Objective: To investigate the effects of Kaixin Jieyu Decoction on the activity of inducible nitric oxide synthase(iNOS)

glutathione peroxidase(GSH-Px) and the content of nitric oxide(NO) in colon tissue of the depressed rats. So as to reveal partial mechanisms of Kaixin Jieyu Decoction for protecting colon of the depression rats. Method: Thirty male SD rats were evenly randomized into normal

model and Kaixin Jieyu Decoction groups

Depression model of rat was produced by using chronic unpredictable mild stress stimulation (forced ice-water swimming

electric shock

tail-clamping

etc) combined with lonely raising for 21 days.At the same time of producing the depression model rats

Kaixin Jieyu Decoction was given to the Kaixin Jieyu Decoction group rats(40g·kg-1)

once daily

continuously for 21 days.The activity of iNOS

GSH-Px and the content of NO in colon of the depressed rats were detected by ultraviolet spectrophotometer method. Result: The levels of iNOS and NO were increased significantly and the activity of GSH-Px was reduced significantly in colon of the model rats compared to that of the normal group (P<0.05); also the levels of iNOS and NO were reduced significantly

the activity of GSH-Px was increased significantly in colon of Kaixin Jieyu Decoction group compared to that of the model group (P<0.05). Conclusion: Kaixin Jieyu Decoction had protective effect for colon tissue function of the depressed rats.