Antidepressant-like effects of Chaihu-Shugan-San via SAPK/JNK signal transduction in rat models of depression

Background: Chaihu-Shugan-San (CHSGS), a traditional Chinese medicinal herbal formula, registered in Jingyue Quanshu, has been indicated that oral administration of the extract from it can remit depressive disorder. C-Jun amino-terminal kinase (JNK/SAPK) signal transduction plays a key role in the apoptosis of nerve cells, be reported closely correlated with depression. This study was designed to investigate CHSGS antidepressant-like effects in rat models of depression and probe its possible mechanism. Materials and Methods: The classical experimental depression model chronic mild unpredictable stress (CMUS) was used to evaluate the antidepressant-like effects of CHSGS. The extracts were administered orally for 14 days, while the parallel positive control was given at the same time using fluoxetine hydrochloride. The expressions of JNK in the hippocampus were detected by real-time fluorescent quantitation PCR and Western blot assay. Results: Intragastric administration of CHSGS for 14 days caused a significant improvement of weight and locomotor activity in the open-field test. In addition, CHSGS treatment inhibited the expressions of JNK in the hippocampus tissue in CMUS rats. Conclusion: CHSGS could obviously improve the depressive state of the model rats and its mechanism may be correlated with regulating the expressions of JNK in the hippocampus.