Effect of Shuyusan on Behavior and Neuropeptide Expression in Hippocampus with Chronic Mild Unpredictable Stressors Depression-like Rats

Objective To investigate the effect of Shuyusan on the behavior, content of tumor necrosisfactor-α(TNF-α) in cortex of cerebral and neuropeptide expression in hippocampus of rats with chronic mild unpredictable stress(CMUS) depression. Methods Fifty mice were randomly divided into 5 groups:normal group, model group, fluoxetine group, and high-, low-dose group of Shuyusan. Except normal group, the other groups were given CMUS. Tail suspend test(TST) and sucrose preference test(SPT) were used to estimate animals' behavior. The contents of TNF-α was determined by enzyme linked immunosorbent assay(ELISA). The immunocytochemical technique was used to evaluate hippocampus neuropeptide immunoreactive expression. Results The fluoxetine group and high dose of Shuyusan group showed significant increase in the sucrose consumption and decrease in the immobility time in TST, there was significant difference compared with CMUS model group(P 0.05). The TNF-α level was significantly lower in fluoxetine group and high dose of Shuyusan group, there difference was significant compared with model group(P 0.05). The neuropeptide immunoreactive neurons in hippocampus area was decreased by a marked number in fluoxetine group and high dose of Shuyusan group, the average optical density decreased significantly, compared with the model group, there were significant differences(P 0.05). Conclusion Shuyusan has anti-depression likely effect, with dose-effect relationship