Abstract: AIM: To study the effect of Cough Ning on Chronic bronchitis.METHODS: The test of xylene-induced ear edema and the abdominal blood permeability in mice were used to investigate the anti-inflammatory effects of Cough Ning. While smoke-induced chronic bronchitis in rats was used to investigate the effect of Cough Ning. The pathomorphological changes in the bronchus and lung tissues were assessed by using an electron microscope. The content of MDA,SOD and NO in blood and lung tissues were measured.RESULTS: Compared with the model group, Cough Ning could significantly inhibit the edema induced by xylene, decrease abdominal blood capillary permeability of mice and reduce the pathological damage of bronchus and lung tissues in rats. It reduced the content of MDA but improved the content of SOD and NO in blood and lung tissues.CONCLUSION: Cough Ning has therapeutic effect on Chronic bronchitis, and the mechanism could be linked to its anti - oxidant effect.

Key words: Cough Ning, chronic bronchitis, antioxidation, NO