Zafirlukast 20mg tablets

Tumor necrosis factor (TNF) plays an important role in the pathogenesis of inflammatory and autoimmune diseases such as rheumatoid arthritis and Crohn's disease. The biological effects of TNF are mediated by binding to TNF receptors, TNF receptor 1 (TNFR1), or TNF receptor 2 (TNFR2), and this coupling makes TNFR1-specific inhibition by small-molecule therapies essential to avoid deleterious side effects. Recently, we engineered a time-resolved fluorescence resonance energy transfer biosensor for high-throughput screening of small molecules that modulate TNFR1 conformational states and identified zafirlukast as a compound that inhibits receptor activation, albeit at low potency. Here, we synthesized 16 analogues of zafirlukast and tested their potency and specificity for TNFR1 signaling. Using cell-based functional assays, we identified three analogues with significantly improved efficacy and potency, each of which induces a conformational change in the receptor (as measured by fluorescence resonance energy transfer (FRET) in cells). The best analogue decreased NF-κB activation by 2.2-fold, IκBα efficiency by 3.3-fold, and relative potency by two orders of magnitude. Importantly, we showed that the analogues do not block TNF binding to TNFR1 and that binding to the receptor's extracellular domain is strongly cooperative. Despite these improvements, the best candidate's maximum inhibition of NF-κB is only 63%, leaving room for further improvements to the zafirlukast scaffold to achieve full inhibition and prove its potential as a therapeutic lead. Interestingly, while we find that the analogues also bind to TNFR2 in vitro, they do not inhibit TNFR2 function in cells or cause any conformational changes upon binding. Thus, these lead compounds should also be used as reagents to study conformational-dependent activation of TNF receptors.

Abstract licence: CC BY-NC-ND

Acute lung injury (ALI) is the result of damage to the capillary endothelia and the alveolar epithelial cell caused by various direct and indirect factors, leading to significant pulmonary interstitial and alveolar edema and acute hypoxic respiratory insufficiency. A subset of ALI cases progresses to irreversible pulmonary fibrosis, a condition with fatal implications. Zafirlukast is a leukotriene receptor antagonist licensed for asthma prevention and long-term treatment. This study demonstrated a significant improvement in lung tissue pathology and a reduction in inflammatory cell infiltration in models of lipopolysaccharide (LPS)-induced ALI and bleomycin (BLM)-induced lung inflammation following zafirlukast administration, both in vivo and in vitro. Moreover, zafirlukast was found to suppress the inflammatory response of alveolar epithelial cells in vitro and lung inflammation in vivo by reducing the activation of the TLR4/NF-κB/NLRP3 inflammasome pathway. In conclusion, zafirlukast relieved lung injury and the infiltration of inflammatory cells in the lung by regulating the TLR4/NF-κB/NLRP3 pathway.

Abstract licence: CC BY-NC-ND

KIRI contains two stages of ischemia and reperfusion. During ischemia stage, the activating resident macrophage to emit macrophages extracellular traps (METosis), contributing to the initial renal inflammation. In the reperfusion stage, a substantial infiltration of peripheral macrophages is accumulated at the site of kidney injury and release inflammatory cytokines through METosis. The above processes contribute to the sterile inflammatory in renal, ultimately lead to acute renal failure and even death. Importantly, we found that Zafirlukast (ZFK) could prospectively target METosis and prevent KIRI development. Tacrolimus is widely used to prevent post-transplant acute kidney injury (AKI) but causes severe toxicities (e.g., nephrotoxicity, hyperglycemia). We repurposed zafirlukast (ZFK), an FDA-approved asthma drug, to address this limitation. In a murine kidney ischemia-reperfusion injury (KIRI) model, ZFK significantly attenuated renal dysfunction, reducing serum creatinine and blood urea nitrogen (BUN) to levels comparable to tacrolimus, without inducing metabolic adverse effects. RNA sequencing revealed that ZFK recapitulated tacrolimus' anti-inflammatory gene signatures while uniquely suppressing macrophage extracellular trap formation (METosis). Mechanistically, ZFK inhibited METosis by downregulating PAD4 and CitH3 expression, confirmed by immunofluorescence and flow cytometry. Single-cell transcriptomics (Tabula Muris and Human database) identified macrophages as the primary target via CysLT1R antagonism. This study provides the first evidence that ZFK protects against KIRI by targeting METosis, a key driver of sterile inflammation. Given its established safety profile, ZFK could bypass Phase I trials, accelerating clinical translation as a safer alternative to calcineurin inhibitors. Our findings also highlight the broader potential of ZFK in METs-related diseases (e.g., sepsis, atherosclerosis) and underscore drug repurposing as a strategic approach for rapid therapeutic development. • ZFK replicates tacrolimus' renoprotection in kidney ischemia-reperfusion injury while avoiding its metabolic toxicities. • ZFK attenuates KIRI by selectively suppressing METosis via PAD4 downregulation-a pathway unexplored in renal ischemia. • ZFK's FDA approval enables rapid clinical adoption as a safer alternative to calcineurin inhibitors in transplantation.

Abstract licence: CC BY-NC-ND

To investigate whether obstructing the cysteinyl leukotriene receptor-1 (CYSLTR1) with zafirlukast diminishes experimentally induced gastric ulcer (GU) in rats by modulating inflammation and apoptosis. Gastric ulcers affect approximately 10% of the global population and can lead to serious complications such as gastrointestinal perforation and bleeding. Leukotrienes are proinflammatory compounds, and cysteinyl leukotrienes, such as LTC4, LTD4, and LTE4, that are potent proinflammatory mediators. Rats were orally administered a single oral dose of 80 mg/kg of indomethacin to induce GU. The rats were administered an oral dose of 20 mg/kg Zafirlukast. Gastric tissues were collected for macrostructural and microstructural analyses. A portion of gastric tissue was used to assess the genetic expression and protein levels of CYSLTR1, NFκB, TNF-α, IL-1β/4/10, JNK, PKB, and caspase-3. The gastric sections were subjected to hematoxylin/eosin and Masson trichrome staining and immunohistochemical staining with anti-TNF-α and anti-caspase-3 antibodies. Zafirlukast blocked the expression of CYSLTR1. Analysis of micro-images of GU rats revealed damage to surface cells and glandular epithelial cells caused by inflammatory cell infiltration, which was mitigated by Zafirlukast. Additionally, Zafirlukast treatment significantly reduced NFκB, TNF-α, IL-1β, JNK, PKB, and caspase-3 while increasing IL-4 and IL-10. Zafirlukast successfully reduced experimentally induced gastric ulcers in rats. Its mechanism of action includes inhibition of CYSLTR1, diminishing the inflammatory pathway. This is demonstrated by a decrease in the levels of NFκB, TNF-α, and IL-1β, along with an increase in the levels of IL-4 and IL-10. Additionally, Zafirlukast exerted anti-apoptotic effects by downregulating the expression of JNK, PKB, and caspase-3.

Abstract licence: CC BY-NC