JM25-1, a Lidocaine Analog Combining Airway Relaxant and Antiinflammatory Properties: Implications for New Bronchospasm Therapy

Anti-Allergic and Anti-Inflammatory Effects of Lidocaine-Derived Organic Compounds in a House Dust Mite-Induced Allergic Rhinitis Mouse Model

Allergic rhinitis (AR) is a common chronic disease that significantly impacts the quality of life. Lidocaine is known to have anti-inflammatory and immunomodulatory effects. This study evaluated the effect of lidocaine analogs in a Dermatophagoides pteronyssinus (DP)-induced AR mouse model. An AR model was developed using BALB/c mice via intraperitoneal sensitization with DP and intranasal challenge with DP. One hour before stimulation with DP, lidocaine analogs, EI137 and EI341 (at a dose of 0.5 or 5 ug/g), were administered intranasally. Nasal symptoms and serum total IgE, interleukin (IL)-4, IL-10, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α levels were evaluated. Reverse-transcription polymerase chain reaction was used to determine IL-4, IL-10, and IFN-γ, as well as the expression of their mRNA transcription factors in the sinonasal mucosa. Histologic changes were evaluated using hematoxylin and eosin and periodic acid-Schiff staining. The DP-induced AR mouse model had increased serum levels of total IgE and cytokines. EI137 and EI341 significantly suppressed the levels of total IgE, IL-4, and TNF-α. Intranasal instillation of EI137 and EI341 significantly inhibited IL-4, IL-10, and IFN-γ mRNA expression, as well as inflammatory cells and mucus-producing goblet cells. Lidocaine analogs also suppressed DP-stimulated IL-4, IFN-γ, and IFN-γ production by splenocytes. Intranasal instillation of EI137 and EI341 exhibited anti-allergic and anti-inflammatory effects, influenced by Th1 and Th2 inflammatory cytokines. These lidocaine analogs suppressed DP-induced sinonasal mucosal inflammation, inflammatory cell infiltration, and mucus hypersecretion.

Effects of Lidocaine-Derived Organic Compounds on Eosinophil Activation and Survival

Lidocaine, a local anesthetic, is known to possess anti-inflammatory properties. However, its clinical use is limited by inconveniences, such as its local synesthetic effects. This study evaluated lidocaine analogs designed and synthesized to overcome the disadvantages of lidocaine, having anti-inflammatory properties. Interleukin 5 (IL-5)-induced eosinophil activation and survival were evaluated using 36 lidocaine analogs with modified lidocaine structure on the aromatic or the acyl moiety or both. Eosinophil survival was evaluated using a CellTiter 96® aqueous cell proliferation assay kit. Superoxide production was determined using the superoxide dismutase-inhibitable reduction of cytochrome C method. Eosinophil cationic protein (ECP), IL-8, and transcription factor expression were determined using enzyme-linked immunosorbent assay. The platelet-activating factor (PAF)-induced migration assay was performed using a Transwell insert system. Compounds EI137 and EI341 inhibited IL-5-induced eosinophil survival and superoxide and ECP production in a concentration-dependent manner. These compounds also significantly reduced IL-8 production. Although compounds EI137 and EI341 significantly reduced phosphorylated ERK 1/2 expression, they did not influence other total and phosphorylated transcription factors. Moreover, 1000 µM of compound EI341 only inhibited PAF-induced migration of eosinophils. Lidocaine analogs EI137 and EI341 inhibited IL-5-mediated activation and survival of eosinophils. These compounds could be new therapeutic agents to treat eosinophilic inflammatory diseases.

A Novel Mast Cell Stabilizer JM25-1 Rehabilitates Impaired Gut Barrier by Targeting the Corticotropin-Releasing Hormone Receptors

Mast cell (MC) plays a central role in intestinal permeability; however, few MC-targeting drugs are currently available for protection of the intestinal barrier in clinical practice. A nonfluorinated Lidocaine analog 2-diethylamino-N-2,5-dimethylphenyl acetamide (JM25-1) displays anti-allergic effect, but its impact on MC remains elusive. In this study, we explored whether JM25-1 has therapeutic potential on intestinal barrier defect through stabilizing MC. JM25-1 alleviated release of β-hexosaminidase and cytokine production of MC. The paracellular permeability was redressed by JM25-1 in intestinal epithelial cell monolayers co-cultured with activated MC. In vivo, JM25-1 diminished intestinal mucosal MC amount and cytokine production, especially downregulating the expression of CRHR1, accompanied by an increase of CRHR2. Protective effects appeared in JM25-1-treated stress rats with a recovery of weight and intestinal barrier integrity. Through network pharmacology analysis, JM25-1 showed a therapeutic possibility for irritable bowel syndrome (IBS) with predictive targeting on PI3K/AKT/mTOR signaling. As expected, JM25-1 reinforced p-PI3K, p-AKT, p-mTOR signaling in MC, while the mTOR inhibitor Rapamycin reversed the action of JM25-1 on the expression of CRHR1 and CRHR2. Moreover, JM25-1 successfully remedied intestinal defect and declined MC and CRHR1 expression in rat colon caused by colonic mucus of IBS patients. Our data implied that JM25-1 possessed therapeutic capacity against intestinal barrier defects by targeting the CRH receptors of MC through PI3K/AKT/mTOR signaling.

Dexamethasone and lidocaine suppress eosinophilopoiesis from umbilical cord blood cells

Background

Eosinophils play an important role in allergic inflammation. Glucocorticosteroids have been used as an anti-inflammatory medication for inflammatory diseases involving eosinophil infiltration. Some effect of nebulized lidocaine has been reported when treating certain patients with asthma, which is also an inflammatory disease. The goal of this study was to examine the effects of dexamethasone and lidocaine on eosinophil proliferation and differentiation using a model of human umbilical cord blood mononuclear cells (UCMC) cultured with IL-5.

Methods

UCMC were cultured with IL-5 (5 ng/mL) for 4 weeks. The effects of dexamethasone and lidocaine on the number and morphology of eosinophilic cells were visualized with Wright-Giemsa and cyanide-resistant peroxidase stains. Moreover, the effect on eosinophil-derived neurotoxin (EDN) and eosinophil peroxidase (EPX) contents in cultured cells were evaluated using radioimmunoassay.

Results

The number of eosinophilic cells and EDN and EPX content in cultured cells increased in a time-dependent manner in the presence of IL-5. Dexamethasone treatment slightly decreased the number of eosinophilic cells in one week, but this effect was lost in 2–4 weeks. Macrophages in cultured UCMC treated with dexamethasone contained more eosinophil granule proteins. Both EDN and EPX content in cultured cells were reduced by dexamethasone. Lidocaine decreased the number of eosinophilic cells and reduced both EDN and EPX contents in cultured cells.

Conclusions

Dexamethasone suppressed the production of eosinophil granule proteins and may also induce apoptosis of eosinophils, while lidocaine suppresses eosinophilopoiesis.

Pharmacological profiling of JME-173, a novel mexiletine derivative combining dual anti-inflammatory/anti-spasmodic functions and limited action in Na+ channels

Existing evidence suggests that the local anaesthetic mexiletine can be beneficial for patients with asthma. However, caution is required since anaesthesia of the airways inhibits protective bronchodilator neuronal reflexes, limiting applications in conditions of hyperirritable airways. Here, we describe the synthesis of a new series of mexiletine analogues, which were screened for reduced activity in Na⁺ channels and improved smooth muscle relaxant effects, that were evaluated using the patch-clamp technique and an isolated tracheal organ bath, respectively. JME-173 (1-(4-bromo-3,5-dimethylphenoxy)propan-2-amine) was the most effective among the four mexiletine analogues investigated. JME-173 was then studied in vivo using a murine model of lung inflammation induced by cigarette smoke (CS) and in vitro using neutrophil chemotaxis and mast cell degranulation assays. Finally, the JME-173 pharmacokinetic profile was assessed using HPLC-MS/MS bioanalytical method. JME-173 directly inhibited IL-8 (CXCL8)- and FMLP-induced human neutrophil chemotaxis and allergen-induced mast cell degranulation. After oral administration 1 h before CS exposure, JME-173 (50 mg/kg) strongly reduced the increased number of macrophages and neutrophils recovered in the bronchoalveolar effluent without altering lymphocyte counts. Pharmacokinetic experiments of JME-173 (10 mg/kg, orally) showed values of maximum concentration (C_max), maximum time (T_max), area under the blood concentration-time curve (AUC_0-t) and area under the blood concentration-time curve from 0-Inf (AUC_0-inf) of 163.3 ± 38.3 ng/mL, 1.2 ± 0.3 h, 729.4 ± 118.3 ng*h/ml and 868.9 ± 117.1 ng*h/ml (means ± S.E.M.), respectively. Collectively, these findings suggest that JME-173 has the potential to be an effective oral treatment for diseases associated with bronchoconstriction and inflammation.

Anti-Bronchospasmodic Effect of JME-173, a Novel Mexiletine Analog Endowed With Highly Attenuated Anesthetic Activity

Local anesthetics (LAs), such as lidocaine and mexiletine, inhibit bronchoconstriction in asthmatics, but adverse effects limit their use for this specific clinical application. In this study, we describe the anti-spasmodic properties of the mexiletine analog 2-(2-aminopropoxy)-3,5-dimethyl, 4-Br-benzene (JME-173), which was synthesized and screened for inducing reduced activity on Na⁺ channels. The effectiveness of JME-173 was assessed using rat tracheal rings, a GH3 cell line and mouse cardiomyocytes to access changes in smooth muscle contraction, and Na⁺, and Ca⁺⁺ionic currents, respectively. Bronchospasm and airway hyper-reactivity (AHR) were studied using whole-body barometric plethysmography in A/J mice. We observed that the potency of JME-173 was 653-fold lower than mexiletine in inhibiting Na⁺ currents, but 12-fold higher in inhibiting L-type Ca⁺⁺ currents. JME-173 was also more potent than mexiletine in inhibiting tracheal contraction by carbachol, allergen, extracellular Ca⁺⁺, or sodium orthovanadate provocations. The effect of JME-173 on carbachol-induced tracheal contraction remained unaltered under conditions of de-epithelized rings, β₂-receptor blockade or adenylate cyclase inhibition. When orally administered, JME-173 and theophylline inhibited methacholine-induced bronchospasm at time points of 1 and 3 h post-treatment, while only JME-173 remained active for at least 6 h. In addition, JME-173 also inhibited AHR in a mouse model of lipopolysaccharide (LPS)-induced lung inflammation. Thus, the mexiletine analog JME-173 shows highly attenuated activity on Na⁺ channels and optimized anti-spasmodic properties, in a mechanism that is at least in part mediated by regulation of Ca⁺⁺ inflow toward the cytosol. Thus, JME-173 is a promising alternative for the treatment of clinical conditions marked by life-threatening bronchoconstriction.

Nickel-Catalyzed Amide Bond Formation from Methyl Esters

Despite being one of the most important and frequently run chemical reactions, the synthesis of amide bonds is accomplished primarily by wasteful methods that proceed by stoichiometric activation of one of the starting materials. We report a nickel-catalyzed procedure that can enable diverse amides to be synthesized from abundant methyl ester starting materials, producing only volatile alcohol as a stoichiometric waste product. In contrast to acid- and base-mediated amidations, the reaction is proposed to proceed by a neutral cross coupling-type mechanism, opening up new opportunities for direct, efficient, chemoselective synthesis.

Repeated Allergen Exposure in A/J Mice Causes Steroid-Insensitive Asthma via a Defect in Glucocorticoid Receptor Bioavailability

The importance of developing new animal models to assess the pathogenesis of glucocorticoid (GC)-insensitive asthma has been stressed. Because of the asthma-prone background of A/J mice, we hypothesized that asthma changes in these animals would be or become resistant to GCs under repeated exposures to an allergen. A/J mice were challenged with OVA for 2 or 4 consecutive d, starting on day 19 postsensitization. Oral dexamethasone or inhaled budesonide were given 1 h before challenge, and analyses were done 24 h after the last challenge. Airway hyperreactivity, leukocyte infiltration, tissue remodeling, and cytokine levels as well as phosphorylated GC receptor (p-GCR), p-GATA-3, p-p38, MAPK phosphatase-1 (MKP-1), and GC-induced leucine zipper (GILZ) levels were assessed. A/J mice subjected to two daily consecutive challenges reacted with airway hyperreactivity, subepithelial fibrosis, and marked accumulation of eosinophils in both bronchoalveolar lavage fluid and peribronchial space, all of which were clearly sensitive to dexamethasone and budesonide. Conversely, under four provocations, most of these changes were steroid resistant. A significant reduction in p-GCR/GCR ratio following 4- but not 2-d treatment was observed, as compared with untreated positive control. Accordingly, steroid efficacy to transactivate MKP-1 and GILZ and to downregulate p-p38, p-GATA-3 as well as proinflammatory cytokine levels was also seen after two but not four provocations. In conclusion, we report that repeated allergen exposure causes GC-insensitive asthma in A/J mice in a mechanism associated with decrease in GCR availability and subsequent loss of steroid capacity to modulate pivotal regulatory proteins, such as GATA-3, p-p38, MKP-1, and GILZ.

Nebulized lidocaine ameliorates allergic airway inflammation via downregulation of TLR2

Nebulized lidocaine has been suggested to be beneficial in asthma therapy, but the underlying mechanisms are little known. We aimed to investigate whether Toll-like receptor (TLR) 2 was involved in the protective effect of lidocaine on allergic airway inflammation. Female C57BL/6 mice were sensitized and challenged with ovalbumin (OVA). Meanwhile, some of the mice were treated with TLR2 agonist (Pam3CSK4, 100 μg) intraperitoneally in combination with OVA on day 0. Just after allergen provocation, mice were treated with inhaled lidocaine or vehicle for 30 min. In this model, we found that lidocaine markedly attenuated OVA-evoked airway inflammation, leukocyte recruitment and mucus production. Moreover, lidocaine abrogated the increased concentrations of T cytokines and TNF-α in bronchoalveolar lavage fluid (BALF) of allergic mice, as well as reducing the expression of phosphorylated nuclear factor (P-NF)-κBp65 and the NOD-like receptor pyridine containing 3 (NLRP3), which are important for the production of pro-inflammatory cytokines. In addition, our study showed that lidocaine dramatically decreased OVA-induced increased expression of TLR2 in the lung tissues. Furthermore, activation of TLR2 aggravated OVA-challenged airway inflammation, meanwhile, it also elevated OVA-induced expression of P-NF-κBp65 and NLRP3 in the lungs. However, lidocaine effectively inhibited airway inflammation and counteracted the expression of P-NF-κBp65 and NLRP3 in allergic mice pretreated with Pam3CSK4. Taken together, the present study demonstrated that lidocaine prevented allergic airway inflammation via TLR2 in an OVA-induced murine allergic airway inflammation model. TLR2/NF-κB/NLRP3 pathway may serve as a promising therapeutic strategy for allergic airway inflammation.

15-Deoxy-Delta-12,14-Prostaglandin J2 Inhibits Lung Inflammation and Remodeling in Distinct Murine Models of Asthma

15-deoxy-Δ-12,14-prostaglandin J₂ (15d-PGJ₂) has been described as an anti-inflammatory lipid mediator in several in vitro and in vivo studies, but its effect on allergic pulmonary inflammation remains elusive. The aim of this study was to investigate the therapeutic potential of 15d-PGJ₂ based on distinct murine models of allergic asthma triggered by either ovalbumin (OVA) or house dust mite extract (HDM). Characteristics of lung inflammation, airway hyper-reactivity (AHR), mucus exacerbation, and lung remodeling in sensitized A/J mice treated or not with 15d-PGJ₂ were assessed. 15d-PGJ₂ treatments were carried out systemically or topically given via subcutaneous injection or intranasal instillation, respectively. Analyses were carried out 24 h after the last allergen provocation. Irrespective of the route of administration, 15d-PGJ₂ significantly inhibited the peribronchial accumulation of eosinophils and neutrophils, subepithelial fibrosis and also mucus exacerbation caused by either OVA or HDM challenge. The protective effect of 15d-PGJ₂ occurred in parallel with inhibition of allergen-induced AHR and lung tissue production of pro-inflammatory cytokines, such as interleukin (IL)-5, IL-13, IL-17, and TNF-α. Finally, 15d-PGJ₂ was found effective in inhibiting NF-κB phosphorylation upon HDM challenge as measured by Western blotting. In conclusion, our findings suggest that 15d-PGJ₂ can reduce crucial features of asthma, including AHR, lung inflammation, and remodeling in distinct murine models of the disease. These effects are associated with a decrease in lung tissue generation of pro-inflammatory cytokines by a mechanism related to downregulation of NF-κB phosphorylation.

Effect of Proparacaine in a Mouse Model of Allergic Rhinitis

Objectives

Lidocaine, a local anaesthetic is a treatment option in uncontrolled asthma due to its immunomodulatory effects. In the present study, proparacaine (PPC), a derivative of lidocaine was examined for its therapeutic application in a mouse model of allergic rhinitis.

Methods

The mice were grouped into 4 groups: control group, allergic rhinitis (AR) group, ciclesonide (CIC) group, and PPC group. Nasal symptom scores, eosinophil counts, goblet cell counts, and mast cells counts in the nasal mucosa were measured. Serum ovalbumin (OVA)-specific immunoglobulin (Ig) E, OVA-specific IgG1, OVA-specific IgG2a, interleukin (IL)-4, IL-5, and cortisol levels were measured.

Results

Intranasal administration of PPC significantly decreased nasal symptoms, number of eosinophils, goblet cells, and mast cells in the lamina propria of the nasal mucosa. Serum OVA-specific IgE, OVA-specific IgG1, OVA-specific IgG2a was significantly higher in the AR compared with the control group. Serum level of IL-4 was significantly lower in the CIC group and PPC group in comparison with AR group. Serum IL-5 showed no significant difference among all groups. No significant difference in serum cortisol levels was observed among the 4 groups.

Conclusion

PPC appears to have a therapeutic potential in treatment of allergic rhinitis in a mouse model by reducing eosinophil, goblet cell, and mast cell infiltration in the nasal mucosa.

Synthesis, Pharmacological Profile and Docking Studies of New Sulfonamides Designed as Phosphodiesterase-4 Inhibitors

Prior investigations showed that increased levels of cyclic AMP down-regulate lung inflammatory changes, stimulating the interest in phosphodiesterase (PDE)4 as therapeutic target. Here, we described the synthesis, pharmacological profile and docking properties of a novel sulfonamide series (5 and 6a-k) designed as PDE4 inhibitors. Compounds were screened for their selectivity against the four isoforms of human PDE4 using an IMAP fluorescence polarized protocol. The effect on allergen- or LPS-induced lung inflammation and airway hyper-reactivity (AHR) was studied in A/J mice, while the xylazine/ketamine-induced anesthesia test was employed as a behavioral correlate of emesis in rodents. As compared to rolipram, the most promising screened compound, 6a (LASSBio-448) presented a better inhibitory index concerning PDE4D/PDE4A or PDE4D/PDE4B. Accordingly, docking analyses of the putative interactions of LASSBio-448 revealed similar poses in the active site of PDE4A and PDE4C, but slight unlike orientations in PDE4B and PDE4D. LASSBio-448 (100 mg/kg, oral), 1 h before provocation, inhibited allergen-induced eosinophil accumulation in BAL fluid and lung tissue samples. Under an interventional approach, LASSBio-448 reversed ongoing lung eosinophilic infiltration, mucus exacerbation, peribronchiolar fibrosis and AHR by allergen provocation, in a mechanism clearly associated with blockade of pro-inflammatory mediators such as IL-4, IL-5, IL-13 and eotaxin-2. LASSBio-448 (2.5 and 10 mg/kg) also prevented inflammation and AHR induced by LPS. Finally, the sulfonamide derivative was shown to be less pro-emetic than rolipram and cilomilast in the assay employed. These findings suggest that LASSBio-448 is a new PDE4 inhibitor with marked potential to prevent and reverse pivotal pathological features of diseases characterized by lung inflammation, such as asthma.

Potential of PEGylated Toll-Like Receptor 7 Ligands for Controlling Inflammation and Functional Changes in Mouse Models of Asthma and Silicosis

Prior investigations show that signaling activation through pattern recognition receptors can directly impact a number of inflammatory lung diseases. While toll-like receptor (TLR) 7 agonists have raised interest for their ability to inhibit allergen-induced pathological changes in experimental asthma conditions, the putative benefit of this treatment is limited by adverse effects. Our aim was to evaluate the therapeutic potential of two PEGylated purine-like compounds, TMX-302 and TMX-306, characterized by TLR7 partial agonistic activity; therefore, the compounds are expected to induce lower local and systemic adverse reactions. In vitro approaches and translation to murine models of obstructive and restrictive lung diseases were explored. In vitro studies with human PBMCs showed that both TMX-302 and TMX-306 marginally affects cytokine production as compared with equivalent concentrations of the TLR7 full agonist, TMX-202. The PEGylated compounds did not induce monocyte-derived DC maturation or B cell proliferation, differently from what observed after stimulation with TMX-202. Impact of PEGylated ligands on lung function and inflammatory changes was studied in animal models of acute lung injury, asthma, and silicosis following Lipopolysaccharide (LPS), allergen (ovalbumin), and silica inhalation, respectively. Subcutaneous injection of TMX-302 prevented LPS- and allergen-induced airway hyper-reactivity (AHR), leukocyte infiltration, and production of pro-inflammatory cytokines in the lung. However, intranasal instillation of TMX-302 led to neutrophil infiltration and failed to prevent allergen-induced AHR, despite inhibiting leukocyte counts in the BAL. Aerosolized TMX-306 given prophylactically, but not therapeutically, inhibited pivotal asthma features. Interventional treatment with intranasal instillation of TMX-306 significantly reduced the pulmonary fibrogranulomatous response and the number of silica particles in lung interstitial space in silicotic mice. These findings highlight the potential of TMX-306, emphasizing its value in drug development for lung diseases, and particularly silicosis.