Effect of quercetin conjugates on vascular permeability and expression of adhesion molecules.
Quercetin and its glucosides exist in plant foods and are recovered in human plasma as glucuronide and sulfate conjugates. Quercetin and its conjugates show antioxidant activity in model experiments. It remains obscure, however, whether these conjugates retain these biological functions in vivo. We investigated the interaction of quercetin conjugates with lipid bilayers using liposome systems. Less quercetin conjugate was incorporated into liposomes than quercetin aglycone. We also studied the vascular permeability of quercetin-3-glucuronide using cell culture inserts. Incubation of human aortic endothelial cells (HAECs) with IL-1alpha resulted in increased permeability of quercetin-3-glucuronide. Furthermore, quercetin-3-glucuronide showed no suppressive effect on TNF-alpha-induced cell expression of intercellular adhesion molecule-1 (ICAM-1) on HAECs. These observations suggest that circulating conjugates of quercetin pass through the endothelium to reach vascular smooth muscle cells and exert their biological effects in the blood vessels during inflammation followed by deconjugation of the conjugates.
Mochizuki
Mika
M
Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
Kajiya
Katsuko
K
Terao
Junji
J
Kaji
Kazuhiko
K
Kumazawa
Shigenori
S
Nakayama
Tsutomu
T
Shimoi
Kayoko
K
D001011:Aorta; D002199:Capillary Permeability / Q000187:drug effects / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000187:drug effects / Q000235:genetics*; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D006027:Glycosides / Q000494:pharmacology*; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects*; D008051:Lipid Bilayers; D011794:Quercetin / Q000031:analogs & derivatives* / Q000494:pharmacology*
D015815:Cell Adhesion Molecules; D006027:Glycosides; D008051:Lipid Bilayers; C466505:quercetin 3,4'-di-O-glucopyranoside; D018799:Intercellular Adhesion Molecule-1; D011794:Quercetin