Objective: To observe the protective effects and mechanism of Lianhua Qingwen (LHQW) capsule on lung tissue injury and expression of inflammatory cytokines in mice exposed to automobile exhaust. Method: Seventy-five healthy SPF male KM mice were randomly divided into 5 groups:normal group

model group

LHQW 2

4

8 g·kg-1 groups

and exposed to automobile exhaust in homemade cabinet in a noncontinuous way. The experimental animals were euthanatized 24 h later from the last exposure. The blood was used to detect the positive expression ratio of interleukin(IL) -4

IL-6 with flow cytometry. The serum of other animals was adopted to detect the content of IL-12 with ELISA. The pathological changes in lung tissue were determined with hematoxylin and eosin(HE) staining. Western-blot and real-time quantitative PCR were used to analyze the protein and mRNA expression of tumor necrosis factor-α(TNF-α)

IL-1β

IL-4

IL-6

IL-12 and IL-13 in lung tissue. Result: The visible bronchial epithelium swelling

epithelial cell proliferation

necrosis

alveolar hemorrhage and exudation

perivascular edema could be seen in model group

the injury of lung tissue in LHQW 4

8 g·kg-1 group was significantly reduced. The positive expression ratio of IL-6 was 20.1%

17.6%

11.4% in mice blood of LHQW 2

4

8 g·kg-1 group respectively

obviously lower than 32.9% in model group. Compared with normal group

the protein and mRNA expression of TNF-α

IL-1β

IL-4

IL-6

IL-12

IL-13 were significantly increased in the lung tissue of model group

and LHQW at the dose of 2

4

8 g·kg-1 could inhibit the expression at different extent. Conclusion: LHQW capsule could reduce the lung damage in mice exposed to automobile exhaust through reducing the content of inflammatory cytokines in the blood and lung tissues.