Beyond Nrf2 Activation: A Proposed Sulforaphane-Selenium Strategy for Oxidative Stress in COPD

Chronic Obstructive Pulmonary Disease (COPD) is characterized by marked and persistent oxidative stress, which contributes to chronic inflammation, cellular senescence, and progressive lung dysfunction. However, conventional therapies, including corticosteroids and traditional thiol-based antioxidants have shown limited ability to adequately address the underlying oxidant–antioxidant imbalance. Targeting the Nrf2 antioxidant pathway has therefore emerged as a promising therapeutic strategy however, a randomized, placebo-controlled clinical trial demonstrated that oral administration of the Nrf2 activator sulforaphane (SFN) for four weeks did not consistently stimulate the expression of Nrf2 target antioxidant genes in the lungs of patients with COPD. This finding raises the possibility that Nrf2 activation alone may be insufficient to restore effective antioxidant defense in COPD. To address this limitation, we propose a ROS-responsive nanoparticle-based co-delivery system for SFN and selenium. Such nanocarriers can be engineered to respond to elevated ROS levels through oxidation-sensitive components, enabling controlled release of their cargo within oxidative microenvironments. By combining SFN-mediated activation of the Nrf2 pathway with selenium-supported selenoprotein dependent redox defense, particularly thioredoxin reductase activity, this proposed complementary strategy is hypothesized to enhance antioxidant defense and reduce oxidative cellular damage compared with either component alone. This proposed framework provides a testable strategy for investigating whether coordinated targeting of Nrf2 activation and downstream redox machinery can overcome limitations associated with single-agent antioxidant approaches in COPD.