Danggui Shaoyao San ameliorates neuroinflammation in a D-galactose-induced Alzheimer’s disease rat model by suppressing the JAK2/STAT3 pathway and modulating Th17/Treg -related immune dysregulation

Objective: This study investigates the therapeutic potential of Danggui Shaoyao San (DSS), a traditional Chinese herbal formula, focusing on its effects on Th17/Treg -associated immune regulation and the JAK2/STAT3 signaling pathway. Methods: Forty male Sprague-Dawley rats were randomly divided into five groups: control, AD model, low-dose DSS (12 g/kg/day, raw herbal materials), high-dose DSS (24 g/kg/day, raw herbal materials), and donepezil (0.5 mg/kg/day). AD models were established by intraperitoneal injection of D-galactose (100 mg/kg/day) for 8 consecutive weeks. Behavioral tests, flow cytometry, biochemical assays, histological analyses, qPCR, and Western blotting were used to evaluate DSS's effects. Untargeted metabolomics profiled metabolic alterations, while network pharmacology and molecular docking were integrated to predict key targets and pathways. Results: DSS treatment significantly alleviated neuronal damage, suppressed neuroinflammation, and improved learning and memory deficits in AD rats. Moreover, DSS was associated with alterations in Th17- and Treg-related immune dysregulation both in the brain and periphery. Serum metabolomic identified disruptions lipid metabolism and amino acid metabolism pathways. Network pharmacology and experimental validation indicated that DSS exerts its anti-neuroinflammatory effects by inhibiting JAK2 and STAT3 phosphorylation, reducing their nuclear translocation, and consequently suppressing Th17 differentiation and pro-inflammatory cytokine production. Conclusion: DSS is a promising candidate for AD treatment, with neuroprotective and cognitive-enhancing properties mediated through immunomodulation and JAK2/STAT3 pathway inhibition.