Oral administration of eucalyptol reduces cell migration and pain-like behavior in zymosan-induced arthritis mice

Abstract Rheumatoid arthritis (RA) is an inflammatory disease that utilizes nonbiologic and biologic drugs for appropriate disease management. However, high cost, adverse effects, reduced effectiveness, and risk of infection have stimulated the search for safer and more efficacious therapeutic strategies. In the present study, we aimed to evaluate the anti-inflammatory and analgesic properties of eucalyptol in an experimental model of arthritis. Mice were administered zymosan or saline intra-articularly. One hour before the zymosan administration, the mice were treated with oral eucalyptol (200-400 mg/kg) and vehicle. Cell influx, neutrophils, lymphocytes, and monocytes were measured in joint exudates. Joint pain was assessed using paw-pressure tests. Orally administered eucalyptol (200 and 400 mg/kg) significantly reduced cell influx, as well as neutrophils, lymphocytes, and monocytes, when compared with the control. Eucalyptol at a dose of 400 mg/kg significantly reversed joint pain and demonstrated analgesic activity (60%); however, 200 mg/kg failed to alter joint pain. These results indicate that oral eucalyptol promotes anti-inflammatory and analgesic activity in mice subjected to zymosan-induced arthritis.

Expression of glycine receptor α3 subunit in neuropathic and inflammatory central pain sensitization

INTRODUCTION: Increasing evidence suggests that changes in the balance of excitatory/inhibitory neurotransmission are involved in the development of the majority of chronic pain forms. In this context, impairment in glycine mediated inhibitory neurotransmission is thought to play a critical role in the disinhibition that accounts for the development and maintenance of central pain hypersensitivity. AIMS: The goal of this study was to evaluate the Glycine Receptor α3 subunit (α3GlyR) expression in neuropathic (Chronic Constriction Injury, CCI) and inflammatory (Zymosan A injected) animal models of chronic pain. RESULTS AND CONCLUSION: RT-qPCR analysis of spinal cord samples showed that glra3 gene expression does not change after 3 days of CCI and 4 hours of Zymosan A injection. However, we found that protein levels evaluated by Western blot increased after inflammatory pain. These data suggest that central sensitization is differentially regulated depending on the type of pain. α3GlyR protein expression plays an important role in the first step of inflammatory pain establishment.

Agonistic activity of tamoxifen, a selective estrogen-receptor modulator (SERM), on arthritic ovariectomized mice

Arthritis is positively associated with the decline of sex hormones, especially estrogen. Tamoxifen (TMX) is a selective estrogen receptor modulator, possessing agonist or antagonistic activity in different tissues. Thus, the objective of this study was to investigate the effect of TMX on the zymosan-induced arthritis model. Female Swiss normal and ovariectomized (OVX) mice were divided into groups and treated for five days with TMX (0.3, 0.9 or 2.7 mg/kg) or 17-β-estradiol (E2, 50 µg/kg). On the fifth day, arthritis was induced and 4 h later, leukocyte migration into joint cavities was evaluated. The neutrophil migration in OVX animals, but not in normal mice, treated with TMX (all tested doses) was significantly decreased compared with mice that received the vehicle (P≤0.05). Similarly, this effect was also demonstrated in the E2-treated group. Therefore, the present study demonstrates that TMX presented agonist effects in inhibiting neutrophil migration and preventing arthritis progression in OVX mice.

Xylitol Mitigate Neutrophil Inflammatory Response Against Porphyromonas gingivalis Infection

Periodontitis is generally a chronic disorder characterized by breakdown of tooth-supporting tissues, producing dentition loss. Porphyromonas gingivalis (P. gingivalis), a Gram-negative anaerobic rod, is one of the major pathogens associated with periodontitis. Neutrophils are first line defense cells in the oral cavity that play a significant role in inflammatory response. Xylitol is a known anti-caries agent and has anti-inflammatory effects. In this study, we conducted experiments to evaluate anti-inflammatory effects of xylitol on P. gingivalis infected neutrophils for possible usage in prevention and treatment of periodontal infections. P. gingivalis was intraperitoneally injected and peritoneal lavage was collected for cytokine determination. For in vitro study, neutrophils were collected from mouse peritoneal cells after zymosan injection or bone marrow cells. Neutrophils were stimulated with live P. gingivalis and ELISA was used to determine the effect of xylitol on P. gingivalis induced cytokine production. IL-1β, IL-6, TNF-α concentration and neutrophil population in the peritoneal lavage was increased in P. gingivalis-infected mouse. Peritoneal cells infected with live P. gingivalis revealed significantly increased production of IL-1β, IL-6 and TNF-α at multiplicity of infection of 10. Neutrophils from bone marrow and peritoneal lavage revealed increased production of IL-1β, IL-6 and TNF-α. Xylitol significantly mitigated P. gingivalis induced cytokine production in neutrophils. Findings indicate that xylitol is an anti-inflammatory agent in neutrophils infected with live P. gingivalis, that suggests its use in periodontitis management.

STX0119 Ameliorates Arthritis in SKG Mice via Inhibiting T Helper 17

Rheumatoid arthritis (RA) is an autoimmune disease with chronic and excessive inflammation. Upregulation of interleukin (IL)-17 is involved in the pathogenesis of RA. STX0119 is a specific inhibitor of signal transducer and activator of transcription 3 (STAT3) as a potential target for the treatment of RA. STAT3 is a member of DNA-binding molecules that regulates the expression of proinflammatory cytokines involved in the pathogenesis of RA. The objective of this study was to determine whether STX0119 could inhibit STAT3 and IL-17. We demonstrated that STX0119 decreased T helper (Th) 17 differentiation and IL-17 expression in vitro. STX0119 also improved the severity of zymosan induced arthritis and reduced joint inflammation. STX0119 reduced the proliferation of Th17 and phosphorylated STAT3 expression while increasing Treg differentiation and phosphorylated STAT5 expression. Moreover, STX0119 decreased the expression of IL-6 and -17 but not IL-10. These findings suggest that STX0119 can be used to treat autoimmune RA through inhibiting the activation of STAT3.

Evaluation of immunostimulatory activity of Chyawanprash using in vitro assays.

Chyawanprash is an ayurvedic formulation used in Indian traditional medicinal system for its beneficial effect on human health. We investigated the immunostimulatory effects of Chyawanprash (CHY) using in vitro assays evaluating the secretion of cytokines such as Tumor Necrosis Factor-alpha (TNF-α), Interleukin-1beta (IL-1β) and Macrophage Inflammatory Protein-1-alpha (MIP-1-α) from murine bone marrow derived Dendritic Cells (DC) which play pivotal role in immunostimulation. The effects of CHY on phagocytosis in murine macrophages (RAW264.7) and Natural Killer (NK) cell activity were also investigated. At non-cytotoxic concentrations (20–500 µg/ml), CHY enhanced the secretion of all the three cytokines from DC. CHY also stimulated both, macrophage (RAW264.7) as well as NK cell activity, in vitro. In conclusion, the data substantiates the immunoprotective role of CHY at cellular level mediated by immunostimulation in key immune cells viz. dendritic Cells, macrophages and NK cells.

Applications of Microscopic Imaging and Analysis Technology in Studies of Neutrophil Movement and Phagocytosis / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To analyze and evaluate the application of spinning disk confocal microscopy and imaging analysis software in movement and phagocytosis of neutrophils.</p><p><b>METHODS</b>Neutrophils were isolated from bone marrow by centrifugation on discontinuous Percoll gradient, and then were stained with PE Gr-1 antibody and mixed with FITC-labeled Zymosan A bioparticles. Multichannel time-lapse videos were captured by using the spinning disk confocal microscopy. The result was analyzed by using volocity and ImageJ software, the parameters associated with movement and phagocytosis of neutrophils were analyzed, including morphological changes, cell tracking, pseudopod dynamics, binding and phagocytosis index.</p><p><b>RESULTS</b>Most neutrophils would be polarized in response to Zymosan particles during a short time. Binding and phagocytosis process occured in forty minutes.</p><p><b>CONCLUSION</b>A method of precisely quantifying the movement and phagocytosis of neutrophils using microscopic imaging and imaging analysis technique has been set up successfully. Using this method, biological activity and function of neutrophils can be evaluated visually and rapidly. The physiologically rapid response to Zymosan particles can be applied to the neutrophils function research in the future.</p>

Oral administration of curcumin (Curcuma longa) can attenuate the neutrophil inflammatory response in zymosan-induced arthritis in rats

PURPOSE: To evaluate the effect of curcumin in the acute phase of zymosan-induced arthritis. METHODS: Twenty-eight male rats were subjected to intra-articular infiltration of zymosan of both knees and, in four the infiltration was made with saline. The animals were divided into five groups second received every six hours by gavage: corn oil by (positive and negative control); curcumin (100 mg/kg); prednisone 1 mg/kg/day; prednisone 8 mg/kg. All animals were sacrificed after six, 12, 24 and 48 hours of the infiltration. The knees were removed for evaluation of neutrophil infiltration. The number of neutrophils was counted by computer-assisted analysis of the images. The neutrophil infiltrate was stratified into four grades: 0 = normal; + = mild; ++/+++ = moderate; > ++++ = severe. The results were compared using the Mann-Whitney test and the variance by Kruskal-Wallis test adopting a significance level of 5% (p<0.05). RESULTS: Curcumin reduces inflammatory activity in the first six hours after zymosan-induced arthritis when compared to saline (p<0.01). This was also observed in animals subjected to administration of prednisone (1 mg/kg) and those treated with prednisone (8 mg/kg). Curcumin was more effective than lower doses of prednisone in the first six hours after induction of the arthritis. After 12, 24 and 48 hours, curcumin does not have the same anti-inflammatory effects when compared to prednisone. After 48 hours, prednisone is more effective than curcumin in reducing the inflammatory infiltrate regardless of the dose of prednisone used. CONCLUSION: Oral administration of curcumin reduces inflammation in the first six hours after experimentally zymosan-induced arthritis. .

Efeito da nicotina sobre fagócitos ativados / Effect of the nicotine on actived phagocytes

Indivíduos fumantes apresentam aumento na proporção de leucócitos polimorfonucleares (LPMN), como por exemplo, no tecido pulmonar, resultando em aumento nos níveis de enzimas proteolíticas e espécies reativas de oxigênio, que ocasionam efeito destrutivo na matriz celular e contribuem para a progressão da doença pulmonar, além de favorecer o aparecimento de infecções microbianas, e determinam que as células fagocíticas estejam em frequente estado de ativação (fagocitose). Neste trabalho, avaliou-se a influência da nicotina (NIC) sobre a viabilidade de LPMN e macrófagos ativados ou não, pelos estímulos zymosan e acetato de forbol miristato. Os resultados indicaram que a NIC promove aumento na viabilidade de LPMN e macrófagos ativados em relação a essas células ativadas sem a presença de NIC, avaliada 'ex vivo' pelo teste de exclusão do azul de trypan. Esse efeito foi significativamente mais pronunciado sobre LPMN que sobre os macrófagos. Essa redução na citotoxicidade favorece a sobrevida da célula, podendo exacerbar os seus efeitos deletérios, especialmente em no seu estado ativado, pela maior produção de espécies reativas de oxigênio.

Smokers show increased rates of polymorphonuclear leukocytes (PMNL), including in pulmonary tissue, resulting increased levels of proteolytic enzymes and reactive oxygen species, which have a destructive effect on the cellular matrix and contribute to the progression of pulmonary disease, in addition to promoting the onset of microbial infections which cause phagocytic cells to be in a state of frequent activation (phagocytosis). This work evaluated the influence of nicotine (NIC) on the viability of PMNL and macrophages (activated or not), by stimuli zymosan and phorbol myristate acetate. The results indicated that NIC led to increased viability of PMNL and activated macrophages compared to these cells activated without NIC, measured ex vivo by trypan blue exclusion test. This effect was significantly higher on PMNL than on macrophages. This reduction in cytotoxicity favors cell survival, and may exacerbate its deleterious effect, especially in the active state, due to increased production of reactive oxygen species.

Dectin-1 Stimulation Selectively Reinforces LPS-driven IgG1 Production by Mouse B Cells

Dectin-1, which specifically recognizes beta-glucan of fungal cell walls, is a non-Toll-like receptor (TLR) pattern recognition receptor and a representative of C-type lectin receptors (CLRs). The importance of Dectin-1 in innate immune cells, such as dendritic cells and macrophages, has previously been well studied. However, the function of Dectin-1 in B cells is very poorly understood. To determine the role of Dectin-1 in B cell activation, we first investigated whether mouse B cells express Dectin-1 and then assessed the effect of Dectin-1 stimulation on B cell proliferation and antibody production. Mouse B cells express mRNAs encoding CLRs, including Dectin-1, and surface Dectin-1 was expressed in B cells of C57BL/6 rather than BALB/c strain. Dectin-1 agonists, heat-killed Candida albicans (HKCA) and heat-killed Saccharomyces cerevisiae (HKSC), alone induced B cell proliferation but not antibody production. Interestingly, HKSC, HKCA, and depleted zymosan (a selective Dectin-1 agonist) selectively enhanced LPS-driven IgG1 production. Taken together, these results suggest that, during fungal infection, beta-glucan-stimulated Dectin-1 may cooperate with TLR4 to specifically enhance IgG1 production by mouse B cells.

Analgesic effect of calpain inhibitor ALLN on the zymosan-induced paw inflammatory pain and its effect on the expression of cyclooxygenase-2 in the spinal dorsal horn / 中国医学科学院学报

<p><b>OBJECTIVE</b>To examine the analgesic effect of calpain inhibitor ALLN on the zymosan-induced paw inflammatory pain and its effect on the expression of cyclooxygenase-2 (COX-2) in the spinal dorsal horn.</p><p><b>METHODS</b>Forty-eight Sprague-Dawley rats were equally divided into three groups: control group, sham-operated group, and zymosan group. According to Meller's method, zymosan (1.25 mg) was injected intraplantarly to induce paw inflammation in zymosan group; an equal volume of PBS was administered in the sham-operated group. Mechanical withdrawal threshold (MWT) and maximum thickness of paw were tested or measured before and 0.5, 1, 2, 4, 8, and 24 hours after injection. All rats were killed at different occasions following surgery to examine calpain activity in the spinal dorsal horn with Western blot analysis. Another sixty-four Sprague-Dawley rats were divided into three groups: sham-operated group, zymosan-induced paw inflammation with intraperitoneal dimethyl sulphoxide (DMSO) treatment group, and zymosan-induced paw inflammation with intraperitoneal calpain inhibitor ALLN treatment group. MWT and maximum thickness of paw were tested or measured before and 0.5, 1, 2, 4, 8, and 24 hours after injection. All rats were killed at different occasions following surgery to examine the COX-2 expression in the spinal dorsal horn with Western blot analysis.</p><p><b>RESULTS</b>MWT significantly decreased in the rats with zymosan-induced paw inflammation, while the maximum thickness of paw significantly increased, compared with control and sham-operated rats (P < 0.05). Calpain in the ipsilateral spinal dorsal horn was dramatically activated after zymosan injection (P < 0.01). Intraperitoneal ALLN injection significantly increased zymosan-induced MWT and decreased paw edema at the same time points after zymosan injection compared with DMSO treatment group (P < 0.05). Meanwhile, calpain inhibitor ALLN treatment significantly decreased the COX-2 expression in the spinal dorsal horn compared with DMSO treatment (P < 0.01).</p><p><b>CONCLUSION</b>Administration of calpain inhibitor ALLN is effective to attenuate zymosan-induced paw inflammatory pain. Calpain activation may be one aspect of the signaling cascade that increases the COX-2 expression in the spinal cord and contributes to mechanical hyperalgesia after peripheral inflammatory injury.</p>

Pain modality and spinal glia expression by streptozotocin induced diabetic peripheral neuropathy in rats / 한국실험동물학회지

Pain symptoms are a common complication of diabetic peripheral neuropathy or an inflammatory condition. In the most experiments, only one or two evident pain modalities are observed at diabetic peripheral neuropathy according to experimental conditions. Following diabetic peripheral neuropathy or inflammation, spinal glial activation may be considered as an important mediator in the development of pain. For this reason, the present study was aimed to address the induction of pain modalities and spinal glial expression after streptozotocin injection as compared with that of zymosan inflammation in the rat. Evaluation of pain behavior by either thermal or mechanical stimuli was performed at 3 weeks or 5 hours after either intravenous streptozotocin or zymosan. Degrees of pain were divided into 4 groups: severe, moderate, mild, and non-pain induction. On the mechanical allodynia test, zymosan evoked predominantly a severe type of pain, whereas streptozotocin induced a weak degree of pain (severe+moderate: 57.1%). Although zymosan did not evoke cold allodynia, streptozotocin evoked stronger pain behavior, compared with zymosan (severe+moderate: 50.0%). On the other hand, the high incidence of thermal hyperalgesia (severe+moderate: 90.0%) and mechanical hyperalgesia (severe+moderate: 85.7%) by streptozotocin was observed, as similar to that of zymosan. In the spinal cord, the increase of microglia and astrocyte was evident by streptozotocin, only microglia was activated by zymosan. Therefore, it is recommended that the selection of mechanical and thermal hyperalgesia is suitable for the evaluation of streptozotocin induced diabetic peripheral neuropathy. Moreover, spinal glial activation may be considered an important factor.

Preparation of rat model of systemic inflammatory response syndrome induced by zymosan / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To establish a model of systemic inflammatory response syndrome (SIRS) in rats.</p><p><b>METHODS</b>SD rats were intraperitoneally injected with different concentrations of zymosan suspension. The general status, temperature, white cell count, tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), interleukin-10 (IL-10) and the pathological changes of main organs were examined.</p><p><b>RESULTS</b>The conditions of rats receiving zymosan doses of 750 mg/kg and 1000 mg/kg were consistent with the criteria of SIRS model; however, the mortality of 1000 mg/kg group was higher than that of 750 mg/kg group.</p><p><b>CONCLUSION</b>The rat model of systemic inflammatory response syndrome has been successfully induced.</p>

Efeito protetor dos extratos de Ascaris suum e Coccidioides posadasii e da lectina da semente de Dioclea violacea na artrite por zymosan em ratos e camundongos [manuscrito] / Protective effect of Ascaris suum extracts and Coccidioides posadasii and Dioclea seed lectin violacea in arthritis by zymosan in rats and mice [manuscript]

Interações entre a resposta imune inata e adquirida participam na fisiopatologia de doenças auto-imunes. Embora infecções estejam assoviadas ao desenvolvimento de artrites crônicas, é possível que exposição a alguns germes, como hemintos e fungos, potencialmente influencie a prevalência e/ou gravidade de doenças imunomediadas. Lectinas derivadas de plantas, por ação em receptores de resposta inata, podem modular inflamação. Nós investigamos o efeito o efeito dos extratos de Ascaris suum (AS) e de Coccidioides posaadasii (CP) e de uma lectina isolada da Dioclea violacea (Dviol) na artrite induzida por zymosan (AZy). Ratos Wistar e camundongos Swiss receberam 1 mg ou 0,1 mg de zymosan intra-articular (i.art.), respectivamente. Grupos foram pré-tratados (30 min) com os extratos de AS (0,25 - 2,5 mg/animal; i.p. ou p.o.), CP (1 - 100 μg/animal/ i.art., i.p. ou p.o.) ou Dviol (0,3 - 30 μg i.art. ou 1 - 6 mg/Kg e.v.). Grupo não-tratato (NT) recebeu Zy (i.art.) e veículo. Animais naive receberam apenas salina (i.art.) e veículo. A hipernocicepção foi avaliada através do teste de incapacitação articular em s / 1min. O lavado articular foi usado para análise do influxo celular (IC), níveis de nitrito e citocinas...

Relationship between HMGB1 content and MHC-II expression in circulating monocytes and spleen of mice challenged with zymosan / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To observe the regularity of change in high mobility group protein box 1 (HMGB1) content in serum and spleen of mice with multiple organ dysfunction syndrome (MODS), to analyze the correlation between HMGB1 content and major histocompatibility complex (MHC)-II---I-A(b) expression on monocytes in blood and spleen, and to explore the effect of HMGB1 on immune function of circulating monocytes and splenocytes.</p><p><b>METHODS</b>One hundred 8-week-old male 57BL/6 mice were randomly divided into normal group and experimental group subdivided into 8 subgroups: 3, 8, 12 hours, 1, 2, 3, 5-7 days and 10-12 days post zymosan injection (PZI). MODS model was replicated by injecting zymosan into the peritoneal cavity. At each time point, blood and spleen were collected to detect HMGB1 content and the rate of I-A(b) positive monocytes.</p><p><b>RESULTS</b>In normal and PZI 3-hour, 8-hour mice, serum HMGB1 was not detected, but it significantly increased at PZI 12 hours. In spleen of normal mice, there was low level of HMGB1 expression. In zymosan-treated mice, HMGB1 started to rise in spleen at PZI 3 hours. Subsequently, HMGB1 content in both serum and spleen significantly increased, and it reached the peak level in 1-2 days, decreased in 5 days, and then increased in 10-12 days. The number of I-A(b) positive monocytes in circulating blood and spleen decreased at 1-2 days (t equal to 9.589, 4.432, P <0.01) and 10-12 days following the challenge, forming a two trough like decrease, just corresponding with two-peak increase of HMGB1. However, at 3 hours after zymosan challenge, I-A(b) expression on circulating monocytes was downregulated (t =5.977, P less than 0.01), while that in spleen upregulated (t equal to 4.814, P less than 0.01).</p><p><b>CONCLUSION</b>In mice with MODS, up-regulated HMGB1 expression can regulate I-A(b)expression on monocytes to depress their ability of presenting antigen, which results in immune disturbance contributing development of MODS.</p>

Effect of TSP-2 antibody against a single epitope of mouse Toll-like receptor 2 extracellular domain on zymosan A-induced peritonitis in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of the antibody TSP-2 against a single epitope of mouse Toll-like receptor 2 extracellular domain (mTLR2ECD) on the inflammation in mice with zymosan A-induced peritonitis.</p><p><b>METHODS</b>In mice with peritonitis induced by intraperitoneal injection of zymosan A, pretreatments with PBS, normal rabbit IgG and TSP-2 antibody at two different doses (2.5 and 5.0 mg/kg) were administered via the tail vein. Six hours after intraperitoneal injection of zymosan A, Evans blue was injected through the tail vein, and the frequency of writhing of the mice within 20 min were recorded. The mice were then sacrificed for peritoneal lavage, and the lavage fluid was collected to assess the exudation of Evans blue in the supernatant. The peritoneal leukocyte count, mast cell degranulation and release of such inflammatory mediators as platelet activating factor (PAF) and tumor necrosis factor-alpha (TNFalpha) in the lavage fluid were observed by cell counting, specific cell staining, immunohistochemistry and enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>Compared with PBS or rabbit IgG groups, TSP-2 treatment resulted in significantly reduced writhing response of the mice and lowered Evans blue exudation and leukocyte count in the peritoneal lavage, with also decreased degranulation of the mast cells induced by C48/80.</p><p><b>CONCLUSION</b>TSP-2 antibody against a single epitope of mTLR2ECD inhibits the inflammatory response in mice with zymosan A-induced peritonitis.</p>

Innovative technique for the study of pneumoperitoneum in the evaluation of abdominal pain after chemical irritation with zymozan / Técnica original para o estudo da influência do pneumoperitônio na avaliação da intensidade da dor abdominal após irritação química com zimozan

PURPOSE: To assess the influence of pneumoperitoneum in mice submitted to peritoneal irritation provoked by the biological agent Saccharomyces cerevisae, by counting the number of abdominal contractions elicited. METHODS: To study the effects of pneumoperitoneum analgesic action, 60 mice were divided into two groups: the experimental group, subjected to pneumoperitoneum; and the control group, without pneumoperitoneum. The both groups received intraperitoneal injection of zymosan at a dose of 1mg/0,2ml/mouse. RESULTS: The sum of the number of abdominal contractions of the experimental group (with pneumoperitoneum) was significantly lower than that of the control group (without pneumoperitoneum). In the experimental group, a lower number of contractions occurred in each min compared to the control. CONCLUSION: The observation of the analgesic effect of pneumoperitoneum using CO2 in mice submitted to peritoneal irritation by zymosan was verified.

OBJETIVO: Avaliar a influência do pneumoperitônio em animais submetidos à irritação peritoneal provocada pelo agente biológico Saccharomyces cerevisae mediante a contagem do número de contrações abdominais. MÉTODOS: Para o estudo do efeito da ação analgésica do pneumoperitônio os 60 camundongos foram divididos em dois grupos, grupo experimento (com pneumoperitôneo) e controle (sem pneumoperitôneo). Os dois grupos receberam injeção intraperitoneal de zimosan na dose de 1mg/0,2ml/camundongo. RESULTADOS: O somatório do número de contrações abdominais do grupo experimento (com pneumoperitôneo) foi significativamente menor que no grupo controle (sem pneumoperitôneo). O número médio de contrações no grupo controle foi significativamente maior quando comparado com o grupo experimento. CONCLUSÃO: Observou-se efeito analgésico do pneumoperitônio com CO2 em animais submetidos à irritação peritoneal pelo zimosan.

Adenosine Receptor Agonists Modulate Visceral Hyperalgesia in the Rat

BACKGROUND/AIMS: Adenosine is an endogenous modulator of nociception. Its role in visceral nociception, particularly in visceral hyperalgesia, has not been studied. The aim of this study was to determine the effects of adenosine receptor agonists in a model of visceral hyperalgesia. METHODS: The visceromotor response (VMR) in rats to colorectal distension (CRD; 80 mmHg, 20 seconds) was quantified by electromyographic recordings from the abdominal musculature. Three hours after the intracolonic administration of zymosan (25 mg/mL, 1 mL), VMRs to CRD were measured before and after either subcutaneous or intrathecal administration of an adenosine receptor agonist. RESULTS: Subcutaneous injection of 5'-N-ethylcarboxyamidoadenosine (NECA; an A1 and A2 receptor agonist), R(-)-N6-(2-phenylisopropyl)-adenosine (R-PIA; a selective A1 receptor agonist), or CGS-21680 hydrochloride (a selective A2a receptor agonist) dose-dependently (10-100 mg/kg) attenuated the VMR to CRD, although hindlimb weakness occurred at the higher doses tested. Intrathecal administration of NECA or R-PIA dose-dependently (0.1-1.0 microgram/kg) decreased the VMR, whereas CGS-21680 hydrochloride was ineffective over the same concentration range. Higher intrathecal doses of the A1/A2 receptor agonist NECA produced motor weakness. CONCLUSIONS: Adenosine receptor agonists are antihyperalgesic, but also produce motor weakness at high doses. However, activation of the spinal A1 receptor significantly attenuates the VMR to CRD without producing motor weakness.

Korean Mistletoe (Viscum album Coloratum) Extract Induces Eel (Anguilla japonica) Non-specific Immunity

BACKGROUND: The immunomodulatory effects of Korean mistletoe (Viscum album Coloratum) on the innate immune responses of eel (Anguilla japonica) were studied. METHODS: Mistletoe, Freund's complete adjuvant (FCA), or phosphate-buffered saline (PBS) as a control was injected into eel peritoneal cavities. RESULTS: Nitroblue tetrazolium (NBT)-positive cells in the head kidney of eel were significantly augmented by the second day post-injection of mistletoe. Reactive oxygen intermediates (ROI) were more produced in mistletoe-injected fish kidney leucocytes than in FCA-injected ones. The level of lysozyme activity in the serum of fish 2 days after injection with mistletoe was also significantly higher than that in the serum of the control fish. The optimal concentration of mistletoe in inducing the highest serum lysozyme activity was revealed to 500microgram/200 g of fish. In phagocytic activity assay, mistletoe-sensitized eel kidney phagocytes captured more zymosan than did the control fish. CONCLUSION: Korean mistletoe appeared to be a good activator of the non-specific immune responses of eel.

Envolvimento das endotelinas endógenas na artrite experimental em camundongos / Involvement of endogenous endothelins on experimental arthritis in mice

As endotelinas (ETs) são peptídeos, sintetizados por diversos tipos celulares, que exercem seus efeitos através da ligação a dois receptores celulares específicos, ETa e ETb. Níveis aumentados de ET-1 foram encontrados no plasma e no líquido sinovial de pacientes com artrite reumatóide, uma doença autoimune inflamatória crônica caracterizada pelo influxo celular, formação de edema e destruição da articulação. O objetivo deste trabalho foi avaliar o papel das ETs na inflamação articular no modelo de artrite induzida por zimosan. Inicialmente, camundongos C57BL/6 receberam injeção intra-articular (i.a) de ET-1 (10 pmo1/cav) que, nas primeiras 6 h, induziu a migração de leucócitos, principalmente neutrófilos (sal 0,25 mais ou menos 0,005 x ET-1 0,93 mais ou menos 0,007 x 10 elevado a cinco células/cav), a formação de edema (sal 0,12 mais ou menos 0,04 x ET-1 0,47 mais ou menos 0,09 mm/joelho) que atingiu o pico em 6 h e retornou aos níveis basais em 24 h. A sarafotoxina S6c, agonista seletivo do receptor ETb induziu em 6 h o recrutamento celular, predominantemente neutrófilos (sal 0,13 mais ou menos 0,018 x S6c 0,661 mais ou menos 0,134 x 10 elevado a cinco células/cav) e a formação de edema (sal 0,14 mais ou menos 0,04 x S6c 0,37 mais ou menos 0,05 mm/joelho). Em seguida, camundongos C57BL/6 foram pré-tratados i.a. com antagonistas de receptor ETa e ETb (BQ123 e BQ788, 0,15-150 pmo1/cav, respectivamente) 5 min antes da indução da artrite por zimosan. O pré-tratamento com BQ123 ou BQ788 (15 pmo1/cav) reduziu, nas 6 primeiras horas, o acúmulo de neutrófilos (64 e 73 por cento respectivamente), a formação de edema (40 e 61 por cento respectivamente) e a produção de TNF-alfa (39 e 51 por cento respectivamente) induzida por zimosan. Vinte e quatro horas após, ambos pré-tratamentos reduziram o acúmulo de neutrófilos (65 e 61 por cento respectivamente), a formação de edema (43 e 52 por cento respectivamente) e a produção de CXCL1 (12 e 11 por cento respectivamente.

Mais ainda, o estímulo i.a. com zimosan reduziu significativamente a intensidade de expressão de ETb(6 e 24 h) e ETa (24 h). Tomados em conjunto, esses dados apontam para a participação das ETs, atuando através de seus dois receptores, na inflamação articular.