montelukast and Hyperoxia

BACKGROUND Bronchopulmonary dysplasia (BPD) is a chronic lung disease common in preterm infants. Montelukast, an effective cysteinyl leukotriene (cysLT) receptor antagonist, has a variety of pharmacological effects and has protective effects against a variety of diseases. Currently, the efficacy and safety of montelukast sodium in treating BPD has been revealed, however, the precise molecular mechanism of the effect of montelukast on BPD development remain largely unclear. Therefore, this study aimed to investigate the effect and mechanism of montelukast on BPD in vivo and in vitro. MATERIAL AND METHODS A mouse BPD model and hyperoxia-induced lung cell injury model were established and treated with montelukast. Then mean linear intercept (MLI), radial alveolar count (RAC), lung weight/body weight (LW/BW) ratio, pro-inflammatory factors, and oxidative stress-related factors in lung tissues were determined. Cell viability and apoptosis were detected using MTT assay and flow cytometer respectively. RESULTS The results showed that montelukast treatment relieved mouse BPD, evidenced by increased RAC and decreased MLI and LW/BW ratios. We also found that montelukast treatment reduced pro-inflammatory factors (TNF-alpha, IL-6, and IL-1ß) production, enhanced superoxide dismutase (SOD) activity, and reduced malondialdehyde (MDA) content in the lung tissues of BPD mice. Besides, montelukast eliminated the reduced cell viability and enhanced cell apoptosis induced by hyperoxia exposure in vitro. Moreover, the upregulated pro-inflammatory factors production and p-p65 protein level in lung cells caused by hyperoxia were decreased by montelukast treatment. CONCLUSIONS Montelukast protected against mouse BPD induced by hyperoxia through inhibiting inflammation, oxidative stress, and lung cell apoptosis.

Topics: Acetates; Animals; Animals, Newborn; Apoptosis; Bronchopulmonary Dysplasia; Cyclopropanes; Disease Models, Animal; Hyperoxia; Interleukin-1beta; Interleukin-6; Lung; Lung Injury; Mice; Mice, Inbred C57BL; Oxidative Stress; Quinolines; Receptors, Leukotriene; Sulfides; Tumor Necrosis Factor-alpha

Pathological ocular neovascularization is a major cause of blindness. Increased dietary intake of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) reduces retinal neovascularization and choroidal neovascularization (CNV), but ω-3 LCPUFA metabolites of a major metabolizing pathway, cytochrome P450 oxidase (CYP) 2C, promote ocular pathological angiogenesis. We hypothesized that inhibition of CYP2C activity will add to the protective effects of ω-3 LCPUFA on neovascular eye diseases.. The mouse models of oxygen-induced retinopathy and laser-induced CNV were used to investigate pathological angiogenesis in the retina and choroid, respectively. The plasma levels of ω-3 LCPUFA metabolites of CYP2C were determined by mass spectroscopy. Aortic ring and choroidal explant sprouting assays were used to investigate the effects of CYP2C inhibition and ω-3 LCPUFA-derived CYP2C metabolic products on angiogenesis ex vivo. We found that inhibition of CYP2C activity by montelukast added to the protective effects of ω-3 LCPUFA on retinal neovascularization and CNV by 30% and 20%, respectively. In CYP2C8-overexpressing mice fed a ω-3 LCPUFA diet, montelukast suppressed retinal neovascularization and CNV by 36% and 39% and reduced the plasma levels of CYP2C8 products. Soluble epoxide hydrolase inhibition, which blocks breakdown and inactivation of CYP2C ω-3 LCPUFA-derived active metabolites, increased oxygen-induced retinopathy and CNV in vivo. Exposure to selected ω-3 LCPUFA metabolites of CYP2C significantly reversed the suppression of both angiogenesis ex vivo and endothelial cell functions in vitro by the CYP2C inhibitor montelukast.. Inhibition of CYP2C activity adds to the protective effects of ω-3 LCPUFA on pathological retinal neovascularization and CNV.

Topics: Acetates; Angiogenesis Inhibitors; Animals; Aorta; Cells, Cultured; Choroidal Neovascularization; Cyclopropanes; Cytochrome P-450 CYP2C8; Cytochrome P-450 CYP2C8 Inhibitors; Disease Models, Animal; Endothelial Cells; Fatty Acids, Omega-3; Genotype; Humans; Hyperoxia; Lasers; Mice, Inbred C57BL; Mice, Transgenic; Neovascularization, Physiologic; Phenotype; Quinolines; Retinal Neovascularization; Retinopathy of Prematurity; Sulfides; Tissue Culture Techniques

Impaired lung development has been demonstrated in neonatal animals exposed to hyperoxia. High lung cys-leukotriene levels may be a contributing factor towards the increase in oxygen toxicity. We investigated the effect of cysteinyl-leukotriene inhibition using the receptor antagonist, montelukast (MK, Singulair), on hyperoxia-induced changes in lung parenchymal structure in neonatal rat pups. Rat pups were exposed to 21% O(2) (air) or 50% O(2) (moderate hyperoxia) from days 1-14 after birth, and were administered the cys-leukotriene receptor antagonist MK (1 mg/kg/day) or normal saline from days 4-14. Somatic growth and morphometric measurements were done on day 15. There was a significant increase in bronchoalveolar lavage fluid cysteinyl-leukotriene levels (+61.9%) when animals were exposed to hyperoxia. O(2) exposure significantly decreased the specific internal surface area by 13%. There was a nonsignificant 5.8% and 19.6% increase in mean chord length and mean alveolar diameter, respectively, as well as an 8.6% decrease in lung volume to body weight ratio. Inhibition of only one arm of the arachidonic-acid cascade by MK was not sufficient to prevent these oxygen-induced changes.

Topics: Acetates; Animals; Animals, Newborn; Cyclopropanes; Hyperoxia; Leukotriene Antagonists; Pulmonary Alveoli; Quinolines; Rats; Rats, Wistar; Sulfides