🧬 BDNF Extraction Viewer

A converging mechanistic theme across mental disorders involves impaired neuroplasticity and reduced brain-derived neurotrophic factor (BDNF). Glucagon-like peptide-1 receptor agonists (GLP-1RAs), used for type 2 diabetes and obesity, have shown neuroprotective potential, but whether these effects are mediated by BDNF is unclear. This systematic review synthesised molecular evidence linking GLP-1RA administration to BDNF changes and evaluated their contribution to illness progression in neurodegenerative and psychiatric disorders. A systematic search of PubMed, Ovid and Google Scholar from inception to September 6, 2025, identified studies reporting BDNF-related outcomes following GLP-1RA treatment. Eligible studies included primary in vivo or in vitro research on GLP-1RAs in models of neurodegenerative or psychiatric disorders. Risk of bias was assessed using SYRCLE and QUIN tools. The initial search yielded 300 records, of which 18 met the inclusion criteria. Across these studies, GLP-1RAs consistently enhanced BDNF expression and signalling in models of diabetes, neurodegeneration and neurotoxicity, with diabetic models included for their relevance to GLP-1RA pharmacology and shared neuroinflammatory pathway. Reported increases in BDNF expression ranged from 76 % to 377 %, correlating with improved synaptic plasticity, cognition and neuronal survival. In vitro, GLP-1 and exendin-4 increased BDNF expression and axonal transport even under Aβ oligomer exposure. While most neuroprotection aligned with BDNF upregulation, some effects occurred independently through alternative pathways. GLP-1RAs upregulate BDNF in preclinical models, supporting its role as a key mediator of neuroprotection. Despite some BDNF-independent actions, the consistent restoration of neurotrophic support positions BDNF as a central pathway for disease modification.