Anti-proliferative effect of ginseng saponins on human prostate cancer cell line

Ginseng is a medicinal herb widely used in Asian countries, and many of its pharmacological actions are attributed to the ginsenosides. In a study of the anti-proliferative activity of ginsenosides using human prostate carcinoma LNCaP cell line, ginsenoside Rg3 displayed growth inhibitory activity. The cells lost its adherent property after incubation in the presence of 250 microM of ginsenoside for 48h. The expression of biomarker genes, including prostate specific antigen (PSA), androgen receptor (AR) and 5alpha-reductase (5alphaR), and that of the proliferating cell nuclear antigen (PCNA), were suppressed. Ginsenoside Rg3 induced classic apoptotic morphology and interfered with the expression of apoptosis-related genes, bcl-2 and caspase-3, in LNCaP cells, as demonstrated by fluorescence microscopy, flow cytometry and reverse transcriptase-polymerase chain reaction. Taken our results together, we suggested that ginsenoside Rg3 activated the expression of cyclin-kinase inhibitors, p21 and p27, arrested LNCaP cells at G1 phase, and subsequently inhibited cell growth through a caspase3-mediated apoptosis mechanism.

Ocular Hypotensive FP Prostaglandin (PG) Analogs: PG Receptor Subtype Binding Affinities and Selectivities, and Agonist Potencies at FP and Other PG Receptors in Cultured Cells

Natural prostaglandins (PGs) such as PGD2, PGE2, PGF2(2alpha), and PGI2 exhibited the highest affinity for their respective cognate receptors, but were the least selective agents when tested in receptor binding assays. Travoprost acid ([+]-fluprostenol) was the most FP-receptor-selective compound, exhibiting a high affinity (Ki = 35 +/- 5 nM) for the FP receptor, and minimal affinity for DP (Ki = 52,000 nM), EP1 (Ki = 9540 nM), EP3 (Ki = 3501 nM), EP4 (Ki = 41,000 nM), IP (Ki > 90,000 nM), and TP (Ki = 121,000 nM) receptors. Travoprost acid was the most potent PG analog tested in FP receptor functional phosphoinositide turnover assays in the following cell types: human ciliary muscle (EC50 = 1.4 nM), human trabecular meshwork (EC50 = 3.6 nM), and mouse fibroblasts and rat aortic smooth muscle cells (EC50 = 2.6 nM). Although latanoprost acid exhibited a relatively high affinity for the FP receptor (Ki = 98 nM), it had significant functional activity at FP (EC50 = 32-124 nM) and EP1 (EC50 = 119 nM) receptors. Bimatoprost acid was less selective, exhibiting a relatively high affinity for the FP (Ki = 83 nM), EP1 (Ki = 95 nM), and EP3 (Ki = 387 nM) receptors. Bimatoprost acid exhibited functional activity at the EP1 (EC50 = 2.7 nM) and FP (EC50 = 2.8-3.8 nM in most cells) receptors. Bimatoprost (nonhydrolyzed amide) also behaved as an FP agonist at the cloned human FP receptor (EC50 = 681 nM), in h-TM (EC50 = 3245 nM) and other cell types. Unoprostone and S-1033 bound with low affinity (Ki = 5.9 microM to > 22 microM) to the FP receptor, were not selective, but activated the FP receptor. In conclusion, travoprost acid has the highest affinity, the highest FP-receptor-selectivity, and the highest potency at the FP receptor as compared to the other ocular hypotensive PG analogs known so far, including free acids of latanoprost, bimatoprost, and unoprostone isopropyl ester.

Inhibition of histamine-induced human conjunctival epithelial cell responses by ocular allergy drugs

OBJECTIVE

To evaluate the effects of topical ocular drugs with histamine H1-antagonist activity on histamine-stimulated phosphatidylinositol turnover and interleukin (IL) 6 and IL-8 secretion from human conjunctival epithelial cells.

METHODS

Primary human conjunctival epithelial cell cultures were stimulated with histamine in the presence or absence of test drugs. Phosphatidylinositol turnover was quantified by ion exchange chromatography and cytokine content of supernatants by enzyme-linked immunosorbent assay.

RESULTS

Antazoline hydrochloride, emedastine difumarate, levocabastine hydrochloride, olopatadine hydrochloride, and pheniramine maleate attenuated histamine-stimulated phosphatidylinositol turnover and IL-6 and IL-8 secretion. Emedastine was the most potent in ligand binding, phosphatidylinositol turnover, and IL-6 secretion, with dissociation constant and 50% inhibitory concentrations of 1-3 nmol/L. Olopatadine, antazoline, and pheniramine exhibited similar H1-binding affinities (32-39 nmol/L). However, olopatadine was approximately 10-fold more potent as an inhibitor of cytokine secretion (50% inhibitory concentration, 1.7-5.5 nmol/L) than predicted from binding data, while antazoline and pheniramine were far less potent (20- to 140-fold) in functional assays. Levocabastine (dissociation constant, 52.6 nmol/L) exhibited greater functional activity (50% inhibitory concentration, 8-25 nmol/L) than either antazoline or pheniramine.

CONCLUSIONS

Histamine-stimulated phosphatidylinositol turnover and cytokine secretion by human conjunctival epithelial cells are attenuated by compounds with H1-antagonist activity. However, antihistaminic potency alone does not predict anti-inflammatory potential. Olopatadine, emedastine, and levocabastine were notably more potent than pheniramine and antazoline.

CLINICAL RELEVANCE

Selected topical ocular drugs with antihistaminic activity may offer therapeutic advantages to patients with allergic conjunctivitis by inhibiting proinflammatory cytokine secretion from human conjunctival epithelial cells.

Olopatadine (AL-4943A): ligand binding and functional studies on a novel, long acting H1-selective histamine antagonist and anti-allergic agent for use in allergic conjunctivitis

AL-4943A (Olopatadine) is a new antihistaminic and anti-allergic drug. It was tested for its ability to compete for [3H]pyrilamine, [3H]tiotidine and [3H]N-methyl histamine binding to H1, H2 and H3 histamine receptors, respectively. AL-4943A exhibited the highest affinity (Ki = 41.1 +/- 6.0 nM) for H1-receptors and a significantly lower affinity for H2- (Ki = 43,437 +/- 6,257 nM) and H3-receptors (Ki = 171,666 +/- 6,774 nM), respectively. These data showed AL-4943A to be an H1-selective compound, being 1,059- and 4,177-times more selective for H1- than H2- and H3-receptors. AL-4943A was more H1-selective than levocabastine, ketotifen, antazoline and pheniramine and, also, exhibited a low affinity for 38 nonhistamine receptor binding sites. AL-4943A antagonized histamine-induced phosphoinositide (PI) turnover in cultured human conjunctival epithelial cells (IC50 = 9.5 +/- 1.5 nM, n = 3), human corneal fibroblasts (IC50 = 19 nM) and transformed human trabecular meshwork cells (IC50 = 39.9 nM). These data have shown AL-4943A to be a high affinity, high potency H1-selective histamine antagonist. This information, coupled with a long duration of action in an in vivo model of allergic conjunctivitis, suggests that AL-4943A may be a useful drug to treat various ocular allergic diseases, including allergic conjunctivitis.

Regulation of D1A and D2 dopamine receptor mRNA during ontogenesis, lesion and chronic antagonist treatment

The developmental characteristics of D1A and D2 dopamine receptor mRNA levels were determined by Northern blot analyses. Striatal D1A and D2 dopamine receptor mRNAs of male Fischer 344 rats were about 60% of adult (day 120) levels at postnatal day 1 and reached their highest levels at day 30 (126 and 139% adult levels) and then decreased by day 120 (100%). D1 and D2 dopamine receptors showed much greater quantitative changes with densities at day 30 about 6- and 14-fold higher than at day 1, respectively, while mRNA levels showed only a 2-fold increase. The highest level of D2 dopamine receptor mRNA in the midbrain was reached at day 14 (195% of adult levels) while the level at day 1 was 31% higher than that at day 120. Striatal beta-actin mRNA levels decreased gradually as the rats developed with the level at postnatal day 1 almost twice that at day 120 postpartum. Treatment of adult rats with the selective D2 dopamine receptor antagonist, haloperidol (0.5 mg/kg/day, s.c., for 2 h, 7, 14, 21 days or 21 days + 3 days withdrawal) had no effect on striatal D2 dopamine receptor mRNA levels in spite of significant increases in dopamine receptor density at the later time points. However, 21 days following a 6-hydroxydopamine lesion of the nigrostriatal pathway, striatal D2 dopamine receptor mRNA levels were increased by 53%.

Steroidal saponins from Anemarrhena asphodeloides and their effects on superoxide generation

A new steroidal saponin, timosaponin F, along with six known compounds was isolated from the rhizomes of Anemarrhena asphodeloides Bge. On the basis of chemical and spectroscopic evidence, the structure of timosaponin F was elucidated as (5beta, 25 S):-spirostan-3beta,15alpha,23alpha-triol-3-O-beta- glucopyranosyl-(1--->2)-beta-galactopyranoside. The six known compounds were anemarrhenasaponin I, anemarrhenasaponin Ia, timosaponin BI, timosaponin BII, timosaponin B, timosaponin AIII; their effects on superoxide generation are also reported.

Flavonoid ketohexosefuranosides from the leaves of Crataegus pinnatifida Bge. var. major N.E.Br

Four flavonoid ketohexosefuranosides, pinnatifinoside A, pinnatifinoside B, pinnatifinoside C, and pinnatifinoside D were isolated from the leaves of Crataegus pinnatifida Bge. var. major N.E.Br. Their structures were elucidated by spectroscopic analysis (UV, IR, MS and 1D, 2D NMR) and chemical evidence.

Levobetaxolol (Betaxon) and other beta-adrenergic antagonists: preclinical pharmacology, IOP-lowering activity and sites of action in human eyes

The pharmacological characteristics of levobetaxolol, a single active isomer of betaxolol, were determined and compared with activities of other beta-adrenoceptor antagonists. Levobetaxolol (43-fold beta1-selective) exhibited a higher affinity at cloned human beta1 (Ki = 0.76 nM) than at beta2 (Ki = 32.6 nM) receptors, while dextrobetaxolol was much weaker at both receptors. Levobetaxolol potently antagonized functional activities at cloned human beta1 and beta2 receptors, and also at guinea pig atrial beta1, tracheal beta2 and rat colonic beta3 receptors (IC50s = 33.2 nM, 2970 nM and 709 nM, respectively). Thus, levobetaxolol was 89-times beta1-selective (vs beta2). Levobetaxolol (Ki = 16.4 nM) was more potent than dextrobetaxolol (Ki = 2.97 microM) at inhibiting isoproterenol-induced cAMP production in human non-pigmented ciliary epithelial cells. Levobunolol and (l)-timolol had high affinities at beta1 and beta2 receptors but were considerably less beta1-selective than levobetaxolol. Levo-, dextro- and racemic-betaxolol exhibited little or no affinity, except at sigma sites and Ca2+-channels (IC50s > 1 microM), at 89 other receptor/ligand binding sites. Levobetaxolol exhibited a micromolar affinity for L-type Ca2+-channels. In conscious ocular hypertensive cynomolgus monkeys, levobetaxolol was more potent than dextrobetaxolol, reducing intraocular pressure by 25.9+/-3.2% at a dose of 150 microg/eye (n = 15-30). Quantitative [3H]-levobetaxolol autoradiography revealed high levels of binding to human ciliary processes, iris, choroid/retina, and ciliary muscles. In conclusion, levobetaxolol is a potent, high affinity and beta1-selective IOP-lowering beta-adrenoceptor antagonist.

Speciation of tissue and cellular iron with on-line detection by inductively coupled plasma-mass spectrometry

Iron accumulating to excess in tissues of humans and animal models occurs mainly as complexes with transferrin, ferritin, other hemoproteins, and insoluble hemosiderin particles. To determine the distribution of Fe amongst these molecular species, we have used inductively coupled plasma-mass spectrometry as a means of on-line, isotope-specific detection for their liquid chromatographic separation. The stable isotope 57Fe is a suitable isotope for monitoring the Fe content of each fraction, and its availability at high isotopic enrichment makes it an attractive choice for tracer studies when the use of a radioisotope is undesirable, e.g., in human subjects. The detection system offers the advantages of high sensitivity (detection limits in the parts per billion range), a wide dynamic range (linearity of the calibration curve over several orders of magnitude), and on-line analysis facilitating real-time evaluation of the chromatographic separation, in addition to isotope-specific information. The Fe distributions in healthy rat livers, liver and heart tissue from Fe-loaded human subjects, and human hepatocyte cultures are reported. The ferritin:hemosiderin ratio in these samples is shown to be an indicator of the degree of Fe loading and correlates well with that determined by Zeeman-corrected electrothermal atomic absorption as an alternative means of detection.

Dauricoside, a new glycosidal alkaloid having an inhibitory activity against blood-platelet aggregation

Dauricoside (1), a new glycosidal alkaloid, was isolated from the rhizomes of Menispermum dauricum DC. along with dauricine (2), daurisoline (3), dauriporphine (4), menisporphine (5), and 6-O-demethylmenisporphine (6), and its structure was determined by means of spectroscopic methods. Compounds 1, 2, and 3 inhibited blood-platelet aggregation induced by adenosine 5'-diphosphate (ADP).

Expression of rat striatal D1 and D2 dopamine receptor mRNAs: Ontogenetic and pharmacological studies

The developmental characteristics of D1 and D2 dopamine receptor mRNA levels were determined by Northern blot analyses. Striatal D1 and D2 receptor mRNAs of male Fischer 344 rats were about 60% of adults levels at postnatal day 1 and reached their highest measured levels at day 30 (126-139% adults levels) and then decreased by day 120 (100%). D1 and D2 receptor densities at day 30 were about 8-fold higher than at day 1, while mRNA levels showed only a 2-fold increase. The highest level of D2 receptor mRNA in midbrain as reached at day 14 (195% adult level) while levels at day 1 were 31% higher than dose at day 120. Treatment with selective D2 receptor antagonist, haloperidol (0.5 mg/kg/day, s.c., for 2 h, 7, 14, 21 days or 21 days + 3 days withdrawal) had no effect on Sprague-Dawley rat striatal D2 receptor mRNA levels in spite of significant increases in receptor density at the later time points. However, the selective D1 receptor antagonist, SCH 23390 (0.5 mg/kg/day, s.c.) produced increases in striatal D1 receptors and mRNA levels after treatments of 7, 14 and 21 days + 3 days withdrawal.

Five saponins from the root bark of Aralia elata

Five saponins, 3-O-[beta-D-glucopyranosyl (1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl]-oleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin V), 3-O-[beta-D-glucopyranosyl (1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl]-echinocystic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin VI), 3-O-beta-D-glucopyranosyl (1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl]-hederagenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin VII), 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl]-caulophyllogenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin VIII), 3-O-[beta-D-glucopyranosyl (1-->2)-[beta-D-glucopyranosyl(1-->3)]-alpha-L-arabinopyranosyl]-hederagenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin IX), were isolated from the root bark of Aralia elata (Miq.) Seem., together with four known compounds. Their structures were determined on the basis of chemical and spectroscopic methods.

Human conjunctival epithelial cells express histamine-1 receptors coupled to phosphoinositide turnover and intracellular calcium mobilization: role in ocular allergic and inflammatory diseases

Dispase-dissociated primary cultures of human conjunctival epithelial (HCE) cells were stimulated with histamine and the generation of inositol phosphates ([3H]IPs) from [3H]phosphoinositide (PI) hydrolysis and the mobilization of intracellular calcium ([Ca2+]i) were studied using ion exchange chromatography and Fura-2 fluorescence techniques, respectively. Histamine (100 microM) maximally stimulated PI turnover in HCE cells by 210 +/- 10% (n = 21) above basal levels and with a potency (EC50) of 3.3 microM (n = 4). Histamine (EC50 = 5.8 microM, n = 3) rapidly mobilized [Ca2+]i which peaked within 10 sec but which was still significantly elevated 20 min after stimulation. The histamine-induced [Ca2+]i responses did not desensitize upon repeated applications of histamine. The effects of histamine (100 microM) on PI turnover and [Ca2+]i were potently antagonized by the H1-antagonists, emedastine (IC50 = 1.6-2.9 nM), triprolidine (IC50 = 3.1 nM) and levocabastine (IC50 = 8 nM), but weakly by the H2-(ranitidine/cimetidine) and H3-(thioperamide) antagonists (IC50s = 10-100 microM). In conclusion, HCE cells have been shown to possess functional H1-histamine receptors that couple to inositol phosphates generation which then mobilize intracellular calcium. These intracellular signaling mechanisms may be intimately linked with the process of inflammatory cytokine secretion from the HCE cells after stimulation by histamine released from the conjunctival mast cells. The current results strongly suggest that the HCE cells are active participants in mediating, and perhaps amplifying, the pro-inflammatory and allergic effects of histamine which is released from conjunctival mast cells during ocular allergic and inflammatory reactions.

Cloning of hypoxia-inducible factor 1alpha cDNA from a high hypoxia tolerant mammal-plateau pika (Ochotona curzoniae)

Hypoxia-inducible factor 1 is a transcription factor composed of HIF-1alpha and HIF-1beta. It plays an important role in the signal transduction of cell response to hypoxia. Plateau pika (Ochotona curzoniae) is a high hypoxia-tolerant and cold adaptation species living only at 3000-5000 m above sea level on the Qinghai-Tibet Plateau. In this study, HIF-1alpha cDNA of plateau pika was cloned and its expression in various tissues was studied. The results indicated that plateau pika HIF-1alpha cDNA was highly identical to those of the human (82%), bovine (89%), mouse (82%), and Norway rat (77%). The deduced amino acid sequence (822bp) showed 90%, 92%, 86%, and 86% identities with those of the human, bovine, house mouse, and Norway rat, respectively. Northern blot analyses detected two isoforms named pLHIF-1alpha and pSHIF-1alpha. The HIF-1alpha mRNA was highly expressed in the brain and kidney, and much less in the heart, lung, liver, muscle, and spleen, which was quite different from the expression pattern of mouse mRNA. Meanwhile, a new variant of plateau pika HIF-1alpha mRNA was identified by RT-PCR and characterized. The deduced protein, composed of 536 amino acids, lacks a part of the oxygen-dependent degradation domain (ODD), both transactivation domains (TADs), and the nuclear localization signal motif (NLS). Our results suggest that HIF-1alpha may play an important role in the pika's adaptation to hypoxia, especially in brain and kidney, and pika HIF-1alpha function pattern may be different from that of mouse HIF-1alpha. Furthermore, for the high ratio of HIF-1alpha homology among the animals, the HIF-1alpha gene may be a good phylogenetic performer in recovering the true phylogenetic relationships among taxa.

Pharmacological characterization of bradykinin receptors coupled to phosphoinositide turnover in SV40-immortalized human trabecular meshwork cells

This study sought to pharmacologically characterize bradykinin receptors on SV40-immortalized human trabecular meshwork (HTM3) cells. Phosphoinositide (PI) turnover studies were conducted using [3H]myo-inositol-labeled HTM3 cells and anion exchange chromatography to quantify [3H]inositol phosphates generated in response to bradykinin (BK) and various BK analogs. The blockade of these responses was studied using two potent and receptor-subtype selective antagonists. BK and T-kinin (Ile-Ser-BK:TK) induced a 4.2-4.4 fold stimulation of PI turnover above base levels at 1-10 microM. Several other peptides unrelated to BK, including angiotensin II, endothelin, cholecystokinin, bombesin and peptide YY tested at 1-10 microM were essentially inactive. The molar potencies (EC50) of BK, TK and close analogs were: BK = 4.5 +/- 0.5 nM (n = 6), Lys-BK = 6.5 +/- 0.7 nM (n = 3), TK = 38.8 +/- 6.6 nM (n = 8), Met-Lys-BK = 41.5 +/- 13.4 nM (n = 4), Des-Arg9-BK = 2093 +/- 626 nM (n = 4). All the latter BK-related peptides were full agonists. The actions of BK and TK were potently and competitively antagonized by Hoe-140 (molar potency = 0.6-1 nM; pA2 = 8.97-9.21. n = 3-4) and by D-Arg0[Hyp3,-Thi5.8,-DPhe7]-BK (molar potency = 251 nM; -log potency, pKb = 6.6), two selective B2-type BK antagonists. In conclusion, rank order of potency of BK agonists and the blockade of BK- and TK-induced PI turnover by the selective antagonists are consistent with the classification of the BK receptors on HTM3 cells as the B2-receptor subtype.

Four new saponins from the root bark of Aralia elata

Four new saponins, 3-O-[beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl]-16a lpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (called aralia-saponin I), 3-O-[beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl]-16a lpha-hydroxyhederagenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin II), 3-O-[beta-D-glucopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->3)-alpha-L-+ ++arabinopyranosyl]-16alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin III), 3-O-[beta-D-glucopyranosyl(1-->3)-beta-D-gucopyranosyl(1-->3)-beta -D-glucucopyranosyl]-16alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin IV), were isolated from the root bark of Aralia elata (Miq.) Seem., together with nineteen known compounds including glycosides of (20S)-protopanaxadiol and (20S)-protopanaxatriol. Their structures were determined on the basis of chemical and spectroscopy methods.

Effect of Chronic Nicotine Treatment and Withdrawal on Rat Striatal D1 and D2 Dopamine Receptors

The effects on rat striatal dopamine receptors after chronic nicotine administration (3 and 12 mg kg−1 day−1), and after withdrawal from chronic nicotine (12 mg kg−1 day−1), were studied. After 21 days of continuous minipump infusion, the control (saline) and nicotine-treated rats were killed. The nicotine-withdrawal rats were killed on day 28, 7 days after pump removal. Radioligand studies were performed to determine D1 ([3H]SCH23390) and D2 ([3H]spiperone) striatal dopamine receptor affinity (Kd) and maximum binding (Bmax). Dopamine inhibition of antagonist binding at 3 concentrations and the effect of 0·3 Mm GTP on binding affinity were examined. No statistically significant differences between control and nicotine treatment or withdrawal groups were noted in either D1 or D2 receptor Kd or Bmax. Although nicotine has been shown to affect nigrostriatal dopamine release, chronic treatment does not appear to alter overall striatal dopaminergic receptor binding parameters.

Angelol-type coumarins from Angelica pubescence F. biserrata and their inhibitory effect on platelet aggregation

An ethyl acetate-soluble root extract of Angelica pubescence f. biserrata afforded two new angelol-type coumarins, angelols K and L, in addition to angelols B, C, D and G. Some of the compounds were tested on human platelet aggregation and showed significant activity.

Use of a semi-automated, robotic radioimmunoassay to measure cAMP generated by activation of DP-, EP2-, and IP-prostaglandin receptors in human ocular and other cell types

The aim of these studies was to compare the effects of several prostaglandin agonists on adenylyl cyclase activity in embryonic bovine tracheal (EBTr) cells, transformed human nonpigmented ciliary epithelial (NPE) cells and National Cancer Bank (NCB-20) cells. These cell types have been shown to express DP, EP2 and IP prostaglandin (PG) receptors, respectively. Cyclic AMP (cAMP) generation was measured by manual and semi-automated radioimmunoassay (RIA) techniques. ZK118182 (EC50 = 10-27 nM), PGE2 (EC50 = 21-27 nM) and PGI2 (EC50 = 3.5-4 nM) had the highest potency at the DP, EP2 and IP receptors, respectively. A plot of potency (EC50) values generated with both techniques showed a high degree of correlation for all three receptors. These studies provide further characterization of prostanoid receptor functional responses in three cell types and demonstrate the advantages of a semi-automated RIA method for the analysis of the second messenger cAMP.

T helper type 2-polarized invariant natural killer T cells reduce disease severity in acute intra-abdominal sepsis

Sepsis is characterized by a severe systemic inflammatory response to infection that is associated with high morbidity and mortality despite optimal care. Invariant natural killer T (iNK T) cells are potent regulatory lymphocytes that can produce pro- and/or anti-inflammatory cytokines, thus shaping the course and nature of immune responses; however, little is known about their role in sepsis. We demonstrate here that patients with sepsis/severe sepsis have significantly elevated proportions of iNK T cells in their peripheral blood (as a percentage of their circulating T cells) compared to non-septic patients. We therefore investigated the role of iNK T cells in a mouse model of intra-abdominal sepsis (IAS). Our data show that iNK T cells are pathogenic in IAS, and that T helper type 2 (Th2) polarization of iNK T cells using the synthetic glycolipid OCH significantly reduces mortality from IAS. This reduction in mortality is associated with the systemic elevation of the anti-inflammatory cytokine interleukin (IL)-13 and reduction of several proinflammatory cytokines within the spleen, notably interleukin (IL)-17. Finally, we show that treatment of sepsis with OCH in mice is accompanied by significantly reduced apoptosis of splenic T and B lymphocytes and macrophages, but not natural killer cells. We propose that modulation of iNK T cell responses towards a Th2 phenotype may be an effective therapeutic strategy in early sepsis.

Human retina contains polyamine sensitive [3H]-ifenprodil binding sites: implications for neuroprotection?

AIMS

This study characterised the pharmacology of [3H]-ifenprodil binding to the polyamine binding sites (PBS) on the N-methyl-D-aspartate (NMDA) receptor channel complex on human retinas. These data were correlated with the known neuroprotective effects of ifenprodil and eliprodil.

METHODS

Specific binding of [3H]-ifenprodil (under sigma site blockade) was investigated using human retinal homogenates and radioligand binding techniques. Scatchard and competition analyses were utilised to define the pharmacology of the [3H]-ifenprodil binding sites.

RESULTS

Specific binding of [3H]-ifenprodil comprised 73% (SEM 3%) of total and reflected interaction with two affinity sites (Kds = 0.39 and 4.3 microM) of different densities (Bmax = 14.4 and 105 pmol/mg protein) (n = 5). The rank order of affinity of compounds competing for [3H]-ifenprodil binding to the high affinity PBS was: ifenprodil > eliprodil > arcaine > spermine > diaminodecane > spermidine > putrescine >> MK-801 (n = 3-7). However, [3H]-ifenprodil binding was minimally inhibited by glutamate, NMDA, and kainate.

CONCLUSION

These studies have shown, for the first time, the presence of specific [3H]-ifenprodil binding sites in the human retina with pharmacological characteristics of PBS associated with the NMDA receptor ionophore complex. The neuroprotective effects of eliprodil and ifenprodil may, in part, be mediated via these [3H]-ifenprodil labelled sites.

Pharmacological and molecular biological (RT-PCR) characterization of functional TP prostanoid receptors in immortalized human non-pigmented ciliary epithelial cells

Immortalized human non-pigmented ciliary epithelial (NPE) cells (ODM-2) were shown to express the mRNA for the prostanoid TPalpha but not the TPbeta receptor using reverse transcription-polymerase chain reaction (RT-PCR). These TPalpha receptors were coupled to phospholipase C (PLC) and, thus, promoted phosphoinositide (PI) turnover. TP receptor agonists yielded the following potencies (EC50S) in the PI turnover assays: I-BOP = 8.2 +/- 1.1 nM; carbocyclic TA2 = 87.5 +/- 25.3 nM; U-44069 = 1.16 +/- 0.32 microM; U-46619 = 1.2 +/- 0.2 microM (n = 4-17). Agonists selective for other prostanoid receptor subtypes (e.g., fluprostenol and sulprostone) were inactive. The agonist effects of U-44619 and I-BOP were potently blocked, in an apparent non-competitive manner (ki = 53.9 +/- 12 nM; pA2s = 7.6-7.8; pKbs = 7.38), by the TP receptor-selective antagonist, SQ29,548, but were unaffected by other prostanoid receptor antagonists (e.g., AH6809, AL-8810). The PLC inhibitor (U73122) inhibited U-46619-induced PI turnover (IC50 = 4.3 +/- 0.6 microM). The functional potencies of the compounds stimulating or inhibiting the TP receptor-mediated PI turnover in the NPE cells correlated well with the TP receptor binding affinities of these compounds at human platelet TP receptors (r = 0.98). These studies have shown the presence of the mRNA for and the expression of functional TPalpha receptors coupled to PLC in human NPE cells. The TPalpha receptors on NPE cells may be responsible for inhibiting aqueous humor production and may help explain the intraocular pressure-lowering effects of certain TP agonists.

The impact of clinical risk factors in the conversion from acute lung injury to acute respiratory distress syndrome in severe multiple trauma patients

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are different stages of the same disease, the aggravated stage of ALI leading to ARDS. Patients with ARDS have higher hospital mortality rates and reduced long-term pulmonary function and quality of life. It is, therefore, important to prevent ALI converting to ARDS. This study evaluated 17 risk factors potentially associated with the conversion from ALI to ARDS in severe multiple trauma. The results indicate that the impact of pulmonary contusion, APACHE II score, gastrointestinal haemorrhage and disseminated intravascular coagulation may help to predict conversion from ALI to ARDS in the early phase after multiple-trauma injury. Trauma duration, in particular, strongly impacted the short- and long-term development of ALI. Being elderly (aged > or = 65 years) and undergoing multiple blood transfusions in the early phase were independent risk factors correlated with secondary sepsis, deterioration of pulmonary function and transfusion-related acute lung injury due to early multiple fluid resuscitation.

Pharmacology of functional endogenous IP prostanoid receptors in NCB-20 cells: comparison with binding data from human platelets

The objective of these studies was to characterize the effects of a broad range of prostanoid agonists upon the stimulation of cAMP production in National Cancer Bank (NCB-20; mouse neuroblastoma/hamster brain hybridoma) cells. The pharmacology of these functional responses in NCB-20 cells was compared with that of the classic endogenous IP receptor present on human platelets using [3H]-iloprost binding techniques. In both assay systems, agonists from the IP prostanoid class exhibited the highest affinities and functional potencies. Specific prostanoids exhibited the following rank order of potency (EC50 +/- SEM) in stimulating cAMP production in the NCB-20 cells: carbaprostacyclin (4.3 +/- 0.9 nM) = PGI2 (6.6 +/-1.5 nM) > iloprost (75+/-13 nM) > 11-deoxy PGE, (378+/-138 nM) > misoprostol (1,243+/-48) > PGE2 (3020+/-700 nM) > ZK-118182 (7265+/-455 nM). Iloprost wasthe most potent compound in the human platelet binding assay while prostanoidsfromthe DPand EP receptor classes showed modest affinity. These studies provide functional and binding information for a broad range of both natural and synthetic prostanoid receptor ligands at the endogenous IP receptor in two different cell types.

A new sesquiterpene lactone glucoside from Ixeris sonchifolia

A new sesquiterpene lactone glucoside, Ixerin Z1 (1), was isolated from the whole plants of Ixeris sonchifolia (Bge.) Hance, along with 15 known compounds. The structure of 1 was elucidated as 1(10),3,11(13)-guaiatriene-12,6-olide-2-one-3-O-[6'-(p-hydroxyphenylacetyl)]-glucopyranoside by spectroscopic methods including 2D-NMR techniques.