The effects of montelukast on eosinophilic gastroenteritis in a mouse model

Montelukast potentiates the antiinflammatory effect of NSAIDs in the rat paw formalin model and simultaneously minimizes the risk of gastric damage

OBJECTIVE AND DESIGN

Montelukast, a cysteinyl leukotriene receptor antagonist, exhibits antiinflammatory action. We tested whether exposure to montelukast plus nonsteroidal antiinflammatory drugs (NSAIDs) elicits better control of paw inflammation in the rat formalin test and improves associated gastric damage.

MATERIALS

A total of 46 adult male rats were used in the study.

TREATMENTS

We evaluated separate and combined effects of montelukast (20 mg/kg), celecoxib (COX2 inhibitor, 10 mg/kg), and diclofenac (nonselective COX1/COX2 inhibitor, 10 mg/kg) on paw and gastric damage in the rat formalin test.

RESULTS

Individual pretreatments of rats with montelukast, diclofenac, or celecoxib partly reduced formalin-induced increases in (i) paw edema, fibrosis, and inflammatory cells, (iii) serum interleukin-6 (IL-6) and leukotrienes (LTB4 and LTD4), and (iv) paw expressions of inducible nitric oxide synthase (iNOS) and COX2. These effects were accentuated in rats treated with montelukast plus diclofenac or montelukast plus celecoxib. Alternatively, montelukast or celecoxib, but not diclofenac, alleviated formalin-evoked gastric damage and increments in tumor necrosis factor-α and decrements in prostaglandin-E₂. These advantageous gastric influences were potentiated in rats treated with montelukast plus celecoxib.

CONCLUSIONS

While montelukast equally enhances antiinflammatory action of diclofenac or celecoxib via downregulating iNOS/COX2/LTs/IL-6 signaling, its gastroprotective action is preferentially potentiated by celecoxib.

Eicosanoid receptors: Targets for the treatment of disrupted intestinal epithelial homeostasis

The importance of cyclooxygenase and lipoxygenase pathways and the consequent eicosanoid synthesis in the physiology and pathophysiology of the intestinal epithelium is currently being established. Each eicosanoid (prostanoid, leukotriene, hydroxyeicosatetraenoic acid) preferentially recognizes one or more receptors coupled to one or more signal-transduction processes. This overview focuses on the role of eicosanoid receptors in the maintenance of intestinal epithelium physiology through the control of proliferation/differentiation/apoptosis processes. Furthermore, it is reported that the role of these receptors on the regulation of the barrier function of the intestinal epithelium have arisen through the regulation of absorption/secretion processes, tight-junction state and the control of the intestinal immune response. Also, this review considers the implication of AA cascade in the disruption of epithelial homeostasis during inflammatory bowel diseases and colorectal cancer as well as the therapeutic values and potential of the eicosanoid receptors as novel targets for the treatments of the pathologies above mentioned.

New efficacy of LTRAs (montelukast sodium): it possibly prevents food-induced abdominal symptoms during oral immunotherapy

BACKGROUND

The aim of the study was to elucidate whether leukotriene receptor antagonists (LTRAs) can prevent severe allergic reactions, which occur during oral immunotherapy (OIT) in children with food allergies.

FINDINGS

Five children with food allergies [3 allergic to hen's egg (HE), 1 to wheat, and one to cow's milk (CM); aged between 7 and 12 years; median, 8.5 years] who were started on LTRAs during OIT were retrospectively selected from among 63 children undergoing OIT. In the rush phase, after the administration of the initial dose which was set in open food challenge test, the subsequent doses were increased by approximately 1.2 times of the previous dose and were administered every 2 hours, 4 times a day. The target doses of hen's egg, wheat (udon noodle), and cow's milk in the rush phase were 50 g, 200 g, and 200 ml, respectively. The ingestion of the target dose was continued at home every day for at least a year in the maintained phase.Four participants experienced intractable abdominal pain during the rush phase; therefore, the loading dose was not increased in these children. However, the administration of LTRAs prevented their symptoms, resulting in the completion of the rush phase. One participant also experienced intractable abdominal pain during the maintenance phase. After receiving LTRAs, the target dose was able to tolerated.

CONCLUSION

The findings from this retrospective study suggest that the administration of LTRAs is useful for the prevention of adverse allergic reactions such as abdominal pain during OIT.