KP496 significantly inhibits acute (day 7) and chronic (day 21) lung inflammation. KP496 attenuates the number of lymphocytes on day 7 and those of macrophages, neutrophils, and eosinophils on days 7 and 21. KP496 and prednisolone significantly suppress the increase of hydroxyl-L-proline content in the lung. Compare to respective vehicle control group, the inhibition ratio of KP496 and prednisolone for increase of hydroxyl-L-proline content is about 74 and 63%, respectively. The KP496 (100 mg/head) group and prednisolone (10 mg/kg) group exhibit significant inhibition of numbers of infiltrating total cells, eosinophils, monocytes/macrophages, and lymphocytes compare with the control group. Infiltration of all types of cells except neutrophils is decreased in the KP496 (30m g/head) group, though not to significant extents.