Ginsenosides modulate hypothalamic–pituitary–adrenal function by inhibiting FKBP51 on glucocorticoid receptor to ameliorate depression in mice exposed to chronic unpredictable mild stress

Abstract Depression, which affects millions of individuals worldwide, is associated with glucocorticoid (GC) impairment, with the FKBP51 protein playing a pivotal role. Ginsenosides, extracted from the root of Panax ginseng C.A. Mey, have demonstrated the potential to mitigate depression associated with GC dysregulation. This study evaluated the therapeutic efficacy of ethanol extract of P. ginseng (PG) in treating depression and its underlying FKBP51‐linked mechanism. Using chronic unpredictable stress, a depression model was developed in Kunming mice to test the efficacy of PG by observing changes in behaviors and protein expression in depressed mice. The mechanism of action was investigated through transfection with HEK293T cells. Depressed mice treated with PG demonstrated notable improvements: the rate of weight loss was reduced, sucrose preference and open‐field activity were enhanced, and the rate of apoptosis in hippocampal cells was decreased. Additionally, the HPA axis function appeared to be restored. These physiological adjustments coincided with an increase in GR levels and a decrease in FKBP51 levels. Altogether, these results suggested that PG treatment effectively alleviates depressive symptoms in mice. PG also moderated FKBP51‐GR interaction, lessening FKBP51's restraint on GR nuclear entry. This modulation may enhance the sensitivity of the GR response, reinforcing the negative feedback regulation of the HPA axis and thereby reducing depressive symptoms in mice. These findings highlight the potential of PG as a promising curative treatment for depression, providing a basis for the development of innovative treatments targeting the FKBP51‐GR pathway.