Leukotriene receptor antagonists in virus-induced wheezing : evidence to date

A surrogate in vitro experimental model for off-label drug repurposing: inhibitory effect of montelukast on bovine respiratory syncytial virus replication

BACKGROUND

Repurposing off-label drugs during epidemics or pandemics with unknown/known pathogens, particularly when their side effects and complications are already known, can be a strategic approach, as seen during the COVID-19 pandemic. Developing surrogate in vitro experimental models (passage-to-passage), which mimic epidemic/pandemic-like transmission (human-to-human), may enhance this repurposing process. This study evaluates montelukast sodium (MLS), a US FDA-approved leukotriene receptor antagonist for asthma, to explore its potential repurposing antiviral effects against bovine respiratory syncytial virus (BRSV), which has basic similarities to human respiratory syncytial virus (HRSV) as both belong to the Pneumoviridae family.

METHODS

An in vitro serial passage model was developed using MDBK cells infected with a local wild-type strain of BRSV (43TR2018). The cytotoxicity of MLS was assessed via the trypan blue exclusion method, identifying non-toxic concentrations. The impact of MLS on viral spread and infectivity was measured through TCID50 values over 10 passages. Viral loads were confirmed by nested RT-PCR and quantified using qPCR, while apoptosis, necrosis, and nitric oxide production were evaluated through staining and nitrite assays. Data were analyzed using ANOVA and Tukey's test (p < 0.05).

RESULTS

Control cells exhibited 97.16% viability, with 10 µM and 20 µM MLS concentrations maintaining viabilities of 89.2% and 87.3%, respectively. Viral titers significantly decreased at higher concentrations of MLS (up to 99.94% inhibition). Apoptosis rates decreased in MLS-treated cells, and live cell percentages improved, especially at 20 µM. Nitric oxide levels showed no significant differences across groups.

CONCLUSION

MLS demonstrated a dose-dependent antiviral effect against BRSV, achieving 99% viral inhibition properties in MDBK cells. These promising results warrant further investigation into the antiviral mechanisms of MLS.

An Overview on the Primary Factors That Contribute to Non-Allergic Asthma in Children

The prevalence of non-allergic asthma in childhood is low, peaking in late adulthood. It is triggered by factors other than allergens, like cold and dry air, respiratory infections, hormonal changes, smoke and air pollution. In the literature, there are few studies that describe non-allergic asthma in pediatric age. Even though it is a less common disorder in kids, it is crucial to identify the causes in order to keep asthma under control, particularly in patients not responding to conventional treatments. In this review, we discuss non-IgE-mediated forms of asthma, collecting the latest research on etiopathogenesis and treatment.

Effects of non-steroidal anti-inflammatory drugs and other eicosanoid pathway modifiers on antiviral and allergic responses: EAACI task force on eicosanoids consensus report in times of COVID-19

Non‐steroidal anti‐inflammatory drugs (NSAIDs) and other eicosanoid pathway modifiers are among the most ubiquitously used medications in the general population. Their broad anti‐inflammatory, antipyretic, and analgesic effects are applied against symptoms of respiratory infections, including SARS‐CoV‐2, as well as in other acute and chronic inflammatory diseases that often coexist with allergy and asthma. However, the current pandemic of COVID‐19 also revealed the gaps in our understanding of their mechanism of action, selectivity, and interactions not only during viral infections and inflammation, but also in asthma exacerbations, uncontrolled allergic inflammation, and NSAIDs‐exacerbated respiratory disease (NERD). In this context, the consensus report summarizes currently available knowledge, novel discoveries, and controversies regarding the use of NSAIDs in COVID‐19, and the role of NSAIDs in asthma and viral asthma exacerbations. We also describe here novel mechanisms of action of leukotriene receptor antagonists (LTRAs), outline how to predict responses to LTRA therapy and discuss a potential role of LTRA therapy in COVID‐19 treatment. Moreover, we discuss interactions of novel T2 biologicals and other eicosanoid pathway modifiers on the horizon, such as prostaglandin D2 antagonists and cannabinoids, with eicosanoid pathways, in context of viral infections and exacerbations of asthma and allergic diseases. Finally, we identify and summarize the major knowledge gaps and unmet needs in current eicosanoid research.

Treatment of SARS-CoV-2 (COVID-19) cases by the oral administration of montelukast tablets

According to the hypothesis, montelukast may have therapeutic action against severe acute respiratory syndrome (SARS) occurred by coronavirus 2 (CoV-19). The research was aimed to evaluate the therapeutic effects of montelukast tablet on coronavirus infectious disease (COVID-19) patients. A total of 20 COVID-19 confirmed patients were included in this study. The presence of COVID-19 infections in all patients was confirmed using real-time polymerase chain reaction (PCR) and computerized tomography (CT) scan. Confirmed cases were treated with oral administration of montelukast (10 mg) tablet for 10 days. The study population was included 18 to 82 years old patients (10 males and 10 females). The mean age of studied men and women individuals were 44.7±17 and 41±17.45 years, respectively. Frequency of respiratory distress, cough, abdominal cramps/diarrhea, fever, and odor disorder clinical signs amongst the examined patients were 85%, 90%, 20%, 70%, and 65%, respectively. Our findings revealed that all patients who were received 10 days of oral administration of montelukast tablets (10 mg) were recovered from the COVID-19 disease. Additionally, all of the clinical signs of COVID-19 patients, including respiratory distress, cough, and odor disorder, were gradually disappeared. Our findings revealed that widespread oral administration of montelukast tablets (10 mg) is a potential treatment for COVID-19 disease. However, several double-blind and multifactorial clinical trials should perform to determine the other clinical aspects of the treatment of COVID-19 patients by oral administration of montelukast.

Montelukast's ability to fight COVID-19 infection

Montelukast can be effective in the treatment of SARS-CoV-2 infection.

Treatment of allergic rhinitis reduces acute asthma exacerbation risk among asthmatic children aged 2-18 years

BACKGROUND/PURPOSE

Asthma and allergic rhinitis (AR) frequently coexist in the same individuals in childhood and adolescence. We evaluated whether AR had an impact on acute exacerbation (AE) and whether intranasal corticosteroid (INCS) and second-generation antihistamines (SGH) for AR modified the association of AR with AE in asthmatics aged 2-6 years and 7-18 years.

METHODS

Using the National Health Research Institutes (NHRI) Database 2005 of Taiwan, we investigated patients who had been diagnosed with asthma in the years 2000 through 2012 and who had then been followed-up with for at least one year. The risk factors of AE were evaluated using multiple Cox proportional hazards regression analysis.

RESULTS

The incidence of AE was higher in the preschool group than the older group (adj. HR: 1.68, 95% CI: 1.44-1.95). The AR with INCS and/or SGH group was found to have a lower risk of AE than the non-AR group (adj. HR: 0.32, 0.44 and 0.30), but the AR without treatment group did not have a significant difference with the non-AR group. After propensity score matching, the use of INCS and/or SGH was associated with a significant reduction in the occurrence of AE among AR patients aged 2-6 years old (adj. HR: 0.38, 0.57 and 0.45) and 7-18 years old (adj. HR: 0.50, 0.52 and 0.35).

CONCLUSION

The preschool patients had a higher incidence of AE than the older patients in general. Adequate treatment with INCS and/or SGH in asthma with AR patients is important for reducing the incidence of AE of asthma.

The leukotriene receptor antagonist montelukast and its possible role in the cardiovascular field

BACKGROUND

Cysteinyl leukotrienes (LTC4, LTD4, and LTE4) are pro-inflammatory mediators of the 5-lipooxygenase (5-LO) pathway, that play an important role in bronchoconstriction, but can also enhance endothelial cell permeability and myocardial contractility, and are involved in many other inflammatory conditions. In the late 1990s, leukotriene receptor antagonists (LTRAs) were introduced in therapy for asthma and later on, approved for the relief of the symptoms of allergic rhinitis, chronic obstructive pulmonary disease, and urticaria. In addition, it has been shown that LTRAs may have a potential role in preventing atherosclerosis progression.

PURPOSE

The aims of this short review are to delineate the potential cardiovascular protective role of a LTRA, montelukast, beyond its traditional use, and to foster the design of appropriate clinical trials to test this hypothesis.

RESULTS AND CONCLUSIONS

What it is known about leukotriene receptor antagonists? •Leukotriene receptor antagonist, such as montelukast and zafirlukast, is used in asthma, COPD, and allergic rhinitis. • Montelukast is the most prescribed CysLT₁ antagonist used in asthmatic patients. • Different in vivo animal studies have shown that leukotriene receptor antagonists can prevent the atherosclerosis progression, and have a protective role after cerebral ischemia. What we still need to know? • Today, there is a need for conducting clinical trials to assess the role of montelukast in reducing cardiovascular risk and to further understand the mechanism of action behind this effect.

Stimulus-selective regulation of human mast cell gene expression, degranulation and leukotriene production by fluticasone and salmeterol

Despite the fact that glucocorticoids and long acting beta agonists are effective treatments for asthma, their effects on human mast cells (MC) appear to be modest. Although MC are one of the major effector cells in the underlying inflammatory reactions associated with asthma, their regulation by these drugs is not yet fully understood and, in some cases, controversial. Using a human immortalized MC line (LAD2), we studied the effects of fluticasone propionate (FP) and salmeterol (SM), on the release of early and late phase mediators. LAD2 cells were pretreated with FP (100 nM), SM (1 µM), alone and in combination, at various incubation times and subsequently stimulated with agonists substance P, C3a and IgE/anti-IgE. Degranulation was measured by the release of β-hexosaminidase. Cytokine and chemokine expression were measured using quantitative PCR, ELISA and cytometric bead array (CBA) assays. The combination of FP and SM synergistically inhibited degranulation of MC stimulated with substance P (33% inhibition compared to control, n = 3, P<.05). Degranulation was inhibited by FP alone, but not SM, when MC were stimulated with C3a (48% inhibition, n = 3, P<.05). As previously reported, FP and SM did not inhibit degranulation when MC were stimulated with IgE/anti-IgE. FP and SM in combination inhibited substance P-induced release of tumor necrosis factor (TNF), CCL2, and CXCL8 (98%, 99% and 92% inhibition, respectively, n = 4, P<.05). Fluticasone and salmeterol synergistically inhibited mediator production by human MC stimulated with the neuropeptide substance P. This synergistic effect on mast cell signaling may be relevant to the therapeutic benefit of combination therapy in asthma.

Montelukast in asthma: a review of its efficacy and place in therapy

Many studies have been published in the last 10 years on the efficacy and safety of montelukast in asthma since this drug entered the market. Experimental studies, in vitro and in vivo, and clinical studies on large numbers of patients with asthma of different severity have clearly demonstrated that montelukast is able to modify the pathophysiological mechanisms of the disease, and to improve to some extent the clinical and functional manifestations of asthma. Studies of montelukast as monotherapy or in combination with other drugs, mainly inhaled corticosteroids (ICS), versus different comparator drugs have contributed to the positioning of montelukast in the different levels of asthma treatment, according to the Global Initiative for Asthma Guidelines. Montelukast may be used as monotherapy as an alternative to low-dose ICS (particularly in a step-down strategy) or in addition to ICS for improving clinical manifestations by an increase in anti-inflammatory effects and a sparing of corticosteroids. The heterogeneity of asthma has received a large amount of attention in the last few years in order to better tailor treatment according to the different clinical and biological phenotypes of asthma. Montelukast has proven to be particularly effective in exercise-induced asthma and in asthma associated with allergic rhinitis. Other phenotypes where montelukast is effective include asthma in obese patients, asthma in smokers, aspirin-induced asthma and viral-induced wheezing episodes. The safety profile of montelukast is very good, and the suspicions of increased risk of Churg-Strauss syndrome or suicide have not been confirmed.

That ICS should be first line therapy for asthma--con

Asthma is a heterogeneous disease and it is therefore unrealistic to expect that inhaled corticosteroids (ICS) would be appropriate first line preventer therapy for all children with asthma. There is good theoretical and clinical trial evidence demonstrating that leukotriene receptor antagonists (LTRAs) are more effective than ICS for viral induced wheezing and equivalent to ICS for mild persistent asthma in children. LTRAS do not have the systemic adverse effects of ICS, are generally well tolerated and their once daily oral administration enhances adherence. LTRAs should therefore be first line preventer therapy for children with frequent intermittent or mild persistent asthma while ICS should be reserved as first line treatment for children with moderate to severe persistent asthma. Given the skew in paediatric asthma severity towards the milder end, this effectively means that LTRAs should be tried first in 2 of every 3 children with asthma requiring preventer treatment.

The transient value of classifying preschool wheeze into episodic viral wheeze and multiple trigger wheeze

BACKGROUND

A recently proposed method for classifying preschool wheeze is to describe it as either episodic (viral) wheeze or multiple trigger wheeze. In research studies, phenotype is generally determined by retrospective questionnaire.

AIM

To determine whether recently proposed phenotypes of preschool wheeze are stable over time.

METHODS

In all, 132 two to six-year-old children with doctor diagnosed asthma on maintenance inhaled corticosteroids were classified as having episodic (viral) wheeze or multiple trigger wheeze at a screening visit and then followed up at three-monthly intervals for a year. At each follow-up visit, standardized questionnaires were used to determine whether the subjects wheezed only with, or also in the absence of colds. Stability of the phenotypes was assessed at the end of the study.

RESULTS

Phenotype as determined by retrospective parental report at the start of the study was not predictive of phenotype during the study year. Phenotypic classification remained the same in 45.9% of children and altered in 54.1% of children.

CONCLUSION

When children with preschool wheeze are classified into episodic (viral) wheeze or multiple trigger wheeze based on retrospective questionnaire, the classification is likely to change significantly within a 1-year period.

Variable expression of cysteinyl leukotriene type I receptor splice variants in asthmatic females with different promoter haplotypes

BACKGROUND

Cysteinyl leukotrienes are potent inflammatory mediators implicated in the pathogenesis of asthma. Human cysteinyl leukotriene receptor 1 (CYSLTR1) gene contains five exons that are variably spliced. Within its promoter few polymorphisms were described. To date, there has been no evidence about the expression of different splice variants of CysLT1 in asthma and their association with CYSLTR1 promoter polymorphisms.The goal of our study was to investigate CysLT1 alternative transcripts expression in asthmatic patients with different CYSLTR1 promoter haplotypes.The study groups consisted of 44 patients with asthma, diagnosed according to GINA 2008 criteria and 18 healthy subjects. Genomic DNA and total RNA was extracted from peripheral blood mononuclear cells. Real-time PCR was performed with specific primers for transcript I [GenBank:DQ131799] and II [GenBank:DQ131800]. Fragments of the CYSLTR1 promoter were amplified by PCR and sequenced directly to identify four single nucleotide polymorphisms: C/T [SNP:rs321029], A/C [SNP:rs2637204], A/G [SNP:rs2806489] and C/T [SNP:rs7066737].

RESULTS

The expression of CysLT1 transcript I and II in asthma did not differ from its expression in healthy control group. However, in major alleles homozygotic CAAC/CAAC women with asthma we found significantly higher expression of transcript I as compared to heterozygous CAAC/TCGC women in that loci. CysLT1 transcript I expression tended to negative correlation with episodes of acute respiratory infection in our asthmatic population. Moreover, expression of CysLT1 transcript II in CAAC/CAAC homozygotic women with asthma was significantly lower than in CAAC/CAAC healthy control females.

CONCLUSIONS

Genetic variants of CYSLTR1 promoter might be associated with gender specific expression of CysLT1 alternative transcripts in patients with asthma. CysLT1 splice variants expression might also correlate with the susceptibility to infection in asthmatic population.

Montelukast inhibits neutrophil pro-inflammatory activity by a cyclic AMP-dependent mechanism

BACKGROUND AND PURPOSE

The objective of this study was to characterize the effects of the cysteinyl leukotriene receptor antagonist, montelukast (0.1-2 micromol x L(-1)), on Ca(2+)-dependent pro-inflammatory activities, cytosolic Ca(2+) fluxes and intracellular cAMP in isolated human neutrophils activated with the chemoattractants, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (1 micromol x L(-1)) and platelet-activating factor (200 nmol x L(-1)).

EXPERIMENTAL APPROACH

Generation of reactive oxygen species was measured by lucigenin- and luminol-enhanced chemiluminescence, elastase release by a colourimetric assay, leukotriene B(4) and cAMP by competitive binding ELISA procedures, and Ca(2+) fluxes by fura-2/AM-based spectrofluorimetric and radiometric ((45)Ca(2+)) procedures.

KEY RESULTS

Pre-incubation of neutrophils with montelukast resulted in dose-related inhibition of the generation of reactive oxygen species and leukotriene B(4) by chemoattractant-activated neutrophils, as well as release of elastase, all of which were maximal at 2 micromol x L(-1) (mean percentages of the control values of 30 +/- 1, 12 +/- 3 and 21 +/- 3 respectively; P < 0.05). From a mechanistic perspective, treatment of chemoattractant-activated neutrophils with montelukast resulted in significant reductions in both post-peak cytosolic Ca(2+) concentrations and store-operated Ca(2+) influx. These montelukast-mediated alterations in Ca(2+) handling by the cells were associated with a significant elevation in basal cAMP levels, which resulted from inhibition of cyclic nucleotide phosphodiesterases.

CONCLUSIONS AND IMPLICATIONS

Montelukast, primarily a cysteinyl leukotriene (CysLT(1)) receptor antagonist, exhibited previously undocumented, secondary, neutrophil-directed anti-inflammatory properties, which appeared to be cAMP-dependent.