Antidepressant-like effects of psoralen isolated from the seeds of Psoralea corylifolia in the mouse forced swimming test.

The forced swimming test (FST) is suggested to produce abnormalities in the serotonergic and hypothalamic-pituitary-adrenal (HPA) axis systems. Therefore, compounds that attenuate these neurobiological alterations may have potential as antidepressants. The behavioral and biochemical effects of psoralen, a major furocoumarin isolated from Psoralea corylifolia, were investigated in the FST model of depression in male mice. Psoralen significantly reduced immobility and increased swimming without altering climbing in the mouse FST. Psoralen remarkably reversed FST-induced alterations in serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels in frontal cortex and hippocampus in mice. Furthermore, psoralen attenuated FST-induced elevations in serum corticotropin-releasing factor (CRF) and corticosterone concentrations to normalize the HPA axis activity. These results suggested that psoralen possessed potent antidepressant-like properties which were at least in part mediated by improving the abnormalities in the serotonergic and the HPA axis systems.