摘要Objective To investigate the protective effects of β-carotene in rats against the development of chronic bronchitis induced by cigarette smoking. Results Long-term cigarette smoking caused an obvious increase in the amount of IL-6, IL-8 and LPO and a sharp decrease in the levels of NO and SOD in smoking animals compared to controls. β-carotene intake reversed all the changes induced by smoking and alleviated the pathological changes caused by chronic bronchitis. Conclusions Quantitative oral intake of β-carotene had protective effects against chronic bronchitis induced by long-term cigarette smoking, which was associated with the increased production of NO, the clearance of some oxidative free radicals (OFR) and the alleviation of chronic inflammation.