Ehrlich tumor induces TRPV1-dependent evoked and non-evoked pain-like behavior in mice

We standardized a model by injecting Ehrlich tumor cells into the paw to evaluate cancer pain mechanisms and pharmacological treatments. Opioid treatment, but not cyclooxygenase inhibitor or tricyclic antidepressant treatments reduces Ehrlich tumor pain. To best use this model for drug screening it is essential to understand its pathophysiological mechanisms. Herein, we investigated the contribution of the transient receptor potential cation channel subfamily V member 1 (TRPV1) in the Ehrlich tumor-induced pain model. Dorsal root ganglia (DRG) neurons from the Ehrlich tumor mice presented higher activity (calcium levels using fluo-4 fluorescent probe) and an increased response to capsaicin (TRPV1 agonist) than the saline-injected animals

[Ru(bpy)2(NO)SO3](PF6), a Nitric Oxide Donating Ruthenium Complex, Reduces Gout Arthritis in Mice

Monosodium urate crystals (MSU) deposition induces articular inflammation known as gout. This disease is characterized by intense articular inflammation and pain by mechanisms involving the activation of the transcription factor NFκB and inflammasome resulting in the production of cytokines and oxidative stress. Despite evidence that MSU induces iNOS expression, there is no evidence on the effect of nitric oxide (NO) donors in gout. Thus, the present study evaluated the effect of the ruthenium complex donor of NO {[Ru(bpy)2(NO)SO3](PF6)} (complex I) in gout arthritis. Complex I inhibited in a dose-dependent manner MSU-induced hypersensitivity to mechanical stimulation, edema and leukocyte recruitment. These effects were corroborated by a decrease of histological inflammation score and recruitment of Lysm-eGFP+ cells. Mechanistically, complex I inhibited MSU-induced mechanical hypersensitivity and joint edema by triggering the cGMP/PKG/ATP-sensitive K (+) channels signaling pathway. Complex I inhibited MSU-induced oxidative stress and pro-inflammatory cytokine production in the knee joint. These data were supported by the observation that complex I inhibited MSU-induced NFκB activation, and IL-1β expression and production. Complex I also inhibited MSU-induced activation of pro-IL-1β processing. Concluding, the present data, to our knowledge, is the first evidence that a NO donating ruthenium complex inhibits MSU-induced articular inflammation and pain. Further, complex I targets the main physiopathological mechanisms of gout arthritis. Therefore, it is envisaged that complex I and other NO donors have therapeutic potential that deserves further investigation

Therapeutic activity of lipoxin A4 in TiO2-induced arthritis in mice: NF-κB and Nrf2 in synovial fluid leukocytes and neuronal TRPV1 mechanisms

BackgroundLipoxin A4 (LXA4) has anti-inflammatory and pro-resolutive roles in inflammation. We evaluated the effects and mechanisms of action of LXA4 in titanium dioxide (TiO2) arthritis, a model of prosthesis-induced joint inflammation and pain.MethodsMice were stimulated with TiO2 (3mg) in the knee joint followed by LXA4 (0.1, 1, or 10ng/animal) or vehicle (ethanol 3.2% in saline) administration. Pain-like behavior, inflammation, and dosages were performed to assess the effects of LXA4in vivo.ResultsLXA4 reduced mechanical and thermal hyperalgesia, histopathological damage, edema, and recruitment of leukocytes without liver, kidney, or stomach toxicity. LXA4 reduced leukocyte migration and modulated cytokine production. These effects were explained by reduced nuclear factor kappa B (NFκB) activation in recruited macrophages. LXA4 improved antioxidant parameters [reduced glutathione (GSH) and 2,2-azino-bis 3-ethylbenzothiazoline-6-sulfonate (ABTS) levels, nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA and Nrf2 protein expression], reducing reactive oxygen species (ROS) fluorescent detection induced by TiO2 in synovial fluid leukocytes. We observed an increase of lipoxin receptor (ALX/FPR2) in transient receptor potential cation channel subfamily V member 1 (TRPV1)+ DRG nociceptive neurons upon TiO2 inflammation. LXA4 reduced TiO2‐induced TRPV1 mRNA expression and protein detection, as well TRPV1 co-staining with p-NFκB, indicating reduction of neuronal activation. LXA4 down-modulated neuronal activation and response to capsaicin (a TRPV1 agonist) and AITC [a transient receptor potential ankyrin 1 (TRPA1) agonist] of DRG neurons.ConclusionLXA4 might target recruited leukocytes and primary afferent nociceptive neurons to exert analgesic and anti-inflammatory activities in a model resembling what is observed in patients with prosthesis inflammation

Fermented (By <i>Monascus purpureus</i> or <i>Aspergillus oryzae</i>) and Non-Fermented Defatted Soybean Flour Extracts: Biological Insight and Mechanism Differences in Inflammatory Pain and Peritonitis

Background: Monascus purpureus and Aspergillus oryzae have been used to ferment defatted soybean flour (DSF: DSFF-Mp and DSSF-Ao, respectively) extract, improving antioxidant availability and conversion of the glycosylated isoflavones to aglycones. The aim of the present study was to evaluate the biological activity of fermented and non-fermented DSF extracts in pain and inflammation, which has not yet been explored. Methods: Phenolic compounds of extracts were determined. Non-fermented DSF (DSF-Non), DSFF-Mp, and DSFF-Ao (10–100 mg/kg) were administrated i.p., 30 min before i.pl. or i.p. carrageenan stimulus. Mechanical and thermal hyperalgesia, edema, histopathology, leukocyte recruitment, and oxidative stress in the paw tissue, and inflammatory cell recruitment, NFκB activation, and cytokine production were assessed in the peritoneum. Stomach and kidney toxicity were evaluated. Results: DSF-Non, DSFF-Mp, and DSFF-Ao extracts inhibited mechanical and thermal hyperalgesia, paw edema, histopathology, neutrophil recruitment, and oxidative stress, as well as inhibited peritoneal leukocyte recruitment. DSF-Non increased IL-10, and DSFF-Ao reduced IL-33 levels. DSFF-Mp increased IL-10 and reduced IL-33 production, and NFκB activation in CD45+ cells, without inducing toxicity. Conclusions: The present data reveal for the first time that fermented/non-fermented DSF extracts are analgesic and anti-inflammatory, showing differences in the mechanism of action depending on fungi applied for fermentation

The nitroxyl donor, Angeli's salt, reduces chronic constriction injury-induced neuropathic pain.

Chronic pain is a major health problem worldwide. We have recently demonstrated the analgesic effect of the nitroxyl donor, Angeli's salt (AS) in models of inflammatory pain. In the present study, the acute and chronic analgesic effects of AS was investigated in chronic constriction injury of the sciatic nerve (CCI)-induced neuropathic pain in mice. Acute (7th day after CCI) AS treatment (1 and 3 mg/kg; s.c.) reduced CCI-induced mechanical, but not thermal hyperalgesia. The acute analgesic effect of AS was prevented by treatment with 1H-[1,2, 4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, a soluble guanylate cyclase inhibitor), KT5823 (an inhibitor of protein kinase G [PKG]) or glibenclamide (GLB, an ATP-sensitive potassium channel blocker). Chronic (7-14 days after CCI) treatment with AS (3 mg/kg, s.c.) promoted a sustained reduction of CCI-induced mechanical and thermal hyperalgesia. Acute AS treatment reduced CCI-induced spinal cord allograft inflammatory factor 1 (known as Iba-1), interleukin-1β (IL-1β), and ST2 receptor mRNA expression. Chronic AS treatment reduced CCI-induced spinal cord glial fibrillary acidic protein (GFAP), Iba-1, IL-1β, tumor necrosis factor-α (TNF-α), interleukin-33 (IL-33) and ST2 mRNA expression. Chronic treatment with AS (3 mg/kg, s.c.) did not alter aspartate aminotransferase, alanine aminotransferase, urea or creatinine plasma levels. Together, these results suggest that the acute analgesic effect of AS depends on activating the cGMP/PKG/ATP-sensitive potassium channel signaling pathway. Moreover, chronic AS diminishes CCI-induced mechanical and thermal hyperalgesia by reducing the activation of spinal cord microglia and astrocytes, decreasing TNF-α, IL-1β and IL-33 cytokines expression. This spinal cord immune modulation was more prominent in the chronic treatment with AS. Thus, nitroxyl limits CCI-induced neuropathic pain by reducing spinal cord glial cells activation.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Brazil); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, Brazil); Coordenadoria de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, Brazil); Ministerio da Ciencia, Tecnologia e Inovacao (MCTI, Brazil); Secretaria da Ciencia, Tecnologia e Ensino Superior (SETI, Brazil)/Fundacao Araucaria (Brazil); Parana State Goverment (Brazil); CAPES/Fundacao Araucaria; CAPES; National Institutes of Health [R01-GM076247]Available online 7 June 2016; 12 month embargo.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Ehrlich Tumor Induces TRPV1-Dependent Evoked and Non-Evoked Pain-like Behavior in Mice

We standardized a model by injecting Ehrlich tumor cells into the paw to evaluate cancer pain mechanisms and pharmacological treatments. Opioid treatment, but not cyclooxygenase inhibitor or tricyclic antidepressant treatments reduces Ehrlich tumor pain. To best use this model for drug screening it is essential to understand its pathophysiological mechanisms. Herein, we investigated the contribution of the transient receptor potential cation channel subfamily V member 1 (TRPV1) in the Ehrlich tumor-induced pain model. Dorsal root ganglia (DRG) neurons from the Ehrlich tumor mice presented higher activity (calcium levels using fluo-4 fluorescent probe) and an increased response to capsaicin (TRPV1 agonist) than the saline-injected animals (p &lt; 0.05). We also observed diminished mechanical (electronic von Frey) and thermal (hot plate) hyperalgesia, paw flinching, and normalization of weight distribution imbalance in TRPV1 deficient mice (p &lt; 0.05). On the other hand, TRPV1 deficiency did not alter paw volume or weight, indicating no significant alteration in tumor growth. Intrathecal injection of AMG9810 (TRPV1 antagonist) reduced ongoing Ehrlich tumor-triggered mechanical and thermal hyperalgesia (p &lt; 0.05). Therefore, the contribution of TRPV1 to Ehrlich tumor pain behavior was revealed by genetic and pharmacological approaches, thus, supporting the use of this model to investigate TRPV1-targeting therapies for the treatment of cancer pain

First determination of UV filters in marine mammals. Octocrylene levels in Franciscana dolphins

Most current bioexposure assessments for UV filters focus on contaminants concentrations in fish from river and lake. To date there is not information available on the occurrence of UV filters in marine mammals. This is the first study to investigate the presence of sunscreen agents in tissue liver of Franciscana dolphin (Pontoporia blainvillei), a species under special measures for conservation. Fifty six liver tissue samples were taken from dead individuals accidentally caught or found stranded along the Brazilian coastal area (six states). The extensively used octocrylene (2-ethylhexyl-2-cyano-3,3- diphenyl-2-propenoate, OCT) was frequently found in the samples investigated (21 out of 56) at concentrations in the range 89-782 ng·g-1 lipid weight. São Paulo was found to be the most polluted area (70% frequency of detection). Nevertheless, the highest concentration was observed in the dolphins from Rio Grande do Sul (42% frequency of detection within that area). These findings constitute the first data reported on the occurrence of UV filters in marine mammals worldwide. © 2013 American Chemical Society.This research was funded by the Spanish Ministry of Economy and Competitiveness through the Project CEMAGUA (CGL2007-64551/HID). This work was also partly supported by the Generalitat de Catalunya (Consolidated Research Group: Water and Soil Quality Group 2009-SGR-965). Gago- Ferrero acknowledges his fellowship to Junta para la Ampliacion de Estudios (JAE). This research was also funded by the Ministry of Education of Brazil e CAPES (fellowship to M.B. Alonso “Sandwich Programme” e PDEE; “Ciencias do Mar” e Proc. 23038.051661/2009-18), Brazilian Research Council e CNPq (Grant No. 304826/2008- 1), FAPERJ (Jovem Cientista do Nosso Estado No. 101.449/2010), Mount Sinai School of Medicine (NY/USA), Fogarty International Center NIH/USA (grant 1D43TW0640). We are grateful to the fishermen and cetacean research group staffs for the assistance in fieldwork, as well as Cetacean Society Interna- tional (CSI), Society for Marine Mammalogy (SMM) and Yaqu Pacha. A.F.A. and J.L.-B. have research grant from CNPq (PQ- 2) and FAPERJ (JCNE). We give special thanks to students from Environmental Chemistry Lab (IDAEA-CSIC, Spain), Radioisotope Lab (UFRJ e Brazil) and Aquatic Mammal and Bioindicator Lab (UERJ e Brazil).Peer Reviewe

Resolvin D5 (RvD5) Reduces Renal Damage Caused by LPS Endotoxemia in Female Mice

In self-revolving gram-negative Escherichia coli infection, Resolvin D5 (RvD5) was found to enhance bacteria phagocytosis and reduce the production of inflammatory mediators, contributing to the resolution of infection. LPS (lipopolysaccharide) is a gram-negative bacterial structure product which activates the immune system and, at high doses, leads to endotoxemia. To our knowledge, the effect of RvD5 against LPS endotoxemia has not been investigated to date. Female Swiss mice received an i.p. treatment with RvD5 (0.1, 1 or 10 ng/animal). After 1 h, they were stimulated with LPS (10 mg/kg, i.v.), and samples were collected after additional 6 h. The resulting data demonstrated that RvD5 protected the kidneys (urea and creatinine serum levels) from tissue injury. These effects were related to an improvement in histopathological parameters and a reduction of enzymatic markers of leukocyte infiltration, pro-inflammatory cytokine (IL-1&beta;, TNF-&alpha;, and IL-6) production, and oxidative stress. Antioxidant markers were also increased by RvD5, but IL-10 (an anti-inflammatory cytokine) levels were unaltered. We also observed that RvD5 reduced the infiltration of CD45+ hematopoietic cells into the kidneys, reduced the activation of NF&kappa;B and promoted the Nrf2 pathway by reducing Keap-1 levels. Our data indicate that RvD5 may be a therapeutic possibility to reduce kidney lesions in LPS endotoxemia

Hesperidin Methyl Chalcone Reduces the Arthritis Caused by TiO₂ in Mice: Targeting Inflammation, Oxidative Stress, Cytokine Production, and Nociceptor Sensory Neuron Activation

Arthroplasty is an orthopedic surgical procedure that replaces a dysfunctional joint by an orthopedic prosthesis, thereby restoring joint function. Upon the use of the joint prosthesis, a wearing process begins, which releases components such as titanium dioxide (TiO2) that trigger an immune response in the periprosthetic tissue, leading to arthritis, arthroplasty failure, and the need for revision. Flavonoids belong to a class of natural polyphenolic compounds that possess antioxidant and anti-inflammatory activities. Hesperidin methyl chalcone’s (HMC) analgesic, anti-inflammatory, and antioxidant effects have been investigated in some models, but its activity against the arthritis caused by prosthesis-wearing molecules, such as TiO2, has not been investigated. Mice were treated with HMC (100 mg/kg, intraperitoneally (i.p.)) 24 h after intra-articular injection of 3 mg/joint of TiO2, which was used to induce chronic arthritis. HMC inhibited mechanical hyperalgesia, thermal hyperalgesia, joint edema, leukocyte recruitment, and oxidative stress in the knee joint (alterations in gp91phox, GSH, superoxide anion, and lipid peroxidation) and in recruited leukocytes (total reactive oxygen species and GSH); reduced patellar proteoglycan degradation; and decreased pro-inflammatory cytokine production. HMC also reduced the activation of nociceptor-sensory TRPV1+ and TRPA1+ neurons. These effects occurred without renal, hepatic, or gastric damage. Thus, HMC reduces arthritis triggered by TiO2, a component released upon wearing of prosthesis