Antidepression of Ping Yu Formula via the Regulation of cAMP Signaling Pathway

The study is aiming to investigate the anti-depression effect and possible mechanism of Pingyu Formula (Pingyu), which is an herbal supplement derived from Chinese Traditional Medicine. Tail suspension test (TST) and forced swimming test (FST) were used to investigate the anti-depression effect. The cyclic AMP (cAMP) levels, CREB and BDNF mRNA expression in rats' hippocampi were investigated via ELISA or RT-PCR method respectively. The results showed that Pingyu (75.0, 150 mg/kg, p.o.) reduced the duration of immobility in the FST and TST significantly, while the locomotor activity was not affected. Furthermore, the cAMP level was significantly increased after the treatment of Pingyu (50.0 mg/kg, p.o.) compared with the control group. Levels of the CREB-1, CREB-2 and BDNF mRNA expression were also increased after treatment of Pingyu. In summary, a possible pharmacological mechanism on anti-depression effect of Pingyu was related to the regulation of cAMP signaling pathway.