Background: The cysteinyl leukotriene receptor 1 (cysLTR1) antagonists are useful for oral treatment of bronchial asthma. The underlying mechanism of cysLTR1 antagonists on inhibition of inflammatory cytokine production is yet to be determined.
Objective: The present study was designed to determine the effect of pranlukast, a cysLTR1 antagonist, on production of inflammatory cytokines by allergen-stimulated peripheral blood monocytes (PBM) from atopic asthmatics.
Methods: PBM were obtained from normal control (n = 10) and Dermatophagoides farinae (Der f) allergen-sensitized atopic asthmatics (n = 12), and were cultured in the presence of Der f allergen. The production of TNF-alpha and nuclear-translocation of nuclear factor kappa B (NF-kappa B) was determined. In atopic asthmatics, pranlukast, tacrolimus or dexamethasone was added before stimulation by Der f. The additive effect of pranlukast and dexamethasone was also determined.
Results: PBM from atopic asthmatics cultured with Der f exhibited a significant increase in TNF-alpha production and nuclear translocation of NF-kappa B compared with normal control (P < 0.01). Pranlukast, tacrolimus and dexamethasone significantly inhibited production of TNF-alpha and nuclear-translocation of NF-kappa B in PBM of atopic asthmatics (P < 0.01). An additive effect of pranlukast on low-dose dexamethasone was also demonstrated. However, LTD4 did not induce TNF-alpha production or NF-kappa B nuclear translocation.
Conclusion: Our results suggest that pranlukast may inhibit TNF-alpha production via suppression of NF-kappa B activation through pathways distinct from cysLTR1 antagonism.