[Quercetin permeability across blood-brain barrier and its effect on the viability of U251 cells].

Objective: To investigate the permeability of quercetin across blood-brain barrier (BBB) and its impact on the proliferation and apoptosis of U251 cells.

Methods: The BBB model was established through culture of primary brain microvessel endothelial cells (BMVEC) and primary astroglia cells (AC), which was confirmed by transmission electron microscopy (TEM) and trans epithelial electric resistance (TEER). High pressure liquid chromatography (HPLC) was performed to determine quercetin permeability across BBB. U251 cells were exposed to quercetin. MTT assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), single-cell gel electrophoresis (SCGE) and flow cytometry (FCM) were performed to analyze cell proliferation, apoptosis, DNA damage and cell cycle distribution.

Results: The BBB was constructed successfully. Up to 65.54% of quercetin permeated across the BBB. Quercetin attenuated the proliferation of U251 and induced apoptosis. The FCM revealed that the U251 cells were inhibited at the G2/M point.

Conclusion: Quercetin can permeate across the BBB effectively, restraining the proliferation of U251 cells and inducing apoptosis.