Abstract
Hyperhomocysteinemia (HHcy) is a significant risk factor for cognitive impairment (CI), yet effective therapeutic interventions remain limited. Pterostilbene (PTE), a natural stilbene derivative, possesses antioxidant, anti-inflammatory, and neuroprotective properties; however, its mechanisms of action in HHcy-induced CI remain unclear. This study investigated the molecular basis of PTE-mediated neuroprotection using integrated network pharmacology, proteomics, and experimental validation. Key signaling pathways identified included cAMP/PKA/CREB and TLR4-mediated inflammatory signaling. HHcy was induced in rats by oral L-methionine administration, followed by assessment of cognitive performance, neuronal integrity, mitochondrial function, inflammation, and synaptic plasticity. PTE treatment significantly improved spatial learning, memory retention, and recognition memory while preserving hippocampal cytoarchitecture. Mechanistically, PTE restored mitochondrial biogenesis and function through upregulation of PGC-1α and TFAM, normalization of respiratory chain complex activities, and preservation of mitochondrial ultrastructure. Furthermore, PTE enhanced synaptic plasticity by increasing the expression of PSD95, GAP43, and synaptophysin, activated the cAMP/PKA/CREB signaling pathway, and suppressed neuroinflammation through inhibition of TLR4 signaling. Collectively, these findings demonstrate that PTE ameliorates HHcy-induced cognitive deficits by improving mitochondrial function, promoting synaptic integrity, and modulating neuroprotective and inflammatory pathways, highlighting its potential as a promising therapeutic candidate for HHcy-associated cognitive impairment.