Objective      To investigate the effect of Zhaqijiangtang decoction (a traditional Chinese medicine) on the expression of nephrin in kidney of diabetic nephropathy (DN) rats and its mechanism.        Methods      A total of 60 SD rats were randomly divided into a normal control group

a model control group

a glibenclamide group

and Zhaqijiangtang decoction high-dose

middle-dose and low-dose groups. Except for the rats of the normal control group

the other rats were injected with streptozotocin (STZ) to establish DN model rats

and different drugs were intragastrically administered in each group. At the end of the 10th week

the renal tissues were collected to observe the pathological

and ultrastructural changes. The mRNA and protein expression levels of nephrin were determined by RT-PCR and Western blotting.       Results      Compared with the normal control group

the pathological and ultrastructural changes of renal tissues in the model control group were significantly different

and the mRNA and protein expression levels of nephrin were significantly lower (

P

0.01). The mRNA and protein expression levels of nephrin increased significantly in the Zhaqijiangtang decoction high-dose group and middle-dose group and glibenclamide group compared with the model control group (

P

0.05).       Conclusion      Zhaqijiangtang decoction has protective effect on kidney of DN rats

and the mechanism may involve reducing the injury of podocytes by up-regulating nephrin expression.