PingYu Capsule Activates cAMP/PKA/CREB Signaling Pathway in Rat Hippocampus: A Possible Mechanism for Antidepressant-Like Effect

PingYu capsule was a novel compound botanical drug, being composed of the extracts from Radix et Rhizoma Ginseng, Fructus Jujubae and Radix et Rhizoma Glycyrrhizae, which were the classical herbal medicines in China. Depression is one of psychological and/or physiological disorders. In the recent decades, depression affected the people´s health seriously. This study was designed to demonstrate the possible mechanism on antidepressant-like effect of PingYu capsule. Rats were used as an animal model and the hippocampus were removed from the rat brain after the administration of PingYu capsule 8 hours later. The weighed hippocampus were homogenized quickly and the total protein content, cyclic adenosine monophosphate (cAMP) level, cAMP dependent protein kinase (PKA) activity, and phosphorylated cAMP response element binding protein (CREB) level were examined via ELISA as well as the determination of phosphodiesterase type IV (PDE4) activity. As a result, the PDE4 activity was inhibited significantly by PingYu capsule at the dose of 0.5 mg/ml in vitro. The cAMP level, PKA activity, and Phospho- CREB level were all markedly increased after the treatment of PingYu capsule (50 mg/kg, p.o.) compared to the blank control. In conclusion, the possible mechanism on antidepressant-like effect of PingYu capsule was involved with the activation of cAMP / PKA / CREB Signaling Pathway.