Anti-inflammatory and Antinociceptive Activity of Ouabain in Mice

Ouabain, an inhibitor of the Na+/K+-ATPase pump, was identified as an endogenous substance of human plasma. Ouabain has been studied for its ability to interfere with various regulatory mechanisms. Despite the studies portraying the ability of ouabain to modulate the immune response, little is known about the effect of this substance on the inflammatory process. The aim of this work was to study the effects triggered by ouabain on inflammation and nociceptive models. Ouabain produced a reduction in the mouse paw edema induced by carrageenan, compound 48/80 and zymosan. This anti-inflammatory potential might be related to the inhibition of prostaglandin E2, bradykinin, and mast-cell degranulation but not to histamine. Ouabain also modulated the inflammation induced by concanavalin A by inhibiting cell migration. Besides that, ouabain presented antinociceptive activity. Taken these data together, this work demonstrated, for the first time, that ouabain presented in vivo analgesic and anti-inflammatory effects

Dietary Supplementation with Omega-3-PUFA-Rich Fish Oil Reduces Signs of Food Allergy in Ovalbumin-Sensitized Mice

We investigated the effect of dietary supplementation with n-3 PUFA (fish oil source) in an experimental model of food allergy. Mice were sensitized (allergic group) or not (nonallergic group) with OVA and were fed with OVA diet to induce allergy signals. Mice were fed with regular diet in which 7% of lipid content was provided by soybean (5% of n-3 PUFA) or fish (25% of n-3 PUFA) oil. Allergic group mice had increased serum levels of antiovalbumin IgE and IgG1 and changes in small intestine, characterized by an increased edema, number of rolling leukocytes in microcirculation, eosinophil infiltration, mucus production, and Paneth cell degranulation, in comparison to non-allergic group. All these inflammatory parameters were reduced in mice fed high-n-3-PUFA diet. Our data together suggest that diet supplementation with n-3 PUFA from fish oil may consist of a valid adjuvant in food allergy treatment

The combination of high-fat diet-induced obesity and chronic ulcerative colitis reciprocally exacerbates adipose tissue and colon inflammation

<p>Abstract</p> <p>Background</p> <p>This study evaluated the relationship between ulcerative colitis and obesity, which are both chronic diseases characterized by inflammation and increases in immune cells and pro-inflammatory cytokines.</p> <p>Methods</p> <p>Mice with chronic ulcerative colitis induced by 2 cycles of dextran sodium sulfate (DSS) in the first and fourth week of the experiment were fed a high-fat diet (HFD) to induce obesity by 8 weeks. The animals were divided into 4 groups (control, colitis, HFD and colitis + HFD).</p> <p>Results</p> <p>Obesity alone did not raise histopathology scores, but the combination of obesity and colitis worsened the scores in the colon compared to colitis group. Despite the reduction in weight gain, there was increased inflammatory infiltrate in both the colon and visceral adipose tissue of colitis + HFD mice due to increased infiltration of macrophages, neutrophils and lymphocytes. Intravital microscopy of VAT microvasculature showed an increase in leukocyte adhesion and rolling and overexpression of adhesion molecules compared to other groups. Moreover, circulating lymphocytes, monocytes and neutrophils in the spleen and cecal lymph nodes were increased in the colitis + HFD group.</p> <p>Conclusion</p> <p>Our results demonstrated the relationship between ulcerative colitis and obesity as aggravating factors for each disease, with increased inflammation in the colon and adipose tissue and systemic alterations observed in the spleen, lymph nodes and bloodstream.</p

Ouabain immunomodulatory activity in the acute inflammatory process

Ouabain (OUA), a potent inhibitor of the Na+,K+-ATPase pump, was identified as an endogenous substance of human plasma. In recent years, ouabain was shown to affect various immunological processes. Mechanisms that involve cellular differentiation, proliferation, activation and migration, as well as inflammatory mediators release, are activated during inflammation and homeostasis is usually reestablished. This study demonstrated the modulatory ability of OUA on inflammatory process. Aim: This study aimed to evaluate ouabain immunomodulatory role on acute inflammatory process using a murine model. Methods: Initially, a dose and time-response curve was performed with OUA (0.10 mg/kg, 0.31 mg/kg and 0.56 mg/kg) intraperitoneally administered on the paw edema induced by zymosan (10 mg/mL). Mice were also intraperitoneally (i.p.) stimulated with zymosan (2 mg/mL). After 4h, the peritoneal fluid was removed for total and differential cell counts. Neutrophils and macrophages population, as well as cell viability, were analyzed using an annexin KIT by flow cytometry. The concentrations of the cytokines IL-1β, TNF-α, IL-6 and IL-10 in peritoneal lavage fluids were assayed using ELISA kit. Ouabain influence in the vascular permeability increase was determined using evans blue dye. OUA, in vitro, influence on nitric oxide (NO) production was also studied. Results: It was observed that OUA 0,56 mg/kg injected for three consecutive days prevented zymosan edema formation . After induction of inflammation, treatment with OUA led to a 42% reduction in the total cell numbers in the peritoneal cavity, as a reflex of the inhibition of polymorphonuclear leukocytes (54%), which was not due to cell apoptosis. Ouabain also decreased zymosan-induced plasma exudation (33%). Furthermore, OUA decreased the levels of TNF-α (64%) and IL-1β (63%), without interference on IL-6 and IL-10 levels. It was also demonstrated, using peritoneal macrophages, that ouabain did not interfere on LPS induced NO production. Conclusion: Ouabain modulated the acute inflammatory response induced by zymosan. However, further studies are necessary to elucidate the mechanisms involvedCoordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESA ouabaína (OUA), um potente inibidor da Na+/K+-ATPase, foi identificada como uma substância endógena presente no plasma humano. Nos últimos anos, foi evidenciado que a OUA é capaz de interferir em diversos aspectos do sistema imunológico. Durante o processo inflamatório, são ativados mecanismos que envolvem a diferenciação, proliferação, ativação e migração celular, além da liberação de mediadores inflamatórios, e geralmente, ocorre o retorno à homeostasia. Este trabalho demonstrou a capacidade moduladora da OUA no processo inflamatório. Objetivo: Avaliar o papel imunomodulador da OUA na inflamação aguda em modelo murino. Métodos: Inicialmente, foi realizada uma curva de tempo e dose-resposta com a OUA (0,10 mg/kg; 0,31 mg/kg e 0,56 mg/kg) administrada de forma intra-peritoneal (i.p.) no modelo de edema de pata induzido por zimosan (10mg/mL). Os camundongos também foram estimulados com zimosan i.p.(2mg/ml). Após 4h, o fluido peritoneal foi removido para a contagem total e diferencial das células. Foi realizada a análise das populações de neutrófilos e macrófagos, além da viabilidade celular utilizando o kit anexina por citometria de fluxo. As concentrações das citocinas IL-1β, TNF-α, IL-6 e IL-10 no fluido peritoneal foram testadas por ELISA. Foi determinada a interferência do tratamento com a OUA no aumento da permeabilidade vascular. Também foi estudado, in vitro, o efeito de diferentes concentrações de OUA (10 nM, 100 nM e 1000 nM) na produção de óxido nítrico (NO). Resultados: No modelo do edema de pata, observamos que são necessários três dias consecutivos de tratamento na dose de 0,56 mg/kg para que a atividade anti-inflamatória da OUA seja identificada. No modelo de peritonite induzida por zimosan, o pré-tratamento com a OUA reduziu em 42% no número total de células na cavidade peritoneal, como um reflexo da inibição de leucócitos polimorfonucleares (54%). No entanto, este fenômeno não esta associado a apoptose destas células. A OUA também diminuiu o extravasamento de plasma induzido por zimosan (33%) e reduziu os níveis de TNF-α (64%) e IL-1β (63%), sem alterar os níveis de IL-6 e IL-10. Na cultura de macrófagos peritoneais, a OUA não interferiu na produção de NO. Conclusão: Este conjunto de dados sugere que a OUA possui uma atividade anti-inflamatória. No entanto, mais estudos são necessários para elucidar os mecanismos envolvidos

Evaluation of the role of ouabain in the hypothalamic-pituitary-adrenal axis in rats submitted to unpredictable chronic stress.

A ouabaína (OUA), um inibidor da Na+ ,K+-ATPase, foi identificada como uma substância endógena presente no plasma humano, e parece estar envolvida na resposta ao estresse agudo, em animais e seres humanos. O estresse crônico é um importante fator agravante de doenças psiquiátricas, incluindo depressão e ansiedade. Além disso, problemas cognitivos são cada vez mais reconhecidos como importantes componentes da ansiedade e depressão. Diante disto, o presente trabalho buscou investigar os efeitos da OUA (1,8 mg/kg) na hiperatividade do eixo HPA, na neuroinflamação, na expressão de receptores e proteínas envolvidos na plasticidade sináptica, nos efeitos comportamentais (como déficit de memória de longa duração, depressão e ansiedade) e atividade da Na+,K+-ATPase induzidos pelo protocolo de estresse crônico imprevisível (CUS) realizado ao longo de 14 dias em ratos. Nossos resultados demonstraram que o tratamento intermitente com OUA é capaz de reverter a hiperatividade do eixo HPA induzido pelo CUS, por meio da redução de glicocorticoide, redução na expressão de CRH-CRHR1, bem como diminuir a neuroinflamação, e aumentar os níveis de BDNF e fazer o que na expressão dos receptores CRHR2. Essas alterações bioquímicas contribuíram para uma reversão nos prejuízos na memória de longo prazo induzida pelo CUS. Ademais os animais tratados apenas com OUA, bem como os submetidos ao CUS e tratados com OUA obtiveram uma melhora na memória emocional, averiguada no teste comportamental de condicionamento da memória ao medo. Os resultados encontrados sugerem que o protocolo de CUS por 14 dias promove uma adaptação neuronal facilitando a redesignação da memória ao medo, aqui configurado pelo choque, e o tratamento com a OUA abrevia esse processo. Em conclusão os nossos resultados sugerem que o tratamento intermitente com OUA suscita uma adaptação no eixo HPA, por meio de alterações na expressão dos receptores para CRH no hipocampo e hipotálamo, resultando em uma adaptação na memória emocional relacionada ao medo.Ouabain (OUA), an inhibitor of Na+, K+ -ATPase, has been identified as an endogenous substance present in human plasma, and appears to be involved in the response to acute stress in animals and humans. Chronic stress is an important aggravating factor of psychiatric illness, including depression and anxiety. In addition, cognitive problems are increasingly recognized as important components of anxiety and depression. The present work aimed to investigate the effects of OUA (1.8 mg/kg) on HPA axis hyperactivity, neuroinflammation, expression of receptors and proteins involved in synaptic plasticity, behavioral effects (such as long-term memory deficit duration, depression and anxiety) and Na+,K+-ATPase activity induced by the unpredictable chronic stress protocol (CUS) performed over 14 days in rats. Our results demonstrated that intermittent treatment with OUA was able of reversing CUS-induced HPA axis hyperactivity, by reducing glucocorticoid levels, CRH-CRHR1 expression, as well as reducing CUS-induced low-grade neuroinflammation, and increase BDNF levels and expression of CRHR2 receptors. These biochemical changes contributed to a reversal in CUS-induced long-term memory impairment. In addition, animals treated only with OUA, as well as those submitted to CUS, and also treated with OUA obtained an improvement in emotional memory, which was explored in the fear conditioning test. These results suggest that the CUS protocol of 14 days promotes a neural adaptation facilitating a reassignment of the memory to the fear, here configured by the shock, and the treatment with the OUA shortens that process. In conclusion, our results suggest that intermittent treatment with OUA induces an adaptation on the HPA axis, through alterations in the expression of receptors for CRH in the hippocampus and hypothalamus, resulting in an adjustment in fear-related emotional memory

Obesity with no metabolic syndrome and adipose tissue expansion based solely on risk factors and inflammatory marker of coronary heart disease in premenopausal women

The objective of this study was to analyze whether obese women with no metabolic syndrome (MetS) have increased cardiometabolic risk compared to non-obese women and to observe the correlations between adiposity and coronary heart disease (CHD) risk factors in metabolically healthy women. 20-40 year old non-obese (n=41), obese with no MetS (n=30) and obese with MetS (n=28) women were studied. Lipid profile, blood pressure, CHD family history, physical inactivity, high-sensitivity C-reactive protein (hs-CRP), fibrinogen, interleukin-1β and tumor necrosis factor-alpha were analyzed. A subset of obese (13) and non-obese (33) women with no major components of MetS (except waist circumference) were further compared. Obese women with no MetS and non-obese women presented a similar metabolic profile that was statistically different from those seen in obese women with MetS. The number of obese women with no MetS and non-obese women presenting two or more risk factors (23.3 and 19.5%, respectively) or presenting high Framingham Risk Score (6.7 and 2.4%, respectively) were also similar. The only pro inflammatory protein correlated to waist circumference was hs-CRP. These data suggest that obesity with no MetS induce a CHD risk comparable to the risk seen in non-obese women. However, when women with no major components of MetS alone were considered, adiposity was positively correlated to blood pressure and hs-CRP. Although CHD risk of obese women with no MetS is closer to non-obese women, adipose tissue expansion was positively correlated to blood pressure and hs-CRP that are important risk factors for CHD