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Newly emerging roles of LRRC8 volume-regulated anion channels (VRAC) raise important questions about the therapeutic potential of VRAC in the treatment of epilepsy, type 2 diabetes, and other human diseases. A critical barrier to evaluating whether VRAC represents a viable drug target is the lack of potent and specific small-molecule inhibitors and activators of the channel. Here we review recent progress in developing the molecular pharmacology of VRAC made by screening a library of FDA-approved drugs for novel channel modulators. We discuss the discovery and characterization of cysteinyl leukotriene receptor antagonists Pranlukast and Zafirlukast as novel VRAC inhibitors, and zinc pyrithione (ZPT), which apparently activates VRAC through a reactive oxygen species (ROS)-dependent mechanism. These ongoing efforts set the stage for developing a pharmacological toolkit for probing the integrative physiology, molecular pharmacology, and therapeutic potential of VRAC.

For leukotriene receptor antagonists (LTRAs), especially pranlukast, safety data during pregnancy is limited. Therefore, we conducted a prospective, two‐centered cohort study using data from teratogen information services in Japan to clarify the effects of LTRA exposure during pregnancy on maternal and fetal outcomes. Pregnant women who being counseled on drug use during pregnancy at two facilities were enrolled. The primary outcome of this study was major congenital anomalies. The incidence of major congenital anomalies in women exposed to montelukast or pranlukast during the first trimester of pregnancy was compared with that of controls. Logistic regression analysis was performed to analyze the effects of maternal LTRA use during the first trimester of pregnancy on major congenital anomalies. The outcomes of 231 pregnant women exposed to LTRAs (montelukast n = 122; pranlukast n = 106; both n = 3) and 212 live births were compared with those of controls. The rate of major congenital anomalies in the LTRA group was 1.9%. Multivariable logistic regression analysis revealed that LTRA exposure was not a risk factor for major congenital anomalies (adjusted odds ratio, 0.78; 95% confidence interval, 0.23–2.05; p = 0.653). In addition, no significant difference was detected in stillbirth, spontaneous abortion, preterm birth, and low birth weight between the two groups. The present study revealed that montelukast and pranlukast were not associated with the risk of major congenital anomalies. Our findings suggest that LTRAs could be safely employed for asthma therapy during pregnancy. [ABSTRACT FROM AUTHOR]

Inés Velázquez-Quesada,1,2 Angel J Ruiz-Moreno,1,3,4 Diana Casique-Aguirre,1 Charmina Aguirre-Alvarado,1 Fabiola Cortés-Mendoza,1,5 Marisol de la Fuente-Granada,6 Carlos García-Pérez,7 Sonia M Pérez-Tapia,2,8 Aliesha González-Arenas,6 Aldo Segura-Cabrera,9 Marco A Velasco-Velázquez1,10 1Department of Pharmacology, School of Medicine, Universidad Nacional Autónoma de México, Mexico City, Mexico; 2Research and Development in Bioprocess Unit, National School of Biological Sciences, Instituto Politécnico Nacional, Mexico City, Mexico; 3Graduate Program in Biomedical Sciences, Universidad Nacional Autónoma de México, Mexico City, Mexico; 4Department of Drug Design, Graduate School of Science and Engineering, University of Groningen (RUG), Groningen, The Netherlands; 5Graduate Program in Biochemical Sciences, Universidad Nacional Autónoma de México, Mexico City, Mexico; 6Department of Genomic Medicine and Environmental Toxicology, Institute for Biomedical Research, Universidad Nacional Autónoma de México, Mexico City, Mexico; 7Center for Genomic Biotechnology, Instituto Politécnico Nacional, Reynosa, Tamaulipas, Mexico; 8National Laboratory for Specialized Services of Investigation, Development and Innovation (I+D+i) for Pharma Chemicals and Biotechnological Products, LANSEIDI-FarBiotec-CONACyT, Mexico City, Mexico; 9European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, UK; 10Peripherical Unit for Research in Translational Biomedicine, School of Medicine, Universidad Nacional Autónoma de México, Mexico City, MexicoCorrespondence: Marco A Velasco-VelázquezSchool of Medicine, Universidad Nacional Autónoma de México, Circuito Interno s/n, Mexico City 04510, MexicoTel/Fax +52 55 5623 2282Email marcovelasco@unam.mxIntroduction: Cancer stem cells (CSCs) drive the initiation, maintenance, and therapy response of breast tumors. CD49f is expressed in breast CSCs and functions in the maintenance of stemness. Thus, blockade of CD49f is a potential therapeutic approach for targeting breast CSCs. In the present study, we aimed to repurpose drugs as CD49f antagonists.Materials and Methods: We performed consensus molecular docking using a subdomain of CD49f that is critical for heterodimerization and a collection of pharmochemicals clinically tested. Molecular dynamics simulations were employed to further characterize drug-target binding. Using MDA-MB-231 cells, we evaluated the effects of potential CD49f antagonists on 1) cell adhesion to laminin; 2) mammosphere formation; and 3) cell viability. We analyzed the effects of the drug with better CSC-selectivity on the activation of CD49f-downstream signaling by Western blot (WB) and co-immunoprecipitation. Expressions of the stem cell markers CD44 and SOX2 were analyzed by flow cytometry and WB, respectively. Transactivation of SOX2 promoter was evaluated by luciferase reporter assays. Changes in the number of CSCs were assessed by limiting-dilution xenotransplantation.Results: Pranlukast, a drug used to treat asthma, bound to CD49f in silico and inhibited the adhesion of CD49f+ MDA-MB-231 cells to laminin, indicating that it antagonizes CD49f-containing integrins. Molecular dynamics analysis showed that pranlukast binding induces conformational changes in CD49f that affect its interaction with β 1-integrin subunit and constrained the conformational dynamics of the heterodimer. Pranlukast decreased the clonogenicity of breast cancer cells on mammosphere formation assay but had no impact on the viability of bulk tumor cells. Brief exposure of MDA-MB-231 cells to pranlukast altered CD49f-dependent signaling, reducing focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI3K) activation. Further, pranlukast-treated cells showed decreased CD44 and SOX2 expression, SOX2 promoter transactivation, and in vivo tumorigenicity, supporting that this drug reduces the frequency of CSC.Conclusion: Our results support the function of pranlukast as a CD49f antagonist that reduces the CSC population in triple-negative breast cancer cells. The pharmacokinetics and toxicology of this drug have already been established, rendering a potential adjuvant therapy for breast cancer patients.Keywords: CD49f, alpha6 integrin, breast cancer stem cells, pranlukast, drug repositioning, triple-negative breast cancer cells

Reflux of gastroduodenal contents into the esophagus leads to the development of esophagitis and inflammation-associated pathologies, such as Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). The role of the lipoxygenase (LOX) pathway in carcinogenesis has been recently reported; however, its involvement in esophageal carcinogenesis remains unclear. To address this, the present study investigated the potential of pranlukast, a cysteinyl leukotriene receptor-1 antagonist, to suppress the progression of BE and EAC in a rat duodenogastroesophageal reflux (DGER) model. Male Wistar rats that underwent DGER were divided into two groups. One group was fed commercial chow (control group), and the other was fed experimental chow containing pranlukast (pranlukast group). The rats were sacrificed at 10, 20, 30 and 40 weeks after surgery, and their esophagi were examined. Expression levels of 5-LOX, CD68, IL-8, VEGF and Ki-67 were investigated using immunohistochemistry, and apoptosis was analyzed using the TUNEL method. In the pranlukast group, esophagitis was milder, and the incidence of BE and EAC was significantly lower (P<0.05) compared with that in the control group at 40 weeks after surgery. The number of cells positive for IL-8 and VEGF were significantly lower in the pranlukast group compared with the control group. Proliferative activity was also lower in the pranlukast group compared with the control group (P<0.05). Pranlukast treatment increased apoptosis (P<0.05). Overall, Pranlukast suppressed esophageal carcinogenesis in a rat DGER model, decreasing inflammatory cytokines such as IL-8 and VEGF. [ABSTRACT FROM AUTHOR]

Tuberculosis caused by the bacterium, Mycobacterium tuberculosis (Mtb), continues to remain one of the most devastating infectious diseases afflicting humans. Although there are several drugs for treating tuberculosis available currently, the emergence of the drug resistant forms of this pathogen has made its treatment and eradication a challenging task. While the replication machinery, protein synthesis and cell wall biogenesis of Mtb have been targeted often for anti‐tubercular drug development a number of essential metabolic pathways crucial to its survival have received relatively less attention. In this context a number of amino acid biosynthesis pathways have recently been shown to be essential for the survival and pathogenesis of Mtb. Many of these pathways and or their key enzymes homologs are absent in humans hence they could be harnessed for anti‐tubercular drug development. In this review, we describe comprehensively the amino acid metabolic pathways essential in Mtb and the key enzymes involved therein that are being investigated for developing inhibitors that compromise the survival and pathogenesis caused by this pathogen. [ABSTRACT FROM AUTHOR]

• 5-Lipoxygenase regulates APP and other A-beta processing genes. • Cysteinyl leukotriene receptors are increased in models of Alzheimer's. • 5-Lipoxygenase and cysteinyl leukotriene receptor blockers alleviate Alzheimer's-related cognitive decline. • 5-Lipoxygenase and cysteinyl leukotriene receptor blockers alleviate Alzheimer's-related neuroinflammation. 5-lipoxygenase (ALOX5) is an enzyme involved in arachidonic acid (AA) metabolism, a metabolic pathway in which cysteinyl leukotrienes (CysLTs) are the resultant metabolites. Both ALOX5 and CysLTs are clinically significant in a number of inflammatory diseases, such as in asthma and allergic rhinitis, and drugs antagonizing the effect of these molecules have long been successfully used to counter these diseases. Interestingly, recent advances in 'neuroinflammation' research has led to the discovery of several novel inflammatory pathways regulating many cerebral pathologies, including the ALOX5 pathway. By means of pharmacological and genetic studies, both ALOX5 and CysLTs receptors have been shown to be involved in the pathogenesis of Alzheimer's disease (AD) and other neurodegenerative/neurological diseases, such as in Parkinson's disease, multiple sclerosis, and epilepsy. In both transgenic and sporadic models of AD, it has been shown that the levels of ALOX5/CysLTs are elevated, and that genetic/pharmacological interventions of these molecules can alleviate AD-related behavioral and pathological conditions. Clinical relevance of these molecules has also been found in AD brain samples. In this review, we aim to summarize such important findings on the role of ALOX5/CysLTs in AD pathophysiology, from both the cellular and the molecular aspects, and also discuss the potential of their blockers as possible therapeutic choices to curb AD-related conditions. [ABSTRACT FROM AUTHOR]

To study the effect of pranlukast (Pran) on neonatal rats with periventricular leukomalacia (PVL). Methods The rats, aged 3 days, were randomly divided into a sham-operation group, a PVL group, and a Pran group. A rat model of PVL was prepared by right common carotid artery ligation and postoperative hypoxia. The rats in the sham-operation group were given isolation of the right common carotid artery without ligation or hypoxic treatment. The rats in the Pran group were given intraperitoneal injection of Pran (0.1 mg/kg) once every 12 hours, for 3 consecutive days, and those in the sham-operation group and the PVL group were given intraperitoneal injection of an equal volume of normal saline. On day 14 after modeling, hematoxylin-eosin (HE) staining was used to observe the pathological changes of brain tissue; immunofluorescent staining was used to measure the expression of myelin basic protein (MBP) in brain tissue (n=8); Western blot was used to measure the expression of cyclic nucleotide phosphodiesterase (CNPase), MBP, and G protein-coupled receptor 17 (GPR17) (n=8). On day 21 after modeling, Morris water maze test was used to evaluate the learning and memory abilities of rats in each group (n=8). Results The results of HE staining showed that the PVL group had greater pathological changes of white matter than the sham-operation group, and compared with the PVL group, the Pran group had a significant improvement in such pathological changes. The results of immunofluorescence assay showed that the PVL group had a lower mean fluorescence intensity of MBP than the shamoperation group (P<0.05), and the Pran group had a higher mean fluorescence intensity of MBP than the PVL group (P<0.05). Western blot showed that compared with the sham-operation group, the PVL group had significantly lower relative expression of MBP and CNPase (P<0.05) and significantly higher relative expression of GPR17 (P<0.05), and compared with the PVL group, the Pran group had significantly higher relative expression of MBP and CNPase (P<0.05) and significantly lower relative expression of GPR17 (P<0.05). Morris water maze test showed that compared with the sham-operation group, the PVL group had a significant increase in escape latency and a significant reduction in the number of platform crossings, and compared with the PVL group, the Pran group had a significant reduction in escape latency and a significant increase in the number of platform crossings (P<0.05). Conclusions Pran can alleviate brain damage, promote myelination, and improve long-term learning and memory abilities in neonatal rats with PVL, possibly by reducing the expression of GPR17. [ABSTRACT FROM AUTHOR]

Cysteinyl leukotriene receptor 1 antagonists (CysLT1RA) are frequently used as add-on medication for the treatment of asthma. Recently, these compounds have shown protective effects in cardiovascular diseases. This prompted us to investigate their influence on soluble epoxide hydrolase (sEH) and peroxisome proliferator activated receptor (PPAR) activities, two targets known to play an important role in CVD and the metabolic syndrome. Montelukast, pranlukast and zafirlukast inhibited human sEH with IC50 values of 1.9, 14.1, and 0.8 μM, respectively. In contrast, only montelukast and zafirlukast activated PPARγ in the reporter gene assay with EC50 values of 1.17 μM (21.9% max. activation) and 2.49 μM (148% max. activation), respectively. PPARα and δ were not affected by any of the compounds. The activation of PPARγ was further investigated in 3T3-L1 adipocytes. Analysis of lipid accumulation, mRNA and protein expression of target genes as well as PPARγ phosphorylation revealed that montelukast was not able to induce adipocyte differentiation. In contrast, zafirlukast triggered moderate lipid accumulation compared to rosiglitazone and upregulated PPARγ target genes. In addition, we found that montelukast and zafirlukast display antagonistic activities concerning recruitment of the PPARγ cofactor CBP upon ligand binding suggesting that both compounds act as PPARγ modulators. In addition, zafirlukast impaired the TNFα triggered phosphorylation of PPARγ2 on serine 273. Thus, zafirlukast is a novel dual sEH/PPARγ modulator representing an excellent starting point for the further development of this compound class.

TREK2 (KCNK10, K 2P 10.1) is a two-pore domain potassium (K2P) channel and a potential target for the treatment of pain. Like the majority of the K2P superfamily, there is currently a lack of useful pharmacological tools to study TREK2. Here we present a strategy for identifying novel TREK2 activators. A cell-based thallium flux assay was developed and used to screen a library of drug-like molecules, from which we identified the CysLT1 antagonist Pranlukast as a novel activator of TREK2. This compound was selective for TREK2 versus TREK1 and showed no activity at TRAAK. Pranlukast was also screened against other members of the K2P superfamily. Several close analogues of Pranlukast and other CysLT1 antagonists were also tested for their ability to activate K2P channels. Consistent with previous work, structure activity relationships showed that subtle structural changes to these analogues completely attenuated the activation of TREK2, whereas for TREK1, analogues moved from activators to inhibitors. Pranlukast's activity was also confirmed using whole-cell patch clamp electrophysiology. Studies using mutant forms of TREK2 suggest Pranlukast does not bind in the K2P modulator pocket or the BL-1249 binding site. Pranlukast therefore represents a novel tool by which to study the mechanism of TREK2 activation. • Two-pore domain potassium channels (K2Ps) carry background (or leak) potassium current. • Lack of specific, pharmacological tools which target K2Ps. • TREK2 is a potential target for the treatment of pain. • Developed an assay to screen compounds and identify novel activators of TREK2. • Pranlukast is a novel activator of TREK2. [ABSTRACT FROM AUTHOR]

Cysteinyl leukotriene receptor 1 antagonists (CysLT1RA) are frequently used as add-on medication for the treatment of asthma. Recently, these compounds have shown protective effects in cardiovascular diseases. This prompted us to investigate their influence on soluble epoxide hydrolase (sEH) and peroxisome proliferator activated receptor (PPAR) activities, two targets known to play an important role in CVD and the metabolic syndrome. Montelukast, pranlukast and zafirlukast inhibited human sEH with IC50 values of 1.9, 14.1, and 0.8 μM, respectively. In contrast, only montelukast and zafirlukast activated PPARγ in the reporter gene assay with EC50 values of 1.17 μM (21.9% max. activation) and 2.49 μM (148% max. activation), respectively. PPARα and δ were not affected by any of the compounds. The activation of PPARγ was further investigated in 3T3-L1 adipocytes. Analysis of lipid accumulation, mRNA and protein expression of target genes as well as PPARγ phosphorylation revealed that montelukast was not able to induce adipocyte differentiation. In contrast, zafirlukast triggered moderate lipid accumulation compared to rosiglitazone and upregulated PPARγ target genes. In addition, we found that montelukast and zafirlukast display antagonistic activities concerning recruitment of the PPARγ cofactor CBP upon ligand binding suggesting that both compounds act as PPARγ modulators. In addition, zafirlukast impaired the TNFα triggered phosphorylation of PPARγ2 on serine 273. Thus, zafirlukast is a novel dual sEH/PPARγ modulator representing an excellent starting point for the further development of this compound class. [ABSTRACT FROM AUTHOR]

Leukotriene receptor antagonists (LTRAs) are identified as a monotherapy for asthma and allergic rhinitis; however, their use in children for treatment of these diseases has not been examined. Accordingly, the present study investigated the efficacy of pranlukast dry syrup for children with both pollinosis and asthma. The subjects were children receiving treatment for asthma who were also diagnosed with cedar pollen allergy. Patients were divided into a group that received continuous treatment with pranlukast (group A; n=20) and a group that commenced add-on treatment for pollinosis following the onset of symptoms (group B; n=20). Patients in group B were randomly allocated to subgroup B1 (add-on treatment with pranlukast dry syrup) or subgroup B2 (add-on treatment with a second-generation antihistamine). In both groups, nasal and ocular symptoms were evaluated every day and recorded in a diary. Exacerbation of nasal obstruction was demonstrated in group B; however, not in group A. There was a significant difference in symptoms observed between the two groups during the late peak pollen period (P<0.05). The incidence of nasal obstruction (defined as a nasal obstruction score =3 or use of a nasal steroid spray) was significantly lower in group A compared with group B (P<0.05). The maximum scores for sneezing and nasal obstruction during the late peak of the pollen season were lowest in group A, followed by subgroup B1 and subgroup B2. The present study demonstrated that long-term administration of LTRA for the management of asthma may improve nasal symptoms of pollinosis during the pollen season in children with pollinosis and asthma. [ABSTRACT FROM AUTHOR]

The introduction of second generation serotonin 5-HT 3 receptor (5-HT 3 ) antagonist palonosetron combined with long-acting substance P neurokinin NK 1 receptor (NK 1 ) antagonists (e.g. netupitant) has substantially improved antiemetic therapy against early- and delayed-phases of emesis caused by highly emetogenic chemotherapeutics such as cisplatin. However, the improved efficacy comes at a cost that many patients cannot afford. We introduce a new class of antiemetic, the antiasthmatic leukotriene CysLT1 receptor antagonist pranlukast for the suppression of cisplatin-evoked vomiting. Pranlukast (10 mg/kg) by itself significantly reduced the mean frequency of vomits (70%) and fully protected least shrews from vomiting (46%) during the delayed-phase of cisplatin (10 mg/kg)-evoked vomiting. Although, pranlukast tended to substantially reduce both the mean frequency of vomits and the number of shrews vomiting during the early-phase, these reductions failed to attain significance. When combined with a first (tropisetron)- or a second (palonosetron)-generation 5-HT 3 receptor antagonist, pranlukast potentiated their antiemetic efficacy during both phases of vomiting. In addition, pranlukast by itself prevented several intracellular signal markers of cisplatin-evoked delayed-vomiting such as phosphorylation of ERK1/2 and PKA. When pranlukast was combined with either palonosetron or tropisetron, these combinations suppressed the evoked phosphorylation of: i) ERK1/2 during both acute- and delayed-phase, ii) PKCα/β at the peak acute-phase, and iii) PKA at the peak delayed-phase. The current and our published findings suggest that overall behavioral and intracellular signaling effects of pranlukast via blockade of CysLT1 receptors generally appear to be similar to the NK 1 receptor antagonist netupitant with some differences. [ABSTRACT FROM AUTHOR]

Pranlukast is a potent selective cysteniyl leukotriene receptor antagonist to treat bronchial asthma and allergic rhinitis, which exists in several crystal forms. In this work, solution-mediated phase transformation process from Pranlukast DMF solvate to the hemihydrate form was studied by using the focused beam reflectance measurement probe combined with powder X-ray diffraction. The influence factors such as temperature, solvent composition, amount of added solid, and stirring rate were investigated. Results showed that higher temperature, larger mole fraction of water, lower amount of added solid, and faster stirring rate could accelerate the solution-mediated phase transformation process. [ABSTRACT FROM AUTHOR]

Ampelopsin (AMP) is isolated from the Chinese medicinal herb Ampelopsis grossedentata (Hand-Mazz) and has been associated with numerous biological and pharmacological activities. However, it is not clear whether AMP has a direct protective effect on cerebral ischemia reperfusion injury. Therefore, the present study investigated its role in acute brain injury following focal cerebral ischemia in rats. The current study induced transient focal cerebral ischemia by performing middle cerebral artery occlusion (MCAO) for 60 min, followed by 24 h of reperfusion. Rats were exposed to 40, 80 and 160 mg/kg AMP by oral administration 30 min prior to MCAO and the cysteinyl leukotriene receptor 1-antagonist, pranlukast (0.1 mg/kg, i.p.) was used as a positive control. Neurological deficit scores were observed and an inclined board test was used to assess behavioral dysfunction. The coronal slices were stained with 3,5-triphenyltetrazolium chloride to determine the infarct volume and brain edema. Neuronal morphology was assessed in brain sections stained with cresyl violet and degenerating neurons were identified using Fluoro-Jade B staining. Blood-brain barrier permeability was determined with immunoglobulin (Ig)G immunohistochemistry. Interleukin (IL)-1β, tumor necrosis factor-α (TNF-α) in serum and cerebrospinal fluid were measured using ELISA kits. AMP at 80 and 160 mg/kg attenuated neurological deficits, reduced infarct volume, brain edema, IgG exudation and neuron degeneration and loss. Similar to pranlukast, AMP also inhibited the MCAO-induced IL-1β and TNF-α release. Thus, AMP has a neuroprotective effect on acute brain injury following focal cerebral ischemia in rats at an effective oral dose of 80-160 mg/kg. The results of the current study indicate a therapeutic role for AMP in the treatment of ischemic stroke. [ABSTRACT FROM AUTHOR]

Our previous studies showed that cysteinyl leukotrienes receptor 1 (CysLT 1 R) is upregulated in amyloid-β (Aβ)-induced neurotoxicity and that administration of CysLT 1 R antagonists such as pranlukast or montelukast can ameliorate memory impairment in mice. In the current study, we sought to explore the role of CysLT 1 R in intracerebroventricular streptozotocin (STZ-ICV)-induced mouse model of memory impairment and neuroinflammation through shRNA-mediated knockdown of CysLT 1 R and also its pharmacological blockade by pranlukast. ICR mice were infused with STZ (3.0 mg/kg) by a single bilateral stereotaxic ICV microinjection followed by administration of CysLT 1 R-shRNA (intra-hippocampal) or pranlukast (intragastric, IG). After 21 days, a set of behavioral and biochemical tests were performed in order to assess the degree of memory impairment and neuroinflammation in mice. STZ-infused mice spent less time in the target quadrant of Morris water maze test and took more time to find the shock-free arm in modified Y-maze test, which were rescued in the CysLT 1 R-knockdowned or pranlukast-treated mice. STZ-induced memory impairment was also accompanied by an elevated level of hippocampal CysLT 1 R, microglial activation, increased IL-1β, and TNF-α. Such elevation of these factors was found to be mediated through the classical NF-κB pathway and administration of CysLT 1 R-shRNA or pranlukast for 21 days reversed all these parameters, suggesting a role of CysLT 1 R in STZ-induced memory deficit and neuroinflammation. [ABSTRACT FROM AUTHOR]

Previously we reported that cysteinyl leukotrienes (Cys-LTs) and the type 1 receptor for Cys-LTs (CysLT 1 R) are related to amyloid β (Aβ)-induced neurotoxicity. The aim of the current study was to find out the role of CysLT 1 R on lipopolysaccharide (LPS)-induced cognitive deficit and neurotoxicity. shRNA-mediated knockdown or pharmacological blockade (by pranlukast) of CysLT 1 R were performed in ICR mice for 21 days prior to systemic infusion of LPS. From day 22, LPS was administered for 7 days and then a set of behavioral, histopathological and biochemical tests were employed to test memory, neuroinflammation and apoptotic responses in the mouse hippocampus. LPS (only)-treated mice showed poor performance in both Morris water maze (MWM) and Y-maze tests. However, shRNA-mediated knockdown or pranlukast-treated blockade of CysLT 1 R improved performance of the mice in these tests. To find out the possible underlying mechanisms, we assessed several parameters such as microglial activation (by immunohistochemistry), level of CysLT 1 R (by WB and qRT-PCR) and the inflammatory/apoptotic pathways (by ELISA or TUNEL or WB) in the mouse hippocampus. LPS-induced memory impairment was accompanied by activation of microglia, higher level of CysLT 1 R, IL-1β, TNF-α and nuclear NF-κB p65. LPS also caused apoptosis in the hippocampus as detected by TUNEL staining, further supplemented by detection of increased Caspase-3 and a reduced Bcl-2/Bax ratio. All of these adverse changes in the mouse hippocampus were inhibited by pretreatment with CysLT 1 R-shRNA and pranlukast. Through this study we suggest that CysLT 1 R shares a strong correlation with LPS-associated memory deficit, neuroinflammation and apoptosis and CysLT 1 R could be a novel target for preventive measures to intervene the progression of Alzheimer’s disease (AD)-like phenotypes. [ABSTRACT FROM AUTHOR]

Background: During the course of development of montelukast, a cysteinyl leukotriene receptor 1 antagonist, for treatment of seasonal allergic rhinitis, a double-blind, non-inferiority study was carried out to evaluate the efficacy and safety of montelukast 5 mg and 10 mg compared with pranlukast 450 mg, which has a similar mechanism of action. Methods: Montelukast 5 mg, 10 mg or pranlukast 450 mg and the corresponding placebo were orally administered to patients with seasonal allergic rhinitis three times a day for 2 weeks. Non-inferior efficacy of montelukast 5 mg and 10 mg to pranlukast 450 mg was investigated by the change from the baseline in the composite nasal symptoms scores over the 2-week treatment period. Results: Montelukast 5 mg, 10 mg once daily and the pranlukast 450 mg/day showed significant improvements in the change from the baseline in the composite, daytime and nighttime nasal symptom scores, and the improvement lasted for 2 weeks. Montelukast 5 mg and 10 mg were non-inferior to pranlukast 450 mg in the change from the baseline in the composite nasal symptoms scores. The incidence rates of adverse experiences and drug-related adverse experiences were not significantly different among the three treatment groups. Conclusions: The results indicate that administration of montelukast 5 mg and 10 mg once daily are potent alternatives for the treatment of seasonal allergic rhinitis and demonstrated that the efficacy and the safety profiles are comparable with pranlukast 450 mg/day.

We developed a synthetic route for producing 3-amino-2-hydroxy acetophenone (3AHAP) from m-nitroacetophenone (3NAP) using an in vitro approach. Various reaction systems were evaluated, and a direct reaction method with crude enzyme and supersaturated substrates for optimal catalytic efficiency was chosen. The reaction system included three enzymes and was enhanced by adjusting enzyme molar ratios and optimizing ribosomal binding sites. We performed substrate docking and alanine scanning to identify key sites in the enzymes nitrobenzene nitroreductase (nbzA) and hydroxylaminobenzene mutase (habA). The optimal mutant was obtained through site-directed mutagenesis, and incorporated into the reaction system, resulting in increased product yield. After optimization, the yield of 3AHAP increased from 75 mg/L to 580 mg/L within 5 hours, the highest reported yield using biosynthesis. This work provides a promising strategy for the efficient and sustainable production of 3AHAP, which has critical applications in the chemical and pharmaceutical industries., (© 2023 Wiley-VCH GmbH.)

Objective Conventional treatment for acute otitis media mainly targets bacteria with antibiotics, neglecting to control for mediators of inflammation. Mediators of inflammation, such as leukotrienes, have been identified in patients with acute otitis media (AOM) or subsequent secretory otitis media (SOM). They can cause functional eustachian tube dysfunction or increase mucous in the middle ear, causing persistent SOM following AOM. The objective of the present study was to evaluate whether or not administration of pranlukast, a widely used leukotriene C4, D4, and E4 antagonist, together with antibiotics could inhibit the progression to SOM. Methods Children with AOM, who were from two to 12 years old, were randomly divided into two groups as follows: a control group in which 50 patients received antibiotic-based conventional treatment according to guidelines for treating AOM proposed by the Japan Otological Society (version 2006); and a pranlukast group, in which 52 patients were administered pranlukast for up to 28 days as well as given conventional treatment. Cases were regarded as persistent SOM when a tympanogram was type B or C2 four weeks after treatment was initiated. Results Two patients in the pranlukast group and 3 patients in the control group were excluded because they relapsed AOM within 28 days after initial treatment. Therefore, the analysis included 50 and 47 subjects in the pranlukast and control groups, respectively. The percentage of patients diagnosed with persistent SOM (22.0%) was significantly smaller in the pranlukast group compared with the control group (44.7%) ( p = 0.018, chi-squared test). Conclusion The results indicate that combined treatment of AOM with antibiotics and a leukotriene antagonist to control inflammation is useful for preventing progression to persistent SOM. [ABSTRACT FROM AUTHOR]

Objectives: To study the binding of pranlukast to hRKIP and its regulatory role in the Raf1/MEK/ERK signal pathway. Results: NMR and fluorescence experiments demonstrated hRKIP could bind pranlukast with a binding constant of 1016 mM. Residues (Y81, S109 and Y181) on the conserved ligand-binding pocket of hRKIP played a crucial role in binding pranlukast, and their mutations reduced the binding affinity more than 85 %. Furthermore, 25 μM pranlukast could up-regulate the ERK phosphorylation by about 17 %. Conclusion: Pranlukast may be used as a potential drug precursor for treating hRKIP involved diseases. [ABSTRACT FROM AUTHOR]

Background: Pranlukast and Montelukast are Cysteinyl leukotriene receptor antagonists with almost the same pharmacological activity. However, I will describe a case in which these drugs showed different therapeutic effects on clinical symptoms during the daytime and eosinophilic inflammation in the peripheral airway. Methods: A 70-year-old male patient with non-atopic bronchial asthma who was treated with 400 μg/day of Budesonide Turbuhaler® (BUD-TH) changed from Pranlukast (225 mg, twice daily) to Montelukast (10 mg, one tablet before sleeping), resulting in worsening clinical symptoms consisting of sputum and cough in the daytime, mainly at lunch time. Due to the fact that the symptoms did not improve sufficiently, instead of increasing the dose of BUD-TH, we investigated the clinical symptoms and pulmonary functions as well as measured the mean eosinophil count, eosinophil cationic protein (ECP) and eotaxin in the hypertonic saline-induced sputum prior to administration of Pranlukast, and 4 and 8 weeks after the re-administration of Pranlukast from Montelukast. Results: Following the re-administration of Pranlukast, the clinical symptoms disappeared within a few days and pulmonary function improved within 4 weeks. Eosinophils in the induced sputum almost completely disappeared for 4 weeks. The sputum ECP and eotaxin before and 4 weeks after the re-administration of Pranlukast changed from 700 μg/l to 192 μg/l, and 69.9 pg/ml to 30.6 pg/ml, respectively. After 8 weeks, no sputum induction was found. Conclusions: The clinical difference between these two similar antagonists may be caused by the time difference relating to when and how often each drug is administered, suggesting the existence of the lunchtime dip.

Background: This is the first report about the pharmacokinetics (PK) of pranlukast in children. The aim of the present study was to assess the PK parameters of pranlukast in children and to compare them with those in adults. Methods: Six healthy adult male volunteers and 22 children with bronchial asthma at 3–14 years of age were enrolled in the study. Both 225 and 112.5 mg pranlukast hydrate dry syrup was administered orally to adults, whereas 3.5 mg/kg pranlukast hydrate dry syrup was given to children. Blood samples were obtained at approximately 20 time points per adult (n=121) and at two or three time points per child (n=54). Population PK analysis was performed using NONMEM (Globomax, Hanover, MD, USA). The concentration-time-course of pranlukast was described by using a one-compartment model with first-order absorption. The robustness of the final model was evaluated using 200 bootstrap samples. Results: Apparent clearance (CL/F) was 1.81 and 1.14 L/h per kg in children and adults, respectively. According to subgrouping of children, no significant difference was observed in CL/F between infants (3–6 years of age) and schoolchildren (7–14 years of age). The interindividual variability of CL/F accounted for 48.7%. The additive and proportional residual variability was 7.33 ng/mL and 73.8%, respectively. All fixed effect parameters fell within 10% of the bootstrapped mean. Conclusions: Compared with adults, children showed a higher CL/F and more rapid elimination after ingestion of pranlukast hydrate dry syrup. However, no significant variation was seen in CL/F between infants and schoolchildren.

Although the efficacy of cysteinyl leukotriene receptor antagonists in asthma therapy has been established through controlled clinical trials, there are no data concerning the effectiveness of their use in clinical practice, in which there is no rigid selection based on specific inclusion and exclusion criteria. The aim of the present study was to evaluate the effectiveness of pranlukast in clinical practice. More than 2500 outpatients with mild to severe persistent asthma answered an input questionnaire, which consisted of 33 items assessing asthma symptoms in terms of six activities of daily living during the previous 2 weeks. Of these patients, 1138 received treatment with pranlukast and answered the same questionnaire 4–6 weeks after the start of treatment. In 923 of these 1138 patients, we examined the impact of concomitantly used inhaled steroids, β2-adrenergic agonists or sustained-release theophylline on the effectiveness of pranlukast treatment. One hundred and sixty-seven control patients completed the questionnaire twice but did not receive pranlukast treatment. We found a significant decrease in the number of asthma symptoms reported among both the 1138 patients treated with pranlukast and the 167 control patients. However, the magnitude of the decrease in symptoms was significantly (P < 0.001) greater with pranlukast treatment. Moreover, pranlukast was equally efficacious in the presence and absence of concomitantly used inhaled steroids, β2-adrenergic agonists or sustained-release theophylline. In conclusion, pranlukast was shown to have clinical effectiveness in the treatment of mild to severe persistent asthma symptoms.

Pranlukast (PRS) is a leukotriene receptor antagonist for the treatment of bronchial asthma. In this study, six new solvates and one new cocrystal of PRS were characterized by PXRD, TG–DTA, DSC, vapor sorption analysis and the dissolution test. In addition, the crystal structures were determined by single crystal X-ray structure analysis. PRS was found to be a rare example of a promiscuous multicomponent crystal former. The crystal packing patterns of these crystals can be categorized into the sheet-like and channel-like patterns. The ethanol solvate (PRS/ethanol) and urea cocrystal (PRS/urea) were more stable than the others under humid conditions. PRS/ethanol showed an improved dissolution profile compared to PRS HH and PRS/urea. [ABSTRACT FROM AUTHOR]

Pranlukast (PRS) is a leukotriene receptor antagonist for the treatment of bronchial asthma. Pranlukast is formulated as a hemihydrate (HH) form in the drug product. Here, we report three new anhydrate forms of PRS (AH, form I–III). These polymorphs and PRS HH were characterized by PXRD, TG-DTA, simultaneous PXRD-DSC and vapor sorption analysis. In addition, the crystal structures of HH and AH-I were determined by single crystal X-ray structure analysis for the first time. HH transformed to AH-I, AH-II and AH-III as the temperature was increased from 25 °C to 210 °C. At 25 °C, AH-I transformed to HH at above 5%RH. HH and AH-I possessed similar crystal packing patterns and molecular structures. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to investigate the effect of particle size on the dissolution and oral absorption of pranlukast microsuspensions and nanosuspensions stabilized by hydroxypropylmethyl cellulose. Four pranlukast suspensions with different mean particle sizes (0.16, 0.89, 3.13, and 18.21μm) were prepared by various top-down processes such as jet milling, high pressure homogenization, and bead milling. The dissolution rate and oral absorption of pranlukast suspensions were significantly affected by the particle size. The in vivo pharmacokinetic parameters of pranlukast suspensions were increased with decreasing mean particle size of suspensions. Especially, the AUC0→24h and C max values of pranlukast nanosuspension with a particle size of 0.16μm were approximately 3.5- and 6.3-fold greater, respectively, than that of pranlukast microsuspension with a particle size of 18.21μm. Therefore, the preliminary results from our study suggest that a pranlukast nanosuspension with a mean particle size of about 0.16μm may have significant potential for clinical application. [Copyright &y& Elsevier]

Deposition of extracellular amyloid-β (Aβ) peptide is one of the pathological hallmarks of Alzheimer's disease (AD). Accumulation of Aβ is thought to associate with cognition deficits, neuroinflammation and apoptosis observed in AD. However, effective neuroprotective approaches against Aß neurotoxicity are unavailable. In the present study, we analysed the effects of pranlukast, a selective cysteinyl leukotriene receptor 1 (CysLT)R) antagonist, on the impairment of learning and memory formation induced by Aß and the probable underlying electrophysiological and molecular mechanisms. We found that bilateral intrahippocampal injection of Aβ1-42 resulted in a significant decline of spatial learning and memory of mice in the Morris water maze (MWM) and Y-maze tests, together with a serious depression of in vivo hippocampal long-term potentiation (LTP) in the CAI region of the mice. Importantly, this treatment caused significant increases in CysLTiR expression and subsequent NF-/cB signaling, caspase-3 activation and Bcl-2 downregulation in the hippo-campus or prefrontal cortex. Oral administration of pranlukast at 0.4 or 0.8 mg/kg for 4 wk significantly reversed Aβ1-42-induced impairments of cognitive function and hippocampal LTP in mice. Furthermore, pranlukast reversed Aβ1-42-induced CysLT1R upregulation, and markedly suppressed the Aβ-triggered NF-KB pathway, caspase-3 activation and Bcl-2 downregulation in the hippocampus and prefrontal cortex in mice. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay confirmed its presence in the brain after oral administration of pranlukast in mice. These data disclose novel findings about the therapeutic potential of pranlukast, revealing a previously unknown therapeutic possibility to treat memory deficits associated with AD. [ABSTRACT FROM AUTHOR]

Abstract: Cysteinyl leukotriene receptor 1 (CysLT1 receptor) antagonists were found to inhibit chloride secretion in human airway epithelial cells. Since chloride secretion in renal epithelial cells, which shares common mechanisms with airway epithelial cells, plays important roles in renal cyst progression in polycystic kidney disease (PKD), this study was aimed to investigate effects of drugs acting as CysLT1 receptor antagonists on renal cyst progression and its underlying mechanisms. Effects of CysLT1 receptor antagonists on renal cyst growth and formation were determined using Madine Darby canine kidney (MDCK) cyst models. Mechanisms of actions of CysLT1 receptor antagonists were determined using short-circuit current measurement, assays of cell viability and cell proliferation, and immunoblot analysis of signaling proteins. Of the three drugs acting as CysLT1 receptor antagonists (montelukast, pranlukast and zafirlukast) tested, pranlukast was the most promising drug that inhibited MDCK cyst growth and formation without affecting cell viability. Its effect was independent of the inhibition of CysLT1 receptors. Instead, it reduced cAMP-activated chloride secretion and proliferation of MDCK cells in an AMP-activated protein kinase (AMPK)-dependent manner and had no effect on CFTR protein expression. Interestingly, pranlukast enhanced AMPK activation via calcium/calmodulin-dependent protein kinase kinase beta (CaMKKβ) with consequent activation of acetyl-CoA carboxylase (ACC) and suppression of mammalian target of rapamycin (mTOR) pathway. These results indicate that pranlukast retards renal epithelial cyst progression by inhibiting cAMP-activated chloride secretion and cell proliferation via CaMKKβ-AMPK-mTOR pathway. Therefore, pranlukast represents a class of known drugs that may have potential utility in PKD treatment. [Copyright &y& Elsevier]

Newly emerging roles of LRRC8 volume-regulated anion channels (VRAC) raise important questions about the therapeutic potential of VRAC in the treatment of epilepsy, type 2 diabetes, and other human diseases. A critical barrier to evaluating whether VRAC represents a viable drug target is the lack of potent and specific small-molecule inhibitors and activators of the channel. Here we review recent progress in developing the molecular pharmacology of VRAC made by screening a library of FDA-approved drugs for novel channel modulators. We discuss the discovery and characterization of cysteinyl leukotriene receptor antagonists Pranlukast and Zafirlukast as novel VRAC inhibitors, and zinc pyrithione (ZPT), which apparently activates VRAC through a reactive oxygen species (ROS)-dependent mechanism. These ongoing efforts set the stage for developing a pharmacological toolkit for probing the integrative physiology, molecular pharmacology, and therapeutic potential of VRAC.

Abstract: Because of their favourable safety profile and beneficial anti-inflammatory properties, the CysLT1 receptor antagonists (LTRA), montelukast, zafirlukast and pranlukast are approved for the treatment of asthma and are frequently prescribed as add-on therapeutics to reduce the amount of inhaled glucocorticoids and β2-agonists. There is evidence that some of these anti-inflammatory properties might be of a secondary nature and therefore, unrelated to the CysLT1 antagonism. Here, we show that LTRA inhibit PGE2 formation in cytokine-stimulated Hela and A549 carcinoma cells and in lipopolysaccharide (LPS)-stimulated human leukocyte preparations (IC 50 ∼20μM). Neither expression of enzymes involved in PGE2 synthesis nor arachidonic acid release and COX activities were inhibited by the compounds. In contrast, mPGES-1 activity was suppressed at low micromolar levels (IC 50 between 2 and 4μM). This suppression was specific for PGE2 synthesis, since PGD2 and PGI2 levels in LPS-stimulated leukocyte preparations were not negatively affected. PGF2α levels were concomitantly inhibited, probably due to its direct synthesis from PGE2. Several major conclusions can be drawn from this study: (A) clinical trials investigating elevated doses of the compounds are helpful to confirm suppression of PGE2 synthesis in vivo; (B) studies investigating the role of CysLTs in cell culture or animal models of inflammation and cancer have to be reassessed carefully, if higher doses of LTRA were applied or serum levels in cell culture assays were low; and (C) LTRA may serve as new scaffolds for the development of potent, selective and well tolerated mPGES-1 inhibitors. [Copyright &y& Elsevier]