Flavanone and diphenylpropane glycosides and glycosidic acyl esters from Viscum articulatum.

Seven new compounds including three flavanone glycosides, visartisides A-C (1-3), three glycoside acyl esters, visartisides D-F (4-6), and one diphenylpropane glycoside, (4'-hydroxy-2',3',6',3''-tetramethoxy-1,3-diphenylpropane)-4''-O-beta-d-glucopyranoside (7), along with four known flavanone glycosides (8-11) were isolated from the leaves and stems of Viscum articulatum. The structure elucidation of 1-7 was based on spectroscopic data analysis. Biological evaluation showed that 1, 2, and 10 exhibited antioxidant activity using a DPPH method and that compounds 1, 3, and 11 were active in a lipopolysaccharide-induced nitric oxide assay.

A triterpenoid methyl antcinate K isolated from Antrodia cinnamomea promotes dendritic cell activation and Th2 differentiation.

Dendritic cells (DC) play a central role in the initiation and regulation of immune responses. Increasing evidence has indicated that manipulation of DC can serve as a therapeutic mechanism for immunomodulation. In this study we tested some unique compounds isolated from Antrodia cinnamomea, a medicinal fungus in Taiwan, on mouse bone marrow-derived DC activation. A triterpenoid methyl antcinate K (me-AntK) promoted DC maturation by enhancing the expression of MHC class II, CD86, and reducing the endocytosis. TNF-alpha, MCP-1, and MIP-1beta were secreted by DC after me-AntK treatment, indicating augmentation of innate immunity by me-AntK. Interestingly, the me-AntK-activated DC induced Ag-specific T-cell proliferation and facilitated Th2 differentiation. Examining signaling responses, we found that me-AntK treatment uniquely activated JNK and ERK in DC. Our results demonstrate that me-AntK is the first natural triterpenoid to promote the ability of DC to prime Th2 responses. This suggests that me-AntK can potentially be applied to enhance immune responses and modulate DC function in immunotherapy.

Lanostanes from Phellinus igniarius and their iNOS inhibitory activities.

Four new lanostanol-type triterpenoids, igniarens A - D ( 1- 4), were isolated from the fruit body of Phellinus igniarius together with two known triterpenoids, and two known ergostanes. These four new compounds were identified by spectroscopic analysis as 22 R-hydroxy-24-methylene-29-norlanost-7, 9(11)-dien-3-one (1), 3alpha,22 R-dihydroxy-24-methylene-29-norlanost-7, 9(11)-diene (2), 3alpha,22 R-dihydroxy-24-methylene-29-norlanost-8-ene ( 3), and 3alpha,22 R-dihydroxy-24-methylenelanost-8-ene ( 4). Their effects on NO production in lipopolysaccharide (LPS)-activated macrophages were assessed. Compounds 1- 8 inhibited NO production in activated RAW 264.7 cells to various degrees. The most potent compound 5alpha,8alpha-epidioxy-22 E-ergosta-6,22-dien-3beta-ol ( 7) significantly inhibited LPS-induced NO production in a concentration-dependent manner without affecting the cellular viability, with an IC (50) of 37.57 +/- 1.38 microM.

Compound MMH01 possesses toxicity against human leukemia and pancreatic cancer cells.

MMH01 is a compound isolated from Antrodia cinnamomea. MMH01 markedly inhibited growth of human leukemia U937 and pancreatic cancer BxPC3 cells. It resulted in distinct patterns of cell cycle distribution in U937 (G2/M, sub-G1 and polyploidy) and BxPC3 cells (G0/G1 and sub-G1). The modes of cell death in U937 cells include apoptosis and mitotic catastrophe, whereas apoptosis-associated events or necrosis in BxPC3 cells. Neither mitochondrial membrane permeabilization nor caspase dependence was noted. Proteins involving mitotic catastrophe-associated cell death such as cyclin B1 and checkpoint kinase 2 were activated in U937 cells. Only slight to moderate viability inhibition was noted to human monocytes, the normal counterpart of these myeloid leukemic cells. In conclusion, MMH01 possesses cytotoxicity against human leukemia and pancreatic cancer cells.

Lanostane-triterpenoids from the fungus Phellinus gilvus.

Triterpenoids gilvsins A-D (1-4), with oxygenated lanostane skeletons, were isolated from the fruiting body of Phellinus gilvus, together with two known compounds, 24-methylenelanost-8-ene-3beta, 22-diol and 5alpha-ergosta-7,22-diene-3-one. The structures of 1-4 were deduced from analysis of spectroscopic data. The absolute configuration at C-22 of 1 was determined by the modified Mosher's method and the structure of 1 was confirmed by X-ray analysis. The hypoglycemic activities of the crude extract of P. gilvus and the isolated compounds were also evaluated, but were not promising for further investigation.

Promotion of hyphal growth and underlying chemical changes in Antrodia camphorata by host factors from Cinnamomum camphora.

The aim of this research was to investigate the hyphal growth-promoting factors (HGFs) of Antrodia camphorata from the host-related species, Cinnamomum camphora (CC) and the underlying chemical produced. The HGF was identified in the polysaccharide fraction of CC at levels ranging from 80 to 320 mg L(-1), and it maximally stimulated growth to 5.50 g L(-1) during a 14-day culture period compared to that of the control of 2.88 g L(-1). We also investigated the nature and chemical composition of the CC polysaccharide. Herein, size-exclusion column chromatography followed by high-performance anion-exchange chromatography after complete hydrolysis of the CC polysaccharide was performed to derive its molecular weight and sugar composition. The Mw values of the CC polysaccharide were determined to be 728.2, 187.5, 28.7, 7.5, and 1.9 kDa. Compositional analysis of the CC polysaccharide showed that galactosamine, mannose, and glucose were the major monosaccharides. Time-course studies of mycelial extracts of cultures revealed that prolonged incubation with the water-soluble extracts of CC resulted in an increase in the relative amounts of two lanostane-type compounds, i.e., dehydrosulphurenic acid and 15alpha-acetyl-dehydrosulphurenic acid, which are found in the fruiting bodies of A. camphorata. This finding offers the possibility of the reliable production of this medicinal fungus under laboratory conditions compared to its limited slow growth in nature.

Involvement of Bcl-2 family, cytochrome c and caspase 3 in induction of apoptosis by beauvericin in human non-small cell lung cancer cells.

Beauvericin (BEA), a cyclic hexadepsipeptide from Codyceps cicadae, possesses anti-convulsion, anti-arrhythmia, sedation, and anti-tumor activities. It has been reported that BEA induces apoptosis in several cancer cell lines. However, the molecular mechanism underlying the BEA-induced apoptotic process is not yet clearly understood. In the present study, the intracellular signaling pathways of BEA-induced apoptosis in human non-small cell lung cancer (NSCLC) A549 cells were investigated using morphological analysis and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) technique. In this study, BEA-induced apoptosis in human NSCLC A549 cells demonstrated a BEA concentration- and treatment time-dependent manner. This BEA-induced apoptosis in human NSCLC A549 cells was also accompanied by the up-regulation of Bax, Bak, and p-Bad and down-regulation of p-Bcl-2, but no effect on the levels of Bcl-X(L) or Bad proteins. Moreover, the BEA treatment resulted in a significant reduction of mitochondrial membrane potential, increase in the release of mitochondrial cytochrome c (cyt c), and activation of caspase 3. Furthermore, treatment with caspase 3 inhibitor (z-DEVD-fmk) was capable to prevent the BEA-induced caspase 3 activity and cell death. These results clearly demonstrate that the induction of apoptosis by BEA involves multiple cellular/molecular pathways and strongly suggest that pro- and anti-apoptotic Bcl-2 family proteins, mitochondrial membrane potential, mitochondrial cyt c, and caspase 3, they all participate in BEA-induced apoptotic process in human NSCLC A549 cells.

Beauvericin activates Ca2+-activated Cl- currents and induces cell deaths in Xenopus oocytes via influx of extracellular Ca2+.

Beauvericin is a mycotoxin that infects a wide variety of cereal grains. The toxicological importance of beauvericin is implicated by its cytotoxicity in animal and human cells, which has been suggested to result from an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)). Despite the fact that beauvericin may activate extracellular Ca(2+) influx, beauvericin-induced cell deaths has been suggested to be exclusively due to Ca(2+) release from internal Ca(2+) stores. We endeavored to elucidate the mechanism of beauvericin-induced [Ca(2+)](i) increase by studying the effects of beauvericin in Xenopus oocytes. By applying a -140-mV prepulse prior to a series of test pulses, we found that beauvericin induced small inward currents at -140 mV, followed by outwardly rectifying currents that displayed an apparent reversal potential close to the expected equilibrium potential of Cl(-). Both the inward and outward currents induced by beauvericin were blocked by niflumic acid, a specific blocker for Ca(2+)-activated Cl(-) currents (I(Cl,Ca)). Removal of extracellular Ca(2+), as well as perfusion of lanthanide, abrogated beauvericin-induced currents. Beauvericin also displayed prominent cytotoxic effects in Xenopus oocytes in a dose-dependent manner. In the absence of extracellular Ca(2+), cytotoxicity-induced by 10 and 30 microM, but not 50 microM, of beauvericin was significantly diminished. Our results are consistent with the idea that beauvericin induces extracellular Ca(2+) influx, which in turn activates I(Cl,Ca) and contributes to beauvericin-induced cell deaths in Xenopus oocytes.

DNA topoisomerase I inhibitor, ergosterol peroxide from Penicillium oxalicum.

Recently, we found that the MeOH extract of Penicillium oxalicum showed inhibitory activity towards DNA topoisomerase I. Subsequently, ergosterol peroxide, ergosterol, palmitoleic acid, and linoleic acid were isolated from the cultured mycelia of P. oxalicum. The structural determinations were based on physical and spectral analyses. Biological evaluation revealed that ergosterol peroxide inhibited the relaxation of supercoiled DNA (pBR322) induced by DNA topoisomerase I, and also showed marginal, selective cytotoxic activity against human colon tumor cells [COLO-205 (ED50=8.56 microg/mL].

Beauvericin induces cytotoxic effects in human acute lymphoblastic leukemia cells through cytochrome c release, caspase 3 activation: the causative role of calcium.

Beauvericin (BEA), a cyclic hexadepsipeptide, induces cell death in human leukemia cells (CCRF-CEM) and the process of BEA-induced cell death has been speculated to undergo an apoptotic pathway. In the present study, several well-characterized factors, known to play important roles in apoptotic pathway, were investigated in BEA-induced CCRF-CEM cell death. CCRF-CEM cells were treated with BEA at concentrations from 1 to 10 microM for up to 24 h. The incidence of nuclear fragmentation and apoptotic body formation in the cells, cytosolic caspase-3 activity, mitochondrial membrane potential, and release of cytochrome c (Cyt c) from mitochondria in BEA-treated cells were determined and compared with that in untreated cells. Moreover, to investigate the role of intracellular Ca++ in this cell death process, CCRF-CEM cells were primed with 3 microM of BAPTA/AM, a Ca++ chelator, to exclude intracellular Ca++ prior to the BEA treatment. The data revealed that BEA-induced cell death in CCRF-CEM cells exhibited a dose- and time-dependent manner. The incidence of nuclear fragmentation and apoptotic body formation was significantly increased in CCRF-CEM cells treated with BEA at concentrations of 1 microM or greater. Increase of cytosolic caspase-3 activity was also observed in BEA-treated cells with a dose-dependent manner. In addition, increased release of Cyt c from mitochondria was also observed in the cells treated with 10 microM BEA in a time-dependent pattern. The BAPTA/AM pretreatment partially blocked BEA-induced cell death in CCRF-CEM cells, indicating that intracellular Ca++ plays an important role, maybe as a mediator in cell death signaling, in this cell death pathway. The results support the notion that BEA-induced cell death in CCRF-CEM cells likely undergo through an apoptotic pathway on the basis of increase of release of Cyt c from mitochondria, increase of caspase-3 activity, and some observed typical apoptotic cellular changes in morphology.

Evaluation of the anti-inflammatory activity of zhankuic acids isolated from the fruiting bodies of Antrodia camphorata.

We have previously shown that a concentrated ethanol extract of the fruiting bodies of Antrodia camphorata exhibited immunomodulating effects in human leukocytes and fourteen compounds including zhankuic acids A, B, C, and antcin K were identified in the extract. In this study, an acute cellular model in isolated peripheral human neutrophils was established to elucidate the anti-inflammatory effects of these compounds. Reactive oxygen species (ROS) production and firm adhesion by neutrophils display two important responses during inflammation. To evaluate whether these compounds could prevent inflammatory responses by neutrophils, their effects on N-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol 12-myristate-13-acetate (PMA)-activated peripheral human neutrophils were examined. Pretreatment with 1 - 25 microM of zhankuic acids A, B, C, or antcin K concentration-dependently diminished fMLP- or PMA-induced ROS production, as measured by a lucigenin-amplified chemiluminescence, with IC (50) (microM) around 5 - 20 microM. Zhankuic acids A, B, C, or antcin K also effectively inhibited the fMLP- or PMA-induced firm adhesion without interfering with the up-expression of surface Mac-1 (CD11b/CD18), a beta2 integrin mediating the firm adhesion of neutrophils to endothelium. The anti-inflammatory actions of these drugs were not due to cytotoxic effects because no significant difference in cell viability was observed compared to vehicle control. These data suggest that inhibition of both ROS production and firm adhesion by neutrophils has no significant cytotoxic effect that could give these drugs the potential to be anti-inflammatory agents for the clinical treatment.

Anti-inflammatory activity of the extracts from mycelia of Antrodia camphorata cultured with water-soluble fractions from five different Cinnamomum species.

We have previously reported that polysaccharides extracted from fruiting bodies or cultured mycelia of Antrodia camphorata exhibit an anti-hepatitis B virus effect. In this study, we intended to elucidate the anti-inflammatory potency of six mycelial extracts, namely PDB-ext, CK-ext, CM-ext, CO-ext, CC-ext, and CKO-ext, isolated from mycelia of A. camphorata cultured with six different media including potato dextrose broth (PDB) and five water-soluble fractions from the wood of different Cinnamomum species, i.e. C. kanehirae (CK), C. micranthum (CM), C. osmophloeum (CO), C. camphora (CC), and C. kotoense (CKO), against reactive oxygen species (ROS) production induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol 12-myristate 13-acetate (PMA) in peripheral human neutrophils (PMN) or mononuclear cells (MNC). ROS produced by PMN or MNC act as inflammatory mediators and also signal immune responses. Pretreatment with these mycelial extracts (1-50 microg ml(-1)) concentration-dependently diminished fMLP- or PMA-induced ROS production in PMN or MNC, as measured by lucigenin-amplified chemiluminescence, with 50% inhibition concentrations (IC(50)) ranging from 2 to 20 microg ml(-1). Among these extracts evaluated, CM-ext, CO-ext, or CKO-ext exhibited higher potency than the others. Using high performance liquid chromatography, we identified two lanostane-type compounds, i.e. dehydrosulfurenic acid and 15alpha-acetyl-dehydrosulfurenic acid, which could be involved in the anti-inflammatory actions of these extracts. The anti-inflammatory actions of these extracts were not due to cytotoxic effects. In summary, these data suggest that extracts from cultured mycelia of A. camphorata display anti-inflammatory effects by inhibiting ROS production in human leukocytes at a pharmacologically applicable concentration. The biological activities of these extracts were further promoted when the culture medium was replaced with water-soluble fractions isolated from the wood of CM, CO or CKO.

Phenylpropanoid glycosides from Orobanche caerulescens.

Two new phenylpropanoid glycosides, caerulescenoside ( 1), and 3'-methyl crenatoside ( 2), as well as five known phenylpropanoid glycosides [acteoside ( 3), isoacteoside ( 4), campneoside II ( 5), crenatoside ( 6), and desrhamnosyl acteoside ( 7)] were isolated from the whole plant of Orobanche caerulescens. The antioxidative effects of compounds 1 - 7 on human low-density lipoprotein were evaluated. All these compounds suppress concentration-dependently conjugated diene formation with IC (50) values of 1.25 +/- 0.06, 2.97 +/- 0.31, 0.31 +/- 0.01, 1.01 +/- 0.05, 1.15 +/- 0.04, 1.69 +/- 0.15, and 0.64 +/- 0.03 microM, respectively. Comparison of their antioxidative activities with that of resveratrol (IC (50) : 6.75 +/- 1.05 microM), a natural phenolic antioxidant isolated from grape, demonstrated that the prolonged effect on lag-time and the damping effect on oxidative rate by compounds 1 - 7 were all more potent.

Inhibitory effect of tetrandrine on pulmonary metastases in CT26 colorectal adenocarcinoma-bearing BALB/c mice.

Tumor metastasis is a major cause of mortality in cancer patients. The anti-metastatic effect of tetrandrine, an alkaloid isolated from Stephania tetrandrae S. Moore, was investigated in a pulmonary metastatic model of colorectal cancer-bearing mice. Tetrandrine decreased the viability of murine colorectal adenocarcinoma CT26 cells in a time- and dose-dependent manner. CT26 cells were injected into BALB/c mice via a tail vein to establish pulmonary metastases. After this, the mice were given intraperitoneal injections of tetrandrine (10 mg/kg/day), 5-fluorouracil (5-FU) at the same dose, or vehicle for 5 consecutive days. Mice treated with tetrandrine had 40.3% fewer metastases than vehicle-treated mice, and those treated with 5-FU had 36.9% fewer metastases than controls. Both tetrandrine- and 5-FU-treated mice survived longer than mice in the untreated control group. There was no acute toxicity or obvious changes in body weight in any of the mice. These results suggest that tetrandrine may be a useful anti-metastatic agent.

The vasorelaxation of Antrodia camphorata mycelia: involvement of endothelial Ca(2+)-NO-cGMP pathway.

Antrodia camphorata, a medicinal fungus, has been used to treat cardiovascular diseases such as hypertension for many years. The purpose of this study was to examine the effects of mycelia extracts, from five Antrodia camphorata strains, on vascular tension and underlying mechanisms were explored. In isolated rat aortic rings, accession B86 caused concentration-dependent vasorelaxation with maximal relaxation of 40.34 +/- 7.53% whereas accessions 35398, 35396 and B71 had mild vasorelaxing effects. Strain B85 evoked potent vasorelaxation, partly through an endothelium-dependent mechanism that was inhibited by Nomega-nitro-L-arginine and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ) but not by antagonist of K+ channels, tetraethylammonium. In cultured endothelial cells, B85 stimulated nitric oxide (NO) release and augmented the level of the intracellular Ca2+ concentration. HPLC and LC-MS-MS analysis revealed the presence of adenosine. Our results suggest that B85 produced strongest vasorelaxation in aortic preparations among five test strains. B85 acts in part on endothelial cells by activating the Ca(2+)-NO-cGMP pathway to reduce smooth muscle tone. However, K+ channels had no apparent roles. Adenosine could possibly be involved in the endothelium-dependent pathway of B85-induced vasorelaxation.

Anti-inflammatory properties of piperlactam S: modulation of complement 5a-induced chemotaxis and inflammatory cytokines production in macrophages.

Macrophages infiltrate tissues in response to chemoattractants including complement 5a (C5a). Infiltrating macrophages clear microorganisms but also can cause tissue damage. We hypothesized that prevention of macrophages from excessive recruitment into infected sites may underlie the anti-inflammatory effects of piperlactam S, an alkaloid isolated from Piper kadsura (Choisy) Ohwi. To test this hypothesis, chemotactic migration of RAW264.7 macrophages was induced by C5a and the effects of piperlactam S were studied. The results showed that piperlactam S (1-30 microM) concentration-dependently suppressed C5a-induced migration across a fibrinogen-coated barrier with an IC50 of 4.5 +/- 0.3 microM. At 30 microM, piperlactam S inhibited chemotaxis by more than 95 % and also decreased phagocytosis by 25 % without reducing macrophage viability and adherent capacity. Furthermore, piperlactam S treated cells adhered but failed to spread and elongate as in control cells. Finally, piperlactam S inhibited the C5a-stimulated release of tumor necrosis factor-alpha and interleukin-1beta. We conclude that retardation of macrophage recruitment by interfering with the migration process and suppression of cytokines production might underlie the potential usefulness of piperlactam S as an anti-inflammatory agent.

Cytotoxic naphthoquinones and plumbagic acid glucosides from Plumbago zeylanica.

Two plumbagic acid glucosides, 3'-O-beta-glucopyranosyl plumbagic acid and 3'-O-beta-glucopyranosyl plumbagic acid methylester along with five naphthoquinones (plumbagin, chitranone, maritinone, elliptinone and isoshinanolone), and five coumarins (seselin, 5-methoxyseselin, suberosin, xanthyletin and xanthoxyletin) were isolated from the roots of Plumbago zeylanica. All coumarins were not previously found in this plant. Cytotoxicity of these compounds to various tumor cells lines was evaluated, and plumbagin significantly suppressed growth of Raji, Calu-1, HeLa, and Wish tumor cell lines.

Piperlactam S suppresses macrophage migration by impeding F-actin polymerization and filopodia extension.

This study was designed to evaluate the anti-inflammatory effect of piperlactam S on chemoattractant-induced migration, functions underlying leukocyte recruitment in vitro. Results showed that RAW264.7 macrophages migrate toward complement 5a, a powerful chemoattractant for macrophages. This phenomenon could be suppressed concentration dependently by piperlactam S (0.3-30 microM). Fluorescence staining demonstrated that piperlactam S and cytochalasin B both effectively reversed complement 5a-induced cell polarization, filopodia extension, as well as the increase in the cell content of F-actin. Functional inhibition by antibodies suggested that Mac-1 (CD11b) integrin plays a central role in complement 5a-induced migration. However, piperlactam S failed to modify Mac-1 expression. Furthermore, complement 5a triggered the activation of Cdc42, a Rho-family protein involved in the regulation of filopodia extension, with a time course that paralleled that of filopodia extension and which was inhibited by piperlactam S. In summary, piperlactam S exerts anti-inflammatory effects possibly by interfering with cell migration, impeding F-actin polymerization, filopodia formation, and/or Cdc42 activation. However, the detailed mechanism by which piperlactam S regulates the above processes needs further study.

Immunomodulatory functions of extracts from the Chinese medicinal fungus Cordyceps cicadae.

The effects of Cordyceps cicadae extracted fractions on human mononuclear cells (HMNC) proliferation were determined by tritiated thymidine uptake. The results indicated that aqueous methanol (50%) extracts of C. cicadae ascocarps portion (CC-1-2) enhanced HMNC proliferation activated with phytohemagglutinin (PHA) with an EC(50) of 13.8+/-4.6 micro g/ml. By contrast, the methanol (100%) extracts of C. cicadae insect-body portion (CC-2-1) suppressed HMNC proliferation stimulated by PHA with an IC(50) of 32.5+/-5.2 micro g/ml. Cell viability test indicated that inhibitory effects of CC-2-1 on HMNC proliferation were not through direct cytotoxicity. The action mechanisms of CC-1-2 and CC-2-1 may involve the regulation of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) production in HMNC. Since CC-2-1 suppressed IL-2 and IFN-gamma production in HMNC induced with PHA. The CC-1-2 enhanced IL-2 and IFN-gamma production of HMNC stimulated with PHA in a concentration dependent manner. Therefore, the results demonstrated that C. cicadae contained growth modulators for HMNC.

Evodia rutaecarpa protects against circulation failure and organ dysfunction in endotoxaemic rats through modulating nitric oxide release.

Using a rat model of septic shock we studied the effects of Evodia rutaecarpa, a Chinese herbal medicine with antimicrobial and anti-inflammatory activity, on haemodynamic parameters, biochemical markers of organ function and nitric oxide (NO) production. Anaesthetized rats challenged with a high dosage of endotoxin (Escherichia coli lipopolysaccharide; LPS; 50 mg kg(-1), i.v.) for 6 h showed a severe decrease in mean arterial pressure. This was accompanied by delayed bradycardia, vascular hyporeactivity to phenylephrine and increase in plasma levels of lactate dehydrogenase, aspartate aminotransferase, bilirubin and creatinine, as well as NOx (NO2- plus NO3-). Pretreatment with ethanol extract of E. rutaecarpa (25, 50 and 100 mg kg(-1), i.v.), 1 h before LPS, dose-dependently prevented the circulation failure, vascular hyporeactivity to phenylephrine, prevented liver dysfunction and reduced the NOx over-production in plasma in endotoxaemic rats. A selective inducible NO-synthase (iNOS) inhibitor, aminoguanidine (15 mg kg(-1), i.v.), also effectively ameliorated the above pathophysiological phenomenon associated with endotoxaemia so that the normal condition was approached. Endotoxaemia for 6 h resulted in a significant increase in iNOS activity in the liver homogenate, which was attenuated significantly by E. rutaecarpa pretreatment. In summary, E. rutaecarpa, at the dosages used, exerted these beneficial effects probably through inhibition of iNOS activity and subsequent modulation of the release of NO. These significant results may offer E. rutaecarpa as a candidate for the treatment of this model of endotoxaemia.