Objective: To observe the effect of acupoint application on transforming growth factor (TGF)-β 1/Smad 3 signaling pathway, so as to reveal its mechanism underlying improvement of airway remodeling in chronic asthma mice.
Methods: BALB/c mice were randomly divided into normal group,model group,sham acupoint application group (sham group),acupoint application group, and dexamethasone group (n=8 in each group). The chronic asthma model was established by intraperitoneal injection of ovalbumin sensitization. The acupoint application group was treated with plaster composed with White Mustard Seed, Rhizoma Corydalis, Unprocessed Radix Kansui, and Herba Asari, on bilateral "Feishu" (BL 13), "Xinshu" (BL 15) and "Geshu" (BL 17) points, 6 hours a day for 14 days. The sham group was treated with plaster containing vaseline on bilateral BL 13, BL 15 and BL 17, 6 hours a day for 14 days. The dexamethasone group was treated with dexamethasone 1 mg·kg-1·day-1 intraperi-toneally, once daily for 14 days. At the end of treatment, airway resistance was detected by mouse lung function instrument. Patho-logical changes of airway were observed under light microscope after hematoxylin-eosin staining, and the morphological parameters were measured by image analysis software. Immunohistochemistry method was used to detect the expression of TGF-β 1 and Smad 3 in the lung tissue of mice.
Results: Compared with the normal group, the airway resistance, the total bronchial wall area (WAt)/lumen perimeter (Pi), the smooth muscle wall area (WAm)/Pi, and the expression of TGF-β 1 and Smad 3 in the lung tissues were significantly higher in the model and sham groups (P<0.01). Compared with the model group and the sham group, the airway resistance, WAt/Pi, WAm/Pi, the expression of TGF-β 1 and Smad 3 in the lung tissues were decreased in the acupoint application group and the dexamethasone group (P<0.05). There were no significant differences between the acupoint application group and the dexamethasone group in the above mentioned indexes (P>0.05).
Conclusions: Acupoint application can improve airway remodeling by down-regulating the expression of TGF-β 1/Smad 3 in the airway of chronic asthmatic mice.