Clarithromycin, montelukast, and pentoxifylline combination treatment ameliorates experimental neonatal hyperoxic lung injury

Antileukotrienes for the prevention and treatment of chronic lung disease in very preterm newborns: a systematic review

BACKGROUND

Very preterm infants are at high risk of developing chronic lung disease, which requires respiratory support and might have long-term sequelae. As lung inflammation plays an important role in pathogenesis, antileukotrienes have been explored in both clinical and animal studies. We aimed to assess the benefits and harms of antileukotrienes for the prevention and treatment of respiratory morbidity and mortality in very preterm newborns.

METHODS

In this systematic review, we included randomized trials and non-randomized studies in humans and animals reporting the effects of antileukotrienes in very preterm infants or other mammals within 10 days of birth. Our pre-specified primary outcomes were all-cause mortality and any harm, and, for the clinical studies, incidence of chronic lung disease. Included studies underwent risk of bias-assessment and data extraction performed by two authors independently. There were no language restrictions.

RESULTS

Fifteen studies totally met our inclusion criteria: one randomized trial and four non-randomized studies in humans and 10 animal studies (five in rodents, two in lambs and one in either guinea pigs, rabbits or caprinae). All five clinical studies used montelukast and had a small sample size, ranging from 4 to 77 infants. The randomized trial (n = 60) found no difference in the incidence of chronic lung disease between the groups. Only one clinical study, which enrolled four very preterm infants and had a critical overall risk of bias, reported long-term outcomes. All other studies had unclear or greater overall risk of bias and meta-analyses were therefore deemed unfeasible. Eight of ten animal studies used leukotriene receptor antagonists as antileukotriene (montelukast in three of ten studies) and seven had an experimental study design (i.e. some animals were not exposed to antileukotrienes but no randomization). Three of the ten animal studies assessed different doses. Animal studies found no effect on the outcomes mortality, growth, or lung function related surrogate outcomes.

CONCLUSIONS

Use of antileukotrienes in very preterm infants to prevent or treat chronic lung disease is not supported by the available evidence. Large randomized trials focusing on outcomes relevant to patients, including long-term outcomes, are needed. Studies should also minimize risk of bias.

Using Experimental Models to Identify Pathogenic Pathways and Putative Disease Management Targets in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a common and serious complication of preterm birth. Limited pharmacological and other medical interventions are currently available for the management of severely affected, very preterm infants. BPD can be modelled in preclinical studies using experimental animals, and experimental animal models have been extremely valuable in the development of hallmark clinical management strategies for BPD, including pulmonary surfactant replacement and single-course antenatal corticosteroids. A gradual move away from large animal models of BPD in favor of term-born rodents has facilitated the identification of a multitude of new mechanisms of normal and stunted lung development, but this has also potentially limited the utility of experimental animal models for the identification of pathogenic pathways and putative disease management targets in BPD. Indeed, more recent pharmacological interventions for the management of BPD that have been validated in randomized controlled trials have relied very little on preclinical data generated in experimental animal models. While rodent-based models of BPD have tremendous advantages in terms of the availability of genetic tools, they also have considerable drawbacks, including limited utility for studying breathing mechanics, gas exchange, and pulmonary hemodynamics; and they have a less relevant clinical context where lung prematurity and a background of infection are now rarely present in the pathophysiology under study. There is a pressing need to refine existing models to better recapitulate pathological processes at play in affected infants, in order to better evaluate new candidate pharmacological and other interventions for the management of BPD.

Effect of Montelukast on Bronchopulmonary Dysplasia (BPD) and Related Mechanisms

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/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-α, IL-6, and IL-1β) 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.