Effect of Psoralea corylifolia extract on physically induced depression in mice.

Abstract

The mouse forced swimming test (FST) and tail suspension test (TST) are widely used to predict anti-depressant efficacy indicated by immobility time to be reduced by several different classes of anti-depressant drugs. PCE feeding at the dose of 75,150 and 300 mg/kg reduced the immobility duration at 14-days and 21-days, however the decrease was significant in mice treated with PCE for 21-days also, extract had no effect on spontaneous motor activity in mice, indicating that extract had no excitatory or inhibitory action on central nervous system in effective dose range, which eliminated the probability of false-positive results in forced swimming test and tail suspension test. Interestingly, the dose-response effect of PCE on reduction of serum CRF levels was concomitance with that on increase of brain 5-HT contents, as well as on swimming increase, indicating that the serotonergic system and the HPA axis responds with the production of 5-HT and CRF profiles that is characteristic for PCE applied in the mouse FST. Our results demonstrate that the oral administration of PCE possesses an anti-depressant-like activity, as evidenced by behavioural studies. Detailed investigations are needed to fully elucidate the mechanism of action at cellular level for the bioactive constituents present in the extract.