Herbal formula SYJN increases neurotrophin-3 and nerve growth factor expression in brain regions of rats exposed to chronic unpredictable stress

Aim of the study: SYJN is a Chinese herbal formula that contains four herbs: Bupleurum chinense DC., Gamma aromatica Salisb.. Perilla frutescens (L) Britt., and Acorus tatarinowii Schott. Previous studies conducted in our laboratory have revealed an antidepressant-like effect of the formula in chronic unpredictable stress (CUS)-induced depression model in rats. The present study aimed to investigate whether neurotrophin-3 (NT-3) and nerve growth factor (NGF) are involved in the antidepressant-like action of SYJN by using the same depressive model in rats. Materials and methods: Rats were subjected to an experimental setting of CUS. The mechanism underlying the antidepressant-like action of SYJN was examined by measuring protein and mRNA expression of NT-3 and NGF in brain tissues of CUS-exposed rats. Results: The results showed that NT-3 protein and mRNA expression in the hippocampus and frontal cortex were significantly decreased in CUS-treated rats. CUS treatment also significantly decreased NGF protein and mRNA expression in the frontal cortex of the animals. Daily intragastric administration of SYJN (1300 or 2600 mg/kg/day) during the 4 weeks of CUS significantly suppressed these changes induced by CUS. Conclusion: The results suggest that the antidepressant-like activity of SYJN is likely mediated by the increases in NT-3 and NGF expression in brain tissues. Crown Copyright (C) 2010 Published by Elsevier Ireland Ltd. All rights reserved.