Steroidal saponins from Dioscorea panthaica and their cytotoxic activity

A new steroidal saponin, dioscoreside E (1), and a known compound, protodioscin (2), were isolated from an ethanol extract of the rhizomes of Dioscorea panthaica. The structure of 1 was established as 3-O-[bis-alpha-L-rhamnopyranosyl-(1 --> 2 and 1 --> 4)-beta-D-glucopyranosyl]-26-O-beta-D-glucopyranosyl-20(R)-methoxy-25(R)-furosta-5,22(23)-diene-3beta,26-diol, on the basis of spectral and chemical evidence. Compounds 1 and 2 showed cytotoxic activity against a panel of tumor cell lines.

Two new steroidal saponins from the rhizomes of Dioscorea panthaica and their cytotoxic activity

Two new steroidal saponins, dioscoresides C (1) and D (2), along with a new natural product, pregnadienolone 3-O-beta-gracillimatriose (3), and two known compounds, pregnadienolone 3-O-beta-chacotrioside (4) and pseudoprotodioscin (5), were isolated from the rhizomes of Dioscorea panthaica Prain et Burkill. On the basis of extensive NMR studies and chemical evidence, dioscoresides C and D were determined to be 26-O-beta-D-glucopyranosyl-3 beta,26-dihydroxy-23(S)-methoxy-25(R)-furosta-5,20(22)-dien-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside and 26-O-beta-D-glucopyranosyl-3 beta,26-dihydroxy-20,22-seco-25(R)-furosta-5-en-20,22-dine-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1--> 4)]-beta-D-glucopyranoside. These compounds showed mild cytotoxicity against the cancer cell lines, A375, L929, and HeLa, in a dose-dependent manner.

[A comparison of chemical composition and bioactivity of polypeptides from velvet antlers of Cervus nippon Temminck and Cervus elaphus Linnaeus]

OBJECTIVE

To compare the chemical composition and bioactivity of polypeptides(PPs) isolated from velvet antlers of sika deer (Cervus nippon Temminck) and red deer (Cervus elaphus Linnaeus).

METHOD

The two kind of polypeptides were isolated from the above mentioned velvet antlers with same technology. The chemical composition was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and MALDI-TOF mass spectrometry. Stimulant activity of cells proliferation was measured by [3H] TdR incorporation into DNA.

RESULT

The graphs of SDS-PAGE and MALDI-TOF MS of velvet antler polypeptides (VAPPs) from Chinese and New zealand red deer were very similar, but there were obvious difference in respect of graph between sika deer and red deer. VAPPs 25-50 mg.L-1 showed marked proliferation-promoting activity for rabbit costed chondrocytes, either sika deer or red deer. However, the activity of sika deer VAPPs 12.5 mg.L-1 for epidermal cells was weaker than that of red deer (12.5 mg.L-1).

CONCLUSION

The chemical property and bioactivity of VAPPs from sika deer and red deer are significantly different.

[Metabolism of ginsenoside Rb1 and panaxadiol saponins by fungi]

AIM

To study the metabolic process of ginsenoside Rb1 (G-Rb1) and panaxadiol saponins (PDS) by fungi.

METHODS

Ten strains of fungi were incubated with G-Rb1 and PDS at a certain temperature with shaking. A portion was taken out at different time and mixed up with butanol. The butanol extract was analysed by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and electrospray ionazition mass spectrometry (ESI-MS).

RESULTS

It was found that there were ginsenoside-Rd (G-Rd), ginsenoside-F2 (G-F2), compound K (CK) and 20(S) protopanaxadiol (Ppd) metabolites beside the prodrug G-Rb1 induced by fungi (No. 1, 2, 3, 6, 8, 9).

CONCLUSION

The six strains of fungi have different degrees of ability to metabolize G-Rb1 and PDS. The possible metabolic process could be as follows: G-Rb1 (or PDS)-->G-Rd-->G-F2-->CK-->Ppd.

[Studies on metabolism of oxymatrine by human intestinal bacteria]

OBJECTIVE

To study the oxymatrine metabolism induced by human intestinal bacteria and its absorbed metabolites in blood.

METHOD

TLC and HPLC were used to examine oxymatrine and its metabolites, and UV, IR, NMR and MS were used to confirm the chemical structures of the metabolites.

RESULT

Oxymatrine was transformed into matrine by human intestinal bacteria metabolism in vitro. Rats were given orally oxymatrine 100 mg.kg-1 and were decapitated 3 hours after administration, and their blood was taken to examine serum metabolites by TLC and HPLC, which revealed that oxymatrine and matrine were absorbed into blood.

CONCLUSION

Oxymatrine will be transformed into matrine when it is given orally and both of the alkaloids can be absorbed to blood.

[Research on the transformation of ginsenoside Rg1 by intestinal flora]

OBJECTIVE

The decomposition of Ginsenoside Rg1(Rg1) by intestinal bacteria in rats or human was investigated both in vitro and in vivo.

METHOD

The decompositions were investigated by means of thin-layer chromatography and Electron spurt ion mass.

RESULT

It was found that Rg1 was converted into two metabolites [Rh1 and 20(S)-protopanaxatriol(20S-Ppt)] by human intestinal bacteria in vitro, while three compounds [Rh1, F1, and 20(S)-Ppt] were detected in rat intestinal bacteria metabolism in vitro and in vivo.

CONCLUSION

The decomposition and/or metabolism of Rg1 in rat and human digestive tract was confirmed. The mode of metabolism in rat is Rg1-->Rh1(F1)-->Ppt, while in human it is Rg1-->Rh1-->Ppt.

[Isolation and identification of steroidal saponins from Dioscorea panthaica Prain et Burkill]

AIM

To investigate the chemical constituents of the rhizomes of Dioscorea panthaica Prain et Burkill and look for new active compounds.

METHODS

The compounds were isolated with silica gel and HPLC, and their structures were elucidated on the basis of chemical evidences and spectral analysis (IR, ESI-MS, 1HNMR, 13CNMR, DEPT, 1H-1H COSY, HMQC, HMBC, NOESY).

RESULTS

Three steroidal saponins were isolated from the rhizomes of Dioscorea panthaica. They were elucidated as 26-O-beta-D-glucopyranosyl-3 beta, 26-diol-23(S)-methoxy-25(R)-delta 5,20(22)-diene-furosta-3-O-[alpha-L-rhamnopyranosyl-(1-->2)- O-alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (I), pseudoprotodioscin (II), 26-O-beta-D-glucopyranosyl-3 beta, 26-diol-25 (R)-delta 5,20(22)-diene-furosta-3-O-alpha-L-rhamnopyranosyl- (1-->2)-O-beta-D-glucopyranoside (III).

CONCLUSION

Compound I is a new steroidal saponin and was named as dioscoreside C. Compound II and III were obtained from this genus for the first time.

Effects of polysaccharides (FI0-b) from mycelium of Ganoderma tsugae on proinflammatory cytokine production by THP-1 cells and human PBMC (I)

AIM

To compare the effects of water-soluble polysaccharides, FI0-b, and its formic acid-modified derivative, FI0-b-H, on production of human proinflammatory cytokines.

METHODS

The polysaccharides were modified by formic acid. Cytokine production was quantitated by radioimmunoassay. mRNA for cytokines was measured by semi-quantitative RT-PCR.

RESULTS

FI0-b and FI0-b-H 4, 40, and 400 mg/L significantly downregulated interleukin-1 alpha (IL-1 alpha) production by THP-1 cells induced by lypopolysaccharide (LPS) 1 or 10 mg/L and phorbol myristate acetate (PMA) 200 nmol/L. At lower stimulation with LPS 10 mg/L and PMA 200 nmol/L, both polysaccharides significantly upregulated tumor necrosis factor alpha (TNF alpha) production by THP-1 cells. However, at higher stimulation with LPS 100 mg/L and PMA 200 nmol/L, they downregulated TNF alpha production. FI0-b-H downregulated interleukin-8 (IL-8) production by THP-1 cells at a lower-dose of LPS 1 mg/L and PMA 200 nmol/L, but upregulated IL-8 production at a higher-dose of LPS 10 mg/L and PMA 200 nmol/L. Production of cytokines (IL-1 alpha and TNF alpha) was transcriptionally or post-transcriptionally regulated by FI0-b and FI0-b-H.

CONCLUSION

The water-soluble polysaccharides of Ganoderma tsugae mycelium have bidirectional immunomodulatory effects on cytokine production in different stimulatory conditions in a dose-dependent manner. Compared with FI0-b, FI0-b-H has more marked effects on human proinflammatory cytokine production.

Effects of polysaccharides (FI0-c) from mycelium of Ganoderma tsugae on proinflammatory cytokine production by THP-1 cells and human PBMC (II)

AIM

To study the effects of water-soluble polysaccharides. FI0-c, and its sulfated derivative, FI0-c-S, on production of human proinflammatory cytokines, interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha).

METHODS

The herbal polysaccharides were modified by chlorosulfornic acid in dimethyl sulfoxide (Me2SO). Cytokine production was measured by radioimmunoassay, mRNA for the cytokines was measured by semi-quantitative RT-PCR.

RESULTS

FI0-c 4 mg/L itself induced IL-1 alpha production by THP-1 cells without stimulants, such as lipopolysaccharides (LPS) and phorbol myristate acetate (PMA). On the other hand, FI0-c and FI0-c-S inhibited the IL-1 alpha production by THP-1 cells with these stimulants. FI0-c and FI0-c-S significantly upregulated TNF alpha production by THP-1 cells without stimulants or at a low dose of LPS 10 mg/L and PMA 200 nmol/L, whereas these polysaccharides markedly downregulated the TNF alpha production by a high dose of LPS 100 mg/L and PMA. Human peripheral blood mononuclear cells (PBMC) responded to FI0-c and FI0-c-S in IL-1 alpha and TNF alpha production in a fashion similar to THP-1 cell responses. FI0-c 4 mg/L downregulated high-dose LPS- and PMA-induced IL-1 alpha or TNF alpha mRNA and their protein production by THP-1 cells.

CONCLUSION

The water-soluble polysaccharides of Ganoderma tsugae mycelium have bidirectional immunomodulatory effects on cytokine production in different cell stimulatory conditions. Chemical modification of this polysaccharide changed the intensity of regulatory effect on cytokine production.

Metabolism of ginsenoside Rg1 by intestinal bacteria. II. Immunological activity of ginsenoside Rg1 and Rh1

AIM

To compare the effect of ginsenoside Rg1 and its metabolite Rh1 on proinflammatory cytokines and their mRNA expression by THP-1 cells.

METHODS

Human peripheral blood mononuclear cells (PBMC) were incubated with Rg1 and Rh1 at concentrations of 0.1, 1, 10, and 100 mg/L, and the cell proliferation was measured 24 h after incubation. Radioimmunoassay (RIA) was used to detect the production of proinflammatory cytokines, TNF alpha, IL-1 alpha, and IL-8. TNF alpha mRNA level was detected by reverse transcription polymerase chain reaction (RT-PCR) after administration of Rg1 and Rh1.

RESULTS

Rg1 and Rh1 (at concentration of 0.1, 1, 10, 100 mg/L) had no effect on PBMC proliferation. Rh1 1 mg/L could upregulate the productions of TNF (and IL-8 induced by lipopolysaccharides (LPS) 10 mg/L plus phorbol myristate acetate (PMA) 200 nmol/L, however, Rg1 showed an inhibitory effect on TNF alpha production induced by LPS 100 mg/L. Rg1 1 mg/L and Rh1 100 mg/L enhanced the production of IL-1 alpha level in THP-1 cells in the presence of LPS 10 mg/L. RT-PCR revealed that Rh1 stimulated TNF alpha mRNA expression in suitable stimulatory conditions.

CONCLUSION

Rg1 and Rh1 have different effects on the production of cytokines produced THP-1 cells stimulated by LPS and PMA.

Oxidative modification of neurogranin by nitric oxide: an amperometric study

Neurogranin (Ng) is a neuron-specific protein kinase C (PKC) substrate, which contains four cysteine (Cys) residues. Recently, it has been shown that Ng is a redox-sensitive protein and is a likely target of nitric oxide (NO) and other oxidants [F.-S. Sheu, C.W. Mahoney, K. Seki, K.-P. Huang, Nitric oxide modification of rat brain neurogranin affects its phosphorylation by protein kinase C and affinity for calmodulin, J. Biol. Chem. 271 (1996) 22407-22413: J. Li, J.H. Pak, F.L. Huang, K.-P. Huang, N-methyl-D-aspartate induces neurogranin/RC3 oxidation in rat brain slices, J. Biol. Chem. 274 (1999) 1294-1300]. In this study, we directly examine the redox reactions between dissolved NO and Cys as well as between NO and bacterial expressed Ng in its reduced form, at concentrations approximate to the physiological levels in phosphate buffer solution (PBS) under aerobic conditions. The reaction kinetics are measured directly by our newly developed electrochemical sensor. Our sensor is based on the chemical modification of electrode with immobilized nanoparticles of transition metal palladium (Pd) which serves as catalytic centers for the electrochemical oxidation of thiol and NO selectively and quantitatively at different potentials. It detects Cys and Ng in a linear range from nano to micromolar concentration at + 450 mV, vs. a saturated calomel reference electrode (SCE), while the detection of NO at the sensor can be optimally achieved at + 700 mV (vs. SCE) with a linear current-to-concentration range of nM to microM. It thus provides a selective control to monitor two reactants independently. With this sensor as a detector, we found that (1) the oxidation of either Cys or Ng by NO is a fast reaction which reaches a near completion within 1-2 min at its physiological concentration; and (2) after the completion of reaction, NO is mostly, if not all, regenerated, an observation consistent with the reaction mechanism involving the formation of S-nitrosothiol as an intermediate. The reaction kinetics of both NO to Cys and NO to Ng implies that NO can achieve local action on cellular proteins in addition to its effect on targets located in neighboring cells via concentration-gradient-dependent diffusion.

Velvet antler polypeptides promoted proliferation of chondrocytes and osteoblast precursors and fracture healing

AIM

To study the effects of velvet antler (VA) total polypeptides (VATP) and VA polypeptides, VAP-A, VAP-B, and VAP-C on proliferation of chondrocytes and osteoblast precusors.

METHODS

Chondrocytes (rabbit and human fetus) and osteoblast precusors (chick embryo) were incubated in the culture medium containing VATP or VAP-A, VAP-B, and VAP-C. [3H]TdR incorporation into DNA was measured. Fracture healing-promoting action of VATP was determined in rats.

RESULTS

VATP 50-200 mg.L-1 and VAP-B 12.5, 25, and 50 mg.L-1 showed most marked proliferation-promoting activity for rabbit costed chondrocytes and increased incorporation of [3H]TdR from (73 +/- 9) Bq (control group) to (272 +/- 55), (327 +/- 38), and (415 +/- 32) Bq, respectively (P < 0.01). The activity of VAP-A was weaker than that of VAP-B, and VAP-C had no activity. VATP 10 and 20 mg.kg-1 by local injection into the cross-section fracture area accelerated healing of radial fracture. The healing rate of VATP-treated group was higher (75%) than that of control group (25%) (P < 0.05).

CONCLUSION

VATP accelerated fracture healing by stimulating proliferation of chondrocytes and osteoblast precursors.

[Anti-inflammatory effects of pilose antler peptide]

Pilose antler peptide (PAP:MW:7200; amino acid residue:68) isolated from the antlers of Cervus nippon temminck 10 and 20 mg.kg-1 i.p. produced inhibitions towards acute and chronic inflammations in a dose-dependent manner. PAP reduced ascorbic acid and cholesterol contents in adrenal glands and decreased the serum hydrocortisone level of rats. The reduction of ascorbic acid and cholesterol contents were unaffected by the pretreatment of dexamethasone. PAP also showed an anti-inflammatory action on the swelling of carrageenan-induced hind paw in adrenalectomized rats. The results suggest that the anti-inflammatory effects of PAP do not depend absolutely on pituitary-adrenal system.

The effect of pressure on ultrasonic testing sensitivity of hot steel blooms by pressure contact method

The effect of exerted pressure of the buffer rod on the sensitivity of ultrasonic testing of hot steel blooms by the pressure contact method is discussed. The formula describing their linear relation is introduced. Results show that, at a given temperature, sensitivity increases linearly with pressure until a certain pressure is reached where sensitivity is rather insensitive to pressure variations. However, this pressure region is not always used. The proper choice of exerted pressure for practical use is analyzed.

[A tablet of Tripterygium wilfordii in treating lupus erythematosus]

Twenty-three cases of lupus erythematosus, including 15 cases of SLE and 8 cases of DLE treated with Tripterygium wilfordii (TW, three tablets thrice a day, each tablet contains 5 gm of crude TW) were reported. As controls, 19 cases of SLE were treated with prednisone alone at the same time. 9/15 cases in the former group and 6/19 in the latter got improvement after treatment. There was no significant difference between the two groups (P greater than 0.10). However, TW had beneficial effects to remission of arthralgia (7/10 in the former group and 7/15 in the latter group) and erythematosus rash (6/8 in the former group and 5/12 in the latter). Clinically, four out of eight cases of DLE improved after treatment with TW. TW had some toxic effects, such as decrease of peripheral blood leukocyte and kidney damage. Since the toxic dose and effective dose could be quite close, special attention should be paid when the drug was being used, especially on those patients with nephropathy. So the authors suggested that the indication of TW could include the patients of DLE and SLE without nephropathy.

Biochemical changes related to aging in the senescence-accelerated mouse

Several biochemical parameters reflecting the degree of senescence were compared between senile-prone (P) and resistant (R) strains of male senescence-accelerated mouse (SAM) at 11 to 12 months of age. Plasma testosterone in SAM-P amounted to half the concentration in SAM-R. In the liver and brain of SAM-P, the content of malondialdehyde (MDA) and the activity of monoamine oxidase B (MAO-B) were significantly higher than those in SAM-R. Moreover, large amounts of fluorescent lipofuscin were detected in the SAM-P liver. Compared with SAM-R, both membrane and cytosolic fractions from the SAM-P liver contained small amounts of protein and showed less activity of superoxide dismutase (SOD). The present findings suggest that the male SAM-P rapidly acquires biochemical changes which are considered to be part of the normal aging process.

Induction of rat hepatic cytochromes P-450 by environmental nitropolycyclic aromatic hydrocarbons

Nitrated polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants that result from various incomplete combustion processes. We have examined the activity of hepatic microsomal enzymes in rats pretreated with a series of environmentally occurring nitrated PAHs including: 1- and 4-nitropyrene, 1,3-, 1,6- and 1,8-dinitropyrene, 6-nitrochrysene, 7-nitrobenz[a]anthracene, 3-nitrofluoranthene, and 1-, 3-, and 6-nitrobenzo[a]pyrene. None of the compounds increased the cytochrome P-450 content more than 2-fold. 1,8-Dinitropyrene, 6-nitrochrysene, and 1- and 3-nitrobenzo[a]pyrene significantly increased arylhydrocarbon hydroxylase activity 2- to 8-fold higher than solvent-treated controls. The induction of 7-ethoxycoumarin O-deethylase activity paralleled that found with arylhydrocarbon hydroxylase. The maximum induction of aminopyrine N-demethylase was only 1.5-fold, and none of the nitrated PAHs caused significant increases in epoxide hydrase or NADPH-cytochrome c reductase. 1-Nitropyrene reductase activity was induced by each of the compounds with the exception of 6-nitrobenzo[a]pyrene. The greatest increase was caused by 1-nitrobenzo[a]pyrene followed by 1,3-dinitropyrene, 3-nitrobenzo[a]pyrene and 6-nitrochrysene. These data suggest that nitrated PAHs may potentiate the effects of subsequent exposures to various chemical carcinogens.