Effects of Shenqi Jieyu Formula on perfusion and brain structure in the hippocampus and prefrontal cortex of postpartum depressed rats: A functional magnetic resonance imaging study

Abstract

Postpartum depression (PPD) is a prevalent mental disorder affecting approximately 20 % of mothers, with profound implications for maternal and infant health. Current pharmacotherapies pose risks during lactation, highlighting the urgent need for safer alternatives. Shenqi Jieyu Formula (SQJYF) is a traditional Chinese medicine herbal preparation that has demonstrated clinical efficacy in alleviating PPD symptoms, yet its neurobiological mechanisms remain unclear. This study nvestigated the effects of SQJYF on cerebral blood flow and microstructure in the hippocampus (HP) and prefrontal cortex (PFC) using a maternal separation-induced PPD rat model. We established a maternal separation model of PPD. 24 SD rats were randomized into normal group, PPD group, SQJYF-treated group and fluoxetine-treated group. Maternal separation was performed from the first day to the 21st day, 4 hours a day, controls remained undisturbed. Pharmacological intervention was applied from postnatal day 15, SQJYF (1.25 g/100 g/d) or Fluoxetine Hydrochloride Capsules or saline was administered by gavage for 1 week. Forced swim test, sucrose preference test and open field test were conducted post-intervention. Rats were scanned with functional magnetic resonance imaging, arterial spin labeling (ASL) measured cerebral blood flow, and diffusion tensor imaging (DTI) assessed fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in HP and PFC. Results demonstrated that maternal separation induced depressive-like behaviors and also caused hypoperfusion and impaired tissue integrity in the HP and PFC. SQJYF could alleviate depressive-like behavior in PPD rats, also restore cerebral perfusion levels and improve tissue integrity damage. Compared with the PPD group, the horizontal and vertical scores were significantly increased (P < 0.01), sucrose consumption was significantly increased (P < 0.01), and immobility time was significantly reduced (P < 0.01). the perfusion level of bilateral HP and PFC were significantly increased (P < 0.01, P < 0.05), ADC values of bilateral HP and PFC were significantly reduced (P < 0.01, P < 0.05), FA values of bilateral PFC and left HP were significantly increased (P < 0.01). These findings highlight SQJYF;s dual neurorestorative role in ameliorating PPD through enhanced cerebral perfusion and microstructural repair. This study provides the multimodal neuroimaging evidence supporting SQJYF’s efficacy, bridging traditional medicine with modern neurobiological insights to address a critical gap in PPD therapeutics.