ReviewJournal of xenobiotics2026
Environmental Metal Exposure and Brain-Derived Neurotrophic Factor (BDNF): A Systematic Review of Human and Experimental Evidence.
Review in Journal of xenobiotics, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundBrain-derived neurotrophic factor (BDNF) is central to synaptic plasticity and neurodevelopment. Toxic metal exposure is linked to oxidative stress and neuroinflammation, yet its effects on BDNF signaling remain unclear.
objectivesTo systematically synthesize evidence from human and experimental studies on the association between environmental or occupational metal exposure and BDNF alterations, and to highlight research gaps with an emphasis on hexavalent chromium (Cr(VI)).
methodsPubMed, Scopus, and ScienceDirect were searched following PRISMA guidelines. Eligible studies included human observational research and animal models reporting quantitative associations between metal exposure (biomarkers/environmental measures) and BDNF outcomes (protein or gene expression). Data were extracted on exposure assessment, BDNF measurement, and neurobehavioral outcomes. Study quality was assessed using NOS (human studies) and SciRAP (experimental studies).
resultsNineteen studies were included. Across metals such as Pb, Hg, Cd, As, Mn, and mixtures, exposure was associated with altered BDNF levels in blood or brain tissue, often alongside oxidative stress markers, inflammatory changes, and cognitive or behavioral impairment in animal models. Most human studies reported decreased circulating BDNF with higher exposure, while experimental evidence suggested context-dependent regulation across exposure windows and brain regions.
conclusionsThe available evidence supports a biologically plausible link between metal exposure and BDNF dysregulation. No eligible studies evaluated BDNF in relation to Cr(VI), indicating a major research gap. Future studies should integrate neurotrophic biomarkers with exposome-oriented designs to clarify chromium-related neurotoxicity and support Adverse Outcome Pathway (AOP)-informed frameworks.
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