SOD1 and chronic obstructive pulmonary disease: 2005). Fengbaisan represses the expression of MMP-9 and TIMP-1 in the bronchial and lung tissues of COPD rats and regulates the imbalance of MMP-9/TIMP-1 (Wang and Su 2011; Wang et al. 2014). Fengbaisan increases γ-GCS expression and SOD activity in the lung tissue of COPD rats, and it plays a vital role in anti-airway remodelling, antioxidative stress and delays the progression of COPD (Pan et al. 2009).