Resveratrol promotes an inhibitory effect on the turbot scuticociliate parasite Philasterides dicentrarchi by mechanisms related to cellular detoxification.

The mechanisms involved in antiparasitic activity of the natural nonflavonoid polyphenol resveratrol (RESV) on the turbot (Psetta maxima) scuticoliate parasite Philasterides dicentarchi were investigated. At concentrations higher than 50microM, RESV caused significant inhibition of the in vitro growth of the ciliates, which was apparent on the third day of culture and, at the same concentration, RESV caused significant inhibition of O(2) consumption. RESV, at a concentration of 100microM, produced a significant increase in the production of intracellular reactive oxygen species (ROS), which were inhibited by the addition of 1mM of L (+) ascorbic acid. RESV (100microM) also caused significant inhibition of peroxidase, catalase and superoxide dismutase activities, but stimulated the activity of the redox regulating enzyme glutathione S-transferase. Confocal microscopy with the mitochondria-sensitive dye MitoTracker Orange CMTMRos revealed that RESV at concentrations higher than 50microM significantly increased the levels of fluorescence inside mitochondria and, at the same concentration, also caused an increase in the vacuolization of the trophozoites. The results obtained in the present study suggest that the inhibitory activity of RESV on the ciliate P. dicentrarchi is related to the induction of oxidative stress and to the inability of the parasite to eliminate ROS as a result of modified activity of antioxidant enzymes.

Short-term or long-term treatments with a phosphodiesterase-4 (PDE4) inhibitor result in opposing agonist-induced Ca(2+) responses in endothelial cells.

BACKGROUND AND PURPOSE: We previously reported that agonist-induced rises in cytoplasmic Ca(2+) concentration ([Ca(2+)](i)) in human umbilical vein endothelial cells (HUVEC) were inhibited after a short-term (2 min) pre-treatment with cAMP-elevating agents. The aim of this work was to study the effects of longer term (8 h) pre-treatment with dibutyryl-cAMP (db-cAMP) or rolipram, a specific inhibitor of phosphodiesterase-4 (PDE4), on [Ca(2+)](i), cAMP levels and PDE activity and expression in HUVEC. EXPERIMENTAL APPROACH: [Ca(2+)](i) changes were measured in isolated HUVEC by Fura-2 imaging. Intracellular cAMP levels and PDE4 activity were assessed by enzyme-immunoassay and radio-enzymatic assay, respectively. PDE expression was measured by northern and western blot analysis. KEY RESULTS: Long-term pre-treatment of HUVEC with rolipram or db-cAMP significantly increased ATP-, histamine- and thrombin-induced [Ca(2+)](i) rises. Short-term pre-treatment with rolipram was associated with an increase in cAMP, whereas long-term pre-treatment was associated with a decrease in cAMP. Long-term pre-treatment with rolipram or db-cAMP induced a significant increase in PDE4 activity and the expression of 74 kDa-PDE4A and 73 kDa-PDE4B was specifically enhanced. All these effects were suppressed by cycloheximide. CONCLUSIONS AND IMPLICATIONS: Our data suggest that sustained inhibition of PDE4 by rolipram induced an increase in PDE4 activity, possibly as a compensatory mechanism to accelerate cAMP degradation and that PDE4A and PDE4B were implicated in the regulation of [Ca(2+)](i). Thus, isozyme-specific PDE4 inhibitors might be useful as therapeutic agents in diseases where [Ca(2+)](i) handling is altered, such as atherosclerosis, hypertension and tolerance to beta-adrenoceptor agonists.

Resveratrol modulates innate and inflammatory responses in fish leucocytes.

Resveratrol (RESV; trans-3,5,4'-trihydroxystilbene), a phytoalexin that is produced by some plants, among other effects has well-known antioxidant, anti-inflammatory and immunomodulatory activities in mammals. In the present study, the effects of RESV on several functions of turbot, Psetta maxima (L.), kidney leucocytes (KLs) related to the innate and inflammatory responses were investigated. RESV exerted a dose-dependent inhibitory effect on the migratory response and on the production of reactive oxygen species in KL, after stimulation of the respiratory burst activity with phorbol myristate acetate (PMA). RESV also significantly inhibited the generation of the pro-inflammatory mediator prostaglandin E(2) (PGE(2)) in the supernatant of KL cultures stimulated with acidic sulphated polysaccharides (ASPs) from the seaweed Ulva rigida. The effects of the polyphenol on enzymatic activity and on myeloperoxidase (MPO) gene expression in neutrophils were also tested. It was found that RESV strongly inhibited intracellular and extracellular MPO activity, behaving as a noncompetitive and reversible inhibitor, and also induced a decrease in MPO mRNA levels in turbot neutrophils. These findings indicate that RESV exerts important modulatory effects on inflammatory responses in fish, and considering the importance of innate immunity in these vertebrates and the similarities with mammals, it may be possible to use fish for analysis of the effects of different substances on inflammatory responses.

Comparative studies of the antioxidant effects of cis- and trans-resveratrol.

Resveratrol (3,4',5-trihydroxystilbene, RESV) is a natural phenolic compound that exists as cis and trans isomers [c-RESV or (Z)-RESV and t-RESV or (E)-RESV, respectively]. t-RESV is a natural component of Vitis vinifera L. (Vitaceae), abundant in the skin of grapes (but not in the flesh) and in the leaf epidermis, and present in wines, especially red wines. In in vitro, ex vivo and in vivo experiments t-RESV exhibits a number of biological activities, including anti-inflammatory and anticarcinogenic properties. RESV also exists in wines as a cis isomer, which (unlike t-RESV) is not currently available commercially; as a result, little is known about this isomer's pharmacological activity. In this review, I will focus on the few comparative studies of the antioxidant effects of the two RESV isomers in different experimental models.

Regulation of cytosolic calcium levels in vascular smooth muscle.

Ca2+ plays an important role in the contraction of skeletal, cardiac, and smooth muscle, as well as in a number of important processes, such as secretion and neuronal activity. In this review, I focus on the various mechanisms by which cytosolic Ca2+ concentration is regulated in vascular smooth muscle, in the resting state and during activation. Particular attention is paid to the calcium pumps of the plasmalemma and the sarcoplasmic reticulum, to the inositol 1,4,5-trisphosphate- and ryanodine-sensitive calcium channels of the sarcoplasmic reticulum, and to voltage-dependent and voltage-independent calcium channels of the plasmalemma.

Effect of cis-resveratrol on genes involved in nuclear factor kappa B signaling.

This study investigated for the first time the effects of the cis isomer of RESV (c-RESV), a polyphenol present in red wine, on an array of genes whose expression is controlled by nuclear factor kappa B (NF-kappaB) and whose transcriptional activation is critical in a number of pathologies (including some cardiovascular diseases). In inflammatory peritoneal macrophages stimulated with lipopolysaccharide (LPS) and gamma interferon (IFN-gamma), c-RESV significantly blocked the expression of genes related to the REL/NF-kappaB/IkappaB family, adhesion molecules and acute-phase proteins; however, the greatest modulatory effect was obtained on the expression of genes related to the pro-inflammatory cytokines. c-RESV down-regulated the nuclear factor of kappa light chain gene enhancer in B-cells 1 (NFkappaBL1) gene product p105 and up-regulated the nuclear factor of kappa light chain gene enhancer in B-cells inhibitor alpha (IkappaBalpha) gene. c-RESV also significantly inhibited intercellular adhesion molecule-1 (ICAM-1) gene expression and the transmembrane receptors RIP (receptor TNFRSF) and TLR3 (toll-like receptor 7). At 100 muM, c-RESV significantly inhibited transcription of Scya2 (chemokine MCP-1), the chemokine RANTES (regulated on activation, normal T cell expressed and secreted), pro-inflammatory cytokines that attract monocyte-granulocyte cells such as M-CSF (colony-stimulating factor 1), GM-CSF (colony-stimulating factor 2) and G-CSF (colony-stimulating factor 3), the cytokine tumor growth factor beta (TGF-beta) and the extracellular ligand IL-1alpha. In contrast, c-RESV stimulated transcription of the pro-inflammatory cytokines IL-6 and tumor necrosis factor alpha (TNF-alpha), the extracellular ligand IL-1beta, and the IFN regulatory factor (IRF)-1. In conclusion, c-RESV has a significant modulatory effect on the NF-kappaB signaling pathway and, consequently, an important antioxidant role that may partially explain the cardioprotective effects attributed to long-term moderate red wine consumption.

Synthesis and antidopaminergic activity of some 3-(aminomethyl)tetralones as analogues of butyrophenone.

Starting from beta-benzoylpropionic acid we synthesized 3-(aminomethyl)tetralones in which the amino substituent was 4-(N-piperazinyl)-p-fluorobutyrophenone, 4-benzoylpiperidine, 4-hydroxy-4-phenylpiperidine or 4-(o-methoxyphenyl)piperazine. The possible dopamine antagonist activity of these compounds was investigated in both "in vitro" and "in vivo" experiments. These compounds potently inhibited [3H]spiperone binding to D2 striatal receptors and moderately inhibited [3H]SCH-23390 binding to D1 striatal receptors (Kis in the nanomolar and micromolar ranges, respectively). Apomorphine-induced stereotypies and amphetamine group toxicity were antagonized, to different extents, by the compounds under study, with a potency similar to that of haloperidol. Interestingly, no catalepsy was observed after administration of the new compounds (2-8 mg/kg). The most active compounds "in vivo" 14 and 15 possessed two butyrophenone pharmacophores. However, the tetralone moiety appeared not critical for their antidopaminergic activity, since all target compounds were less active than haloperidol. These studies provide a pharmacological basis for future research on these new compounds devoid of cataleptogenic activity.

Study of the in vivo and in vitro cardiovascular effects of a hydralazine-like vasodilator agent (HPS-10) in normotensive rats.

1. In this work, the cardiovascular effects of HPS-10, a new vasodilator agent, were studied in rats. 2. In conscious normotensive rats, oral administration of HPS-10 (4-9 mg kg-1) produced a dose-related and long-lasting fall in systolic arterial blood pressure (ED30 of 5.32 mg kg-1), accompanied by an increase in heart rate (ED30 of 8.43 mg kg-1). This tachycardia was totally inhibited by pretreatment with (+/-)-propranolol (10 mg kg-1, p.o.). 3. In anaesthetized normotensive rats, HPS-10 (0.3-0.6 mg kg-1, i.v.) produced a gradual, dose-dependent and sustained decrease in systolic, diastolic and mean arterial pressure (MAP) (ED30 for MAP of 0.41 mg kg-1, i.v.), accompanied by a significant bradycardia at high doses (> 0.4 mg kg-1; ED20 of 0.61 mg kg-1, i.v.). HPS-10 (0.5 mg kg-1, i.v.) did not modify the positive chronotropic effects induced by intravenous administration of noradrenaline (NA; 5 micrograms kg-1), angiotensin II (AII; 0.2 microgram kg-1) and nicotine (200 micrograms kg-1) but markedly inhibited the hypertensive response produced by these agents. 4. In rat isolated rubbed aorta, HPS-10 (0.1-1 mM) non-competitively and with almost equal effectiveness antagonized the contractions induced by NA, AII (in normal Krebs solution) and Ca2+ (in depolarizing Ca(2+)-free high-K+ 50 mM solution). In the experiments in Ca(2+)-free medium, HPS-10 (1 mM) considerably inhibited the contractions induced by NA, AII and caffeine in rat aorta. 5. Furthermore, in the studies with radioactive Ca2+, HPS-10 (1 mM) did not modify the basal uptake of 45Ca2+ but strongly decreased the influx of 45Ca2+ induced by NA, AII and K+ in rat aortic rings. 6. In rat isolated atria, HPS-10 (1 mM) produced a positive inotropic/negative chronotropic effect. 7. HPS-10 (0.3 mM) significantly inhibited the sustained and transient Ba2+ inward current (IBa) recorded in whole-cell clamped rat aortic myocytes. 8. These results indicate that the non-selective vasorelaxant effects of HPS-10 in rat aortic rings can be attributed to transmembrane Ca(2+)-antagonist activity and an intracellular action on smooth muscle cells. The direct vasodilator action of HPS-10 observed in rat isolated aorta may be responsible for the HPS-10 hypotensive activity in anaesthetized normotensive rats.

Study of the in vivo and in vitro cardiovascular effects of (+)-glaucine and N-carbethoxysecoglaucine in rats.

1. The cardiovascular and vasorelaxant effects of (+)-glaucine and of a semisynthetic derivative (N-carbethoxysecoglaucine) were studied in rats. 2. N-carbethoxysecoglaucine did not modify either systolic arterial pressure or heart rate values in conscious (25 mg kg-1, p.o.) and anaesthetized normotensive rats (5 mg kg-1, i.v.). Furthermore, this compound showed no activity in the experiments carried out on rat isolated aorta [contractility and 45Ca2+ influx assays (5 microM)] and did not modify the rate and force of contraction in rat isolated atria (5 microM). 3. In conscious normotensive rats, oral administration of (+)-glaucine (25 mg kg-1) did not modify either systolic arterial pressure or heart rate. 4. In anaesthetized normotensive rats, (+)-glaucine (5 mg kg-1, i.v.) produced a remarkable fall in mean arterial pressure (MAP) accompanied by a significant decrease in heart rate. In the same preparation, (+)-glaucine (5 mg kg-1, i.v.) did not modify the cardiovascular effects induced by noradrenaline (NA) (5 micrograms kg-1) and 5-hydroxytryptamine (5-HT) (300 micrograms kg-1) but markedly inhibited those induced by nicotine (200 micrograms kg-1). 5. In isolated intact aorta of rat, (+)-glaucine (0.15-5 microM) competitively inhibited the contractions induced by NA (with a pA2 value of 7.14) and non-competitively those induced by 5-HT (in normal Krebs solution) and Ca2+ (in depolarizing Ca(2+)-free high-K+ 50 mM solution), with depression of the maximal response and with pD2 values of 5.56 and 5.26, respectively. 6. In experiments in Ca2+-free medium, (+)-glaucine (3 microM) inhibited the contractions induced by NA and had no effect on either 5-HT- or caffeine-induced contractions.7. Furthermore, in the experiments with radioactive Ca2+, (+)-glaucine (3 microM) did not modify the basal uptake of 45Ca2+ but strongly inhibited the influx of 45Ca2+ induced by NA, 5-HT and K+.8. (+)-Glaucine (5microM) had no effect on rate and force of contraction in rat isolated atria.9. These results indicate that: (a) the cardiovascular effects (hypotension and bradycardia) of (+)-glaucine in anaesthetized normotensive rats (5 mg kg-1) may be due, at least in part, to a ganglioplexic effect; (b) the vasorelaxant action of ( + )-glaucine (0.15-5 microM) in rat isolated aorta can be attributed to an alpha1-adrenoceptor blocking property (which may explain its inhibition of noradrenaline-induced 45Ca2+influx and contractions in normal Krebs solution and noradrenaline-induced contractions in Ca2+-free medium) and to a Ca2+-antagonist activity (which may be responsible, at least in part, for the inhibition of 45Ca2+ uptake induced by NA, 5-HT and K+ and the contractions induced by both NA and 5-HT in normal Krebs solution and by Ca2+ in Ca2+-free high-K+ medium) and (c) there is no correlation between the mechanisms of action observed for (+ )-glaucine in vivo and in vitro, which suggests that the vasorelaxant activity of this alkaloid does not contribute to its hypotensive activity.

Study of the mechanism of the relaxant action of (+)-glaucine in rat vas deferens.

1. Effects of the aporphinoid alkaloid, (+)-glaucine, on rat vas deferens were investigated. 2. (+)-Glaucine (2-18 microM) competitively inhibited contractions induced by noradrenaline and methoxamine with a pA2 value of about 6. 3. (+)-Glaucine (2 and 18 microM) did not change the accumulation of tritium during incubation of the vas deferens with [3H]-noradrenaline. 4. (+)-Glaucine (0.3 nM-0.1 mM) inhibited specific [3H]-prazosin binding to membranes from rat vas deferens with a pKi value of 6.63, which is close to the pA2 value obtained against noradrenaline and methoxamine in functional studies. 5. In electrically-stimulated rat vas deferens, (+)-glaucine (0.3-10 microM) enhanced twitch contractions and competitively antagonized the inhibitory effect of clonidine with a pA2 value of 5.91. 6. In tissues incubated in depolarizing calcium-free high-potassium medium, (+)-glaucine (30-80 microM) inhibited Ca(2+)-induced contractions with depression of the maximal response at higher doses and with a pD'2 value of 3.65. Furthermore, (+)-glaucine (50 microM) did not modify basal 45Ca uptake but strongly inhibited the influx of 45Ca induced by K+. 7. These results suggest that (+)-glaucine has non-selective alpha 1- and alpha 2-adrenoceptor blocking properties. At higher doses, (+)-glaucine shows calcium antagonist activity which may be responsible, at least in part, for the inhibition of the contractions induced by Ca2+ in calcium-free high-potassium medium.

Effects of ATP on cultured smooth muscle cells from rat aorta.

1. Membrane ionic currents provoked by externally applied ATP were studied by patch-clamp techniques in cultured aortic smooth muscle cells of the rat. 2. Using standard bath and pipette solutions and whole-cell voltage-clamp, ATP evoked an inward current when the cell membrane potential was held at -50 mV and an outward current when the potential was held at 30 mV, with a reversal potential near -10 mV. 3. Application of ATP gamma S gave results similar to those obtained with ATP, while adenosine, AMP and alpha,beta-methylene ATP were ineffective. The ATP-activated current was inhibited by suramin, 100 microM. 4. ATP also induced a biphasic rise in internal free Ca levels as shown directly by Fura-2 measurements and by the increase in Ca-dependent K single-channel activity in cell-attached patches. 5. With outward current through K channels blocked by internal Cs and TEA, modification of the ionic composition of bath and pipette solutions revealed that the reversal potential for the ATP-induced whole-cell current closely followed ECl, the chloride equilibrium potential, and was insensitive to manipulations of the monovalent cation gradient. 6. These results indicate that in rat cultured aortic smooth muscle cells, ATP binding to P2-purinoceptors produces increases of internal free Ca levels and subsequent activation of both Ca-dependent K and Cl currents.

Effects of alprazolam on T-cell immunosuppressive response to surgical stress in mice.

Mice submitted to surgical stress induced by laparotomy and treated with chronic alprazolam (1 mg/kg) showed a reduction in stress-induced suppression of thymus and spleen cellularity, as well as in peripheral T lymphocyte population. The blastic response of spleen lymphoid cells was also assessed and found to partially supress the inhibitory effect of surgery.

Role of the endothelial system in Bay K 8644 enantiomer and nifedipine vasomodulator action in rat aorta.

The potential importance of the endothelial system in regulating the effects of (-)-Bay K 8644 (0.1 microM), (+)-Bay K 8644 (0.1 microM) and nifedipine (10 nM) on resting tension, on contractile responses to noradrenaline (NA) and Ca2+ (in a Ca(2+)-free high-K+ solution), and on basal, NA-induced and K(+)-induced 45Ca2+ uptake, was investigated in rat aorta rings. Mechanical removal of endothelium considerably potentiated the contractile response induced by NA in standard medium and by Ca2+ in Ca(2+)-free high-K+ (15 mM) medium, but did not modify the response induced by Ca2+ in Ca(2+)-free high-K+ (55 mM) medium or by NA in Ca(2+)-free medium. Furthermore, the basal 45Ca2+ uptake and that induced by NA (10 microM) or KCl (15 and 55 mM) were similar in endothelium-rubbed and intact rings. (-)-Bay K 8644 (0.1 microM) shifted the NA and Ca2+ concentration-response curves to the left with potentiation of the maximal contraction. However, (+)-Bay K 8644 (0.1 microM) and nifedipine (10 nM) caused a shift to the right, with depression of the maximal contraction. The NA concentration-response curves, and those of Ca2+ in Ca(2+)-free high-K+ (55 mM) medium, were affected by the drugs to similar extents, and were not modified by the presence or absence of endothelial cells. The drugs tested did not affect resting tension. Basal 45Ca2+ uptake was not modified by either nifedipine or the Bay K 8644 enantiomers.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological study of several effects of hydralazine in the bisected rat vas deferens.

We have studied several effects of hydralazine in the bisected rat vas deferens. Hydralazine produced a shift to the left of the concentration-response curve for noradrenaline, with potentiation of the maximal response in both portions of the vas deferens. In contrast it caused a shift to the right of the concentration-response curve for noradrenaline in preparations pretreated with cocaine (inhibitor of catecholamine neuronal uptake), and of the curve for methoxamine and for CaCl2 (in depolarizing medium with K+ 55 mM), in all cases with depression of the maximal response. Hydralazine enhanced the contractions induced by noradrenaline in Ca(2+)-free medium, except in the presence of cocaine. It had no effect on [3H]noradrenaline neuronal uptake into noradrenergic neurons of the vas deferens, nor did it affect basal or K(+)-induced 45Ca2+ uptake. These results suggest that hydralazine potentiates the contractions elicited by noradrenaline by a mechanism other than blockade of the neuronal uptake of this catecholamine. Our results also suggest that the inhibition by hydralazine of the contractions elicited by Ca2+ (in Ca(2+)-free depolarizing high-K+ 55 mM solution) and by methoxamine is not due to an action on voltage-dependent Ca2+ channels, but may reflect an intracellular site of action.

Study of in vivo and in vitro resting vasodilator nitric oxide tone in normotensive and genetically hypertensive rats.

The effects of NG-nitro-L-arginine (L-NNA) on mean arterial pressure and the effects of both L-NNA and methylene blue on isolated aorta tone, were studied in order to elucidate potential alterations in vasodilator resting nitric oxide (NO) tone in genetic hypertension. L-NNA produced a significantly greater increase of mean arterial pressure in spontaneously hypertensive rats (SHR) than in Wistar Kyoto (WKY) rats; in both cases, L-arginine completely inhibited the L-NNA hypertensive effect. Neither ganglion blockade with hexamethonium nor cyclooxygenase inhibition with indomethacin significantly modified the effect of L-NNA in both rat strains. In intact aorta rings, after submaximally contraction with KCI (25 mM), both L-NNA and methylene blue induced strong dose-dependent contractions. The maximum contractions were, however, significantly greater in WKY rats than in SHR. The mechanical elimination of endothelium markedly inhibited both L-NNA and methylene blue maximum contractions. In intact rings, L-arginine completely inhibited the L-NNA effects in both rat strains; in rubbed rings, the L-arginine inhibitory effects were strong in WKY rats but not important and erratic in SHR. L-Arginine had no effect on the contractions induced only by KCI in any of the preparations. In WKY rat-rubbed rings, sodium nitroprusside was significantly more effective in relaxing the contractions in response to 25 mM KCI than the contractions in response to methylene blue. These results indicate that contractions induced by L-NNA and methylene blue in isolated aorta are principally due to the inhibition of an important endothelial resting vasodilator NO tone. They also show that hypertension reduces the resting vasodilator NO tone in isolated rat aorta, in spite of enhancing the total vasodilator NO tone in anaesthetized rat.

Effect of (-)-epigallocatechin-3-gallate on respiratory burst of rat macrophages.

The toxic effects derived from overproduction of oxygen radicals [reactive oxygen species (ROS)] by immune cells can be partially abolished by the antioxidant activities of plant polyphenols. In the present study, we investigated the antioxidant action of a catechin, (-)-epigallocatechin-3-gallate (EGCG), on the respiratory-burst responses of rat peritoneal macrophages. EGCG at concentrations of 50-200 microM blocked the production of nitric oxide by macrophages stimulated in vivo with sodium thioglycollate then 5 days later in vitro with lipopolysaccharide and gamma-interferon. At 1-100 microM, EGCG also inhibited the extracellular liberation of oxygen radicals by resident peritoneal macrophages stimulated with the protein kinase C activator phorbol 12-myristate 13-acetate (PMA). At low concentrations (1-5 microM), EGCG increased the reduction of nitro blue tetrazolium (NBT) by the superoxide anions generated in the non-enzymatic system NADH/PMS, acting as a pro-oxidant agent, while at concentrations above 10 microM, EGCG acts as a scavenger of superoxide anions. These results show that EGCG is capable of modulating ROS production during the respiratory burst of rat peritoneal macrophages by acting as a superoxide anion scavenger. EGCG may therefore be useful in the prevention and treatment of diseases due to increased free radical production.

Resveratrol modulates rat macrophage functions.

This study investigated the effects of trans-resveratrol (trans-3,4',5-trihydroxystilbene, RESV), a natural polyphenol from grapes with known antioxidant activity, on the respiratory-burst responses and phagocytic activity of rat macrophages. RESV at concentrations of 1-10 microM significantly and dose-dependently inhibited (a) the extracellular production of reactive oxygen intermediates (ROls) by resident peritoneal macrophages stimulated with phorbol 12-myristate 13-acetate (PMA) (a potent activator of protein kinase C, PKC) and (b) intracellular production of ROIs after opsonin-independent phagocytosis of Kluyveromyces lactis cells. Over the 10-100 microM concentration ranges, RESV likewise inhibited the production of reactive nitrogen intermediates (RNIs) by macrophages stimulated with thioglycollate. RESV concentrations above 10 microM also dose-dependently inhibited the phagocytosis of K. lactis cells. The results obtained demonstrate that RESV is a potent inhibitor of the antipathogen responses of rat macrophages and, thus, suggest that this agent may have applications in the treatment of diseases involving macrophage hyperresponsiveness.

An Anacardiaceae preparation reduces the expression of inflammation-related genes in murine macrophages.

This study investigated the effects of an aqueous extract of the stem bark of Mangifera indica L. (Anacardiaceae; Vimang), which contains a defined mixture of components including polyphenols (principally mangiferin, MA), triterpenes, phytosteroids, fatty acids and microelements, on expression of inflammation mediators in inflammatory murine macrophages after stimulation in vitro with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). In vitro treatment with Vimang at 4 microg/ml reduced levels of NOS-2 mRNA and NOS-2, while treatment at 40 microg/ml also reduced levels of COX-2 mRNA, COX-2, and prostaglandin E2 (PGE2). Results suggested that MA is involved in these effects. In vitro treatment with Vimang at 40 microg/ml also inhibited mRNA levels of the proinflammatory cytokines interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha) and colony-stimulating factor (GM-CSF), but did not affect mRNA levels of IL-6 or tumor growth factor-beta (TGF-beta). Extracellular release of TNF-alpha by inflammatory macrophages was inhibited by in vitro treatment with Vimang at the same concentrations that showed inhibition of TNF-alpha mRNA levels. The inhibition of TNF-alpha production appears to be at least partially attributable to MA. Vimang at 4 microg/ml decreased mRNA levels of nuclear factor-kappaB (NF-kappaB) but did not affect expression of the NF-kappaB inhibitor (IkappaB). These data indicate that the potent anti-inflammatory effects of Vimang are due to selective modulation of the expression of inflammation-related genes, leading to attenuation of macrophage activation.

Cyproheptadine analogues: synthesis, antiserotoninergic activity, and structure-activity relationships.

A series of cyproheptadine related compounds was synthesized and tested pharmacologically. In comparison with cyproheptadine, these compounds do not have a central ring and some contain groups other than N-methyl. Synthesis was carried out with low-valent titanium to generate the exocyclic double bond. The serotoninergic activity of the compounds was determined by standard determination of pA2 (-log of the motor concentration of antagonist required to maintain a constant response when concentration of agonist is doubled) for the inhibition of serotonin-induced contractions in rat stomach fundus. Two of the nitrogen-containing compounds were active, but their activities were lower than that of cyproheptadine. Structure-activity relationships were studied by Mulliken net charges, molecular electrostatic potentials, and conformational analysis; activities are better correlated with electrostatic potentials than with net charges. The decrease in potency of the open cyproheptadine analogues may be due to "dilution" of the active conformer as the result of their conformational flexibility.

Pyridazine derivatives. XI: Antihypertensive activity of 3-hydrazinocycloheptyl[1,2-c]pyridazine and its hydrazone derivatives.

3-Hydrazinocycloheptyl[1,2-c]pyridazine (4) and its hydrazone derivatives 3-[N1-(isopropylidene)]hydrazinocycloheptyl[1,2-c]pyridazine [correction of hydrazinocyclohexyl] (5) and 3-[N1-(isobutylidene)]hydrazinocycloheptyl[1,2-c]pyridazine (6) were prepared, and their activity against genetic, neurogenically-induced, and deoxycorticosterone acetate -NaCl-induced hypertension was found to be at least as great as that of hydralazine. The results of studying vasorelaxation of rat aorta by 4 and hydralazine suggest that both these compounds owe their antihypertensive activity to direct relaxation of vascular smooth muscle.