Abstract: Objective To investigate the impacts of dihydroartemisinin (DHA) on airway inflammation and lung injury in chronic obstructive pulmonary disease (COPD) rats by inhibiting interleukin (IL)-6/signal transducer and activator of transcription (STAT) 3 signaling pathway. Methods SD rats were randomly divided into control group, COPD group, low and high dose DHA (L-DHA, H-DHA) groups and neutralized IL-6 group. The inflammatory factors[IL-6, IL-1β, IL-17, tumor necrosis factor alpha (TNF-α)] in bronchoalveolar lavage fluid (BALF) were measured by ELISA; The total number of cells in BALF and the numbers of inflammatory cell types[eosinophils (Eos), neutrophils (Neu), lymphocytes (Lym)] were counted. The pathological changes of lung tissue were microscopied with HE staining and Masson staining; The expression of IL-6/STAT3 signaling pathway proteins in lung tissue was measured by Western blot. Results Compared with the control group, the level of IL-6, IL-1β, IL-17, TNF-α, the total number of cells, the numbers of Eos, Neu and Lym cells in the BALF of the COPD group all increased (P＜0.05); The lung tissue was obviously damaged, and the phosphorylation level of IL-6 protein and STAT3 in lung tissue increased (P＜0.05). After the intervention with L-DHA, H-DHA and neutralized IL-6, the above conditions were improved (P＜0.05). Conclusions DHA can reduce airway inflammation and lung tissue damage in COPD rat models, the potential mechanisms may be related to the inhibition of IL-6/STAT3 signaling pathway.

Key words: dihydroartemisinin, chronic obstructive pulmonary disease, IL-6/STAT3 signaling pathway, airway inflammation, lung injury