Expression of bilitranslocase in the vascular endothelium and its function as a flavonoid transporter

Alessandra Maestro, Michela Terdoslavich, Andreja Vanzo, Adenike Kuku, Federica Tramer, Vanessa Nicolin, Fulvio Micali, Giuliana Decorti, Sabina Passamonti

Research output: Contribution to journalArticlepeer-review


AimsIngestion of flavonoid-rich beverages acutely affects endothelial function, causing vasodilation. This effect might be dependent on flavonoid transport into the endothelium. We investigated flavonoid uptake into vascular endothelial cells and whether this was mediated by bilitranslocase (TC 2.A.65.1.1), a bilirubin-specific membrane carrier that also transports various dietary flavonoids.Methods and resultsHuman and rat aortic primary endothelial cells as well as Ea.hy 926 cells were found to express bilitranslocase, as assessed by immunocytochemistry and immunoblotting analysis using anti-sequence bilitranslocase antibodies targeting two distinct extracellular epitopes of the carrier. Bilitranslocase function was tested by measuring the rate of bromosulfophthalein (a standard bilitranslocase transport substrate) uptake into endothelial cells and was inhibited not only by bilitranslocase antibodies but also by quercetin (a flavonol). Similarly, uptake of both quercetin and malvidin 3-glucoside (an anthocyanin) were also found to be antibody-inhibited. Quercetin uptake into cells was inhibited by bilirubin, suggesting flavonoid uptake via a membrane pathway shared with bilirubin.ConclusionThe uptake of some flavonoids into the vascular endothelium occurs via the bilirubin-specific membrane transporter bilitranslocase. This offers new insights into the vascular effects of both flavonoids and bilirubin.

Original languageEnglish
Pages (from-to)175-183
Number of pages9
JournalCardiovascular Research
Issue number1
Publication statusPublished - Jan 2010


  • Bilirubin
  • Bilitranslocase
  • Flavonoids
  • Membrane transport
  • Vascular endothelium

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)
  • Physiology


Dive into the research topics of 'Expression of bilitranslocase in the vascular endothelium and its function as a flavonoid transporter'. Together they form a unique fingerprint.

Cite this