BACKGROUND: The purpose of the present study was to investigate the function and mechanism of dihydroartemisinin (DHA) in treating ovalbumin-induced asthma in BALB/c mice.

MATERIAL AND METHODS: Thirty female BALB/c mice were randomly separated into 3 groups: the control group, the asthma model group stimulated by ovalbumin (OVA group), and the DHA treatment group (DHA group). The therapeutic effects and potential pharmacological mechanisms of DHA were specifically clarified by examining its effects on asthma-related phenomena, such as body weight, lung function, cell counts in bronchoalveolar lavage fluid (BALF), and hemotoxin and eosin staining. In addition, the expression of inflammatory factors was checked by enzyme-linked immunosorbent assay kits, and fractions of Th17 cells were detected by FACS analysis. Moreover, the downstream molecular pathway of IL-6/Stat3 (interleukin-6/signal transducer and activator of transcription 3) and expression of miR-183C was investigated by western blot and/or quantitative real-time polymerase chain reaction. Luciferase assay was used to reveal the function of miR-183C on the transcriptional regulation of Foxo1 (forkhead box O).

RESULTS: DHA administration significantly relieved the severity of the asthma through its effect on body weight, survival rate, and airway pressure. DHA was able to ameliorate lung damage in terms of pathological morphology and it reduced the percentage of helper T 17 (Th17) cells and the secretion of cytokines. As a result, the activity of the IL-6/Stat3 pathway was inhibited by DHA. In addition, the adoption of DHA decreased the expression of miR-183C but increased the expression of the transcription factor Foxo1.

CONCLUSIONS: Our results suggest that the therapeutic effects of DHA on asthma are partially realized via the regulation of miR-183C and IL-6/Stat3 pathway.

Keywords: Artemisinins, Asthma, Forkhead Transcription Factors, Th17 Cells, Allergens, Bronchoalveolar Lavage Fluid, Cytokines, Lung, Ovalbumin, T-Lymphocytes, Regulatory