Quercetin exhibits a specific fluorescence in cellular milieu: a valuable tool for the study of its intracellular distribution.
The elaboration of novel techniques for flavonoid intracellular tracing would elucidate the compounds' absorption and bioavailability and assist molecular and pharmacological approaches, as they are promising candidates for drug development. This study exploited the properties of quercetin (3,3',4',5,7-pentahydroxyflavone), found in high concentrations in the majority of edible plants. Through the use of UV-vis spectroscopy, confocal microscopy, and HPLC-ESI-MS, native quercetin, at physiologically relevant concentrations, was found to exhibit a specific fluorescence (488 nmex/500-540 nmem) upon internalization. This fluorescence shift is due to a non-covalent binding to intracellular targets (probably proteins) and compatible with the settings applied in confocal microscopy. This property provides a valuable, selective alternative technique for quercetin tracing in cellular systems, permitting the quantitative evaluation of its transit at pharmacologically relevant concentrations and the validation of a number of already described molecular functions.
Nifli
Artemissia-Phoebe
AP
Laboratories of Experimental Endocrinology and Biochemistry, Faculty of Medicine, University of Crete, 71003 Heraklion, Greece.
Theodoropoulos
Panayiotis A
PA
Munier
Sylvie
S
Castagnino
Chantal
C
Roussakis
Emmanuel
E
Katerinopoulos
Haralambos E
HE
Vercauteren
Joseph
J
Castanas
Elias
E
D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D004247:DNA / Q000378:metabolism; D005453:Fluorescence; D022781:Hepatocytes / Q000737:chemistry; D006801:Humans; D008113:Liver Neoplasms; D018613:Microscopy, Confocal; D010945:Plants, Edible / Q000737:chemistry; D011794:Quercetin / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D013050:Spectrometry, Fluorescence
D004247:DNA; D011794:Quercetin