In this in vitro study, we test our hypothesis that Broccoli-derived vesicles (BDVs), combining the
anti-oxidant properties of their components and the advantages of their structure, can influence the metabolic activity of different
cancer cell lines. BDVs were isolated from homogenized fresh broccoli (Brassica oleracea L.) using a
sucrose gradient ultracentrifugation method and were characterized in terms of physical properties, such as particle size, morphology, and surface charge by transmission electron microscopy (TEM) and
laser doppler electrophoresis (LDE).
Glucosinolates content was assessed by RPLC-ESI-MS analysis. Three different human
cancer cell lines (colorectal
adenocarcinoma Caco-2,
lung adenocarcinoma NCI-H441 and
neuroblastoma SHSY5Y) were evaluated for metabolic activity by the MTT assay, uptake by fluorescence and confocal microscopy, and
anti-oxidant activity by a fluorimetric assay detecting intracellular
reactive oxygen species (ROS). Three bands were obtained with average size measured by TEM based size distribution analysis of 52 nm (Band 1), 70 nm (Band 2), and 82 nm (Band 3).
Glucobrassicin,
glucoraphanin and
neoglucobrassicin were found mostly concentrated in Band 1. BDVs affected the metabolic activity of different
cancer cell lines in a dose dependent manner compared with untreated cells. Overall, Band 2 and 3 were more toxic than Band 1 irrespective of the cell lines. BDVs were taken up by cells in a dose- and time-dependent manner. Pre-incubation of cells with BDVs resulted in a significant decrease in ROS production in Caco-2 and NCI-H441 stimulated with
hydrogen peroxide and SHSY5Y treated with
6-hydroxydopamine, with all three Bands. Our findings open to the possibility to find a novel "green" approach for
cancer treatment, focused on using vesicles from broccoli, although a more in-depth characterization of bioactive molecules is warranted.