Mechanism of action of theophylline in bronchial asthma is :

Theophylline is used in bronchial asthma. Its mechanism of action is: Inhibition of phosphodiesterases particularly PDE-4. Antagonism of adenosine receptors. Enhancement of histone deacetylation. Acetylation of histone is required for activation of inflammatory gene tran­scription. By inhibiting this process, low-dose theophylline may restore responsiveness to corticosteroids.