Selegiline’s Protective Role Against Elastase-Induced Oxidative Stress in A549 Cells via NRF2/Keap1 Pathway

Background: Chronic obstructive pulmonary disease (COPD) is a global health concern characterized by oxidative stress and inflammation leading to lung tissue damage. Elastase contributes to the progression of COPD by increasing reactive oxygen species (ROS) and degrading elastin. Selegiline, due to its antioxidant properties, demonstrates potential therapeutic benefits in COPD by modulating oxidative stress and improving lung function. Objectives: This study investigated selegiline’s ability to reduce oxidative stress in A549 lung epithelial cells via the NRF2/Keap1 pathway, focusing on the percentage change in ROS levels and the fold-change in NRF2 and Keap1 mRNA expression. Methods: Human lung epithelial A549 cells were cultured under standard conditions in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with 10% FBS and antibiotics. Six groups were established: Control, H2O2, elastase, and elastase co-treated with selegiline (20, 30, and 40 µM). Cell viability, ROS levels, catalase (CAT) activity, and mRNA expression of NRF2 and Keap1 were assessed using qRT-PCR, with GAPDH as the reference gene. Results: Elastase significantly increased ROS production and lipid peroxidation while suppressing antioxidant activity via downregulating NRF2 and Keap1 mRNA expression. Selegiline treatment, particularly at 20 µM, reduced ROS levels (P < 0.001), increased CAT activity (P < 0.001), significantly increased NRF2, and decreased Keap1 gene expression (P < 0.001), compared to the elastase group. Conclusions: Selegiline mitigates elastase-induced damage, suggesting its potential as a therapeutic agent for COPD. Selegiline also ameliorates the damaging impact of elastase on A549 cells by regulating the expression of the NRF2/Keap1 pathway. Hence, in vivo studies are recommended to confirm clinical relevance.