Dang Shen [Codonopsis pilosula (Franch.) Nannf] herbal formulae for chronic obstructive pulmonary disease: a systematic review and meta-analysis

This systematic review and meta-analysis assessed the efficacy and safety of Dang shen [Codonopsis pilosula (Franch.) Nannf., root] formulae for the treatment of chronic obstructive pulmonary disease (COPD). English and Chinese databases were searched, and 48 randomized controlled trials were included. Dang shen formulae improved lung function forced expiratory volume in 1 s compared with conventional pharmacotherapy (CP) [mean difference (MD) 0.22 L, 95% confidence interval (CI) 0.13-0.31, p<0.001, I2 = 5%] and quality of life (St. Georges Respiratory Questionnaire) compared with placebo (MD 7.19, 95% CI 10.82 to 3.56, p<0.001, I2 = 0%) and when combined with CP versus CP (MD 9.05, 95% CI 12.72 to 5.38, p<0.001, I2 = 89%). Dang shen formulae also increased distance walked in 6 min when combined with CP versus CP alone (MD 51.43 m, 95% CI 30.06-72.80, p<0.001, I2 = 27%) and reduced frequency/days with COPD exacerbations. Risk of bias was evaluated using the Cochrane tool. Methodological shortfalls were identified. Adverse events were low and not different between intervention and control groups. Thirty-three events were reported, including gastrointestinal upset, dry mouth, and insomnia. Dang shen formulae appear to improve some aspects of the included COPD outcomes. However, owing to methodological flaws, the current evidence is inadequate to support the routine use of Dang shen formulae outside of Chinese medicine practice. However, these results justify further investigation.