MPO and acute respiratory distress syndrome: In vivo examinations indicated that apremilast alleviated lung neutrophil infiltration, myeloperoxidase (MPO) activity, pulmonary oedema, and alveolar damage in LPS-induced ARDS.<h4>Conclusion</h4>Apremilast inhibits inflammatory responses after neutrophil activation via cAMP/PKA-dependent inhibition of ERK and JNK activation.