Pranlukast (ONO-1078) is a cysteinyl leukotriene receptor-1 antagonist. It antagonizes or reduces bronchospasm caused, principally in asthmatics, by an allergic reaction to accidentally or inadvertently encountered allergens.

LTD4:0.99 nM (Ki), LTC4:5640 nM (Ki), LTE4:0.63 nM (Ki)

Pranlukast significantly reduces the volume of injury in the cortical and hippocampal CA1 regions of the ischemic hemisphere in mice and increases neuronal density. Additionally, Pranlukast markedly thins the scar wall in the ischemic hemisphere of mice.

In sensitized guinea pig tracheas, 5 mM of either Pranlukast or Zafirlukast significantly inhibited ovalbumin-induced secretion by 70% and 65%, respectively. These compounds also markedly inhibited 35SO4 release triggered by 10 mM LTD4 in a concentration-dependent manner, with Pranlukast showing a peak inhibition of 83% and Zafirlukast 78% at 10 mM, having IC50 values of 0.3 mM and 0.6 mM, respectively. Pranlukast suppressed the activation of NF-κB in 1.3% DMSO-differentiated U-937 and Jurkat cells, with inhibition rates of 40% and 30%; it also demonstrated a dose-dependent inhibition of NF-κB activation in combination with MK-571. Pranlukast and MK-571 diminished LPS-induced IL-6 production in PBMCs by approximately 65% and 15%. Additionally, Pranlukast inhibited the activation of NF-κB induced by phorbol 12-myristate 13-acetate and significantly reduced LPS-induced MUC2 mRNA expression in NCI-H292 cells, as determined by reverse transcription-polymerase chain reaction. Pranlukast also suppressed the expression of the MUC2 gene in LPS-stimulated HM3-MUC2 cells.