LC-MS-based metabolomics revealed promising role of leukotriene receptor antagonists against colorectal cancer.

Colorectal cancer (CRC) remains one of the leading causes of cancer-related mortality worldwide. Current treatments are often limited by multidrug resistance and significant side effects, underscoring the urgent need for novel therapeutic strategies. Leukotriene receptor antagonists (LTRAs), including montelukast, zafirlukast, and pranlukast, have shown promising anticancer potential; however, their underlying molecular mechanisms remain insufficiently understood. In this study, the antiproliferative effects of montelukast, zafirlukast, and pranlukast on CRC cell lines (HCT-116 and Caco-2) were evaluated using cell viability and proliferation assays. Montelukast and zafirlukast were further examined using a liquid chromatography-mass spectrometry (LC-MS)-based metabolomics to assess any possible metabolic alterations in HCT-116 cells, along with flow cytometry to determine their effects on cell death. Montelukast and zafirlukast were found to significantly inhibit the cell proliferation of HCT-116 in a dose-dependent manner, with IC₅₀ values of 57.4 μM and 73.28 μM, respectively. Flow cytometry demonstrated that apoptosis was the predominant mode of cell death with both drugs. Neither montelukast nor zafirlukast showed any significant in vitro antioxidant effects. LC-MS Metabolomics revealed that montelukast and zafirlukast induced distinct metabolic changes with 47 and 34 significantly altered metabolites, respectively. Montelukast notably affected mannosamine, 5-oxo-L-proline, acetyl-phenylalanine, acetoin, and taurine, implicating pathways related to amino acid metabolism, redox homeostasis, and mitochondrial function. In contrast, zafirlukast impacted nucleotide-related metabolites, including inosine, adenine, cytidine, deoxyguanosine, and itaconate, highlighting nucleotide biosynthesis and immunometabolism disruptions. These findings demonstrate the antiproliferative potential of montelukast and zafirlukast in CRC and provide new insights into their distinct molecular mechanisms of action. This supports their potential repurposing as adjunctive therapies in CRC treatment.