Innovative Insights: Unveiling the Mechanism of Ginsenoside Re in Parkinson's Disease Therapy via BDNF/TLR4 Axis with Proteomics Approach

Background Brain derived neurotrophic factor (BDNF) is essential for neuronal survival, synaptic maintenance, and functional plasticity. Nevertheless, its specific pathophysiological role, particularly in the context of dopaminergic neurodegeneration and neuroimmune dysregulation in Parkinson’s disease (PD), remains incompletely defined. Ginsenosides (GSs), bioactive triterpenoid saponins derived from Panax ginseng, exhibit broad neuroprotective properties across preclinical models of neurodegeneration; however, the identity of their principal pharmacologically active constituents and the precise molecular mechanisms governing their modulation of neuroinflammatory pathways in PD are still insufficiently characterized. Purpose This study seeks to elucidate the functional consequences of BDNF deficiency in PD related neurodegeneration and neuroinflammation. Then, systematically evaluate the therapeutic efficacy of ginsenosides in an established PD model as well as identify the dominant bioactive monomer and rigorously define its mechanism of action, with emphasis on BDNF dependent regulation of microglial activation and downstream inflammatory signaling. Methods A multimodal strategy integrating in silico network pharmacology with vivo and vitro experimental validation was elected. A well characterized MPTP induced murine model of PD was employed for vivo studies. Comprehensive assessments included longitudinal behavioral testing (rotarod, pole test, open field), immunohistochemical quantification of tyrosine hydroxylase (TH) positive neurons in the substantia nigra pars compacta (SNpc) and striatal dopamine terminals, ELISA based cytokine profiling, immunoblotting of key signaling proteins (e.g., TrkB, p-NF-κB p65, IκBα, STAT1, caspase-3) and quantitative proteomic analysis of the nigrostriatal pathway. Additional vitro experiments utilized MPP⁺ treated primary mesencephalic neurons and BV2 microglial cells to dissect cell type specific mechanisms. Results Network pharmacology predicted BDNF as a central node linking ginsenoside targets to neuroinflammatory and anti-apoptotic pathways, hypotheses robustly confirmed experimentally. Ginsenoside Re (GsRe) was identified as the most potent and pharmacokinetically favorable monomer, demonstrating superior blood brain barrier permeability and selective accumulation in the SNpc and striatum. Mechanistically, GsRe enhanced BDNF expression and potentiated BDNF mediated suppression of TLR4 signaling, leading to downregulation of WDFY1, a critical adaptor facilitating TRIF dependent NF-κB/STAT1 activation. This cascade inhibition attenuated microglial pro-inflammatory polarization, reduced caspase-3 mediated neuronal apoptosis, preserved dopaminergic integrity, and significantly improved motor function in PD mice. Conclusion The BDNF/TLR4/WDFY1 axis as a pivotal regulatory hub in PD associated neuroinflammation was established and GsRe as a mechanistically grounded, brain penetrant candidate for disease modifying intervention was identified. These results advance the understanding of natural product mediated neuron microglia crosstalk and provide a rational framework for developing targeted therapeutics that restore neuroimmune homeostasis in PD and related disorders.