[Effects of Xiaotan Jieyu Recipe on behaviors of tumor-bearing rats with chronic mild stress and the mechanism].

Objective: To investigate the effects of unpredictable chronic mild stress and Xiaotan Jieyu Recipe (XTJYR), a compound traditional Chinese herbal medicine, on the behaviors of Walker 256 tumor-bearing rats and to explore the mechanism.

Methods: Sixty Wistar rats were randomly divided into control group, stress group, tumor-bearing group, stress plus tumor-bearing group, fluoxetine group and XTJYR group. After treatment, sucrose solution consumption, score of ethology, body weight and serum levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were detected, expressions of Bcl-2 and phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) proteins in hippocampus were detected by Western blotting method, and expression of Bcl-2 mRNA was measured by polymerase chain reaction method.

Results: Sucrose solution consumption, behavioral scores and body weight of rats were decreased in the stress group and the tumor-bearing group as compared with the control group. There were significant differences in expressions of Bcl-2 mRNA and Bcl-2 and p-ERK1/2 proteins in hippocampus and contents of serum TNF-alpha and IL-6 in the stress group and the tumor-bearing group as compared with those in the control group. XTJYR had the efficacy in improving behavioral scores of stress rats and tumor-bearing rats, down-regulating the contents of serum TNF-alpha and IL-6 and increasing the expressions of proteins of Bcl-2 and p-ERK1/2.

Conclusion: Tumor-bearing rats are prone to behave depressively after exposure to chronic mild stress and XTJYR can improve the behavioral scores of the rats. The mechanisms of XTJYR may relate to regulating contents of serum TNF-alpha and increasing the protein expressions of Bcl-2 and p-ERK1/2.