Shen-Qi-Jie-Yu-Fang has antidepressant effects in a rodent model of postpartum depression by regulating the immune organs and subsets of T lymphocytes

BACKGROUND Shen-Qi-Jie-Yu-Fang (SJ Fang) is a herbal preparation used in traditional Chinese medicine, and is a potentially important new therapeutic agent in postpartum depression (PPD). Previously, we have elucidated the effects of SJ Fang on hormone receptors and monoamine neurotransmitters involved in the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes in PPD rats. However, the immune-modulating effects of SJ Fang in PPD are still unknown. In this study, we explored the effects of SJ Fang on the immune organs and subsets of T lymphocytes in PPD rats. METHODS PPD was created in Sprague-Dawley rats by inducing hormone-simulated pregnancy followed by hormone withdrawal. After hormone withdrawal, the PPD rats were then treated with fluoxetine at 1, 2, and 4 weeks, and the SJ Fang rats were also treated at 1, 2, and 4 weeks. Depressive behavior in the rats was evaluated by the forced swim test, sucrose consumption test, and open field test. The thymus index and spleen index were calculated. Hematoxylin-eosin staining was used to identify pathological features in the thymus and spleen. CD3, CD4, and CD8 lymphocyte subsets were analyzed by flow cytometry. RESULTS Both fluoxetine and SJ Fang decreased immobility time, increased sucrose consumption, an horizontal and vertical movement. After 4 weeks of treatment with fluoxetine or SJ Fang, the thymus index and spleen index were significantly higher than at baseline, and the morphology of the thymus and spleen were returning to normal. Two weeks after hormone withdrawal, subsets of T lymphocytes indicated a shift from immune activation to immune suppression, which was reversed by 4 weeks of treatment with fluoxetine or SJ Fang. CONCLUSION It is suggested that T-cell mediate immune responses which may play a role in the etiopathology of postpartum depression. SJ Fang had an antidepressant effect on the immune system in rats with PPD.