Antidepressant effects and mechanisms of Wuhua herbal tea in a rat model of chronic unpredictable mild stress

To evaluate the effects of Wuhua herbal tea on chronic unpredictable mild stress (CUMS)-induced depression and explore its mechanism of action in combating depression.

We tested the antidepressant effects of Wuhua herbal tea in a rat model of CUMS-induced depression using fluoxetine as a positive control. The rats were divided into four groups: control group, model group, fluoxetine group, and Wuhua herbal tea group. The rats underwent body weight measurements, sucrose preference test, and open-field test. Enzyme-linked immunosorbent assay kits were used to detect the serum levels of serotonin, dopamine, adrenocorticotropic hormone (ACTH), corticosterone, norepinephrine, and interleukin-6. Intergroup comparisons and detection of brain-derived neurotrophic factor (BDNF), cAMP-response element binding protein (CREB), Janus kinase 2 (JAK2), and signal transducer and activator of transcription 3 (STAT3) mRNA expression in the hippocampus were performed using RT-PCR. Immunohistochemistry was used to identify the expression of phosphorylated JAK2 (p-JAK2) and phosphorylated STAT3 (p-STAT3) proteins in hippocampal paraffin sections of CUMS rats.

Compared with the control group, the model group rats had depressive tendencies, exhibiting low vitality and interest in various behavioral indicators which were signs of despair. The Wuhua herbal tea group statistically increased the levels of serotonin and dopamine in the serum of CUMS rats to varying degrees (P = .015 and P = .002); reduced serum levels of ACTH, corticosterone, norepinephrine, and interleukin-6 (all P < .05); and decreased mRNA expression of BDNF, CREB, JAK2, and STAT3 in the hippocampus (all P < .05); and decreased p-STAT3 protein levels (P = .006).

Wuhua herbal tea shows antidepressant potential in CUMS rats by modulating the HPA axis and inhibiting JAK2-STAT3 overactivation, alleviating neuroinflammation. It also restores BDNF-CREB pathway function, reducing depressive symptoms.