Apple derived extracellular vesicles as positive modulators of glial inflammation and gut–brain axis signaling

Plant-derived extracellular vesicles (PDEVs) are emerging as bioactive dietary particles with the capacity to modulate mammalian physiology. Here, we characterize the structure and functional properties of apple-derived extracellular vesicles (ADEVs) and evaluate their relevance to neuroimmune and gut-brain communication. ADEVs exhibit canonical PDEV features and elicit rapid IP₃-dependent Calcium (Ca²⁺) signaling in fibroblasts while preserving blood-brain barrier integrity. Neural assays reveal marked cell-type specificity: ADEVs are efficiently internalized by glial cells and activate glial Ca²⁺ signaling yet display minimal neuronal uptake and no detectable Ca²⁺ response in differentiated SH-SY5Y neurons. Consistent with this selectivity, ADEVs attenuate TNF-α-induced cytokine secretion in activated glia but remain inert in resting neural cells. Although capable of encapsulating L-DOPA efficiently, ADEVs fail to deliver functional neuroprotection against rotenone toxicity, indicating limited neuronal compatibility for dopaminergic cargo. In parallel, using advanced in vitro colon simulation platforms, ADEVs modulate the colonic microbiome in a dose-dependent manner, promoting carbohydrate fermentation and short-chain fatty acid production while reducing proteolytic metabolism under physiologically relevant conditions, with sustained, region-specific effects during prolonged exposure. In vivo, ADEV administration in dogs with chronic intestinal inflammation is associated with altered circulating serotonin levels, suggesting engagement of gut-brain neurochemical pathways with potential implications for mood regulation. Collectively, these findings identify ADEVs as biocompatible, glia-responsive plant vesicles with potential neuromodulatory activity, while delineating intrinsic constraints in their use as neuronal drug-delivery systems.