Effect of L-cycloserine on cellular responses mediated by macrophages and T cells

In this study, we examined the immunoregulatory roles of L-cycloserine (L-CS), a sphingolipid metabolism regulator with inhibitory activity of serine palmitoyltransferase (SPT), on immune responses mediated by monocytes/macrophages and T cells. Mitogenic responses of splenic lymphocytes induced by LPS, PHA, and Con A were very strongly suppressed by L-CS with IC(50) values ranging from 0.5 to 1 muM. In contrast, this compound less strongly blocked IL-2-induced CD8+ CTLL-2 cell proliferation with an IC(50) value of 540 muM. Interestingly, L-CS enhanced the number of IL-4-producing helper T cells, indicating the favored induction of Th2 condition. Although tumor necrosis factor (TNF)-alpha and nitric oxide (NO) production was not altered under 10% FCS condition, U937 cell-cell adhesion as well as the surface level of adhesion molecules (CD29 and CD98) were significantly suppressed by L-CS. In particular, reduced serum level (5%) under L-CS treatment strongly enhanced the production of TNF-alpha and the inhibitory potency of NO production and cell adhesion. Finally, sphingolipids (D-sphingosine and DL-dihydrosphingosine) did not remarkably abrogate L-CS-mediated T cell proliferation. Therefore our data suggest that de novo sphingolipid metabolism may represent an important aspect of immunomodulatory activities mediated by T cells and macrophages/monocytes, depending on serum level.     

Inhibition of interleukin-2 production and lymphocyte responsiveness by the cell activation inhibitor, CI-959.

CI-959 (5-methoxy-3-(1-methylethoxy)-N-1H-tetrazol-5-yl-benzo [b]-thiophene-2-carboxamide), an antiallergy compound, blocked release of IL-2 from Con A stimulated rat splenocytes and human lymphocytes with respective IC50s of 19.1 and 23.1 microM. Inhibition of IL-2 production required the presence of CI-959 in culture medium for the first 9 hr. CI-959 also inhibited Con A-stimulated rat and human lymphocyte proliferation with IC50s of 4.7 and 5.4 microM, respectively. Inhibition of the Con A proliferative response could not be overcome by exogenous recombinant human IL-2 (300 units/ml) in either the rat or human systems. Although potent in the human mixed lymphocyte reaction (IC50 = 3.5 microM), CI-959 was less effective in blocking the PHA response (IC50 = 43.9 microM), and had minimal effect on the release of IL-1 and TNF alpha from LPS-stimulated human monocytes. These findings suggest that CI-959 selectively inhibits some lymphocyte functions, as opposed to monocyte functions, and that among these is the production of IL-2.     

Inhibition of lymphocyte activation and function by the prenylation inhibitor L-778,123

Prenylated Ras GTPases transduce signals from the T cell receptor, CD28 costimulatory receptor and IL-2 receptor. Since signals from these receptors mediate T cell activation, proliferation and survival, we hypothesized that the prenylation inhibitor L-778,123 would impart immunomodulation.The effect of L-778,123 on T cell activation (CD71 or CD25 surface expression) was determined by flow cytometry. Peripheral blood mononuclear cell (PBMC) proliferation in the presence of L-778,123 and/or cyclosporine (CsA) was determined by [3H]thymidine incorporation. The ability of L-778,123 to inhibit IL-2 receptor signaling was investigated by measuring IL-2 induced proliferation in CTLL-2 cells and IL-2 prevention of apoptosis in activated human PBMC. L-778,123 inhibited lectin induced expression of CD71 and CD25 with IC50's of 6.48 +/- 1.31 microM and 84.1 +/- 50.0 microM, respectively. PBMC proliferation was inhibited by L-778,123 with an IC50 of 0.92 +/- 0.23 microM, and addition of CsA did not increase the potency. L-778,123 did not inhibit IL-2 and IFN-gamma production by T cells. L-778,123 abrogated IL-2 induced proliferation of CTLL-2 cells with an IC50 of 0.81 +/- 0.44 microM. However, L-778,123 minimally reversed the prosurvival effect of IL-2 in activated lymphocytes. IL-2 ligand and receptor production during T cell activation are relatively unaffected by L-778,123. However, the activation and proliferative effects of IL-2 on T cells are potently blocked by L-778,123. These results reveal a selective blockade of the IL-2 cytokine axis distal to the IL-2 receptor by the L-778,123 and warrant evaluation of prenylation inhibitors in treating transplant rejection and autoimmune diseases.     

Comparison of the pharmacological effects of Panax ginseng and Panax quinquefolium

Medical application of Panax ginseng was first found in "Shen-Nong Herbal Classic"around 200 AD Panax quinquefolium was first introduced in "Essential of Materia Medica" in 1694 in China. The most important bioactive components contained in P ginseng and P quinquefolium are ginseng saponins (GS). The contents of ginsenoside Rb1, Re, and Rd in P quinquefolium are higher than they are in P ginseng. In P ginseng, the contents of Rg1,Rb2, and Rc are higher than they are in P quinquefolium. P ginseng had a higher ratio of Rg1: Rb1, and which was lower in P quinquefolium. After steaming for several hours, the total GS will decrease. However, some ginsenosides (Rg2, 20R-Rg2, Rg3, Rh1 and Rh2) increase, while others (Rb1, Rb2, Rb3, Rc, Rd, Re, and Rg1) decrease. However, variation, especially in P quinquefolium, is high. P ginseng and P quinquefolium are general tonics and adaptogens. Rg1 and Rb1 enhance central nervous system (CNS) activities, but the effect of the latter is weaker. Thus, for the higher contents of Rg1, P ginseng is a stimulant, whereas the Rb1 contents of P quinquefolium are mainly calming to the CNS. Re, Rg1, panaxan A and B from P ginseng are good for diabetes. Re and Rg1 enhance angiogenesis, whereas Rb1, Rg3 and Rh2 inhibit it. Rh2, an antitumor agent, can be obtained from Rb1 by steaming. The content of Re in P quinquefolium are higher than in P ginseng by 3-4 times. The vasorelax, antioxidant, antihyperlipidemic, and angiogenic effects of Re are reported. Thus, for the CNS "hot," wound healing and hypoglycemic effects, P ginseng is better than P quinquefolium. For anticancer effects, P quinquefolium is better.     

Reduction of electrically evoked neural activity by ginseng saponin in rat hippocampal slices

It is well established that ginseng saponin has positive influences on various neural diseases, but little is known about its electrophysiological effects in the central nervous system. In this study, we examined the electrophysiological effects of ginseng saponin in rat hippocampal slices. Total saponin from ginseng root reduced the slope of fEPSPs (field excitatory postsynaptic potentials) in the CA1 area in a dose-dependent manner (9.1 +/-5.4%, 48.4+/-12.1%, and 60.5+/-15.3% at 10, 50, and 100 microg/ml, respectively), which was reversed within 10 min of washout. Seven different ginsenosides resulted in varied degrees of fEPSPs reduction. The rank order of reduction was Rb1, Rg1 >Rg2, Rh1, Rc>Rd, Re within a range of 5-64% reduction. No difference in the suppressive action between protopanaxadiol (Rb1, Rc, Rd) and protopanaxatriol (Rg1, Rg2, Re, Rh1) saponins was shown; the slope of fEPSPs was reduced by 38% and 40% on average, respectively. The possible role of gamma-aminobutyric acid (GABA(A)) receptor in the suppressive action of ginseng saponins was tested using whole cell patch recording in acutely isolated hippocampal neurons. Ginsenosides did not induce chloride current nor modified GABA-induced current. Also, the suppressive effect of ginsenosides on fEPSPs was still observed in the presence of the GABA(A) receptor antagonist, bicuculline methiodide 50 microM. These results suggest that the suppressive effect is not attributable to regulation of GABA(A) receptor activation.     

A comparative study on commercial samples of ginseng radix

A total of 37 commercial samples of Ginseng Radix, the origins of which belonged to Panax ginseng C. A. Meyer, P. quinquefolia Linn. (American ginseng), and P. notoginseng Burkill (sanchi-ginseng), respectively, were collected from the Taiwan herbal markets. The contents of nine ginsenosides, Rb(1), Rb(2), Rc, Rd, Re, Rf, Rg(1), Rg(2), R(0), and three malonylginsenosides, mRb(1), mRb(2), mRc, in these samples were determined by high-performance liquid chromatography. It was found that the saponin contents in P. notoginseng and P. quinquefolia were generally higher than in P. ginseng. The ginsenosides that were of the highest contents in the white-ginseng, red-ginseng, and shihchu-ginseng samples of P. ginseng were Rb(1) and Rg(1); those in the root-hair of P. ginseng were Rb(1) and Re, those in P. notoginseng were Rb(1), Rg(1) and Rd, and those in P. quinquefolia were Rb(1), Re, and mRb(1). Among the samples, those of P. quinquefolia did not contain Rf and Rg(2), whilst those of shihehu-ginseng and red-ginseng of P. ginseng contained none or only traces of the malonylginsenosides. From the data of chemical analysis of a herb's constituents and its external appearance, we can postulate not only the quality but also the origin of the herb.     

In vitro effects of the antiallergy compound, CI-949, on interleukin-1 and 2 release, and on mitogen and alloantigen responsiveness

CI-949 (5-methoxy-3-(1-methylethoxy)-1-phenyl-N-1H-tetrazol-5-yl-1H -indole- 2-carboxamide, L-arginine salt), an antiallergy compound, was found to be a weak inhibitor of IL-1 release from LPS-stimulated murine peritoneal exudate cells and human peripheral blood leukocytes, with IC50S of 186.2 and 267.9 microM, respectively. CI-949 was also a poor inhibitor of release of IL-2 from Con A-stimulated rat splenocytes (37% inhibition at 100 microM). CI-949 did produce concentration-related inhibition of the response of human lymphocytes to PHA and Con A (IC50S = 44.7 and 21.5 microM, respectively) as well as in the mixed lymphocyte reaction (MLR) (IC50 = 16.8 microM). The clinical significance of these latter findings is unknown at present.     

In vitro effect of standardized ginseng extracts and individual ginsenosides on the catalytic activity of human CYP1A1, CYP1A2, and CYP1B1.

Ginseng extract has been reported to decrease the incidence of 7,12-dimethylbenz[a]anthracene (DMBA)-initiated tumorigenesis in mice. A potential mechanism for this effect by ginseng is inhibition of DMBA-bioactivating cytochrome P450 (P450) enzymes. In the present in vitro study, we examined the effect of a standardized Panax ginseng (or Asian ginseng) extract (G115), a standardized Panax quinquefolius (or North American ginseng) extract (NAGE), and individual ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, and Rg1) on CYP1 catalytic activities, as assessed by 7-ethoxyresorufin O-dealkylation. G115 and NAGE decreased human recombinant CYP1A1, CYP1A2, and CYP1B1 activities in a concentration-dependent manner. Except for the competitive inhibition of CYP1A1 by G115, the mode of inhibition was the mixed-type in the other cases. A striking finding was that NAGE was 45-fold more potent than G115 in inhibiting CYP1A2. Compared with G115, NAGE also preferentially inhibited 7-ethoxyresorufin O-dealkylation activity in human liver microsomes. Rb1, Rb2, Rc, Rd, Re, Rf, and Rg1, either individually or as a mixture and at the levels reflecting those found in an inhibitory concentration (100 microg/ml) of NAGE or G115, did not influence CYP1 activities. However, at a higher ginsenoside concentration (50 microg/ml), Rb1, Rb2, Rc, Rd, and Rf inhibited these activities. Overall, our in vitro findings indicate that standardized NAGE and G115 extracts, which were not treated with calf serum or subjected to acid hydrolysis, inhibited CYP1 catalytic activity in an enzyme-selective and extract-specific manner, but the effects were not due to Rb1, Rb2, Rc, Rd, Re, Rf, or Rg1.     

Asian ginseng enhances the anti-proliferative effect of 5-fluorouracil on human colorectal cancer: Comparison between white and red ginseng

Previous studies showed that Asian ginseng, Panax ginseng C.A. Meyer, may have anti-cancer properties. However, there is limited data exploring the use of Asian ginseng as an adjuvant to chemotherapy, and minimal mechanistic studies related to their possible synergistic activities. In this study, the content of 8 ginsenosides, Rb1, Rb2, Rb3, Rc, Rd, Re, Rg1 and Rg3, in the extracts of white ginseng (WG) and red ginseng (RG) were determined by HPLC. Using HCT-116 human colorectal cancer cells, we compared the efficacy of WG and RG. We evaluated the synergy between ginseng and 5-fluorouracil (5-FU), and explored the mechanism of their anti-proliferative effects. As single extract, WG or RG used at concentrations of 0.1, 0.2 and 0.3 mg/mL, inhibited HCT-116 cell proliferation in a concentration-related manner. WG at 0.2 mg/mL did not show obvious synergy with 5-FU co-treatment, while RG at 0.2 and 0.3 mg/mL significantly enhanced the anti-proliferative effects of 5-FU at concentrations of 10, 50 and 100 μM (P < 0.05). Using flow cytometric assay, RG 0.3 mg/mL did not affect cancer cell apoptotic induction activity. However, the RG induced cell cycle arrest in the G1 phase, while 5-FU arrested the cell in the S phase. Different ginsenoside profiles are responsible for the observed differences in pharmacological effects. The effects of 8 ginsenosides on HCT-116 cells were assayed. Rd and Rg3 showed positive anti-proliferative effect. Our data suggested a potential for RG as an adjuvant therapy in the treatment of colorectal cancer, via a synergistic action.     

Proanthocyanidin from grape seeds potentiates anti-tumor activity of doxorubicin via immunomodulatory mechanism

The purpose of this study was to investigate the anti-tumor activities of proanthocyanidin (PA) from grape seeds and doxorubicin (DOX) in vitro as well as in vivo, either alone or in combination and to explore the immunomodulatory mechanism in tumor-bearing mice. PA (12.5 approximately 200 mg/l) or DOX (0.01 approximately 1 mg/l) for 24 h significantly inhibited YAC-1 cell proliferation (IC(50) 57.53 or 0.198 mg/l, respectively) in a concentration-dependent manner using microculture tetrazolium (MTT) assay. Meanwhile, a combination of PA (12.5, 25 mg/l) with DOX strongly inhibited cell proliferation with IC(50) values of DOX decreasing by 0.09 and 0.045 mg/l, respectively. In mouse tumor xenograft models, intraperitoneal administrations of PA (10 mg/kg) daily or DOX (2 mg/kg) every other day for 9 days significantly inhibited the growth of sarcoma 180, whereas a combination of the two strongly inhibited tumor growth as compared with PA or DOX alone (p<0.01). In contrast to PA treatment, DOX inhibited Con A-stimulated lymphocyte proliferation, IL-2 and IFN-gamma productions, NK cell cytotoxicity and CD4+/CD8+ ratio, while the administration of PA combined with DOX significantly enhanced the above immune responses as compared with the tumor-bearing control (p<0.01). Taken together, these results suggest that PA has anti-tumor activity and increases the anti-tumor activity of DOX, and the mechanism might be related partially to immunopotentiating activities through the enhancements of lymphocyte proliferation, NK cell cytotoxicity, CD4+/CD8+ ratio, IL-2 and IFN-gamma productions.     

Immunomodulatory effect of nonsteroidal anti-inflammatory drugs (NSAIDs) at the clinically available doses

Non-steroidal anti-inflammatory drugs (NSAIDs) with cyclooxygenase (COX) inhibitory activity are commonly used in various inflammatory diseases. In this study, to examine the immunomodulatory effects of well known NSAIDs at clinically available doses, macrophage- and T cell-mediated immune responses such as tumor necrosis factor (TNF)-alpha release and nitric oxide (NO) production, cell-cell adhesion, phagocytic uptake and lymphocyte proliferation were investigated. NSAIDs tested significantly enhanced TNF-alpha release from lipopolysaccharide (LPS)-activated RAW264.7 cells at certain concentrations (fenoprofen, indomethacin, piroxicam, aceclofenac, diclofenac and sulindac) or in a dose-dependent manner (aspirin and phenylbutazone). Of NSAIDs, phenylbutazone and aspirin most potently attenuated NO production, although sulindac was the only compound with cytoprotective activity against LPS-induced cytotoxicity. Most NSAIDs used displayed weak or no modulatory effects on phagocytic uptake and CD29- or CD43-mediated cell-cell adhesion. Interestingly, however, phenylbutazone itself triggered cell-cell clustering under normal culture conditions and enhanced the phagocytic activity. Aspirin and phenylbutazone also dose-dependently attenuated CD4+ T cell proliferation stimulated by concanavalin A (Con A) and CD8+ CTLL-2 cell proliferation induced by interleukin (IL)-2. Sulindac only blocked CTLL-2 cell proliferation. These results suggest that NSAIDs may differentially exert immunomodulatory effects on activated macrophages and lymphocytes, and some of the effects may enforce NSAID's therapeutic effect against inflammatory symptoms.     

The antiviral drug amantadine has a direct inhibitory effect on T-lymphocytes

We investigated the effect of the antiviral drug amantadine (AmTd) on polyclonal activation of thymic-dependent (T) and thymic-independent (B) lymphocytes from normal mice. In the present studies, T-lymphocytes are defined by their response to concanavalin A (Con A) and B-lymphocytes by their response to lipopolysaccharide (LPS). Polyclonal activator-induced lymphocyte proliferation was assessed by quantifying cellular incorporation of tritiated thymidine. The results show that, in a dose-dependent manner, AmTd exhibits at least 2-fold greater inhibitory activity against Con A-responding T-cells than against LPS-responding B-cells. Further, several findings demonstrate that AmTd has a direct inhibitory effect on T-lymphocytes. First, AmTd pulse treatment of isolated T-cells, but not accessory cells, abolished the T-cell response to Con A. Second, AmTd pulse treatment of the cytotoxic T-lymphocyte line, CTLL-2, markedly reduced their ability to undergo IL-2-induced proliferation. Third, proliferation of T-cells which had already undergone activation by ConA was inhibited by AmTd. Further, the finding that addition of IL-1, IL-2 or both to cultures failed to reverse inhibition of the response to ConA argues that AmTd did not interfere with endogenous production of these lymphokines. Possible implications of these findings are discussed.     

Chemico-pharmacological studies on saponins of Panax ginseng C. A. Meyer. II. Pharmacological part.

The pharmacological properties of seven pure saponins isolated from Panax ginseng C. A. Meyer were studied. 1. The ginseng saponins showed weak toxicities in mice. Especially, Rg1, Rf and Rb 1, which contained glucose as a sugar component, were weaker in their toxicities than the rest, which contained arabinose and/or rhamnose. It was also noted that the saponins containing protopanaxadiol as sapogenin were more toxic than those containing protopanaxatriol. 2. All the saponins diminished ACh-induced contraction of the isolated ileum of the guinea pig. On the other hand high concentrations of Rb 2 caused contraction of the ileum by itself. 3. All of the saponins induced a decrease in heart rate and showed biphasic actions on the blood pressure in rats, while they little affected respiration. They caused blood pressure fall preceded by slight rise. Among them, Rg 1 showed the most prominent action and it produced a blood pressure rise with doses of 30 to 100 mg/kg. The pressor as well as depressor action was not influenced by the pretreatment with any of atropine, diphenhydramine, phentolamine and propranolol. 4. Rg 1 and Re showed vasodilator action in dogs, the potencies of which were 1/20 and 1/50 of that of papaverine, respectively. Rc and Rb 2 showed very weak vasodilator actions but Rb 1 did not. 5. Among the 7 saponins, Rd, Re and Rb 2 showed more potent hemolytic actions than those of the rest and the potencies were proportional to their toxicities. 6. Whereas single administration of Rf, Re and Rd significantly suppressed the conditioned avoidance response, repeated administration of them caused facilitation of the response. On the other hand, Rb 2 always showed very weak suppressant action. 7. Rg 1, Rf, Re and Rd significantly suppressed the fighting of mice induced by foot shock, while Rb 1, Rb 2 and Re little affected the fighting. 8. All the saponins showed antifatigue action. They markedly increased the movement after compulsory gait and the action was consistent and independent of their action on the movement before compulsory gait. 9. The saponins showed moderate depressant actions on the EEG and the behavior in cats. They were qualitatively similar in their actions, although Rg 1, Re and Rb 2 were more potent than the rest. They also suppressed EEG arousal response induced by electrical stimulation of the mid brain in cats.     

Inhibitory mechanisms of dihydroginsenoside Rg3 in platelet aggregation: critical roles of ERK2 and cAMP

Ginsenoside Rg3, a single ginseng saponin, is known to be a major anti-platelet component of protopanaxadiol that is isolated from Korean red ginseng. In this study, we investigated whether dihydroginsenoside Rg3, a stable chemical derivative of ginsenoside Rg3, also demonstrated anti-platelet activity. Dihydroginsenoside Rg3 inhibited thrombin-induced platelet aggregation in a concentration-dependent manner with an IC50 (concentration producing 50% inhibition) of 18.8 +/- 0.4 microM. Ginsenoside Rg3 inhibited platelet aggregation which was induced by thrombin (0.1 U mL(-1)) with an IC50 of 40.2 +/- 0.9 microM. We next determined whether dihydroginsenoside Rg3 affected different types of ligand-induced platelet aggregation. We found that dihydroginsenoside Rg3 inhibited collagen-induced platelet aggregation with an IC50 of 20.0 +/- 0.9 microM. To elucidate the inhibitory mechanism of dihydroginsenoside Rg3 on aggregation, we analysed its downstream signalling pathway. It was interesting to note that dihydroginsenoside Rg3 elevated cyclic AMP production in resting platelets, but did not affect cyclic GMP production. In addition, we found that dihydroginsenoside Rg3 potently suppressed phosphorylation of extracellular signal-regulated kinase 2 (ERK2), which was stimulated by collagen (2.5 microg mL(-1)), but not of p38 mitogen-activated protein kinase. Taken together, our results indicate that dihydroginsenoside Rg3 potently inhibited platelet aggregation via the modulation of downstream signalling components such as cAMP and ERK2.     

Effects of ginsenosides,active components of ginseng,on nicotinic acetylcholine receptors expressed in Xenopus oocytes

We investigated the effects of ginsenosides, the active ingredient of ginseng, on neuronal or muscle-type nicotinic acetylcholine receptor channel activity expressed in Xenopus oocytes after injection of cRNA encoding bovine neuronal alpha3beta4, alpha7 or human muscle alphabetadeltavarepsilon subunits. Treatment with acetylcholine elicited an inward peak current (I(ACh)) in oocytes expressing nicotinic acetylcholine receptor subtypes. Cotreatment with ginsenoside Rg2 and acetylcholine inhibited I(ACh) in oocytes expressing with alpha3beta4 or alphabetadeltavarepsilon but not in oocytes expressing alpha7 nicotinic acetylcholine receptors. The inhibition of I(ACh) by ginsenoside Rg2 was reversible and dose-dependent. The half-inhibitory concentrations (IC50) of ginsenoside Rg2 were 60.2+/-14.1 and 15.7+/-3.5 microM in oocytes expressing alpha3beta4 and alphabetadeltavarepsilon nicotinic acetylcholine receptors, respectively. The inhibition of I(ACh) by ginsenoside Rg2 was voltage-independent and noncompetitive. Other ginsenosides besides ginsenoside Rg2 also inhibited I(ACh) in oocytes expressing alpha3beta4 or alphabetadeltavarepsilon nicotinic acetylcholine receptors. The order of potency for the inhibition of I(ACh) was ginsenoside Rg2>Rf>Re>Rg1>Rc>Rb2>Rb1 in oocytes expressing alpha3beta4 nicotinic acetylcholine receptors and was ginsenoside Rg2>Rf>Rg1>Re>Rb1>Rc>Rb2 in oocytes expressing alphabetadeltavarepsilon nicotinic acetylcholine receptors. These results indicate that ginsenosides might regulate nicotinic acetylcholine receptors in a differential manner and this regulation might be one of the pharmacological actions of Panax ginseng.     

Simultaneous quantification of 14 ginsenosides in Panax ginseng C.A. Meyer (Korean red ginseng) by HPLC-ELSD and its application to quality control

A new method of high-performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD) was developed for the simultaneous quantification of 14 major ginsenosides, which are the marker compounds of Panax ginseng C.A. Meyer (Korean red ginseng). Various types of ginseng samples were extracted, and the amounts of the 14 ginsenosides (Rg1, Re, Rf, Rh1, Rg2, Rb1, Rc, Rb2, Rb3, Rd, Rg3, Rk1, Rg5, and Rh2) were determined by reverse-phase HPLC-ELSD using digoxin as an internal standard. The mobile phase consisted of a programmed gradient of aqueous acetonitrile. Calibration curves for each ginsenoside were determined for the quantification. The method was validated for linearity, precision, accuracy, limit of detection, and limit of quantification. This quantification method was applied to several finished ginseng products including white ginseng, red ginseng powder, and red ginseng concentrate. The amounts of the 14 ginsenosides in the various ginseng samples could be analyzed simultaneously. This validated HPLC method is expected to provide a new basis for the quality assessment of ginseng products.     

主要人参皂甙的分布和比例及人参产品的质量控制

采用反相高效液相色谱法，对１５０多种西洋参、人参及三七的根、叶及其产品进行了分析。以８种主要的人参皂甙Ｒｇ，Ｒｅ，Ｒｆ，Ｒｂ１，Ｒｃ，Ｒｂ２，Ｒｇ２和Ｒｄ作为对照品，来评价人参及其产品的质量，这８种人参皂甙的分布及其比例在对人参及其商品的定性、定量分析方面具有显著的意义。本文首次提出了单体皂甙的含量比率这一有价值的数据在人参品种及不同用药部位鉴定方面的有效性。     

人参与附子配伍后不同制备条件下人参皂苷含量变化的研究

目的:研究人参与附子配伍后不同制备条件对人参皂苷Rg1、Re、Rb1含量的影响。方法:采用高效液相色谱法测定人参配伍附子后水煎液、浓缩膏及不同温度下的干燥细粉中人参皂苷的含量。结果:人参与附子配伍后,浓缩、干燥是人参皂苷类成分损失最多的制备工序。结论:人参与附子配伍浓缩、干燥温度不宜高于80℃。     

In vitro inhibitory effect of protopanaxadiol ginsenosides on tumor necrosis factor (TNF)-alpha production and its modulation by known TNF-alpha antagonists

Ginsenosides are the major principles of Panax ginseng C. A. Meyer (Araliaceae) used as a mild oriental folk medicine. In this report, we have examined the inhibitory potency of protopanaxadiol ginsenosides (PPDGs) such as Rb1, Rb2 and Rc, and their co-treatment effect with known tumor necrosis factor (TNF)-alpha antagonists on TNF-alpha production in either murine (RAW264.7) or human (U937) macrophages stimulated with lipopolysaccharide (LPS). Rb1, and Rb2 strongly suppressed TNF-alpha production in RAW264.7 cells with an IC50 of 56.5 and 27.5 microM, respectively, and in differentiated U937 cells with an IC50 of 51.3, and 26.8 microM, respectively. The inhibitory activity of Rb1 and Rb2 was significantly increased by pharmacological agents against protein kinase C, protein tyrosine kinase, and protein kinase A, and anti-rheumatoid arthritis drugs, such as chloroquine and steroid drugs. In contrast, only cyclic AMP phosphodiesterase (cAMP PDE) inhibitors among cAMP-elevating agents did not change the inhibitory potency of PPDGs. These data suggest that PPDGs may possess potential therapeutic efficacy against TNF-alpha mediated disease and the therapeutic potency of PPDGs may be enhanced when co-treated with various kinds of known TNF-alpha antagonists but not with cAMP PDE inhibitors.