Trans-Chalcone Attenuates Pain and Inflammation in Experimental Acute Gout Arthritis in Mice

Gouty arthritis is characterized by an intense inflammatory response to monosodium urate crystals (MSU), which induces severe pain and reduction in the life quality of patients. Trans-Chalcone (1,3-diphenyl-2-propen-1-one) is a flavonoid precursor presenting biological activities such as anti-inflammatory and antioxidant proprieties. Thus, the aim of this work was to evaluate the protective effects of trans-Chalcone in experimental gout arthritis in mice. Mice were treated with trans-Chalcone (3, 10, or 30 mg/kg, per oral) or vehicle (Tween 80 20% plus saline) 30 min before intra-articular injection of MSU (100 μg/knee joint, intra-articular). We observed that trans-Chalcone inhibited MSU-induced mechanical hyperalgesia, edema, and leukocyte recruitment (total leukocytes, neutrophils, and mononuclear cells) in a dose-dependent manner. Trans-Chalcone also decreased inflammatory cell recruitment as observed in Hematoxylin and Eosin (HE) staining and the intensity of fluorescence of LysM-eGFP+ cells in the confocal microscopy. Trans-Chalcone reduced MSU-induced oxidative stress as observed by an increase in the antioxidant defense [Glutathione (GSH), Ferric Reducing (FRAP), and 2,2’-Azinobis-3-ethylbenzothiazoline 6-sulfonic acid (ABTS assays)] and reduction in reactive oxygen and nitrogen species production [superoxide anion (NBT assay) and nitrite (NO assay)]. Furthermore, it reduced in vivo MSU-induced interleukin-1β (IL-1β), Tumor necrosis factor-α (TNF-α), and IL-6 production, and increased Transforming growth factor-β (TGF-β) production. Importantly, trans-Chalcone reduced nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and thereby the mRNA expression of the inflammasome components Nlrp3 (cryopyrin), Asc (apoptosis-associated speck-like protein containing a CARD), Pro-caspase-1 and Pro-IL-1β. In vitro, trans-Chalcone reduced the MSU-induced release of IL-1β in lipopolysaccharide (LPS)-primed macrophages. Therefore, the pharmacological effects of trans-Chalcone indicate its therapeutic potential as an analgesic and anti-inflammatory flavonoid for the treatment of gout

Vinpocetine reduces carrageenan-induced inflammatory hyperalgesia in mice by inhibiting oxidative stress, cytokine production and NF-κB activation in the paw and spinal cord.

Vinpocetine is a safe nootropic agent used for neurological and cerebrovascular diseases. The anti-inflammatory activity of vinpocetine has been shown in cell based assays and animal models, leading to suggestions as to its utility in analgesia. However, the mechanisms regarding its efficacy in inflammatory pain treatment are still not completely understood. Herein, the analgesic effect of vinpocetine and its anti-inflammatory and antioxidant mechanisms were addressed in murine inflammatory pain models. Firstly, we investigated the protective effects of vinpocetine in overt pain-like behavior induced by acetic acid, phenyl-p-benzoquinone (PBQ) and formalin. The intraplantar injection of carrageenan was then used to induce inflammatory hyperalgesia. Mechanical and thermal hyperalgesia were evaluated using the electronic von Frey and the hot plate tests, respectively, with neutrophil recruitment to the paw assessed by a myeloperoxidase activity assay. A number of factors were assessed, both peripherally and in the spinal cord, including: antioxidant capacity, reduced glutathione (GSH) levels, superoxide anion, tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) levels, as well as nuclear factor kappa B (NF-κB) activation. Vinpocetine inhibited the overt pain-like behavior induced by acetic acid, PBQ and formalin (at both phases), as well as the carrageenan-induced mechanical and thermal hyperalgesia and associated neutrophil recruitment. Both peripherally and in the spinal cord, vinpocetine also inhibited: antioxidant capacity and GSH depletion; increased superoxide anion; IL-1β and TNF-α levels; and NF-κB activation. As such, vinpocetine significantly reduces inflammatory pain by targeting oxidative stress, cytokine production and NF-κB activation at both peripheral and spinal cord levels

Vinpocetine inhibits carrageenan-induced decrease in antioxidant capacity.

<p>Mice were treated with vinpocetine (30 mg/kg, p.o.) or vehicle 1 h before carrageenan (100μg, 25 μL) i.pl. injection. Paw skin (Panels A and B) and spinal cord (Panels D and E) samples were collected 3 h after carrageenan injection for measurement of ABTS (Panels A and C) and FRAP (Panels B and D) assays. Results are presented as means ± SEM of 6 mice per group per experiment, and are representative of 2 separate experiments. *<i>P</i> < 0.05 compared with saline group; and ^#<i>P</i> < 0.05 compared with vehicle group. One-way ANOVA followed by Tukey’s <i>t</i> test.</p

Vinpocetine inhibits carrageenan-induced NF-κB activation.

<p>Mice were treated with vinpocetine (30 mg/kg, p.o.) or vehicle 1 h before carrageenan i.pl. injection. Paw skin (Panel A) and spinal cord (Panel B) samples were collected 3 h after stimulus injection in lysis buffer, and the NF-κB activation was measured by ELISA, as a ratio of total NF-κB/phosphorylated NF-κB. Results are presented as means ± SEM of 6 mice per group per experiment, and are representative of 2 separate experiments. *<i>P</i> < 0.05 compared with saline group; and ^#<i>P</i>< 0.05 compared with vehicle group. One-way ANOVA followed by Tukey’s <i>t</i> test.</p

Vinpocetine inhibits overt pain-like behavior.

<p>Panel A: mice were treated with vinpocetine (1, 3, 10, and 30 mg/kg, p.o.) or vehicle (saline) 1 h before acetic acid i.p. injection (0.6% v/v, diluted in saline). Panels B-C: mice were treated with vinpocetine (30 mg/kg, p.o.) or vehicle (saline) 1 h before i.p. injection of phenyl-p-benzoquinone (PBQ, 1890 μg/kg in DMSO 2%, v/v, diluted in saline, panel B), or i.pl. injection of formalin (25 μL of 1.5% formalin, v/v in saline, panel C). The cumulative number of writhing was evaluated over 20 min (Panels A-B) and total number of paw flinches (Panel C) were evaluated over 30 min. Results are presented as means ± SEM of 6 mice per group per experiment, and are representative of 2 separate experiments. *<i>P</i> < 0.05 compared with the saline group; #<i>P</i> < 0.05 compared to the vehicle group; and ^<i>f</i><i>P</i> < 0.05 compared to the vehicle group and the 1 mg/kg vinpocetine dose. One-way ANOVA followed by Tukey’s <i>t</i> test.</p

Vinpocetine inhibits carrageenan-induced hyperalgesia and myeloperoxidase (MPO) activity.

<p>Mice were treated with vinpocetine (3, 10 or 30 mg/kg, p.o.) or vehicle (saline) 1 h before carrageenan (100 μg, 25 μL) i.pl. injection. Mechanical (Panel A) and thermal (Panel B) hyperalgesia were assessed at indicated time points after carrageenan administration using the electronic von Frey and hot plate tests, respectively. Myeloperoxidase (MPO) activity was determined in samples collected 9 h after carrageenan injection. Results are presented as means ± SEM of 6 mice per group per experiment, and are representative of 2 separate experiments. *<i>P</i> < 0.05 compared to saline group; ^#<i>P</i> < 0.05 compared with vehicle group; ^<i>f</i><i>P</i> < 0.05 compared with the dose of 3 mg/kg of vinpocetine; and ^<i>ff</i><i>P</i> < 0.05 compared with the doses of 10 and 30 mg/kg of vinpocetine. One-way ANOVA followed by Tukey’s <i>t</i> test.</p

Vinpocetine inhibits carrageenan-induced depletion of reduced glutathione (GSH) levels and decreased nitroblue tetrazolium reduction (NBT) activity.

<p>Mice were treated with vinpocetine (30 mg/kg, p.o.) or vehicle 1 h before carrageenan i.pl. injection. Paw skin (Panels A and B) and spinal cord (Panels C and D) samples were collected 3 h after stimulus injection for the determination of GSH levels and NBT reduction. Results are presented as means ± SEM of 6 mice per group per experiment, and are representative of 2 separate experiments. *<i>P</i> < 0.05 compared with saline group; and ^#<i>P</i> < 0.05 compared with vehicle group. One-way ANOVA followed by Tukey’s <i>t</i> test.</p

Vinpocetine inhibits carrageenan-induced IL-1β and TNF-α production.

<p>Mice were treated with vinpocetine (30 mg/kg, p.o.) or vehicle 1 h before carrageenan i.pl. injection. Paw skin (Panels A and B) and spinal cord (Panels C and D) samples were collected for the determination of IL-1β (Panels A and C) and TNF-α (Panels B and D) production by ELISA, respectively. Results are presented as means ± SEM of 6 mice per group per experiment, and are representative of 2 separate experiments. *<i>P</i> < 0.05 compared with saline group; and ^#<i>P</i> < 0.05 compared with vehicle group. One-way ANOVA followed by Tukey’s <i>t</i> test.</p

The nitroxyl donor Angeli's salt ameliorates Staphylococcus aureus-induced septic arthritis in mice

Septic arthritis is a severe and rapidly debilitating disease associated with severe joint pain, inflammation and oxidative stress. Nitroxyl (HNO) has become a nitrogen oxide of significant interest due to its pharmacological endpoints that are potentially favorable for treating varied diseases. However, whether HNO also serves as a treatment to septic arthritis is currently unknown. The aim of this study was to investigate the effect of the HNO donor, Angeli's salt (AS), in the outcome of chronic Staphylococcus aureus (S. aureus)-induced septic arthritis in mice. Daily treatment with AS inhibited mechanical hyperalgesia and inflammation (edema, leukocyte migration, cytokines release and NF-κB activation, and oxidative stress) resulting in reduced disease severity (clinical course, histopathological changes, proteoglycan levels in the joints, and osteoclastogenesis). In addition, AS decreased the number of S. aureus colony forming unities in synovial tissue, enhanced the bactericidal effect of macrophages and inhibited the worsening of systemic inflammatory response (leukocyte counts in the lung and systemic proinflammatory cytokine concentration). Our results suggest for the first time the therapeutic potential of AS in a model of septic arthritis by mechanisms involving microbicidal effects, anti-inflammatory actions and reduction of disease severity.CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico); MCTI/SETI/Fundacao Araucaria (Ministerio da Ciencia, Tecnologia e Inovacao/Secretaria da Ciencia, Tecnologia, e Ensino Superior do Parana/Fundacao Araucaria); Decit/SCTIE/MS (Departamento de Ciencia e Tecnologia da Secretaria de Ciencia, Tecnologia e Insumos Estrategicos, Ministerio da Saude); Fundacao Araucaria; Coordenadoria de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); INCT (National Institutes of Science and Technology) - MCTI/CNPq/CAPES/Fundacao Araucaria, Brazil; CAPES [PDSE - 99999.007507/2014-03]; CNPq [161279/2015-5]; CAPES/Fundacao Araucaria; CAPES12 month embargo; available online 15 April 2017This 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]