Abstract
Asthma is a well-known bronchial disease that causes bronchial inflammation, narrowing of the bronchial tubes, and bronchial mucus secretion, leading to bronchial blockade. In this study, we investigated the association between phosphodiesterase (PDE), specifically PDE1, and asthma using 3-isobutyl-1-methylxanthine (IBMX; a non-specific PDE inhibitor) and vinpocetine (Vinp; a PDE1 inhibitor). Balb/c mice were randomized to five treatment groups: control, ovalbumin (OVA), OVA + IBMX, OVA + Vinp, and OVA + dexamethasone (Dex). All mice were sensitized and challenged with OVA, except for the control group. IBMX, Vinp, or Dex was intraperitoneally administered 1 h before the challenge. Vinp treatment significantly inhibited the increase in airway hyper-responsiveness (P<0.001) and reduced the number of inflammatory cells, particularly eosinophils, in the lungs (P<0.01). It also ameliorated the damage to the bronchi and alveoli and decreased the OVA-specific IgE levels in serum, an indicator of allergic inflammation increased by OVA (P<0.05). Furthermore, the increase in interleukin-13, a known Th2 cytokine, was significantly decreased by Vinp (P<0.05), and Vinp regulated the release and mRNA expression of macrophage inflammatory protein-1β (MIP-1β) increased by OVA (P<0.05). Taken together, these results suggest that PDE1 is associated with allergic lung inflammation induced by OVA. Thus, PDE1 inhibitors can be a promising therapeutic target for the treatment of asthma.