Enhanced therapeutic potential of paeoniflorin and vitamin B12 in intracerebropeduncle ethidium bromide-induced multiple sclerosis-like pathology.

Abstract

<p>The study investigates the neuroprotective potential of paeoniflorin (PNN) in mitigating the multifaceted pathology of multiple sclerosis (MS) in an ethidium bromide-induced (EBRO) rat model. A comprehensive approach utilizing in silico, in-vitro, and in-vivo methodologies reveals that PNN targets key molecular pathways implicated in MS, including the GDNF/GFRA1/RET/AKT/ERK1/2/GSK3-Beta signaling cascade. PNN (50&nbsp;mg/kg, 100&nbsp;mg/kg, p.o.) administration, both as monotherapy and in combination with VB-12 (30&nbsp;mg/kg, p.o.), demonstrated significant efficacy in reducing EBRO-induced neurodegeneration, demyelination, synaptic dysfunction, and neuroinflammation. Behavioral assessments such as the rotarod, beam crossing, and Morris water maze tests highlighted PNN capacity to restore motor coordination, spatial memory, and cognitive function. Combination therapy with VB12 (30) further enhanced these outcomes, demonstrating synergistic therapeutic benefits. Histological and molecular analyses revealed that PNN100 alleviates demyelination, reduces inflammatory cytokines TNF-α, IL-1β, and restores anti-inflammatory markers (IL-10) in brain homogenates, CSF, and blood plasma. Moreover, PNN normalized neurotransmitter imbalances, including elevated glutamate and reduced GABA, dopamine, serotonin, and acetylcholine levels, highlighting its role in restoring excitatory-inhibitory balance. ELISA studies confirmed PNN ability to modulate apoptotic markers Bax, Bcl-2, and Caspase-3 and upregulate neurotrophic factors GDNF, and GFRA1 while downregulating hyperactivated pathways like AKT, ERK1/2, and GSK3-Beta. Additionally, hematological parameters disrupted by EBRO were significantly restored by PNN, indicating its systemic anti-inflammatory and hematoprotective effects. This research provides the first evidence of PNN's role in modulating the GDNF/GFRA1/RET/AKT/ERK1/2/GSK3β pathway in MS. Its synergistic action with VB12 underscores its potential as a combinatorial therapeutic strategy. The findings pave the way for innovative treatment approaches to improve outcomes for MS patients by addressing neurodegeneration, inflammation, and systemic immune dysregulation.</p>