N‑acetyl‑L‑cysteine protects rat lungs and RLE‑6TN cells from cigarette smoke‑induced oxidative stress.

Cigarette smoke (CS) is a key contributor of chronic obstructive pulmonary disease (COPD); however, its role in the pathogenesis of COPD has not been fully elucidated. N‑acetyl‑L‑cysteine (NAC), as an antioxidant, has been used in the treatment of COPD; however, the mechanisms of action of NAC are not fully understood. Alveolar epithelial type 2 (ATII) cells serve an essential role in the maintenance of alveolar integrity.