As expected, CSD peptides enhanced HO-1 activity and alleviated pulmonary inflammation, which could be supported by the following evidences: (1) CSD peptides decreased the compartmentalization of HO-1 and Cav-1 on plasma membrane, raised HO-1 activity, and down-regulated the expression of pro-inflammatory cytokines in LPS-challenged AMs and mice; (2) CSD peptides drived macrophage polarization from M1 to M2 phenotype in vitro, inhibited the IκB degeneration and obviously ameliorated the pathology changes in vivo. Here, HMOX1 is linked to inflammation.