Montelukast, current indications and prospective future applications

Montelukast induces beneficial behavioral outcomes and reduces inflammation in male and female rats

Background

Accumulative data links inflammation and immune dysregulation to the pathophysiology of mental disorders; little is known regarding leukotrienes’ (LTs) involvement in this process. Circumstantial evidence suggests that treatment with leukotriene modifying agents (LTMAs) such as montelukast (MTK) may induce adverse neuropsychiatric events. Further methodic evaluation is warranted.

Objective

This study aims to examine behavioral effects, as well as inflammatory mediator levels of chronic MTK treatment in male and female rats.

Methods

Depression-like phenotypes were induced by exposing male and female rats to a chronic unpredictable mild stress (CUMS) protocol for four weeks. Thereafter, rats were treated (intraperitoneally) once daily, for two weeks, with either vehicle (dimethyl sulfoxide 0.2 ml/rat) or 20 mg/kg MTK. Following treatment protocols, behavioral tests were conducted and brain regions were evaluated for inflammatory mediators including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and prostaglandin (PG) E2.

Results

Overall, MTK did not invoke negative behavioral phenotypes (except for an aggression-inducing effect in males). Numerous positive behavioral outcomes were observed, including reduction in aggressive behavior in females and reduced manic/hyperactive-like behavior and increased sucrose consumption (suggestive of antidepressant-like effect) in males. Furthermore, in control males, MTK increased IL-6 levels in the hypothalamus and TNF-α in the frontal cortex, while in control females it generated a robust anti-inflammatory effect. In females that were subjected to CUMS, MTK caused a prominent reduction in TNF-α and IL-6 in brain regions, whereas in CUMS-subjected males its effects were inconsistent.

Conclusion

Contrary to prior postulations, MTK may be associated with select beneficial behavioral outcomes. Additionally, MTK differentially affects male vs. female rats in respect to brain inflammatory mediators, plausibly explaining the dissimilar behavioral phenotypes of sexes under MTK treatment.

Short-acting β2-agonist prescription patterns in patients with asthma in Turkey: results from SABINA III

Background

Over-reliance on short-acting β₂-agonists (SABAs) is associated with poor asthma outcomes. However, the extent of SABA use in Turkey is unclear owing to a lack of comprehensive healthcare databases. Here, we describe the demographics, disease characteristics and treatment patterns from the Turkish cohort of the SABA use IN Asthma (SABINA) III study.

Methods

This observational, cross-sectional study included patients aged ≥ 12 years with asthma from 24 centres across Turkey. Data on sociodemographics, disease characteristics and asthma treatments were collected using electronic case report forms. Patients were classified by investigator-defined asthma severity (guided by the 2017 Global Initiative for Asthma [GINA]) and practice type (primary/specialist care). The primary objective was to describe SABA prescription patterns in the 12 months prior to the study visit.

Results

Overall, 579 patients were included (mean age [standard deviation; SD]: 47.4 [16.1] years; 74.3% female), all of whom were treated by specialists. Most patients had moderate-to-severe asthma (82.7%, GINA steps 3–5), were overweight or obese (70.5%), had high school or university/post-graduate education (51.8%) and reported fully reimbursed healthcare (97.1%). The mean (SD) asthma duration was 12.0 (9.9) years. Asthma was partly controlled/uncontrolled in 56.3% of patients, and 46.5% experienced ≥ 1 severe exacerbation in the preceding 12 months. Overall, 23.9% of patients were prescribed ≥ 3 SABA canisters in the previous 12 months (considered over-prescription); 42.9% received no SABA prescriptions. As few patients had mild asthma, only 5.7% were prescribed SABA monotherapy. Therefore, most patients (61.5%) were prescribed SABA in addition to maintenance therapy, with 42.8% receiving ≥ 3 SABA canisters in the previous 12 months. Inhaled corticosteroids (ICS), ICS + a long-acting β-agonist fixed-dose combination and oral corticosteroids were prescribed to 14.5%, 88.3% and 28.5% of all patients, respectively. Additionally, 10.2% of patients purchased SABA over the counter, of whom 27.1% purchased ≥ 3 canisters in the preceding 12 months.

Conclusions

Despite all patients being treated by specialists and most receiving fully reimbursed healthcare, nearly a quarter of patients received prescriptions for ≥ 3 SABA canisters in the previous 12 months. This highlights a public health concern and emphasizes the need to align clinical practices with the latest evidence-based recommendations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02008-9.

Group 2 innate lymphoid cells (ILC2s) are important in typical type 2 immune-mediated diseases and an essential therapeutic target

The prevalence rate of allergic diseases, such as asthma, atopic rhinitis (AR), and atopic dermatitis (AD), has been significantly increasing over the years because of environmental changes. Type 2 immunity is mediated by allergic inflammation initiated by an innate immune response. This response is orchestrated by type 2 cytokines (interleukin [IL]-4, IL-5, IL-9, and IL-13) together with other cells. The dendritic cell [DC]-T helper 2 (Th2) cell axis is the conventional type 2 immune pathway, and is currently known as the group 2 innate lymphoid cell (ILC2)-DC-Th2 axis that mediates type 2 inflammation. ILC2s strongly mediate type 2 inflammation in allergic diseases. ILC2s are activated by epithelial cell-derived cytokines, such as IL-25 and IL-33, and thymic stromal lymphopoietin. Additionally, ILC2s are activated by mast cell lipid inflammatory mediators, such as cysteinyl leukotrienes and prostaglandin D2. ILC2s produce a large amount of type 2 cytokines. The important role of ILC2s in the pathogenesis of type 2-mediated disease has resulted in ILC2-derived cytokines being a target for therapeutic development. In this review, we discuss type 2 immunity, mainly the ILC2-DC-Th2 axis, and other immune cells, the dominant role of ILC2s in asthma, AR, and AD, and therapeutic targets against type 2 cytokines.

Role of arachidonic acid lipoxygenase pathway in Asthma

The arachidonic acid (AA) metabolism pathways play a key role in immunological response and inflammation diseases, such as asthma, etc. AA in cell membranes can be metabolized by lipoxygenases (LOXs) to a screen of bioactive substances that include leukotrienes (LTs), lipoxins (LXs), and eicosatetraenoic acids (ETEs), which are considered closely related to the pathophysiology of respiratory allergic disease. Studies also verified that drugs regulating AA LOXs pathway have better rehabilitative intervention for asthma. This review aims to summarize the physiological and pathophysiological importance of AA LOXs metabolism pathways in asthma and to discuss its prospects of therapeutic strategies.

The Leukotriene Receptor Antagonist Montelukast Reduces Alpha-Synuclein Load and Restores Memory in an Animal Model of Dementia with Lewy Bodies

Dementia with Lewy bodies (DLB) represents a huge medical need as it accounts for up to 30% of all dementia cases, and there is no cure available. The underyling spectrum of pathology is complex and creates a challenge for targeted molecular therapies. We here tested the hypothesis that leukotrienes are involved in the pathology of DLB and that blocking leukotrienes through Montelukast, a leukotriene receptor antagonist and approved anti-asthmatic drug, might alleviate pathology and restore cognitive functions. Expression of 5-lipoxygenase, the rate-limiting enzyme for leukotriene production, was indeed elevated in brains with DLB. Treatment of cognitively deficient human alpha-synuclein overexpressing transgenic mice with Montelukast restored memory. Montelukast treatment resulted in modulation of beclin-1 expression, a marker for autophagy, and in a reduction in the human alpha-synulcein load in the transgenic mice. Reducing the protein aggregation load in neurodegenerative diseases might be a novel model of action of Montelukast. Moreover, this work presents leukotriene signaling as a potential drug target for DLB and shows that Montelukast might be a promising drug candidate for future DLB therapy development.

Efficacy of Montelukast for Prevention of Upper Respiratory Tract Infection in Children: A Randomized, Placebo-Controlled Trial

Background: Upper Respiratory tract infection (URTI) or common cold is very prevalent in children particularly in young children. Leukotriene receptor antagonists (LTRAs) like montelukast are effective drugs in asthma and some other respiratory diseases. Our purpose was to study preventive effects of montelukast on pediatric URTI. Methods: This randomized, placebo-controlled, and double blind trial was performed on 450 healthy children aged 1-5 year in Amir Kabir Hospital, Arak, Iran. Children were randomized 1:1 to placebo group or montelukast group for 12 weeks. Number of URTI episodes and duration were the primary end points and were compared at baseline and after termination of treatment. Results: Mean age was 28 ± 12.3 months. Mean of URTI episodes was 0.7 ± 0.57 in children treated with montelukast and 1.27 ± 0.72 in children treated with placebo, respectively. Differences were statistically significant (P =0.01). A significant difference was seen in URTI duration between two study groups (6.3 ± 6.1 vs 4.1 ± 3.9, P = 0.05). In addition, duration of fever was shorter in children receiving montelukast (P=0.001). Conclusion: Our study indicates that 3 month treatment with montelukast is effective for reducing the incidence of URTI in young children. This treatment has an acceptable safety without any serious concern.

Effects of anti-inflammatory and adaptogenic herbal extracts on gene expression of eicosanoids signaling pathways in isolated brain cells

INTRODUCTION

The adaptogens modulate expression of genes playing key roles in development of aging-related disorders, which are considered as low-grade systemic inflammatory conditions characterized by an imbalance between pro-and anti-inflammatory eicosanoids.

AIM OF THE STUDY

We compared the effects of anti-inflammatory and adaptogenic plant extracts on the expression of genes involved in biosynthesis of eicosanoids with the purpose to find those plants, which selectively upregulated the expression of anti-inflammatory lipoxins signaling pathways and inhibited pro-inflammatory signaling pathways associated with biosynthesis of leukotrienes, prostaglandins and thromboxanes.

MATERIALS AND METHODS

We conducted transcriptome-wide RNA sequencing to profile gene expression alterations in T98G neuroglia cells upon treatment of plant extract and analyzed the relevance of deregulated genes to eicosanoids signaling pathways using in silico models.

RESULTS

For the first time, we demonstrated that Rhodiola rosea, Withania somnifera and Eleutherococcus senticosus downregulate the expression of key genes (ALOX5AP, DPEP2, LTC4S) involved biosynthesis of leukotrienes A, B, C, D and E, resulting in inhibition of leukotriene signaling pathway suggesting their potential benefits in Alzheimer disease. The common feature for all tested anti-inflammatory plants extracts was related to downregulation of ALOX12, which was also associated with neuroprotective action of these medicinal plants as well as their potential benefits in neurodegenerative diseases. None of tested anti-inflammatory and adaptogenic plants selectively activated the ALOX15-mediated signaling pathway, which is associated with generation anti-inflammatory lipoxins. Almost all tested plants upregulated the expression of the prostaglandin E receptor 3 gene (PTGER3) suggesting their potential benefits in the treatment of cancer.

CONCLUSION

Every single plant tested in this study revealed a specific "signature" on eicosanoid signaling-related gene expression, regardless of their common features as anti-inflammatory or adaptogenic activity. Further studies of the combination of Rhodiola with Withania (Adaptra) for the treatment of Alzheimer disease are required.

Group 2 Innate Lymphoid Cells in Respiratory Allergic Inflammation

Millions of people worldwide are suffering from allergic inflammatory airway disorders. These conditions are regarded as a consequence of multiple imbalanced immune events resulting in an inadequate response with the exact underlying mechanisms still being a subject of ongoing research. Several cell populations have been proposed to be involved but it is becoming increasingly evident that group 2 innate lymphoid cells (ILC2s) play a key role in the initiation and orchestration of respiratory allergic inflammation. ILC2s are important mediators of inflammation but also tissue remodeling by secreting large amounts of signature cytokines within a short time period. Thereby, ILC2s instruct innate but also adaptive immune responses. Here, we will discuss the recent literature on allergic inflammation of the respiratory tract with a focus on ILC2 biology. Furthermore, we will highlight different therapeutic strategies to treat pulmonary allergic inflammation and their potential influence on ILC2 function as well as discuss the perspective of using human ILC2s for diagnostic purposes.