Eutrema japonicum–derived exosome-like nanoparticles as an immunostimulatory nutraceutical candidate with anti-cancer potential

Plant-derived exosome-like nanoparticles (ELNs) are promising bioactive carriers with enhanced stability and delivery capacity. This study explores the anti-cancer nutraceutical potential of Eutrema japonicum-derived ELNs (EJ-ELNs) through immune modulation and tumor suppression. EJ-ELNs were isolated using differential ultracentrifugation, tangential flow filtration, and cushioned ultracentrifugation, and characterized by transmission electron microscopy and nanoparticle tracking analysis. The isolated EJ-ELNs demonstrated excellent colloidal stability, maintaining structural integrity under simulated gastrointestinal fluid, enzymatic degradation (DNase, RNase, Proteinase K) and acidic conditions (pH 2), and diverse storage conditions (25 °C, 4 °C, -80 °C, and lyophilization). In vitro, EJ-ELNs promoted dendritic cell (DC) maturation by upregulating surface molecules and enhancing the secretion of Th1-polarizing cytokine, while suppressing antigen uptake via MAPK and NF-κB pathways. These activated DCs facilitated the differentiation of naïve T cells into IFN-γ-producing Th1 cells and promoted the activation of cytotoxic CD8⁺ T cells. In vivo, oral administration of EJ-ELNs restored DC function and expanded polyfunctional CD4⁺ and CD8⁺ T cells co-expressing CD107a, IFN-γ, IL-2, and TNF-α, ultimately leading to significant tumor suppression. Lipidomic and metabolomic profiling identified ceramide, Hex1Cer, naringenin, and genistein as key immunostimulatory constituents. These findings position EJ-ELNs as a novel anti-cancer nutraceutical candidate, offering a promising strategy for immune activation and tumor suppression in functional food applications.