Rapid inhibitory effect of corticosterone on histamine release from rat peritoneal mast cells.

Glucocorticoids are steroids endowed with powerful anti-inflammatory properties, which are routinely believed to require several hours to take effect through modulation of gene expression. Our recent report has shown that glucocorticoids could inhibit allergic reaction within 10 minutes, which the classical genomic mechanism could not explain. Histamine is thought to be one of major mediators in the allergic reaction, and IgE-mediated histamine release from mast cells plays a pivotal role in allergic diseases. Here, we have determined a rapid effect of corticosterone on histamine release from rat peritoneal mast cells, using fluorometric assay. The results showed that corticosterone could inhibit antigen-induced histamine release from rat peritoneal cells within 15 minutes (p<0.05), which could be mimicked by membrane-impermeable BSA conjugated corticosterone (p<0.05). Neither glucocorticoid nuclear receptor antagonist nor protein synthesis inhibitor could block the rapid action (p<0.05). The study provided evidence that nongenomic mechanism might be involved in rapid effect of glucocorticoids on mast cells in allergic disease.     

INHIBITION OF RAT PERITONEAL MAST CELL EXOCYTOSIS BY FRUSEMIDE:: A COMPARISON WITH DISODIUM CROMOGLYCATE

Among the loop diuretics, frusemide possesses unique airway protective activities which may be due to the inhibition of airway inflammatory cells such as the mast cell. We previously reported that frusemide and disodium cromoglycate (DSCG) demonstrated a similar profile of inhibitory activities against histamine release from rat peritoneal mast cells activated by various stimuli which increased intracellular calcium via different routes. Furthermore, the inhibitory activities of both compounds demonstrated marked tachyphylaxis and we hence postulated that frusemide and DSCG might share the same mechanism of action which involves the prevention of extracellular calcium influx into the mast cell cytoplasm. The present study confirmed the postulation by (a) demonstrating that cross-tachyphylaxis exists between the two compounds and (b) extending the observations on histamine release to the influx of extracellular calcium (⁴⁵Ca) into rat peritoneal mast cells.© 1997 Elsevier Science Inc.     

Role of histamine in the inhibitory effects of phycocyanin in experimental models of allergic inflammatory response

It has recently been reported that phycocyanin, a biliprotein found in the blue-green microalgae Spirulina, exerts anti-inflammatory effects in some animal models of inflammation. Taking into account these findings, we decided to elucidate whether phycocyanin might exert also inhibitory effects in the induced allergic inflammatory response and on histamine release from isolated rat mast cells. In in vivo experiments, phycocyanin (100, 200 and 300mg/kg post-orally (p.o.)) was administered 1 h before the challenge with 1 microg of ovalbumin (OA) in the ear of mice previously sensitized with OA. One hour later, myeloperoxidase activity and ear edema were assessed. Phycocyanin significantly reduced both parameters. In separate experiments, phycocyanin (100 and 200 mg/kg p.o.) also reduced the blue spot area induced by intradermal injections of histamine, and the histamine releaser compound 48/80 in rat skin. In concordance with the former results, phycocyanin also significantly reduced histamine release induced by compound 48/80 from isolated peritoneal rat mast cells. The inhibitory effects of phycocyanin were dose dependent. Taken together, our results suggest that inhibition of allergic inflammatory response by phycocyanin is mediated, at least in part, by inhibition of histamine release from mast cells.     

Mast cells in the focus of an acute infectious inflammation]

On the model of E. coli-induced acute infectious peritonitis in rats it is established that the mast cell reaction and histamine level increase in exudate and inflamed mesentery tissue are biphase and are observed predominantly following the inflammatory agent action, in the period corresponding to the immediate phase of peritoneal cavity vessel permeability increases. The preliminary elimination of mast cells significantly inhibits a rise in the vascular permeability in the immediate phase and slightly affects the delayed phase, thus prolonging exudation. At the same time the dynamics of free histamine indicates its direct involvement in mediation and/or modulation as well as in subsequent inflammatory events. The common rules of mast cell involvement and vascular permeability increase in infectious and aseptic inflammation have been shown.     

Anti-inflammatory activity of tea (Camellia sinensis) root extract

Pharmacological studies were carried out with methanol-water (1:1) extract of dried tea (Camellia sinensis) root extract (TRE). TRE was found to possess anti-inflammatory, analgesic and antipyretic activities at 1/10th of its LD50 dose of 100 mg/kg i.p. It was found that TRE inhibited the arachidonic acid-induced paw oedema in rats which indicated that TRE produced the anti-inflammatory activity by inhibiting both the cyclooxygenase and lypooxygenase pathways of arachidonic acid metabolism. TRE also enhanced peritoneal cell count and the number of macrophages in normal mice. It is plausible that the saponins present in TRE may be responsible for these activities of TRE.     

Analgesic and anti-inflammatory studies of cyclopeptide alkaloid fraction of leaves of Ziziyphus nummularia

Ziziyphus nummularia (family: Rhamnaceae) is a thorny small bush, grows in abundance in the grazing lands of the arid areas of Rajasthan, India. It is an important ethnomedicinal plant of the Thar Desert; local inhabitants use every part of the plant as medicine. Kernels are prescribed in pregnancy as soporific, antiemetic and for relieving abdominal pain. The insect gall is powered and given orally with water to cure bone fracture. Crushed root is applied on the paining shoulder of the bullock. The decoction of leaves is used for the treatment of cough and cold; leaves are also regarded as diaphoretic and prescribed in typhoid. Paste of leaves is used for healing of cuts, boils and cutaneous disease. It is widely used in pain and inflammatory conditions.Z. nummularia contains a unique group of alkaloids known as cyclopeptide alkaloids, in continuation of our work carried out on the leaves of Z. nummularia, present study was initiated to explore antiinflammatory and analgesic potential of cyclopeptide alkaloids isolated from the leaves of Z. nummularia (IFZN). Anti-inflammatory activity was tested against rat paw oedema, mouse peritonitis and cotton pellet granuloma. For screening of analgesic activity, acetic acid induced writhing, tail flick and hot plate test were performed.IFZN 30 mg/kg shows the anti-oedematogenic effect against paw oedema induced by carrageenan, dextran, serotonin and histamine; IFZN 20 and 30 mg/kg were found to have highly significant anti-nociceptive effects.Result of pharmacological studies indicated that IFZN is a potent and efficacious analgesic agent. The analgesic activity of IFZN is mediated by the peripheral as well as central pathways.     

Histamine-releasing reaction induced by the N-terminal domain of Vibrio vulnificus metalloprotease

A zinc metalloprotease secreted by Vibrio vulnificus, an opportunistic human pathogen causing septicemia and wound infection, stimulates exocytotic histamine release from rat mast cells. This protease consists of two functional domains: the N-terminal domain that catalyzes proteolytic reaction and the C-terminal domain that promotes the association with a protein substrate or cell membrane. Like the intact protease, the N-terminal domain alone also induced histamine release from rat peritoneal mast cells in a dose- and time-dependent manner. However, the reaction induced was apparently weak and went on more slowly. The nickel-substituted protease or its N-terminal domain, each of which has the reduced proteolytic activity due to decreased affinity to a substrate, showed much less histamine-releasing activity. When injected into the rat dorsal skin, the N-terminal domain also evoked enhancement of the hypodermic vascular permeability, while the activity was comparable to that of the protease. Taken together, the protease may stimulate histamine release through the action of the catalytic center of the N-terminal domain on the target substance(s) on the mast cell membrane. The C-terminal domain may support the in vitro action of the N-terminal domain by coordination of the association of the protease with the membrane, but it may not modulate the in vivo action.     

Anti-nociceptive and anti-inflammatory properties of the ethanolic extract of Lagenaria breviflora whole fruit in rat and mice

The present study was conducted to evaluate the anti-nociceptive and anti-inflammatory properties of an ethanol extract of whole fruit of Lagenaria breviflora (LB) in rat and mice. Analgesic activity was measured by hot plate, formalin-induced paw licking, and acetic acid-induced abdominal writhing tests, while anti-inflammatory activity was determined by inhibition of carrageenan-induced paw oedema. Extract-treated animals exhibited significantly (P.     

Membrane-modifying effect of taurine

The effect of taurine on membrane-associated processes was studied in rat erythrocytes and peritoneal mast cells. EPR with a spin probe 5-DS revealed a significant decrease in the order parameter S of membrane phospholipid acyl chains in vitro after incubation of erythrocytes with taurine (10 mM, 1 h). Increased susceptibility of the erythrocyte membrane to peroxide-induced lysis was also observed. These effects suggested decreased membrane microviscosity resulting from less dense packing of the phospholipids. The differential effects of taurine on stimulated Ca-dependent functional activity of peritoneal mast cells (histamine liberation) upon different ways of administration (oral, intraperitoneal, or intramuscular) suggest an indirect and complex mechanism of taurine action in the organism.     

Fibrinogen and plantar edema induced by lambda carrageenan

1. Batroxobine which induces fibrinogen consumption, accelerates the development of 48/80 and lambda carrageenan oedema: in the rat the various products released from fibrinogen and fibrin increase these inflammatory reactions. 2. Heparin and epsilon-aminocaproic acid have no influence on carrageenan oedema: the derivatives of fibrinogen do not take part in the constitution of the inflammatory reaction induced by carrageenan. 3. The anti-inflammatory action of this sulfated polygalactose does not depend on its anti-coagulant activity.     

Dual effects of protoporphyrin and long wave ultraviolet light on histamine release from rat peritoneal and cutaneous mast cells.

In this study we investigated the effects of long wave ultraviolet light (UVA) and various doses of protoporphyrin (PP) on the release of histamine from rat peritoneal and cutaneous mast cells. We also correlated these results with morphologic characteristics and viability of the cells. PP at a dose of 30 ng/ml plus UVA-induced negligible histamine release from rat peritoneal mast cells (RPMC), but was able to suppress the ability of the cells to release histamine in response to subsequent exposure to the calcium ionophore A23187, compound 48/80, or the combination of Ag and IgE. This functional change was associated with an increase in cell size, and cell lysis that gradually occurred during 24 h in culture. PP at a dose of 3 ng/ml plus UVA also significantly inhibited secretogogue-induced histamine release from rat peritoneal mast cells, but this dose was not associated with significant changes in morphology or viability. These various effects of PP plus UVA were also observed with mast cell preparations obtained by the enzymatic dispersion of rat skin. The suppression of secretogogue-induced histamine release in rat peritoneal mast cells treated with PP (3 ng/ml) and UVA could not be reversed by culturing the cells in the dark for 24 h in the absence of PP. Unlike the direct cytotoxic histamine releasing action of high doses of PP plus UVA, the suppressive effect of low PP doses could not be inhibited by catalase, but could be reduced by the absence of calcium. Our results indicate that PP plus UVA has dual effects on mast cells, apparently involving distinct mechanisms. This implies the possibility that PP and UVA at appropriate doses could be used in photochemotherapy of mast cell-mediated skin diseases.     

Stimulation of histamine release and arachidonic acid metabolism in rat peritoneal mast cells by thapsigargin, a non-TPA-type tumor promoter

Thapsigargin, a non-TPA-type tumor promoter, releases histamine and stimulates arachidonic acid metabolism in rat peritoneal mast cells. In order to clarify the relationship between the histamine-releasing activity and the arachidonic acid metabolism-stimulating activity of thapsigargin in mast cells, the effects of cyclooxygenase inhibitors, indomethacin and ibuprofen, a lipoxygenase inhibitor, AA861, and dual inhibitors for cyclooxygenase and lipoxygenase, nordihydroguaiaretic acid and BW755C, on histamine release and arachidonic acid metabolism were examined. High-performance liquid chromatography analysis revealed that the peritoneal mast cells preferentially produce prostaglandin D2 by thapsigargin treatment. These inhibitors suppressed thapsigargin-induced prostaglandin D2 production in a dose-dependent manner, but failed to inhibit histamine release, suggesting that the mechanisms for stimulation of histamine release by thapsigargin is not dependent on increased arachidonic acid metabolism. Time-course experiments of histamine release and the release of radioactivity from [3H]arachidonic acid-labeled mast cells also provide evidence for a difference in mechanism.     

Polysaccharide peptides from COV-1 strain of Coriolus versicolor induce hyperalgesia via inflammatory mediator release in the mouse

Polysaccharide peptide (PSP), isolated from Coriolus versicolor COV-1, has been widely used as an adjunct to cancer chemotherapy and as an immuno-stimulator in China. In this study, the anti-nociceptive effects of PSP were investigated in two different pain models in the mouse. In the acetic acid-induced writhing model, initial studies showed that PSP decreased the number of acetic acid-induced writhing by 92.9%, which, by definition, would constitute an analgesic effect. However, further studies showed that PSP itself induced a dose-dependent writhing response. Studies on inflammatory mediator release showed that PSP increased the release of prostaglandin E2, tumor necrosis factor-alpha, interleukin-1beta, and histamine in mouse peritoneal macrophages and mast cells both in vitro and in vivo. The role of inflammatory mediator release in PSP-induced writhing was confirmed when diclofenac and dexamethasone decreased the number of writhing responses by 54% and 58.5%, respectively. Diphenhydramine totally inhibited the PSP-induced writhing. In the hot-plate test, PSP dose-dependently shortened the hind paw withdrawal latency, indicative of a hyperalgesic effect. The hyperalgesic effect was reduced by pretreatment with the anti-inflammatory drugs. In conclusion, the PSP-induced hyperalgesia was related to activation of peritoneal resident cells and an increase in the release of inflammatory mediators.     

Pharmacological profile of AA-861, A 5-lipoxygenase inhibitor

AA-861, a selective 5-lipoxygenase inhibitor, suppressed A23187-induced formations of 5-HETE and LTB₄ in rat peritoneal macrophages. Immunologically-stimulated generation of SRS-A was also inhibited in guinea pig lung and rat peritoneal cavity. AA-861 had no effects on histamine release from rat mast cels or passive cutaneous anaphylaxis in rats. Essentially no antagonistic activity to LDT₄ or histamine was observed. This compound exerted an obvious inhibition of allergic bronchoconstriction in guinea pigs and a moderate reduction of carrageenin-induced paw edema and pleurisy in rats. These findins suggest that SRS-A plays an important role in asthmatic and inflammatory reactions.     

Stem cell factor has histamine releasing activity in rat connective tissue-type mast cells.

Stem cell factor (SCF) was documented to be involved in the growth of mast cells controlled by fibroblasts. We tested the effect of recombinant rat SCF on degranulation from rat peritoneal mast cells (connective tissue-type mast cells: CTMC). SCF induced histamine release (approximately 20% of total histamine content) in a dose-dependent fashion. The release response was relatively rapid and reached a maximum within 5 min. The release showed total dependence on the presence of extracellular phosphatidylserine (PTS). These results reveal that SCF has histamine releasing activity in CTMC.     

Neutrophil defensins induce histamine secretion from mast cells: mechanisms of action.

Defensins are endogenous antimicrobial peptides stored in neutrophil granules. Here we report that a panel of defensins from human, rat, guinea pig, and rabbit neutrophils all have histamine-releasing activity, degranulating rat peritoneal mast cells with EC50 ranging from 70 to 2500 nM, and between 45 and 60% of the total histamine released. The EC50 for defensin-induced histamine secretion correlates with their net basic charge at neutral pH. There is no correlation between histamine release and antimicrobial potency. Degranulation induced by defensins has characteristics similar to those of activation by substance P. The maximum percent histamine release is achieved in <10 s, and it can be markedly inhibited by pertussis toxin (100 ng/ml) and by pretreatment of mast cells with neuraminidase. These properties differ from those for degranulation induced by IgE-dependent Ag stimulation and by the calcium ionophore A23187. GTPase activity, a measure of G protein activation, was induced in a membrane fraction from mast cells following treatment with defensin. Thus, neutrophil defensins are potent mast cell secretagogues that act in a manner similar to substance P and 48/80, through a rapid G protein-dependent response that is mechanistically distinct from Ag/IgE-dependent mast cell activation. Defensins may provide important pathways for communication between neutrophils and mast cells in defenses against microbial agents and in acute inflammatory responses.     

Morphological and functional characteristics of peritoneal mast cells from young rats

To study why neonatal and young rats are resistant to the effects of some secretagogues, such as compound 48/80 and 2.5-S nerve growth factor, we examined peritoneal mast cells from 14–15-day-old rats (young rats) and compared them to peritoneal mast cells from adults. Peritoneal mast cells from young rats contain approximately one-tenth of the amount of histamine observed in adult peritoneal mast cells. However, both cell populations contained similar low levels of the mucosal mast cell-associated protease rat mast cell protease II. Histochemical analysis of peritoneal mast cells from young rats using safranin O and berberine sulphate suggested that only a portion of the granules of these cells contained heparin. At an ultrastructural level the young rat peritoneal mast cell contains relatively few granules. The majority of mast cells from young rats have a bilobed or indented nucleus which is only rarely observed in adult cells. Functionally, the young rat peritoneal mast cell demonstrates a significantly reduced histamine release in response to the connective tissue mast cellspecific secretagogues compound 48/80 and 2.5-S nerve growth factor. In contrast, the percent histamine release in response to the neurotransmitter substance P, which degranulates both connective tissue mast cells and intestinal mucosal mast cells, was similar in the adult cells and the young rat cells. This study demonstrates substantial differences between the young rat and adult peritoneal mast cells which may explain the ability of very young animals to withstand large doses of certain secretagogues.     

Metabolism of leukotriene D4 by rat peritoneal mast cells

Metabolism of sulfidopeptide leukotrienes, leukotrienes (LT) C4 and D4 by rat peritoneal mast cells was studied. Rat peritoneal mast cells converted LTD4 to LTE4 but not LTC4 to LTD4. The LTD4-metabolizing activity was equally distributed on the cell surface and inside cells, but not released to the extracellular milieu even when a considerable portion of histamine and the secretory granule enzymes were released. Among various enzyme inhibitors examined, o-phenanthroline, a metal chelator, and dithiothreitol significantly suppressed the LTD4-metabolizing activity of mast cell. These results would suggest that some metalloenzyme located on the cell surface is involved in the conversion of LTD4 to LTE4 by rat peritoneal mast cells.     

Anti-allergic effects of Artemisia iwayomogi on mast cell-mediated allergy model

The discovery of drugs for the treatment of allergic disease is an important subject in human health. The Artemisia iwayomogi (Compositae) (AIE) has been used as a traditional medicine in Korea and is known to have an anti-inflammatory effect. However, its specific mechanism of action is still unknown. In this report, we investigated the effect of AIE on the mast cell-mediated allergy model and studied the possible mechanism of action. AIE inhibited compound 48/80-induced systemic reactions and plasma histamine release in mice. AIE decreased immunoglobulin E (IgE)-mediated local allergic reaction, passive cutaneous anaphylaxis (PCA) reaction. AIE dose dependently attenuated histamine release from rat peritoneal mast cells activated by compound 48/80 or IgE. AIE decreased the compound 48/80-induced intracellular Ca(2+). Furthermore, AIE decreased the phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated tumor necrosis factor-alpha and interleukin-6 gene expression and production in human mast cells. The inhibitory effect of AIE on the proinflammatory cytokine was p38 mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB (NF-kappaB) dependent. AIE attenuated PMA plus A23187-induced degradation of IkappaBalpha and nuclear translocation of NF-kappaB and specifically blocked activation of p38 MAPK but not that of c-jun N-terminal kinase and extracellular signal-regulated kinase. Our findings provide evidence that AIE inhibits mast cell-derived immediate-type allergic reactions and involvement of intracellular Ca(2+), proinflammatory cytokines, p38 MAPK, and NF-kappaB in these effects.     

The pharmacological profile of ovalbumin-induced paw oedema in rats

Rats are commonly used in anaphylaxis models, mainly in intestinal anaphylaxis. Hypersensitivity mechanisms are complex and they are not clearly defined. Ovalbumin (OVA) is commonly used for studies on the hypersensitivity mechanism. However, the potential pro-inflammatory mediators induced by this antigen in the model of paw oedema in immunized rats are still not completely understood. This work examines the pharmacological modulation of several mediators involved in rat hind paw immune oedema induced by OVA. Wistar rats were previously immunized (14-18 days) with OVA (30 microg, intraperitoneally) or sham-sensitized with aluminum hydroxide (control). The paw volumes were measured before the antigenic stimuli and 1, 2, 3 and 4 h after the intraplantar injection of OVA (10 microg/paw). Subcutaneous injection of dexamethasone, diphenhydramine, cyproheptadine, chlorpromazine or methysergide significantly inhibited (p < 0.05) the allergic paw oedema. The dual inhibitor of cyclooxygenase and lipoxygenase (NDGA), the cyclooxygenase inhibitor (indomethacin), the lipoxygenase inhibitor (MK-886), the PAF antagonist (WEB 2086), the mast cell stabilizer (ketotifen), and the anti-histamine (meclizine) did not inhibit the immune oedema. In addition, thalidomide and pentoxifylline (anti-tumour necrosis factor drugs) were ineffective against OVA-induced oedema. The fact that indomethacin, MK-886, NDGA and WEB 2086 are unable to inhibit this allergic oedema indicates that the dexamethasone action seems not to be via phospholipase A2, but possibly due to the synthesis and/or the inhibitory activity of cytokines. The paw oedema inhibition by diphenhydramine, but not by meclizine, may suggest a different mechanism, which is independent of the effect of histamine. These data indicate that allergic oedema is more sensitive to anti-serotonin drugs, mainly anti-5-HT2, suggesting that the principal mediator of this inflammatory response is serotonin.