Clarithromycin Prevents Smoke-induced Emphysema in Mice

Rationale: Modulating the low-grade chronic inflammation in chronic obstructive pulmonary disease remains challenging. Clarithromycin (CAM), a macrolide antibiotic, reportedly ameliorates chronic inflammation via mechanisms independent of its antibacterial activity.Objectives: The aim of this study was to examine whether CAM can prevent or reduce emphysema induced by chronic cigarette smoke exposure.Methods: Mice were exposed to cigarette smoke daily for 6 months and treated with orally administered CAM at doses of 25 to 100 mg/kg twice a day throughout the course of the experiment to test the preventive effects. The administration of CAM at 50 or 100 mg/kg was performed during the second half of a 6-month exposure period to assess the therapeutic effects. Histologic analysis was performed to evaluate the effect of CAM.Measurements and Main Results: CAM treatment for 6 months decreased airspace enlargement and the destruction of the alveolar walls and impaired the accumulation of macrophages in bronchoalv...