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(M) in the pulmonary tissue were observed under microscope.IL-4 and IFN-γ expression was displayed by using immunohistochemical method.Results: In comparison with control group

the infiltration degrees of Eos

L and M increased significantly in model

DX and acupoint-application groups(P<0.05

0.01);while compared with model group

the infiltration of Eos

L and M in DX group

Eos 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-γ expression decreased considerably in model and DX group(P<0.01);when compared with model group

IL4 in both A-A group and DX group decreased significantly

and IFN-γ 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).Conclusion:Acupoint application of Chinese herbal medicines can balance Th1/Th2 and effectively reduce the infiltration of eosinophils

which may contribute to its therapeutic effect in relieving asthma.