Effect of novel selective non-peptide kinin B(1) receptor antagonists on mouse pleurisy induced by carrageenan

The evolving landscape of IL-10, IL-22 and IL-26 in pleurisy especially in tuberculous pleurisy

Pleurisy can be categorized as primary or secondary, arising from immunological, tumorous, or microbial conditions. It often results in lung structure damage and the development of various respiratory issues. Among the different types, tuberculous pleurisy has emerged as a prominent focus for both clinical and scientific investigations. The IL-10 family, known for its anti-inflammatory properties in the human immune system, is increasingly being studied for its involvement in the pathogenesis of pleurisy. This review aims to present a detailed overview of the intricate role of IL-10 family members (specifically IL-10, IL-22, and IL-26) in human and animal pleuritic diseases or relevant animal models. These insights could serve as valuable guidance and references for further studies on pleurisy and potential therapeutic strategies.

Evaluation of the anti-inflammatory potential of Solidago microglossa (Arnica-brasileira) in vivo and its effects on PPARγ activity

Solidago microglossa is used as an anti-inflammatory agent in traditional Brazilian medicine, and this work evaluated the anti-inflammatory potential of the crude ethanolic extract of the flowers of S. microglossa in vivo, as assayed by paw edema models induced by carrageenan, prostaglandin E2, bradykinin and compound 48/80. In the chemical profile, we identified compounds by electrospray ionization mass spectrometry and quantified them by HPLC-DAD. Additionally, this study analyzed the potential to activate the in vitro transcriptional activity of PPARγ, which is a nuclear receptor linked to the anti-inflammatory response. It was possible to identify five compounds: quinic acid, quercetin, chlorogenic acid, hyperoside, and rutin. In the paw edema evaluation, it was possible to show the potential of reducing edema during the inflammatory process. The crude ethanolic extract of the flowers of S. microglossa activated PPARγ compared to the full agonist rosiglitazone and in a dose-response manner. It is possible to conclude that the extract of the flowers of S. microglossa showed anti-inflammatory activity, and the phenolic compounds present in this species might be responsible for this activity.

Role of selective blocking of bradykinin receptor subtypes in attenuating allergic airway inflammation in guinea pigs

The present study was designed to evaluate the potential role of bradykinin antagonists (R-715; bradykinin B1 receptor antagonist and icatibant; bradykinin B2 receptor antagonist) in treatment of allergic airway inflammation in comparison to dexamethasone and montelukast. R-715 as dexamethasone significantly decreased peribronchial leukocyte infiltration, bronchoalveolar lavage fluid (BALF) albumin and interleukin 1β as well as serum OVA-specific IgE level. Also, R-715 like montelukast significantly decreased BALF cell count (total and eosinophils). Icatibant showed negative results. The current findings suggest that selective bradykinin B1 receptor antagonists may have the therapeutic potential for the treatment of allergic airway inflammation.

Gold nanoparticles and/or N-acetylcysteine mediate carrageenan-induced inflammation and oxidative stress in a concentration-dependent manner

We report the effect of gold nanoparticles (AuNP) in an acute inflammation model induced by carrageenan (CG) and compared this effect with those induced by the antioxidant N-acetylcysteine (NAC) alone and by the synergistic effect of NAC and AuNP together. Male Wistar rats received saline or saline containing CG administered into the pleural cavity, and some rats also received NAC (20 mg/kg) subcutaneously and/or AuNP administered into the pleural cavity immediately after surgery. Four hours later, the rats were sacrificed and pleural exudates obtained for evaluation of cytokine levels and myeloperoxidase activities. Oxidative stress parameters were also evaluated in the lungs. The results demonstrated that the inflammatory process caused by the administration of CG into the pleural cavity resulted in a substantial increase in the levels of tumor necrosis factor-α, interleukin-1β, and myeloperoxidase and a reduction in interleukin-10 levels. These levels seem to be reversed after different treatments in animals. Antioxidant enzymes exhibited positive responses after treatment of NAC + AuNP, and all treatments were effective at reducing lipid peroxidation and oxidation of thiol groups induced by CG. These findings suggest that small compounds, such as NAC plus AuNP, may be useful in the treatment of conditions associated with local inflammation.

Exacerbation of DSS-induced colitis in mice lacking kinin B(1) receptors through compensatory up-regulation of kinin B(2) receptors: the role of tight junctions and intestinal homeostasis

BACKGROUND AND PURPOSE

Kinins are pro-inflammatory peptides that are released during tissue injury, including that caused by inflammatory bowel disease. Herein, we assessed the role and underlying mechanisms through which the absence of kinin B(1) receptors exacerbates the development of dextran sulfate sodium (DSS)-induced colitis in mice.

EXPERIMENTAL APPROACH

B(1) and B(2) receptor antagonists and B(1) receptor knockout mice (B1(-/-) ) were used to assess the involvement of B(1) and B(2) receptor signalling in a DSS-colitis. B(1) receptor, B(2) receptor, occludin and claudin-4 expression, cytokine levels and cell permeability were evaluated in colon from wild-type (WT) and B1(-/-) mice.

KEY RESULTS

DSS-induced colitis was significantly exacerbated in B1(-/-) compared with WT mice. IL-1β, IFN-γ, keratinocyte-derived chemokine and macrophage inflammatory protein-2 were markedly increased in the colon from DSS-treated B1(-/-) compared with DSS-treated WT mice. Treatment of WT mice with a selective B(1) receptor antagonist, DALBK or SSR240612, had no effect on DSS-induced colitis. Of note, B(2) receptor mRNA expression was significantly up-regulated in colonic tissue from the B1(-/-) mice after DSS administration. Moreover, treatment with a selective B(2) receptor antagonist prevented the exacerbation of colitis in B1(-/-) mice following DSS administration. The water- or DSS-treated B1(-/-) mice showed a decrease in occludin gene expression, which was partially prevented by the B(2) receptor antagonist.

CONCLUSIONS AND IMPLICATIONS

A loss of B(1) receptors markedly exacerbates the severity of DSS-induced colitis in mice. The increased susceptibility of B1(-/-) may be associated with compensatory overexpression of B(2) receptors, which, in turn, modulates tight junction expression.

Activation of the alpha-7 nicotinic acetylcholine receptor (α7 nAchR) reverses referred mechanical hyperalgesia induced by colonic inflammation in mice

In the current study, we investigated the effect of the activation of the alpha-7 nicotinic acetylcholine receptor (α7 nAchR) on dextran sulphate sodium (DSS)-induced colitis and referred mechanical hyperalgesia in mice. Colitis was induced in CD1 male mice through the intake of 4% DSS in tap water for 7 days. Control mice received unadulterated water. Referred mechanical hyperalgesia was evaluated for 7 days after the beginning of 4% DSS intake. Referred mechanical hyperalgesia started within 1 day after beginning DSS drinking, peaked at 3 days and persisted for 7 days. This time course profile perfectly matched with the appearance of signs of colitis. Both acute and chronic oral treatments with nicotine (0.1-1.0 mg/kg, p.o.) were effective in inhibiting the established referred mechanical hyperalgesia. The antinociceptive effect of nicotine was completely abrogated by cotreatment with the selective α7 nAchR antagonist methyllycaconitine (MLA) (1.0 mg/kg). Consistent with these results, i.p. treatment with the selective α7 nAchR agonist PNU 282987 (0.1-1.0 mg/kg) reduced referred mechanical hyperalgesia at all periods of evaluation. Despite their antinociceptive effects, nicotinic agonists did not affect DSS-induced colonic damage or inflammation. Taken together, the data generated in the present study show the potential relevance of using α7 nAchR agonists to treat referred pain and discomfort associated with inflammatory bowel diseases.

TRPV1 deletion enhances local inflammation and accelerates the onset of systemic inflammatory response syndrome

The transient receptor potential vanilloid 1 (TRPV1) is primarily localized to sensory nerve fibers and is associated with the stimulation of pain and inflammation. TRPV1 knockout (TRPV1KO) mice show enhanced LPS-induced sepsis compared with wild type (WT). This implies that TRPV1 may have a key modulatory role in increasing the beneficial and reducing the harmful components in sepsis. We investigated immune and inflammatory mechanisms in a cecal ligation and puncture (CLP) model of sepsis over 24 h. CLP TRPV1KO mice exhibited significant hypothermia, hypotension, and organ dysfunction compared with CLP WT mice. Analysis of the inflammatory responses at the site of initial infection (peritoneal cavity) revealed that CLP TRPV1KO mice exhibited: 1) decreased mononuclear cell integrity associated with apoptosis, 2) decreased macrophage tachykinin NK(1)-dependent phagocytosis, 3) substantially decreased levels of nitrite (indicative of NO) and reactive oxygen species, 4) increased cytokine levels, and 5) decreased bacteria clearance when compared with CLP WT mice. Therefore, TRPV1 deletion is associated with impaired macrophage-associated defense mechanisms. Thus, TRPV1 acts to protect against the damaging impact of sepsis and may influence the transition from local to a systemic inflammatory state.

Anti-nociceptive effect of kinin B₁ and B₂ receptor antagonists on peripheral neuropathy induced by paclitaxel in mice

BACKGROUND AND PURPOSE

In the current study, we investigated the role of both kinin B₁ and B₂ receptors in peripheral neuropathy induced by the chronic treatment of mice with paclitaxel a widely used chemotherapeutic agent.

EXPERIMENTAL APPROACH

Chemotherapy-evoked hyperalgesia was induced by i.p. injections of paclitaxel (2 mg·kg⁻¹) over 5 consecutive days. Mechanical and thermal hyperalgesia were evaluated between 7 and 21 days after the first paclitaxel treatment.

KEY RESULTS

Treatment with paclitaxel increased both mechanical and thermal hyperalgesia in mice (C57BL/6 and CD1 strains). Kinin receptor deficient mice (B₁, or B₂ receptor knock-out and B₁B₂ receptor, double knock-out) presented a significant reduction in paclitaxel-induced hypernociceptive responses in comparison to wild-type animals. Treatment of CD1 mice with kinin receptor antagonists (DALBK for B₁ or Hoe 140 for B₂ receptors) significantly inhibited both mechanical and thermal hyperalgesia when tested at 7 and 14 days after the first paclitaxel injection. DALBK and Hoe 140 were also effective against paclitaxel-induced peripheral neuropathy when given intrathecally or i.c.v. A marked increase in B₁ receptor mRNA was observed in the mouse thalamus, parietal and pre-frontal cortex from 7 days after the first paclitaxel treatment.

CONCLUSIONS AND IMPLICATIONS

Kinins acting on both B₁ and B₂ receptors, expressed in spinal and supra-spinal sites, played a crucial role in controlling the hypernociceptive state caused by chronic treatment with paclitaxel.

Kinin B1 receptors mediate depression-like behavior response in stressed mice treated with systemic E. coli lipopolysaccharide

BACKGROUND

Kinin B1 receptors are inducible molecules up-regulated after inflammatory stimuli. This study evaluated the relevance of kinin B1 receptors in a mouse depression behavior model.

METHODS

Mice were exposed to a 5-min swimming session, and 30 min later they were injected with E. coli lipopolysaccharide (LPS). Depression-like behavior was assessed by determining immobility time in a tail suspension test. Different brain structures were collected for molecular and immunohistochemical studies. Anhedonia was assessed by means of a sucrose intake test.

RESULTS

Our protocol elicited an increase in depression-like behavior in CF1 mice, as assessed by the tail-suspension test, at 24 h. This behavior was significantly reduced by treatment with the selective B1 receptor antagonists R-715 and SSR240612. Administration of SSR240612 also prevented an increase in number of activated microglial cells in mouse hippocampus, but did not affect a reduction in expression of mRNA for brain-derived neurotrophic factor. The increased immobility time following LPS treatment was preceded by an enhancement of hippocampal and cortical B1 receptor mRNA expression (which were maximal at 1 h), and a marked production of TNFα in serum, brain and cerebrospinal fluid (between 1 and 6 h). The depression-like behavior was virtually abolished in TNFα p55 receptor-knockout mice, and increased B1 receptor mRNA expression was completely absent in this mouse strain. Furthermore, treatment with SSR240612 was also effective in preventing anhedonia in LPS-treated mice, as assessed using a sucrose preference test.

CONCLUSION

Our data show, for the first time, involvement of kinin B1 receptors in depressive behavioral responses, in a process likely associated with microglial activation and TNFα production. Thus, selective and orally active B1 receptor antagonists might well represent promising pharmacological tools for depression therapy.

The role of kinin B1 and B2 receptors in the scratching behaviour induced by proteinase-activated receptor-2 agonists in mice

BACKGROUND AND PURPOSE

Activation of the proteinase-activated receptor-2 (PAR-2) induces scratching behaviour in mice. Here, we have investigated the role of kinin B(1) and B(2) receptors in the pruritogenic response elicited by activators of PAR-2.

EXPERIMENTAL APPROACH

Scratching was induced by an intradermal (i.d.) injection of trypsin or the selective PAR-2 activating peptide SLIGRL-NH(2) at the back of the mouse neck. The animals were observed for 40 min and their scratching response was quantified.

KEY RESULTS

I.d. injection of trypsin or SLIGRL-NH(2) evoked a scratching behaviour, dependent on PAR-2 activation. Mice genetically deficient in kinin B(1) or B(2) receptors exhibited reduced scratching behaviour after i.d. injection of trypsin or SLIGRL-NH(2). Treatment (i.p.) with the non-peptide B(1) or B(2)receptor antagonists SSR240612 and FR173657, respectively, prevented the scratching behaviour caused by trypsin or SLIGRL-NH(2). Nonetheless, only treatment i.p. with the peptide B(2)receptor antagonist, Hoe 140, but not the B(1)receptor antagonist (DALBK), inhibited the pruritogenic response to trypsin. Hoe 140 was also effective against SLIGRL-NH(2)-induced scratching behaviour when injected by i.d. or intrathecal (i.t.) routes. Also, the response to SLIGRL-NH(2) was inhibited by i.t. (but not by i.d.) treatment with DALBK. Conversely, neither Hoe 140 nor DALBK were able to inhibit SLIGRL-NH(2)-induced scratching behaviour when given intracerebroventricularly (i.c.v.).

CONCLUSIONS AND IMPLICATIONS

The present results demonstrated that kinins acting on both B(1) and B(2) receptors played a crucial role in controlling the pruriceptive signalling triggered by PAR-2 activation in mice.

The kinin B(1) receptor and inflammation: new therapeutic target for cardiovascular disease

The kinin B(1) receptor plays an important role in mediating the inflammatory effects of the kallikrein-kinin pathway. The recent development of orally available non-peptidic antagonists and genetically modified mice deficient in B(1) receptor expression have demonstrated that the receptor plays a pivotal role in the cellular, particularly neutrophil, recruitment associated with an acute inflammatory response. These tools have also enabled elucidation of the pathways involved in mediating this effect and have highlighted a major role for chemokines, particularly CXCL5 and CCL2. Neutrophil recruitment is involved in the pathogenesis of renal disease and has very recently been implicated in the early stages of atherosclerosis. In this review we discuss the most recent evidence linking the B(1) receptor with the pathogenesis of these two inflammatory cardiovascular diseases and highlight the therapeutic potential of the kinin B(1) receptor in these disease states.

Evidence for the role of neurogenic inflammation components in trypsin-elicited scratching behaviour in mice

BACKGROUND AND PURPOSE

We investigated the mechanisms underlying the pruritogenic response induced by trypsin in mice, to assess the relevance of neurogenic inflammation components in this response.

EXPERIMENTAL APPROACH

Itching was induced by an intradermal injection of trypsin in the mouse neck. The animals were observed for 40 min and their scratching behaviour was quantified.

KEY RESULTS

Trypsin-induced itching was blocked by the lima bean trypsin inhibitor, the selective proteinase-activated receptor-2 (PAR-2) antagonist FSLLRY and PAR-2 receptor desensitization. An important involvement of mast cells was observed, as chronic pretreatment with the mast cell degranulator compound 48/80 or the mast cell stabilizer disodium cromoglycate prevented scratching. Also, trypsin response was inhibited by the selective COX-2 inhibitor celecoxib and by the selective kinin B2 (FR173657) and B1 (SSR240612) receptor antagonists. Moreover, an essential role for the mediators of neurogenic inflammation was established, as the selective NK1 (FK888), NK3 (SR142801) and calcitonin gene-related peptide (CGRP(8-37) fragment) receptor antagonists inhibited trypsin-induced itching. Similarly, blockade of transient receptor potential vanilloid 1 (TRPV1) receptors by the selective TRPV1 receptor antagonist SB366791, or by genetic deletion of TRPV1 receptor reduced this behaviour in mice. C-fibre desensitization showed a very similar result.

CONCLUSIONS AND IMPLICATIONS

Trypsin intradermal injection proved to be a reproducible model for the study of itching and the involvement of PAR-2 receptors. Also, trypsin-induced itching seems to be widely dependent on neurogenic inflammation, with a role for TRPV1 receptors. In addition, several other mediators located in the sensory nerves and skin also seem to contribute to this process.

Low level laser therapy modulates kinin receptors mRNA expression in the subplantar muscle of rat paw subjected to carrageenan-induced inflammation

Low level laser therapy (LLLT) has been used clinically in order to treat inflammatory processes. In this work, we evaluated if LLLT alters kinin receptors mRNA expression in the carrageenan-induced rat paw edema. Experimental groups were designed as followed: A1 (Control-saline), A2 (Carrageenan-only), A3 (Carrageenan+laser 660 nm) and A4 (Carrageenan+laser 684 nm). Edema was measured by a plethysmometer. Subplantar tissue was collected for kinin receptors mRNA quantification by Real time-PCR. LLLT of both 660 and 684 nm wavelengths administrated 1 h after carrageenan injection was able to promote the reduction of edema produced by carrageenan. In the A2 group, B1 receptor expression presented a significantly increase when compared to control group. Kinin B1 receptor mRNA expression significantly decreased after LLLT's 660 or 684 nm wavelength. Kinin B2 receptor mRNA expression also diminished after both laser irradiations. Our results suggest that expression of both kinin receptors is modulated by LLLT, possibly contributing to its anti-inflammatory effect.

Anti-inflammatory effects of compounds alpha-humulene and (−)-trans-caryophyllene isolated from the essential oil of Cordia verbenacea

This study evaluated the anti-inflammatory properties of two sesquiterpenes isolated from Cordia verbenacea's essential oil, alpha-humulene and (-)-trans-caryophyllene. Our results revealed that oral treatment with both compounds displayed marked inhibitory effects in different inflammatory experimental models in mice and rats. alpha-humulene and (-)-trans-caryophyllene were effective in reducing platelet activating factor-, bradykinin- and ovoalbumin-induced mouse paw oedema, while only alpha-humulene was able to diminish the oedema formation caused by histamine injection. Also, both compounds had important inhibitory effects on the mouse and rat carrageenan-induced paw oedema. Systemic treatment with alpha-humulene largely prevented both tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) generation in carrageenan-injected rats, whereas (-)-trans-caryophyllene diminished only TNFalpha release. Furthermore, both compounds reduced the production of prostaglandin E(2) (PGE(2)), as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) expression, induced by the intraplantar injection of carrageenan in rats. The anti-inflammatory effects of alpha-humulene and (-)-trans-caryophyllene were comparable to those observed in dexamethasone-treated animals, used as positive control drug. All these findings indicate that alpha-humulene and (-)-trans-caryophyllene, derived from the essential oil of C. verbenacea, might represent important tools for the management and/or treatment of inflammatory diseases.