Figure 2. Paeoniflorin reversed interferon (IFN)-α-induced depressive-like behaviors in vivo.

Experimental design. A. The antidepressant effects of dose-dependent paeoniflorin on IFN-α treated mice for 4weeks. B–H. Mice were pretreated with paeoniflorin 30 min before IFN-α injection for 4weeks. After the 28day IFN-α injection, the mice were subjected to the open field test to evaluate locomotive activity by total distance covered (B), central time (C), and number of vertical movements (D). After 2 weeks of IFN-α administration in the middle period of study, the sucrose preference test (E) was performed to identify whether paeoniflorin or escitalopram had already had an effect; neither was found to have a significant antidepressant effect at this time. After 4 weeks, the sucrose preference test (F), the tail suspension test (G), and the forced-swimming test (H) produced significantly different results in paeoniflorin-treated mice, particularly in the high-dose group, as well as with escitalopram, a commonly used agent for treating depression. n=10 mice per group. *p< 0.05,**p< 0.01,***p< 0.001, compared with the saline-treated group; #p< 0.05, ##p< 0.01, ###p< 0.001 compared with the IFN-α-treated group. Error bars: means±SEM.