RESUMO
<p><b>OBJECTIVE</b>To study on the effect and mechanism of curcumin on inhibiting injury induced by free radical in pulmonary fibrosis.</p><p><b>METHOD</b>One hundred and forty-four male SD rats were randomly divided into 6 groups (24 rats in each group). Rats in the model control group, positive medicine group, and high, moderate and low curcumin groups were injected with a single dose of bleomycin by trachea, and rats in sham-model control group with same volume normal saline. One day after the injection, curcumin solution of different dosages (200,100,50 mg x kg(-1) x d(-1)) was respectively given to rats in the high, moderate and low curcumin group by daily gastrogavage, while equal volume of normal saline was given to those in the sham-model control group and model control group, and an equal volume of prednisone (0.56 mg x kg(-1) x d(-1)) was saline was given to those in positive medicine control group. On the 7, 14, 28 days, the contents of GSH-Px, SOD, MDA and iNOS in pulmonary tissues of different groups were measured.</p><p><b>RESULT</b>Curcumin can raise the content of SOD and GSH-Px and lessen the level of MDA and iNOS.</p><p><b>CONCLUSION</b>Curcumin can regulate the level of free radical in the body of rats with pulmonary fibrosis and lessen the oxidative injury of pulmonary tissues caused by free radical, in the body of rats with pulmonary fibrosis. The mechanisms of curcumin on idiopathic pulmonary fibrosis lie in adjusting the level of free radical and inhibiting the injury of lung tissue induced by free radical.</p>