RESUMO
Milonine is an alkaloid of Cissampelos sympodialis Eichl. (Menispermaceae), a plant used in the northeast of Brazil to treat allergies such as asthma, rhinitis, and other conditions. Previously, several alkaloids were isolated from its roots and leaves with pharmacological properties in asthma and acute inflammation models. Therefore, the aim of this study was to evaluate the milonine effect on mast cells degranulation in vivo and in vitro. Swiss mice (n = 8) were used in models of paw edema induced by carrageenan, compound 48/80, or histamine. One hour before challenge, the animals were treated with milonine (at different doses) or standard drugs and, at different time points, the edema formation was measured. In addition, other different methods, such as anaphylactic shock reaction and scratching behavior models both induced by compound 48/80, a mast cell degranulator, were used to assess milonine effect histamine release in vivo. Moreover, milonine effect on mast cell degranulation in vitro was also carried out. Firstly, it was observed that milonine significantly decreased the carrageenan edema formation only at the beginning of the reaction (i.e., up to 2 h after challenge). Furthermore, this alkaloid decreased the edema induced by compound 48/80, maintained the paw tissue integrity, without modulating histamine-induced paw edema. In anaphylactic shock reaction, milonine increased the time of animal survival when compared with compound 48/80 group. Milonine also significantly decreased the scratching behavior induced by compound 48/80 with decreasing of mast cell degranulation in vitro. Therefore, these data indicated that milonine presents anti-allergic properties by decreasing mast cell degranulation rather than acting on histamine effect.
Assuntos
Antialérgicos/farmacologia , Liberação de Histamina/efeitos dos fármacos , Mastócitos/metabolismo , Morfinanos/farmacologia , Alcaloides/farmacologia , Anafilaxia/tratamento farmacológico , Anafilaxia/prevenção & controle , Animais , Cissampelos/química , Edema/induzido quimicamente , Edema/tratamento farmacológico , Edema/prevenção & controle , Camundongos , Morfinanos/uso terapêutico , Prurido/tratamento farmacológico , Prurido/prevenção & controleRESUMO
BACKGROUND: The prevalence of allergic diseases is globally increasing. We have previously described that glycomacropeptide (GMP), a bioactive milk peptide, has therapeutic value in experimental models of skin hypersensitivity, anaphylaxis, and asthma, as it prevents an excessive T helper type 2 cell immune response. The aim of this study was to analyze the effect of GMP on key elements directly involved in the development or control of allergy, in order to improve the precise knowledge about its mechanism of action. METHODS: Rats were systemically sensitized with ovalbumin and orally treated with GMP. Levels of Lactobacillus, Bifidobacterium, and Bacteroides were analyzed in their feces. Splenocytes were isolated and the production of transforming growth factor (TGF)-ß by allergens was measured. Intradermal skin reactions were developed to evaluate in vivo activation of mast cells. Peritoneal mast cells were isolated and activated by the allergen, and histamine secretion was determined. RESULTS: GMP administration increased the amount of intestinal Lactobacillus and Bifidobacterium of allergen-sensitized animals after 3 days of treatment. The increase in Bacteroides was also significant, but only after 17 days of GMP administration. Ten days after treatment cessation, Lactobacillus and Bacteroides were still elevated. GMP intake also elevated the production of TGF-ß in the splenocytes of sensitized animals. In addition, treatment with GMP attenuated mast cell activation by the allergen and inhibited histamine secretion, without affecting the number of mast cells. CONCLUSIONS: The prebiotic action of GMP on allergy-protective microbiota, an increase in TGF-ß production, and a reduction in mast cell response to allergens are novel mechanisms that explain the antiallergic activity of GMP.
Assuntos
Caseínas/farmacologia , Microbioma Gastrointestinal , Hipersensibilidade/etiologia , Hipersensibilidade/metabolismo , Mastócitos/imunologia , Mastócitos/metabolismo , Fragmentos de Peptídeos/farmacologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Modelos Animais de Doenças , Fezes/microbiologia , Liberação de Histamina/efeitos dos fármacos , Hipersensibilidade/tratamento farmacológico , Imunização , Ratos , Pele/imunologia , Pele/metabolismo , Pele/patologiaRESUMO
Mast cells (MCs) are versatile effector and regulatory cells in various physiologic, immunologic, and pathologic processes. In addition to the well-characterized IgE/FcεRI-mediated degranulation, a variety of biological substances can induce MCs activation and release of their granule content. Sex steroids, mainly estradiol and progesterone, have been demonstrated to elicit MCs activation. Most published studies have been conducted on MCs lines or freshly isolated peritoneal and bone marrow-derived MC without addressing gender impact on MC response. Our goal was to investigate if the effect of estradiol, progesterone, testosterone, and dihydrotestosterone (DHT) on MCs may differ depending on whether female or male rats are used as MCs donors. Our results demonstrated that effect of sex steroids on MCs histamine release is dose- and gender-dependent and can be direct, synergistic, or inhibitory depending on whether hormones are used alone or to pretreat MCs followed by substance P-stimulation or upon IgE-mediated stimulation. In contrast, sex steroids did not have effect on the MC expression of the IgE high affinity receptor, FcεRI, no matter female or male rats were used. In conclusion, MCs degranulation is modulated by sex hormones in a gender-selective fashion, with MC from females being more susceptible than MC from males to the effects of sex steroids.
Assuntos
Hormônios Esteroides Gonadais/farmacologia , Liberação de Histamina/efeitos dos fármacos , Mastócitos/imunologia , Peritônio/citologia , Receptores de IgE/biossíntese , Animais , Degranulação Celular/imunologia , Células Cultivadas , Di-Hidrotestosterona/farmacologia , Estradiol/farmacologia , Feminino , Imunoglobulina E/imunologia , Masculino , Mastócitos/citologia , Progesterona/farmacologia , Ratos , Ratos Sprague-Dawley , Fatores Sexuais , Substância P/metabolismo , Testosterona/farmacologiaRESUMO
Appetitive behaviours occur in a state of behavioural and physiological activation that allows the optimal performance of these goal-directed behaviours. Here, we tested the hypothesis that histamine neurons under the command of the infralimbic cortex are important to provide behavioural activation. Extracellular histamine and serotonin were measured by microdialysis of the medial prefrontal cortex in behaving rats in parallel with a picrotoxin microinjection into the infralimbic cortex. The injection aroused the rats behaviourally, increased histamine release and decreased serotonin levels. Inhibition of the infralimbic cortex with muscimol produced the opposite effects on neurotransmitter release. The behavioural activation induced by motivating hungry rats with caged food was paralleled by an immediate histamine release, whereas awakening induced by tapping their microdialysis bowl increased serotonin, but not histamine levels. In conclusion, picrotoxin injection into the infralimbic cortex produces behavioural activation together with histamine release; in a similar manner, induction of an appetitive state produced histamine release, likely related to increased behavioural activation characteristic of an appetitive behaviour.
Assuntos
Nível de Alerta/fisiologia , Córtex Cerebral/fisiologia , Antagonistas de Receptores de GABA-A/farmacologia , Liberação de Histamina/fisiologia , Motivação/fisiologia , Picrotoxina/farmacologia , Animais , Nível de Alerta/efeitos dos fármacos , Cateteres de Demora , Córtex Cerebral/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Agonistas de Receptores de GABA-A/farmacologia , Histamina/metabolismo , Liberação de Histamina/efeitos dos fármacos , Fome/fisiologia , Masculino , Microdiálise , Motivação/efeitos dos fármacos , Muscimol/farmacologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Ratos Sprague-Dawley , Receptores de GABA-A/metabolismo , Serotonina/metabolismoRESUMO
BACKGROUND: Beekeepers are exposed to frequent honey-bee stings, and have the risk to develop hypersensitivity to bee venom, but long-term exposure can induce immune tolerance in them. Up to 30% of beekeepers show positive skin tests with honey-bee venom. The prevalence of systemic reactions to bee stings in beekeepers is from 14% to 42%. OBJECTIVE: To know the prevalence of hypersensitivity to honeybee venom in Mexican beekeepers and non-beekeepers by the use of skin tests. MATERIAL AND METHODS: A group of 139 beekeepers and a group of 60 non-beekeeper volunteers had a history and physical related to age, sex, family and personal atopic history and time of exposure to bee stings. Both groups received intradermal skin tests with honey-bee venom, 0.1 mcg/mL and 1 mcg/mL, and histamine sulphate 0.1 mg/mL and Evans solution as controls. The skin tests results of both groups were compared by chi-squared test. RESULTS: Of the group of beekeepers, 116 were men (83%) and 23 women, average age was 39.3 years, had atopic family history 28% and personal atopy 13%, average time of exposure to bee stings was 10.9 years, skin tests with honey-bee venom were positive in 16.5% and 11% at 1 mcg/mL and 0.1 mcg/mL, respectively. In the non-beekeepers group venom skin tests were positive in 13.3% and 6.7% at 1 mcg/mL and 0.1 mcg/mL. We did not find significant differences between the two venom concentrations tested in both groups, neither in the number of positive skin tests between the two groups. CONCLUSIONS: We found hypersensivity to honey-bee venom slightly higher in the beekeepers than in the group apparently not exposed. Both honey-bee venom concentrations used did not show difference in the results of the skin tests. The similarity of skin tests positivity between both groups could be explained by immune tolerance due to continued exposure of beekeepers.
ANTECEDENTES: los apicultores están expuestos frecuentemente a picaduras de abejas y tienen el riesgo de volverse hipersensibles al veneno de abejas, pero la exposición a largo plazo puede inducir tolerancia inmunológica. Hasta 30% de los apicultores tienen pruebas cutáneas positivas con veneno de abeja. La prevalencia de reacciones sistémicas por picaduras de abejas en los apicultores es de 14 a 42%. OBJETIVO: conocer la prevalencia de hipersensibilidad al veneno de abeja en apicultores mexicanos y no apicultores, mediante la aplicación de pruebas cutáneas. MATERIAL Y MÉTODOS: estudio transversal que se incluyeron 139 apicultores y 60 voluntarios no apicultores se les elaboró su historia clínica con referencia a la edad, sexo, antecedentes familiares y personales atópicos y tiempo de exposición a picaduras de abejas. A los dos grupos se les aplicaron pruebas cutáneas intradérmicas con veneno de abeja con 0.1 y 1 mcg/mL, y como testigos sulfato de histamina 0.1 mg/mL y solución de Evans. Los resultados de las pruebas cutáneas se compararon entre los dos grupos mediante chi cuadrada. RESULTADOS: del grupo de apicultores 116 fueron hombres (83%) y 23 mujeres, la edad promedio fue de 39.3 años; refirieron atopia familiar 28% y atopia personal 13%; el tiempo de exposición promedio a picaduras de abejas fue de 10.9 años; las pruebas cutáneas con veneno de abeja fueron positivas en 16.5 y 11% a concentraciones de 1 y 0.1 mcg/mL, respectivamente. En el grupo de no apicultores las pruebas cutáneas con veneno resultaron positivas en 13.3 y 6.7% a concentraciones de 1 y 0.1 mcg/mL, respectivamente. No se observaron diferencias significativas entre las dos concentraciones de veneno probadas en ambos grupos, ni en el número de pruebas cutáneas positivas entre los dos grupos. CONCLUSIONES: se encontró hipersensibilidad al veneno de abeja ligeramente mayor en los apicultores que en el grupo aparentemente no expuesto. Las dos concentraciones de veneno de abeja probadas no mostraron diferencia en los resultados de las pruebas cutáneas.
Assuntos
Alérgenos/efeitos adversos , Venenos de Abelha/efeitos adversos , Criação de Abelhas , Abelhas/imunologia , Hipersensibilidade Imediata/etiologia , Doenças Profissionais/etiologia , Adulto , Alérgenos/farmacologia , Animais , Especificidade de Anticorpos , Venenos de Abelha/farmacologia , Estudos Transversais , Relação Dose-Resposta Imunológica , Feminino , Liberação de Histamina/efeitos dos fármacos , Humanos , Hipersensibilidade Imediata/epidemiologia , Hipersensibilidade Imediata/imunologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Mordeduras e Picadas de Insetos/imunologia , Testes Intradérmicos , Masculino , México/epidemiologia , Doenças Profissionais/epidemiologia , Doenças Profissionais/imunologia , PrevalênciaRESUMO
ETHNOPHARMACOLOGY RELEVANCE: Different plant species from Cordia genera are used in folk medicine as anti-inflammatory medication throughout the tropical and subtropical regions of the world. In Brazil, Cordia verbenacea is a medicinal plant known as "erva-baleeira". The alcoholic extracts, decoctions and infusions with leaves of C. verbenacea are used in Brazilian traditional medicine for treatment of cough, pneumonia, parasitic diseases and, especially, the inflammatory processes. Anti-inflammatory activity was already demonstrated; however, molecular mechanisms of action are not completely understood. Considering the importance of histamine in early events of inflammation and in allergic diseases, we evaluated the effect of ethanol extract of leaves of C. verbenacea on histamine release (in vitro and in vivo studies) from different types of mast cells induced by chemical agents using several species of rodents. MATERIALS AND METHODS: The extraction and quantification of histamine were performed by using an automatic fluorometric continuous flow system. RESULTS: The extract of C. verbenacea (30 µg/ml) reduced the in vitro secretion of histamine from rat mast cells induced by ionophore A23187, concanavalin A and compound 48/80, respectively, to 22.1 ± 2.2%, 24.3 ± 2.5% and 21.4 ± 2.1%. At the same concentration, the extract also inhibited the secretion of histamine from mast cells of guinea pig induced by ionophore A23187 to 33.3 ± 2.2%, and mast cells of hamster induced by ionophore A23187 and concanavalin A to 15.8 ± 2.5% and 10.8 ± 2.6%, respectively. The oral treatment with the extract (300 mg/kg) also inhibited the secretion of histamine induced by A23187 about to 36.3 ± 3.2% in rats. CONCLUSIONS: C. verbenacea inhibits the in vitro secretion of histamine from mast cells of different animal species, as well as the secretion of mast cells from animals treated with the extract, which gives not only the proven anti-inflammatory effect of the plant, but also anti-allergic effect, opening new possibilities for future anti-allergic herbal medicine.
Assuntos
Cordia/química , Mastócitos/metabolismo , Extratos Vegetais/farmacologia , Animais , Etanol/química , Cobaias , Liberação de Histamina/efeitos dos fármacos , Masculino , Extratos Vegetais/química , Ratos , Ratos WistarRESUMO
BACKGROUND AND AIM: We investigated the effect of topical application of Brazilian propolis on scratching behavior induced by compound 48/80 in mice. RESULTS: Propolis inhibited compound 48/80-induced scratching behavior when applied immediately after treatment with propolis at a dose of 3 mg/site. Dibucaine 0.3 mg/site also significantly inhibited compound 48/80-induced scratching behavior immediately after application. On the other hand, propolis inhibited compound 48/80-induced scratching behavior even 15, 30 and 60 min after application; however, dibucaine showed no significant inhibition of compound 48/80-induced scratching behavior 15, 30 and 60 min after application. In addition, propolis had no effect on increased vascular permeability just after application, but the drug had a significant effect 15, 30 and 60 min after application. On the contrary, histamine-induced scratching behavior was inhibited significantly by propolis just after application. On the other hand, propolis significantly inhibited histamine release from rat mast cells induced by compound 48/80 at a concentration of more than 10 microg/ml. CONCLUSION: From these results, it can be concluded that inhibition of scratching behavior induced by topical application occurred by both its local anesthetic and systemic action through inhibition of histamine release.
Assuntos
Antipruriginosos/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Própole/uso terapêutico , Prurido/tratamento farmacológico , Administração Cutânea , Animais , Antipruriginosos/administração & dosagem , Antipruriginosos/farmacologia , Brasil , Permeabilidade Capilar/efeitos dos fármacos , Permeabilidade Capilar/imunologia , Modelos Animais de Doenças , Feminino , Liberação de Histamina/efeitos dos fármacos , Mastócitos/efeitos dos fármacos , Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos ICR , Própole/administração & dosagem , Própole/farmacologia , Prurido/imunologia , Prurido/fisiopatologia , Pele/irrigação sanguínea , Pele/efeitos dos fármacos , Pele/imunologia , p-Metoxi-N-metilfenetilaminaRESUMO
Schinus is a genus of the Anacardiaceae family and contains Schinus terebinthifolius, the Brazilian pepper tree that is widely used in folk medicine. We investigate the anti-allergic activity of the ethyl acetate fraction of S. terebinthifolius Raddi (ST fraction). HPLC analysis reveled that gallic acid, methyl gallate and 1,2,3,4,6-pentagalloylglucose are the major aromatic components of the fraction. Oral pre-treatment with the ST fraction (100 mg/kg) significantly inhibited paw edema induced by compound 48/80 (100 ng/paw) and to a lesser extent, the allergic paw edema (OVA, 3 microg/paw). The ST fraction (100 and 200 mg/kg) also inhibited the edema induced by histamine (100 microg/paw), preventing mast cell degranulation and, consequently, histamine release in Wistar rat peritoneal mast cells induced by C 48/80 (5 microg/mL). This histamine inhibition was also observed after mast cell pre-treatment with both methyl gallate and 1,2,3,4,6-pentagalloylglucose (100 microg/mL), the isolated compounds from the ethyl acetate fraction. Pre-treatment with the ST fraction (100 mg/kg) significantly inhibited total leukocyte and eosinophil accumulation in pleural cavities 24 h after the intrathoracic injection of OVA (12.5 microg/cavity). This effect was related to the inhibition of CCL11/eotaxin and CCL5/RANTES in pleural lavage fluid. Pre-treatment with this fraction (100 mg/kg) failed to reduce the cell influx that was observed after LPS-injection into pleural cavity (250 ng/cavity). These findings demonstrate the anti-allergic effect of the ST fraction, which includes the inhibition of edema formation and histamine release caused by mast cell degranulation and eosinophil influx into the pleural cavity probably reflected by the decreased levels of chemokines in recovered pleural lavage fluid.
Assuntos
Anacardiaceae/química , Antialérgicos/uso terapêutico , Edema/tratamento farmacológico , Hipersensibilidade/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Pleurisia/tratamento farmacológico , Animais , Antialérgicos/farmacologia , Quimiocinas/efeitos dos fármacos , Quimiocinas/imunologia , Edema/imunologia , Histamina/administração & dosagem , Histamina/farmacologia , Liberação de Histamina/efeitos dos fármacos , Liberação de Histamina/imunologia , Hipersensibilidade/imunologia , Imunoglobulina E/efeitos dos fármacos , Imunoglobulina E/imunologia , Lipopolissacarídeos/farmacologia , Masculino , Mastócitos/imunologia , Mastócitos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/administração & dosagem , Ovalbumina/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Pleurisia/imunologia , Prometazina/administração & dosagem , Prometazina/farmacologia , Ratos , Ratos WistarRESUMO
BACKGROUND: Basophils and mast cells are the main target cells in chronic idiopathic urticaria (CIU). Besides the basopenia, intrinsic defects of the anti-IgE cross-linking signalling pathway of basophils have been described in CIU. OBJECTIVES: We sought to investigate the profile of expression of activation markers on basophils of patients with CIU and to explore the effect of interleukin (IL)-3 priming upon anti-IgE cross-linking stimuli through expression of activation markers and basophil histamine releasability. METHODS: Evaluation of the surface expression of FcepsilonRIalpha, CD63, CD203c and CD123 on whole blood basophils of patients with CIU undergoing autologous serum skin test (ASST) was performed by flow cytometry. The effect of pretreatment with IL-3 in the anti-IgE response was analysed by the expression of basophil activation markers and histamine release using enzyme-linked immunosorbent assay. RESULTS: Blood basophils of patients with CIU were reduced in number and displayed increased surface expression of FcepsilonRIalpha, which was positively correlated with the IgE serum levels. Upregulation of expression of both surface markers CD203c and CD63 was verified on basophils of patients with CIU, regardless of ASST response. High expression of IL-3 receptor on basophils was detected only in ASST+ patients with CIU. Pretreatment with IL-3 upregulated CD203c expression concomitantly with the excreting function of blood basophils and induced a quick hyper-responsiveness to anti-IgE cross-linking on basophils of patients with CIU compared with healthy controls. CONCLUSIONS: Basophils of patients with CIU showed an activated profile, possibly due to an in vivo priming. Functionally, basophils have high responsiveness to IL-3 stimulation, thereby suggesting that defects in the signal transduction pathway after IgE cross-linking stimuli are recoverable in subjects with chronic urticaria.
Assuntos
Antígenos CD/metabolismo , Basófilos/efeitos dos fármacos , Liberação de Histamina/efeitos dos fármacos , Imunoglobulina E/imunologia , Interleucina-3/farmacologia , Urticária/imunologia , Adulto , Idoso , Basófilos/imunologia , Biomarcadores/análise , Doença Crônica , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Imunoglobulina E/sangue , Masculino , Pessoa de Meia-Idade , Receptores de IgE/metabolismoRESUMO
Warifteine is a bisbenzylisoquinoline alkaloid isolated from the Cissampelos sympodialis Eichl (Menispermaceae). This plant is used in the folk medicine for the treatment of airway respiratory diseases. A murine model of immediate allergic reaction was used to evaluate warifteine treatment in the IgE production, leukocyte activation, thermal hyperalgesia, mast cell degranulation and scratching behavior. BALB/c mice treated with warifteine (0.4-10 mg/Kg) 1 h before OVA sensitization reduced OVA induced paw edema as well as the OVA-specific IgE serum titers as compared with non-treated and OVA-sensitized animals. Warifteine also reduced the mice death evoked by IgE-dependent anaphylactic shock reaction at 30 min after intravenous OVA challenge. To assess the effect of warifteine treatment on T cell proliferative response, spleen cells from warifteine treated or non-treated and OVA-sensitized animals were evaluated. Spleen cells from warifteine treated animals (2.0 mg/kg) did not proliferate following OVA stimulation as compared with spleen cell cultures from non-treated animals. This response may be related with the increase of NO production as observed in peritoneal macrophage cultures treated with warifteine. Thermal hyperalgesia evoked by IgE or histamine/5-hydroxytryptamine challenge was inhibited on rats at dose of 4.0 mg/kg. Warifteine treatment (0.6 or 6.0 microg/ml) also decreased the IgEalphaDNP-BSA sensitized mast degranulation after DNP-BSA challenge measured by histamine release. In addition, compound 48/80-induced scratching behavior was also sensitive to warifteine treatment. These results demonstrate for the first time that warifteine treatment reduced the allergy-associated responses.
Assuntos
Alcaloides/uso terapêutico , Hiperalgesia/tratamento farmacológico , Hipersensibilidade Imediata/tratamento farmacológico , Linfócitos T/imunologia , Alcaloides/administração & dosagem , Alcaloides/isolamento & purificação , Anafilaxia/tratamento farmacológico , Anafilaxia/imunologia , Animais , Degranulação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Liberação de Histamina/efeitos dos fármacos , Hiperalgesia/imunologia , Imunoglobulina E/sangue , Ativação Linfocitária/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Mastócitos/imunologia , Mastócitos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Ovalbumina/imunologia , Ratos , Ratos WistarRESUMO
Compound 48/80 (C48/80) is a synthetic condensation product of N-methyl-p-methoxyphenethylamine with formaldehyde and is an experimental drug used since the 1950s to induce anaphylactic shock through histamine release. This study was carried out to further elucidate the mechanism by which this drug induces nitric oxide (NO) release. Our specific goals were: (a) to verify if C48/80's relaxation occurs through the stimulation of histamine receptors; (b) to evaluate the endothelium-dependent relaxation induced by C48/80; (c) to identify NO as the endothelium-relaxing factor released by C48/80; (d) to identify the NO synthase (NOS) responsible for NO release; and (e) to verify if the relaxation induced by C48/80 is calcium and cyclic guanidine monophosphate (cGMP) dependent. Rabbit aorta segments, with and without endothelium, were suspended in organ chambers (25ml) filled with Krebs solution maintained at 37 degrees C, bubbled with 95% O(2)/5% CO(2) (pH 7.4). Phenylephrine was used to contract the segments. Other protocol drugs included H(1)- and H(2)-receptor antagonists, cyclooxygenase, NOS, guanylyl cyclase and phospholipase C (PLC) inhibitors. Endothelium-dependent relaxation induced by C48/80 was also studied in calcium-free Krebs solution associated with a calcium chelator. In summary, our investigation demonstrated that the C48/80 vasodilating action: (a) does not depend on H(1) and H(2) histamine receptors; (b) is NO endothelium-dependent; (c) is dependent on the endothelial constitutive NOS (NOS-3) isoform activation; (d) is cGMP-dependent; and that NOS-3 activation by C48/80: (a) is independent of PLC up to 25mug/ml and (b) is partially dependent of this lipase in higher doses.
Assuntos
Aorta/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Liberação de Histamina/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , p-Metoxi-N-metilfenetilamina/farmacologia , Animais , Aorta/metabolismo , Cimetidina/farmacologia , Endotélio Vascular/metabolismo , Estrenos/farmacologia , Antagonistas dos Receptores Histamínicos H1/farmacologia , Técnicas In Vitro , Masculino , Relaxamento Muscular/efeitos dos fármacos , Óxido Nítrico/metabolismo , Pirilamina/farmacologia , Pirrolidinonas/farmacologia , CoelhosRESUMO
Myrtaceae is a plant family widely used in folk medicine and Syzygium and Eugenia are among the most important genera. We investigated the anti-allergic properties of an aqueous leaf extract of Syzygium cumini (L.) Skeels (SC). HPLC analysis revealed that hydrolyzable tannins and flavonoids are the major components of the extract. Oral administration of SC (25-100 mg/kg) in Swiss mice (20-25 g; N = 7/group) inhibited paw edema induced by compound 48/80 (50% inhibition, 100 mg/kg; P Assuntos
Antialérgicos/farmacologia
, Edema/tratamento farmacológico
, Liberação de Histamina/efeitos dos fármacos
, Pleurisia/tratamento farmacológico
, Syzygium/química
, Animais
, Antialérgicos/isolamento & purificação
, Cromatografia Líquida de Alta Pressão
, Modelos Animais de Doenças
, Edema/induzido quimicamente
, Edema/imunologia
, Ensaio de Imunoadsorção Enzimática
, Eosinófilos/efeitos dos fármacos
, Masculino
, Mastócitos/efeitos dos fármacos
, Mastócitos/imunologia
, Camundongos
, Camundongos Endogâmicos BALB C
, Cavidade Peritoneal/citologia
, Extratos Vegetais/farmacologia
, Folhas de Planta/química
, Pleurisia/induzido quimicamente
, Pleurisia/imunologia
, Ratos
, Ratos Wistar
RESUMO
Myrtaceae is a plant family widely used in folk medicine and Syzygium and Eugenia are among the most important genera. We investigated the anti-allergic properties of an aqueous leaf extract of Syzygium cumini (L.) Skeels (SC). HPLC analysis revealed that hydrolyzable tannins and flavonoids are the major components of the extract. Oral administration of SC (25-100 mg/kg) in Swiss mice (20-25 g; N = 7/group) inhibited paw edema induced by compound 48/80 (50 percent inhibition, 100 mg/kg; P <= 0.05) and, to a lesser extent, the allergic paw edema (23 percent inhibition, 100 mg/kg; P <= 0.05). SC treatment also inhibited the edema induced by histamine (58 percent inhibition; P <= 0.05) and 5-HT (52 percent inhibition; P <= 0.05) but had no effect on platelet-aggregating factor-induced paw edema. SC prevented mast cell degranulation and the consequent histamine release in Wistar rat (180-200 g; N = 7/group) peritoneal mast cells (50 percent inhibition, 1 æg/mL; P <= 0.05) induced by compound 48/80. Pre-treatment of BALB/c mice (18-20 g; N = 7/group) with 100 mg/kg of the extract significantly inhibited eosinophil accumulation in allergic pleurisy (from 7.662 ± 1.524 to 1.89 ± 0.336 x 10(6)/cavity; P <= 0.001). This effect was related to the inhibition of IL-5 (from 70.9 ± 25.2 to 12.05 ± 7.165 pg/mL) and CCL11/eotaxin levels (from 60.4 ± 8.54 to 32.8 ± 8.4 ng/mL) in pleural lavage fluid, using ELISA. These findings demonstrate an anti-allergic effect of SC, and indicate that its anti-edematogenic effect is due to the inhibition of mast cell degranulation and of histamine and serotonin effects, whereas the inhibition of eosinophil accumulation in the allergic pleurisy model is probably due to an impairment of CCL11/eotaxin and IL-5 production.
Assuntos
Animais , Masculino , Camundongos , Ratos , Antialérgicos/farmacologia , Edema/tratamento farmacológico , Eugenia/química , Liberação de Histamina/efeitos dos fármacos , Pleurisia/tratamento farmacológico , Antialérgicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Edema/induzido quimicamente , Edema/imunologia , Eosinófilos/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Mastócitos/efeitos dos fármacos , Mastócitos/imunologia , Cavidade Peritoneal/citologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Pleurisia/induzido quimicamente , Pleurisia/imunologia , Ratos WistarRESUMO
Endothelin (ET)-1 evokes a burning pruritus sensation when injected intradermally in humans and nocifensive behavior when injected into the hind paw of rodents. Because pain and pruritus are clearly distinct nociceptive sensory modalities in humans, the current study evaluates the potential of ET-1 to elicit scratching behavior in mice. Mice received an intradermal injection of 1-30 pmol ET-1; 10 microg of the mast cell degranulator compound, 48/80; 100 nmol histamine; or vehicle into the scruff, and the number of scratching bouts displayed during the first 40 mins was recorded. ET-1 caused dose-dependent scratching bouts, which, like the responses to histamine and compound 48/80, occurred mainly during the first 5 to 10 mins of injection, but fewer episodes were also seen up to 35 mins. The effect of ET-1 was maximal at 10 pmol (total 40 +/- 7 bouts), a value similar to that caused by histamine (52 +/- 5 bouts) and compound 48/80 (53 +/- 6 bouts). The selective ET(B) receptor agonist, IRL-1620 (10 pmol), was not pruritic per se, and actually inhibited responses to histamine and ET-1. Pruritus induced by ET-1 was inhibited by the ET(A) receptor antagonists, 10 nmol BQ-123 (co-injected; net inhibition, 87%) and 10 mg/kg atrasentan (intraperitoneal administration; net inhibition, 83%), or the ET(B) receptor antagonist, 20 mg/kg A-192621 (intraperitoneal administration; net inhibition, 64%), but the response was augmented by co-injection of the ET(B) receptor antagonist, 3 nmol BQ-788 (net potentiation, 234%). Responses to compound 48/80 or responsiveness of vehicle-treated mice were unaffected by these antagonists. Thus, ET-1 displays potent pruritic actions in the mouse mediated to a substantial extent via local ET(A) receptors. The findings with IRL-1620 and BQ-788 suggest that local ET(B) receptors exert an antipruritic role, but, for reasons still unknown, the results obtained using systemic A-192621 injection are at variance with this view.
Assuntos
Endotelina-1/farmacologia , Prurido/induzido quimicamente , Animais , Comportamento Animal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Histamina/administração & dosagem , Histamina/farmacologia , Liberação de Histamina/efeitos dos fármacos , Injeções Intradérmicas , Masculino , Mastócitos/efeitos dos fármacos , Mastócitos/metabolismo , Camundongos , Tempo de Reação , p-Metoxi-N-metilfenetilamina/administração & dosagem , p-Metoxi-N-metilfenetilamina/farmacologiaRESUMO
Mast cell number and reactivity were shown to be down-regulated under diabetic conditions. Since the balance between globular and filamentous actin plays a pivotal role in the activity of secretory cells, we investigated whether an imbalance in that system could underlie the hyporesponsiveness of mast cells in diabetes. The apoptotic state was also evaluated. By means of rhodamine/phalloidine staining of F-actin, we noted that diabetic mast cells exhibited an increase in fluorescence intensity and reduction in cellular size, when compared with cells from normal animals, in parallel with elevation in the percentage of cells developing apoptosis. The levels of Bax, a pro-apoptotic member of Bcl-2 family, appeared increased at baseline in mast cells from diabetic rats compared with normal cells. These phenomena correlated with reduction in histamine and PGD2 release following antigen challenge in vitro. The steroid antagonist RU 486 abolished the reduction of histamine secretion from diabetic mast cells. We conclude that hyporesponsiveness of mast cells noted in diabetes may be accounted for by reduction in actin filament plasticity, in clear association with the rise in the percentage of cells undergoing apoptosis. In addition, the refractoriness of diabetic mast cells to antigen in vitro seems to be dependent on glucocorticoids.
Assuntos
Actinas/metabolismo , Actinas/ultraestrutura , Apoptose/fisiologia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Mastócitos/fisiologia , Abortivos/farmacologia , Adrenalectomia , Animais , Antineoplásicos/farmacologia , Glicemia/metabolismo , Western Blotting , Peso Corporal/efeitos dos fármacos , Separação Celular , Depsipeptídeos/farmacologia , Citometria de Fluxo , Glucocorticoides/fisiologia , Liberação de Histamina/efeitos dos fármacos , Masculino , Microscopia de Fluorescência , Mifepristona/farmacologia , Prostaglandina D2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Wistar , Proteína X Associada a bcl-2/metabolismoRESUMO
Vimang is the brand name of formulations containing an extract of Mangifera indica L., ethnopharmacologically used in Cuba for the treatment of some immunopathological disorders, including bronchial asthma, atopic dermatitis and other allergic diseases. However, the effects of Vimang on allergic response have not been reported until now. In this study, the effects of Vimang and mangiferin, a C-glucosylxanthone isolated from the extract, on different parameters of allergic response are reported. Vimang and mangiferin showed a significant dose-dependent inhibition of IgE production in mice and anaphylaxis reaction in rats, histamine-induced vascular permeability and the histamine release induced by compound 48/80 from rat mast cells, and of lymphocyte proliferative response as evidence of the reduction of the amount of B and T lymphocytes able to contribute to allergic response. In these experiments, ketotifen, promethazine and disodium cromoglicate were used as reference drugs. Furthermore, we demonstrated that Vimang had an effect on an in-vivo model of inflammatory allergy mediated by mast cells. These results constitute the first report of the anti-allergic properties of Vimang on allergic models, as well as suggesting that this natural extract could be successfully used in the treatment of allergic disorders. Mangiferin, the major compound of Vimang, contributes to the anti-allergic effects of the extract.
Assuntos
Antialérgicos/farmacologia , Hipersensibilidade/tratamento farmacológico , Mangifera , Extratos Vegetais/farmacologia , Xantonas/farmacologia , Anafilaxia/prevenção & controle , Animais , Permeabilidade Capilar/efeitos dos fármacos , Proliferação de Células , Relação Dose-Resposta a Droga , Feminino , Liberação de Histamina/efeitos dos fármacos , Hipersensibilidade/imunologia , Imunoglobulina E/biossíntese , Técnicas In Vitro , Linfócitos/efeitos dos fármacos , Linfócitos/patologia , Masculino , Mastócitos/efeitos dos fármacos , Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Cavidade Peritoneal/citologia , Ratos , Ratos WistarRESUMO
Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A), lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA), and demetallized Con A and C. brasiliensis, using 1-300 microg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5%, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A) and on Rowett nude rat (animal free of immunoglobulins) peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA). No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars). Additionally, the lectins also released histamine from Rowett nude mast cells that are free of immunoglobulins.
Assuntos
Liberação de Histamina/efeitos dos fármacos , Mastócitos/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Animais , Cricetinae , Feminino , Cobaias , Masculino , Mastócitos/metabolismo , Ratos , Ratos WistarRESUMO
Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A), lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA), and demetallized Con A and C. brasiliensis, using 1-300 æg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5 percent, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A) and on Rowett nude rat (animal free of immunoglobulins) peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA). No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars). Additionally, the lectins also released histamine from Rowett nude mast cells that are free of immunoglobulins.
Assuntos
Animais , Cricetinae , Feminino , Cobaias , Masculino , Ratos , Liberação de Histamina/efeitos dos fármacos , Mastócitos/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Mastócitos/metabolismo , Ratos WistarRESUMO
We studied the effect of Brazilian propolis on scratching behavior induced by compound 48/80 and histamine in ICR mice. Propolis granular A.P.C dose-related inhibited scratching behavior induced by compound 48/80 and significant inhibition were observed at 1000 mg/kg. However, histamine-induced scratching behavior was not inhibited by propolis granular A.P.C even at 1000 mg/kg. Propolis ethanol extract at 10 microg/ml or more inhibited histamine release from rat mast cells induced by compound 48/80. In addition, it blocked increased vascular permeability induced by compound 48/80. The inhibitory effect of propolis on scratching behavior induced by compound 48/80 was gradually enhanced by repeated administration, and 500 mg/kg propolis granular A.P.C, which caused no effect through single administration, significantly inhibited scratching behavior after repeated administration for 4 weeks. From these findings, it is assumed that the inhibition of scratching behavior induced by propolis occurs through a mast cell-dependent mechanism.
Assuntos
Comportamento Animal/efeitos dos fármacos , Antagonistas dos Receptores Histamínicos H1/uso terapêutico , Histamina , Própole/uso terapêutico , Prurido/tratamento farmacológico , p-Metoxi-N-metilfenetilamina , Animais , Brasil , Permeabilidade Capilar/efeitos dos fármacos , Relação Dose-Resposta a Droga , Interações Medicamentosas , Feminino , Antagonistas dos Receptores Histamínicos H1/administração & dosagem , Antagonistas dos Receptores Histamínicos H1/farmacocinética , Liberação de Histamina/efeitos dos fármacos , Mastócitos/efeitos dos fármacos , Mastócitos/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Própole/administração & dosagem , Própole/farmacocinética , Prurido/etiologia , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Eosinophilic colitis is a rare entity of unknown etiology characterized by diarrhea, abdominal pain, and gastrointestinal bleeding. Diagnosis includes histopathological infiltration of more than 20 eosinophils in colon. It is frequently associated with milk hypersensitivity and, less usual, with other foods and increased IgE. Histopthological appearance of eosinophil mediators has been observed in the gut. It is sometimes related to the degree of infiltration of eosinophils in the gut as well as to the disease severity. There is not an established treatment for this entity, although systemic steroids have been used with certain efficacy. However, there is a recurrence of the symptoms when the therapy stops, besides the well known side effects of the long-term use of steroids. Cromolyn inhibits mast cell degranulation and prevents liberation of mediators. It is successful in certain cases, specially the severe ones. However, it is not available for its use in our country. Ketotifen, as last resource in our patients with bad response to habitual treatment and restriction diet, was used. Although its use is controversial, we consider that stabilizing mast cell membrane with subsequent inhibition of degranulation and recruitment of eosinophils to sites of inflammation, would also restrain histamine liberation and blockage of H1 receptors, which would diminish local damage induced by eosinophils. Nonetheless ketotifen mechanism of action is unknown, our patients improved after treatment with this drug.