Jincai Lu

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 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.

Antiperoxidation activity of triterpenoids from rhizome of Anemone raddeana

Four triterpenoid compounds hederacolchiside E (1), hederasaponin B (2), raddeanoside 20 (3) and raddeanoside 21 (4) were isolated from ethanol extracts of rhizome of Anemone raddeana Regel. The effects of these triterpenoids on superoxide generation, tyrosyl phosphorylation of proteins and translocation of cytosolic compounds, such as p47(phox), p67(phox) and Rac to the cell membrane in human neutrophils was investigated. The superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was slightly suppressed by hederasaponin B, raddeanoside 20 and raddeanoside 21 in a concentration dependent manner. The superoxide generation induced by arachidonic acid (AA) was suppressed by hederasaponin B and raddeanoside 21 significantly. fMLP- and AA-induced tyrosyl phosphorylation and translocation of the cytosolic proteins: p47(phox), p67(phox), and Rac to the cell membrane were suppressed in parallel with the suppression of stimulus-induced superoxide generation.

Inhibitory Effects of Ginsenosides from the Root of Panax ginseng on Stimulus-Induced Superoxide Generation, Tyrosyl or Serine/Threonine Phosphorylation, and Translocation of Cytosolic Compounds to Plasma Membrane in Human Neutrophils

The effects of five ginsenosides (G-Rh2, -Rd, -Rb1, -Rb2, -Rh1) isolated from the root of Panax gingseng on stimulus-induced superoxide generation in human neutrophils were evaluated by measuring the reduction of ferricytochrome c. The tyrosyl or serine/threonine phosphorylation of neutrophil proteins and translocation of p47phox, p67phox, and Rac to the plasma membrane were detected using specific monoclonal antibodies. G-Rh2 significantly suppressed superoxide generation induced by N-formylmethionyl-leucylphenylalanine (fMLP), phorbol 12-myristate 13-acetate (PMA), and arachidonic acid (AA) in a concentration-dependent manner. G-Rh1 showed a comparably lower suppression on fMLP-induced superoxide generation. G-Rd, -Rb1, and -Rb2 also suppressed AA-induced superoxide generation in high concentrations. G-Rd and G-Rb1 showed no effect on fMLP- and PMA-induced superoxide generation. FMLP-, PMA-, and AA-induced tyrosyl or serine/threonine phosphorylation and translocation of p47phox, p67phox, and Rac to the plasma membrane were in parallel with the suppression of the stimulus-induced superoxide generation.

Structure elucidation of two triterpenoid saponins from rhizome of Anemone raddeana Regel.

Two new 27-hydroxy-oleanolic acid type triterpenoid saponins, raddeanoside 20 (1) and raddeanoside 21(2) were isolated from the rhizome of Anemone raddeana Regel. The structures of the two compounds were elucidated as 27-hydroxy-oleanolic acid 3-O-alpha-L-rhamnopyranosyl(1-->2) [beta-D-glucopyranosyl (1-->4)]-alpha-L-arabinopyranoside (1) and 3-O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranosyl-27-hydroxy-oleanolic acid 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (2) on the basis of chemical and spectral evidence.

New flavonoid glycosides from Sedum aizoon L.

Five new flavonoid glucosides (3-4, 10-12) and a new phenolic derivative (5), together with eight known compounds including three flavonoid glucosides (6-8), three phenolic compounds (1-2, 9) and two megastigmane glucosides (13, 14), were isolated from the ethanol extract of the aerial part of Sedum aizoon L. Among them, compounds 9, 13 and 14 were isolated and identified from this genus for the first time. The structures of compounds were elucidated on the basis of 1D and 2D NMR (HSQC, HMBC and COSY) spectra and the HR-ESI-MS data. These compounds were tested for their antibacterial efficacies against both Gram-positive and Gram-negative bacteria. Compounds 1, 2, 3, 7 and 10 showed certain antibacterial activity; it showed more potency against Gram-positive than against Gram-negative bacteria. Compound 2 showed the most pronounced antibacterial effectiveness against Staphylococcus aureus Rosenbach with MIC value of 7.8μg·mL(-1). The in vitro anti-proliferative activities against HepG2, MCF-7 and A549 tumor cell lines were also evaluated. The result suggested compound 7 exhibited moderate cytotoxic activities with IC50 values of 46.30, 75.27 and 49.76μmol/L, respectively.

Effects of five oleanolic acid triterpenoid saponins from the rhizome of Anemone raddeana on stimulus-induced superoxide generation, phosphorylation of proteins and translocation of cytosolic compounds to cell membrane in human neutrophils

Five oleanolic acid triterpenoid saponins (OTS-1, 2, 3, 4 and 5) were isolated from the rhizome of Anemone raddeana. The effect of these triterpenoid saponins on stimulus-induced superoxide generation in human neutrophils was assayed by measuring the reduction of ferricytochrome c using a dual-beam spectrophotometer. The phosphorylation of neutrophil proteins, and translocation of p67(phox), p47(phox) and Rac to plasma membrane were investigated using specific monoclonal antibodies. The five oleanolic acid triterpenoid saponins used in this experiment suppressed N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced superoxide generation in a concentration-dependent manner. OTS-1, 2 and 4 suppressed phorbol 12-myristate 13-acetate (PMA)- and arachidonic acid (AA)-induced superoxide generation in a concentration-dependent manner, but OTS-3 and 5 showed no effect. fMLP- and PMA-induced tyrosyl or serine/threonine phosphorylation, and fMLP-, PMA- and AA-induced translocation of p67(phox), p47(phox) and Rac to plasma membrane were in parallel with the suppression of the stimulus-induced superoxide generation.

Validated UPLC-MS/MS method for simultaneous quantification of eight saikosaponins in rat plasma: Application to a comparative pharmacokinetic study in depression rats after oral administration of extracts of raw and vinegar-baked Bupleuri Radix

A sensitive and efficient UPLC-MS/MS method was developed and validated for simultaneous quantification of eight saikosaponins (SSa, SSb1, SSb2, SSb3, SSb4, SSc, SSd and SSf) in rat plasma. Furthermore, comparative pharmacokinetic profiles of these sakosaponins were investigated, following oral administration of extracts of raw and vinegar-baked Bupleuri Radix to depression rats. Biosamples were processed with liquid-liquid extraction technique using ethyl acetate. Chromatographic separation was accomplished on Waters BEH C18 UPLC column. 0.05% formic acid in water and acetonitrile as mobile phase was used at a flow rate of 0.40mL/min. The analytes and internal standard, digoxin, were detected using negative ion electrospray ionization in multiple reaction monitoring mode. The lower limit of quantification was less than 0.62ng/mL for the each analyte. The validation parameters investigated, which were specificity, precision, accuracy, matrix effect, recovery and stability, were well within acceptable limits. Results showed that for some of analytes, AUC0-t and Cmax were significantly different after oral administration of extracts of raw and vinegar-baked Bupleuri Radix. Moreover, the pharmacokinetic study in pathological state could provide more useful information to guide the clinical usage of Bupleuri Radix.

A new sesquiterpene lactone glucoside with inhibitory effect on K562 cells from Ixeris sonchifolia (Bge) Hance

A new minor sesquiterpene lactone glucoside, ixerin ZA (1), together with 16 known compounds, were isolated from the whole plants of Ixeris sonchifolia (Bge) Hance. The structure of 1 was elucidated as 1(10),3,11(13)-guaiatriene-12,6-olide-2-one-3-O-[6′-(p-metheoxyphenylacetyl)]-β-glucopyranoside on the basis of spectroscopic and chemical evidence. Compound 1 exhibited an inhibitory effect on K562 cells.

Bioactivity-guided isolation of chemical constituents against H2O2-induced neurotoxicity on PC12 from Cimicifuga dahurica (Turcz.) Maxim

Three new compounds (1, 6, 9), with six known compounds (2-5, 7-8) were obtained from water-soluble extract of Cimicifuga dahurica (Turcz.) Maxim. by bioactivity-guided isolation. Their structures were elucidated by chemical and spectral analysis, including 1D, 2D NMR data and HRESIMS. H2O2-induced neurotoxicity on PC12 cells model were conducted to evaluate the neuro-protective capability of these compounds. The piscidic acid derivatives compounds 4-7 showed marked neuro-protective effect at certain concentration.