Objective To explore the possible mechanism of Fuzheng Quxie Prescription in the treatment of chronic obstructive pulmonary disease in stable phase. Methods Fifty sixty Wistar rats were randomly divided into control group

model group

Fuzheng Quxie group and the antibiotic group

with 14 rats in each group. Except the control group

in the other groups

intratracheal instillation of elastase and bacteria were given to establish rat model with chronic obstructive pulmonary disease in stable phase. After model establishment

the control group and the modelgroup were gavaged with 2 ml of sterile saline; Fuzheng Quxie group was gavaged with 0. 95 g /（ kg · d） of Fuzheng Quxie Prescription

and all the groups were treated one time a day for one month. Antibiotic group was gavaged with 40 mg /（ kg·d） of moxifloxacin hydrochloride tablet

one time a day for 3 days

with one week as a circle

altogether for 4 circles. The pathology and the bacterial colony count of the lung tissue were examined before and after treatment

and the content of rat serum Toll like receptor 4（ TLR4）

nuclear factor κ B（ NF-κB）

β-defensins-2（ h BD-2） were detected. Results The pathological results showed that

in the model group

there were partial deformation

necrosis

and loss in bronchial epithelial cells

alveolar cavity enlargement

and the thinner alveolar

and a large number of inflammatory cell infiltration could be seen around; In each drug intervention group

there were different degree of alveolar structure disorder

alveolar cavity enlargement

the thinner alveolar wall

and alveolar fusion

and a small amount of inflammatory cells could be seen around. There were no isolated bacteria from the lung tissue homogenate of rats in control group before and after treatment. In the model group and the treatment groups

more or less bacteria were isolated

and the bacterial colony counts in each drug intervention group had a downward trend compared with those of before treatment. Compared with the control group

the serum levels of TLR4

NF-κB and h BD-2 were significantly increased in the model group before and after treatment（ P < 0. 05）; Before administration

the serum levels of TLR4

NF-κ B

h BD-2 in Fuzheng Quxie group and antibiotic group were also significantly higher than those in the control group; After administration

the serum levels of TLR4

NF-κB

h BD-2 in these two groups were significantly lower than those before treatment

and also significantly lower than those of the model group after administration（ P < 0. 05）. Conclusion Fuzheng Quxie Prescription could treat rats with chronic obstructive pulmonary disease in stable phase possibly through adjusting TLR4 / NF-κB / h BD-2 signal transduction pathway

regulating the immune inflammatory response

relatively increasing the lower airway tract bacterial load threshold

thus to reduce the damage of pathogens.