RESUMEN
SCOPE: Quercetin (QUE), a phytochemical found in various plant foods, has been shown to have a variety of physiological activities in vivo, though biological sites where it has activities and the mechanisms of transport have not been fully elucidated. METHODS AND RESULTS: In the present study, intracellular uptake of QUE into HT-29 human colon adenocarcinoma cells is found to result in spontaneous release of extracellular vesicles (EVs), which are subsequently embedded with QUE. In addition, QUE-embedded EVs are detected in serum of QUE-administered Sprague-Dawley rats. Interestingly, the rate of cellular uptake of QUE-encapsulated EVs (EV-QUE) into RAW264.7 macrophages is markedly higher than that of free QUE. Moreover, EV-QUE suppresses lipopolysaccharide (LPS)-induced nitric oxide at a lower concentration than free QUE. CONCLUSION: The present findings suggest that QUE may be embedded in EVs in the gastrointestinal tract, then become absorbed and enter the bloodstream to exhibit biological activities.
