A study on the mechanism of Bushen Kaiqiao Formula in modulating microglial activation to alleviate neuroinflammation in ADHD.

BACKGROUND

Growing evidence suggests that dysregulated microglial activation and neuroinflammation in the prefrontal cortex may underlie the pathophysiology of Attention Deficit Hyperactivity Disorder. Utilizing spontaneously hypertensive rats-a well-validated animal model of ADHD-this study aimed to characterize ADHD-like behavioral phenotypes and prefrontal cortical neuronal development and elucidate the neuroimmunological mechanisms through which the Bushen Kaiqiao Formula (BSKQF) exerts its therapeutic effects by modulating microglial activation states.

METHODS

Ultra-high-performance liquid chromatography coupled with a tandem mass spectrometer (UHPLC-MS/MS) was used to qualitatively analyze the chemical composition of Bushen Kaiqiao Formula, and network pharmacology was applied to predict its potential therapeutic targets and ADHD-related pathways ADHD-like behaviors, including hyperactivity, impulsivity, spatial memory, and attention, were assessed using the Open Field Test, Elevated Plus Maze, and Y-Maze Test at weeks 2 and 4. Prefrontal cortical neuronal morphology and dendritic spine density were evaluated using Nissl staining and Golgi-Cox staining, respectively. Microglial activation (Iba-1+/iNOS + immunofluorescence), inflammatory cytokine levels (IL-1β and IL-6 by ELISA), and blood-brain barrier integrity (transmission electron microscopy) were examined. In vitro, primary prefrontal cortical neurons and microglia were isolated from neonatal rats and treated with BSKQF-containing serum at different concentrations, with Methylphenidate (MPH) as a control. An oxygen-glucose deprivation/reoxygenation (OGD/R) model was established to mimic neuroinflammatory conditions with inflammatory signaling pathways assessed.

RESULTS

UHPLC-MS/MS identified key bioactive components of Bushen Kaiqiao Formula. Network pharmacology analysis suggested that BSKQF may ameliorate ADHD-related behavioral deficits by inhibiting the NF-κB signaling pathway. Behavioral assessments demonstrated dose- and time-dependent effects. BSKQF significantly reduced neuronal loss, promoted synaptic plasticity, reduced the proportion of activated microglia (iNOS+/Iba-1+), and lowered IL-1β and IL-6 levels. Additionally, ultrastructural examination indicated restored blood-brain barrier integrity and reduced perivascular edema. In vitro, BSKQF-containing serum suppressed NF-κB pathway activation (p-NF-κB-p65, p-IκBα) and inflammasome-related proteins (NLRP3, caspase-1).

CONCLUSION

BSKQF effectively alleviates ADHD-like behaviors in SHR rats by inhibiting prefrontal microglial activation and neuroinflammation, reducing neuronal apoptosis, restoring synaptic plasticity, and preserving blood-brain barrier integrity.