OBJECTIVE

To observe the effect of acupoint application of Chinese herbal medicines on pathological changes of pulmonary tissue in asthma rats so as to explore its underlying mechanism.

METHODS

A total of 33 Wistar rats were randomized into normal control (n=6), model (n=9), dexamethasone (DX, n=9) and acupoint-application (A-A, n=9) groups. Asthma model was established by intraperitoneal injection of 10% ovalbumin(OVA, 1 mL)and forced inhalation of atomized 2% OVA (25 mL) for 40 min, once daily for 2 weeks. "Dazhui" (GV 14). "Pishu" (BL 20), "Feishu" (BL 13) and "Shenshu" (BL 23) were selected for external application of Chinese medicinal herbs (pricklyash peel, white mustard seeds, asarum herb, etc.) for rats of A-A group, and that of control drugs (ang-kak, black rice, ginger juice, etc) for rats of DX group. Infiltration degrees of eosinophils (Eos), lymphocytes (L) and macrophages (MO) in the pulmonary tissue were observed under microscope. IL-4 and IFN-gamma expression was displayed by using immunohistochemical method.

RESULTS

In comparison with control group, the infiltration degrees of E(OS). L and Mphi increased significantly in model, DX and acupoint-application groups (P < 0.05, 0.01); while compared with model group, the infiltration of E(OS), L and Mphi in DX group, E(OS) in A-A group decreased significantly (P < 0.05, 0.01). No significant differences were found between DX and A-A groups in these 3 indexes (P>> 0.05). Results of immunohisto chemical staining in the lung tissue indicated that compared with control group, IL-4 expression in model increased significantly (P < 0.01), IFN-gamma expression decreased considerably in model and DX group (P < 0.01); when compared with model group, IL-4 in both A-A group and DX group decreased significantly, and IFN-gamma expression in A-A group increased considerably (P < 0.05, 0.01). No significant differences were found between DX and A-A groups in IL-4 expression (P>> 0.05).

CONCLUSIONS

Acupoint application of Chinese herbal medicines can balance Thl/Th2 and effectively reduce the infiltration of eosinophils, which may contribute to its therapeutic effect in relieving asthma.