Lack of Effect of Oral Sulforaphane Administration on Nrf2 Expression in COPD: A Randomized, Double-Blind, Placebo Controlled Trial

Study answer

What this study found

Oral sulforaphane did not produce a meaningful biological or clinical benefit in COPD. It did not increase Nrf2 target gene expression in alveolar macrophages or bronchial epithelial cells, and the authors reported no effect on oxidative stress markers, inflammation, lung function, or patient-reported outcomes versus placebo. Key alveolar macrophage fold-changes at 4 weeks remained close to 1 for NQO1, HO1, AKR1C1, AKR1C3, Nrf2, and Keap1, with no significant dose effects; in bronchial epithelial cells, most markers were also unchanged. Sulforaphane was absorbed and generally well tolerated,…

Study & population

Randomized, double-blind, placebo-controlled trial in adults with COPD who were able to undergo bronchoscopy.

Intervention

Oral sulforaphane extracted from broccoli sprouts was given once daily for 4 weeks at two dose levels: 25 μmoles/day (4.4 mg/day) or 150 μmoles/day (26.6 mg/day).

Key limitation

The study was short duration (4 weeks) and relatively small, limiting power to detect modest effects.

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Original abstract