Chrysin-Loaded Extracellular Vesicles Attenuate LPS-Induced Neuroinflammation in BV2 Microglial Cells In Vitro: A Novel Neuroprotective Strategy.

Neuroinflammation, driven by activated microglia, contributes to the progression of neurodegenerative diseases. Extracellular vesicles mediate intercellular communication and influence immune responses. Chrysin, a natural flavone found in fruits and propolis, has demonstrated anti-inflammatory effects. This study explored the immunomodulatory potential of chrysin-loaded EVs (EVs-Chry) derived from BV2 microglial cells. BV2 cells were treated with chrysin for 24 h to assess cytotoxicity and proliferation. EVs were isolated from treated and untreated cells, characterized by nanoparticle tracking analysis, and applied to naïve BV2 cells prior to LPS stimulation. Effects on cell morphology, migration, cytokine expression (IL-1β, IL-6), inflammasome activity (caspase-1), and apoptosis-related protein Bcl-xL were investigated. Our results show that EVs-Chry significantly reduced LPS-induced cell proliferation, restored resting microglial morphology, and reduced migratory capacity. Furthermore, co-treatment with EVs-Chry and LPS reduced pro-inflammatory cytokines such as IL-1β, IL-6, and caspase-1 expression while enhancing anti-apoptotic Bcl-xL levels, indicating a shift toward an anti-inflammatory, neuroprotective micro-glial phenotype. Together, our results demonstrated that EVs-Chry have neuroprotective effects on LPS-induced microglial activation and modulate microglial responses to inflammatory stimuli, attenuating pro-inflammatory signaling and promoting cellular homeostasis. These findings support the therapeutic potential of EVs-Chry in the context of neuroinflammatory and neurodegenerative disorders.