnopyranoside (RU).

RESULTS

When the cells were preincubated with these five compounds, the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was significantly suppressed in a concentration-dependent manner. The arachidonic acid (AA)-induced superoxide generation was suppressed by TR, AS, HY and RU. On the other hand, the superoxide generation was weakly enhanced by IS in low concentration (5-20 micromol/l), but was suppressed in high concentration (50 micromol/l). The superoxide generation induced by phorbol 12-myristate 13-acetate (PMA) suppressed the TR, IS, HY and RU, but AS gave no effect. When the cells were incubated with fMLP in the presence of TR, IS and RU, fMLP-induced tyrosyl phosphorylation of 45-kDa proteins of the cells was dose-dependently suppressed in parallel to the suppression of fMLP-induced superoxide generation. These five flavonoids showed almost no hemolytic effect even at a concentration of 500 micromol/l.

CONCLUSION

Flavonoid compounds suppressed stimulus-induced superoxide generation and tyrosyl phosphorylation and may have pharmaceutical application.

Effect of three triterpenoids, lupeol, betulin, and betulinic acid on the stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophils

BACKGROUND

The roots of Anemone raddeana are used in Chinese folk medicine for curing rheumatism and neuralgia.

METHODS

The three triterpenoids lupeol, betulin and betulinic acid were isolated from ethanol extracts of the roots of A. raddeana. The effect of these triterpenoids on superoxide generation and tyrosyl phosphorylation of proteins in human neutrophils was investigated.

RESULTS

The superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was significantly suppressed by betulin and lupeol depending on the concentration of the triterpenoids. The suppressive effect of betulinic acid was low. The phorbol 12-myristate 13-acetate (PMA)-induced superoxide generation was suppressed by betulin in a concentration-dependent manner, but not by lupeol and betulinic acid. In contrast, the superoxide generation induced by arachidonic acid (AA) was suppressed by lupeol, while betulin and betulinic acid weakly enhanced the AA-induced superoxide generation. Lupeol and betulin suppressed tyrosyl phosphorylation of a 45.0-kDa protein in fMLP-treated human neutrophils in parallel to the suppression of fMLP-induced superoxide generation, but betulinic acid did not. Lupeol, betulin and betulinic acid showed no hemolytic effect even at a concentration of 500 micromol/l.

CONCLUSIONS

Lupeol and betulin suppress superoxide generation by preventing tyrosyl phosphorylation of a 45.0-kDa protein in human neutrophils, and may have pharmaceutical applications.

Effect of five triterpenoid compounds isolated from leaves of Diospyros kaki on stimulus-induced superoxide generation and tyrosyl phosphorylation in human polymorphonuclear leukocytes

BACKGROUND

The crude drug "kaki-yô" is a traditional medicine used in Japan as a hypotensive drug.

METHODS

The effect of five triterpenoid compounds, isolated from leaves of Diospyros kaki on stimulus-induced superoxide generation and phosphorylation of tyrosine residues of protein in human neutrophils was investigated. The five compounds examined were alpha-amyrin (A), uvaol (UV), ursolic acid (UA), 19 alpha-hydroxy ursolic acid (HU) and 19 alpha,24-dihydroxy ursolic acid (DHU).

RESULTS

When the cells were preincubated with these compounds, the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was significantly suppressed in a concentration-dependent manner. These compounds also suppressed the superoxide generation induced by arachidonic acid (AA) in high concentrations. In the case of the superoxide generation induced by phorbol 12-myristate 13-acetate (PMA), UA, HU and DHU suppressed the superoxide generation but A and UV gave no effect. When the cells were incubated with fMLP in UA, HU and DHU, fMLP-induced tyrosyl phosphorylation of 45 kDa proteins of the cells was dose-dependently suppressed in parallel to the suppression of fMLP-induced superoxide generation.

CONCLUSIONS

Triterpenoid compounds suppress stimulus-induced superoxide generation and tyrosyl phosphorylation and may have pharmaceutical applications.

Effect of six flavonoid compounds from Ixeris sonchifolia on stimulus-induced superoxide generation and tyrosyl phosphorylation in human neutrophils

BACKGROUND

Ixeris sonchifolia (Bge.) Hance is an herbal medication used in China as an analgesic.

METHODS

The effect of six flavonoid compounds isolated from Ixeris sonchifolia (Bge.) Hance on stimulus-induced superoxide generation and phosphorylation of tyrosine residues of protein in human neutrophils was investigated. The six compounds examined were luteolin 7-glucuronide methylester (LGME), luteolin 7-glucuronide ethylester (LGEE), luteolin 7-glucoside (LG), luteolin 7-glucopyranosyl-(1-->6)-glucoside (LGG6), luteolin 7-glucopyranosyl-(1-->2)-glucoside (LGG2) and apigenin 7-glucoside (AG).

RESULTS

When the cells were preincubated with these six flavonoids, the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was significantly suppressed in a concentration-dependent manner. These flavonoids also suppressed the superoxide generation induced by arachidonic acid (AA). The rate of suppression by these flavonoids was AG>LG, LGG6, LGEE, LGG2>LGME. In case of the superoxide generation induced by phorbol 12-myristate 13-acetate (PMA), LG, LGG6 and AG suppressed the superoxide generation but LGME, LGEE and LGG2 gave no effect. When the cells were incubated with fMLP in the presence of LGME, LGEE and AG, fMLP-induced tyrosyl phosphorylation of 45-kDa proteins of the cells was dose-dependently suppressed in parallel to the suppression of fMLP-induced superoxide generation.

CONCLUSION

Flavonoids suppress tyrosine phosphorylase in a dose-dependent manner, and may have pharmacoceutical applications.

Effect of sarsasapogenin and its derivatives on the stimulus coupled responses of human neutrophils

METHODS

The effects of three sapogenins (sarsasapogenin, tigogenin and hecogenin) on the stimulus-induced superoxide generation and protein tyrosyl phosphorylation in human neutrophils were investigated.

RESULTS

When the cells were preincubated with sapogenin, three sapogenins dose-dependently suppressed the superoxide generations induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol 12-myristate 13-acetate (PMA), respectively. In both cases, their effects were in the order: sarsasapogenin>tigogenin>hecogenin. While sarsasapogenin suppressed the superoxide generation induced by arachidonic acid (AA) as well, the superoxide generation was scarcely suppressed by tigogenin and significantly enhanced by hecogenin. In parallel to their effects on the superoxide generation, the three sapogenins dose-dependently suppressed the fMLP-induced and PMA-induced tyrosyl phosphorylations of 45 kDa protein in neutrophils, respectively.

CONCLUSIONS

Of the sapogenins tested, sarsasapogenin may have the most clinical use as it suppresses superoxide generation.

The suppressive effect of mangiferin with exercise on blood lipids in type 2 diabetes

The effect of mangiferin (MF) with exercise on bood lipids was studied in KK-Ay mice, an animal model of type 2 diabetes. MF (30 mg/kg) reduced the blood cholesterol (p<0.05) and triglyceride level (p<0.01) of KK-Ay mice with exercise 2 weeks after oral administration when compared with the control group. Diabetes also often has elevated lipid levels. Therefore, it may be that MF has beneficial effects on hyperlipidemia in type 2 diabetes.

Effect of three flavonoids, 5,7,3',4'-tetrahydroxy-3-methoxy flavone, luteolin, and quercetin, on the stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophil

The effect of three flavonoids, 5,7,3',4'-tetrahydoxy-3-methoxy flavone (THMF), luteolin, and quercetin, on the stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophils were investigated. When the cells were preincubated with these flavonoids, the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was significantly suppressed, showing a dependence on amounts of the flavonoid. The suppressing effect of the flavonoid was THMF > luteolin > quercetin. These flavonoids also suppressed the superoxide generation induced by phorbol 12-myristate 13-acetate. In this case also, THMF was more effective than luteolin and quercetin. On the other hand, the superoxide generation induced by arachidonic acid was markedly suppressed by quercetin. The suppressing effect was quercetin >> THMF > luteolin. THMF, luteolin, and quercetin significantly suppressed tyrosyl phosphorylation of 80.1-, 58.0-, and 45.0-kDa proteins in fMLP-treated human neutrophils. The suppression depended on the concentration of the flavonoids, and the inhibition of tyrosyl phosphorylation was in parallel to that of the fMLP-induced superoxide generation, respectively. While luteolin and quercetin showed a weak hemolytic activity at 2.5 mM, THMF showed almost no hemolytic activity even at 5 mM, suggesting an advantage of THMF for its clinical use.

Effect of five flavonoid compounds isolated from Quercus dentata Thunb on superoxide generation in human neutrophils and phosphorylation of neutrophil proteins

Effect of five yellow compounds isolated from Quercus dentata on superoxide generation and protein phosphorylation in human neutrophils was investigated. The five yellow compounds examined were Kaempferol 3-O-beta-D-glucopyranoside (B), quercetin 3-O-beta-D-glucopyranoside (DA), Kaempferol 3-O-(6"-trans-p-coumaroyl)-beta-D-glucopyranoside (D1), Kaempferol 3-O-(2"-6"-di-trans-p-coumaroyl)-beta-D-glucopyranoside (D7) and Kaempferol 3-O-(2",4"-di-acetyl-3"-cis-p-coumaroyl-6"-trans-p-coumaroyl)-beta-D-glucopyranoside (A). D7 suppressed significantly the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP). D1 and DA suppressed significantly the superoxide generation induced by arachidonic acid (AA). However, the superoxide generation induced by phorbol 12-myristate 13-acetate (PMA) was suppressed by all yellow compounds. When the cells were incubated with fMLP and D7, the tyrosyl phosphorylation of 67, 60, 58 and 38 kDa proteins of the cells was markedly decreased in a concentration-dependent manner.

Effect of six compounds isolated from rhizome of Anemone raddeana on the superoxide generation in human neutrophil

The effect of six compounds isolated from rhizome of Anemone raddeana on the superoxide generation in human neutrophils was investigated. The six compounds examined were 3-acetyloleanolic acid (AOA), oleanolic acid (OA), eleutheroside K (EK), oleanolic acid-3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 4)]-alpha-L-arabinopyranoside (Rd10), raddeanoside 12 (Rd12) and raddeanoside 13 (Rd13). AOA, OA, Rd12 and Rd13 suppressed the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) in a concentration-dependent manner. EK and Rd10 significantly enhanced the fMLP-induced superoxide generation in a specific narrow range of low concentration (0.5-0.75 microM), while these compounds more efficiently suppressed the superoxide generation than the other four compounds in other concentrations. In the case of superoxide generation induced by phorbol 12-myristate 13-acetate (PMA), Rd12, OA, EK and Rd10 dose-dependently suppressed the superoxide generation but AOA and Rd13 gave no effect. Arachidonic acid-induced superoxide generation was suppressed by EK, Rd10, Rd12 and Rd13, but was weakly enhanced by AOA and OA. Rd12 dose-dependently inhibited fMLP-induced tyrosyl phosphorylation of 123.0, 79.4, 60.3, 56.2 and 50.1 kDa proteins in human neutrophil. On the other hand, RD10 and EK enhanced the tyrosyl phosphorylation of these proteins in a low concentration range. These phenomena were parallel to the suppression of the fMLP-induced superoxide generations.

Spirostanols obtained by cyclization of pseudosaponin derivatives and comparison of anti-platelet agglutination activities of spirostanol glycosides

Naturally occurring saponins 3 and 4 have a normal type F ring and alpha-arranged CH(3)-21 group. Treatments of pseudosaponin peracetates 18 and 19 derived from 3 and 4, respectively, with alcoholic KOH, followed by acidification with acetic acid, gave spirostanols 20 and 22 having iso type F rings as major products. Structural analyses of sapogenins and saponins derived from pseudo derivatives 11, 12, 18 and 19 were performed by comparisons of their 1H-NMR spectral data and the X-ray analytical data of 3-O-p-bromobenzoyl sarsasapogenin 7, 3-O-acetyl diosgenin 13 and saponin 20. The mechanisms of ring-closure reaction of the side chain at C-22 of pseudosapogenins and pseudosaponins were deduced using stereomodels of the spirostanols derived from 11 under various reaction conditions. Inhibitory activities of saponin diglycosides 3, 4, 20, 21 and 25 on human platelet agglutinations induced by ADP and ristocetin were compared.

Effect of timosaponin E1 and E2 on superoxide generation induced by various stimuli in human neutrophils and on platelet aggregation in human blood

We have reported that six steroidal saponins isolated from Anemarrhenae rhizoma had various effects on stimulus-induced superoxide generation in human neutrophils. In this paper, two novel steroidal saponins, timosaponins E1 and E2 were isolated from Anemarrhenae rhizoma, and the effects of these steroidal saponins on superoxide generation in human neutrophils were investigated. Timosaponins E1 and E2 significantly inhibited N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced superoxide generation in a concentration-dependent manner, but not that induced by arachidonic acid (AA). On the other hand, both compounds enhanced superoxide generation induced by phorbol 12-myristate 13-acetate (PMA) in a concentration-dependent manner. The superoxide generation induced by PMA with timosaponins E1 and E2 was suppressed by staurosporine, an inhibitor of protein kinase C, but was not suppressed by genistein, an inhibitor of protein tyrosine kinase. Tyrosyl phosphorylation of a 58 kDa protein, which was increased by fMLP, was inhibited by timosaponins E1 and E2. Timosaponins E1 and E2 also inhibited the generation of a 47 kDa protein and platelet aggregation in human blood. The results suggest that protein tyrosine kinase participates in fMLP-mediated superoxide generation by timosaponin E1- and E2-treated human neutrophils.

Effect of six steroidal saponins isolated from anemarrhenae rhizoma on platelet aggregation and hemolysis in human blood

Six steroidal saponins were isolated from Anemarrhena asphodeloides Bunge (Liliaceae), a traditional chinese medicine, and named anemarrhenasaponin I (An-I), anemarrhenasaponin Ia (An-Ia), timosaponin B-I (TB-I), timosaponin B-II (TB-II), timosaponin B-III (TB-III), and timosaponin A-III (TA-III). The effects of these six compounds on platelet aggregation and hemolysis in human blood were studied. All these compounds provoked remarkable inhibiting effect on platelet aggregation, and activated partial thromboplastin times (APTT) are sensitive to the presence of these six compounds. Using an in vitro system, APTT was delayed with the increment of the concentrations of these six compounds. In these six compounds, only timosaponin A-III appeared a strong effect on hemolysis, and anemarrhenasaponin Ia had a slight effect on hemolysis, other had no effect on hemolysis. These results suggested that these steroidal saponins isolated from Anemarrhena asphodeloides Bunge (Liliaceae) might be used as a novel antithrombotic therapeutic agents in post-myocardial infarction.

Effect of steroidal saponins of Anemarrhenae rhizoma on superoxide generation in human neutrophils

Effect of six steroidal saponins isolated from Anemarrhenae rhizoma on superoxide generation in human neutrophils was investigated. The steroidal saponins examined were anemarrhenasaponin-I (An-I), anemarrhenasaponin-Ia (An-Ia), timosaponin B-I (TB-I), timosaponin B-II (TB-II), timosaponin B-III (TB-III) and timosaponin A-III (TA-III). An-I, An-Ia, and TB-III suppressed the superoxide generations induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) and arachidonic acid (AA) in a concentration-dependent manner, but enhanced that induced by phorbol 12-myristate 13-acetate (PMA). While TB-II also suppressed and enhanced the superoxide generations induced by fMLP and PMA, respectively, the compound significantly enhanced the AA-induced superoxide generation. TB-I enhanced the fMLP-induced superoxide generation in a low concentration range (peak at 40 microM), gave no effect on the PMA-induced superoxide generation and weakly enhanced the AA-induced superoxide generation. TA-III enhanced the fMLP-induced superoxide generation more than twice as much as that by TB-I in the same concentration range. However, TA-III enhanced the PMA-induced superoxide generation and most significantly suppressed the AA-induced superoxide generation.