Modulation of Pulmonary Inflammation and the Redox Pathway In Vitro and In Vivo by Fumaric Ester

Chronic obstructive pulmonary disease (COPD) is characterized by chronic pulmonary inflammation and the destruction of the pulmonary parenchyma (emphysema), with only symptomatic treatment available. Molecules with antioxidant and anti-inflammatory properties, such as dimethyl fumarate (DMF), have shown therapeutic potential. This study evaluated the effects of DMF and its metabolite, monomethyl fumarate (MMF), on pulmonary inflammation induced by cigarette smoke (in vitro) and porcine pancreatic elastase (PPE) in mice (in vivo). In vitro, human pulmonary epithelial cells (PC-9) were treated with MMF at concentrations of 10, 30, and 100 µM and exposed to cigarette smoke extract (CSE) to assess cell viability, oxidative stress (ROS), lipid peroxidation, and nitrite production. In vivo, C57BL/6 mice were treated with DMF (30 and 100 mg/kg) during and after the induction of emphysema by PPE. ROS levels, total cell count in bronchoalveolar lavage fluid (BALF), lung histology, and the expression of oxidative stress proteins (SOD1 and HO-1) were analyzed. MMF reduced oxidative stress and lipid peroxidation under in vitro conditions. In vivo, DMF reduced ROS levels, inflammation, and prevented lung damage, such as alveolar enlargement. The expression of SOD1 and HO-1 was modulated by DMF treatment. The results suggest that DMF could be an effective therapeutic alternative for COPD, reducing oxidative stress and inflammation.