Record Details

Monitoring Flavonoid Metabolism in Human Cells by Exploiting Fluorescence Elicited upon Quercetin/Protein Interactions

Croatian International Relations Review

View Archive Info
 
 
Field Value
 
Title Monitoring Flavonoid Metabolism in Human Cells by Exploiting Fluorescence Elicited upon Quercetin/Protein Interactions
Praćenje metabolizma flavonoida u humanim stanicama na temelju fluorescencije izazvane interakcijom kvercetina s proteinima
 
Creator Gutzeit, Herwig O.
Tokalov, Sergey V.
Ludwig-Müller, Jutta
Rusak, Gordana
 
Subject quercetin; protein targets; flavonoid/protein fluorescence; flavonoid metabolism; leukaemia cells
 
Description Despite the wealth of information concerning biological effects of flavonoids, a systematic approach to analyzing the molecular targets is still lacking and, for this reason, a rational evaluation of the risks or benefits of flavonoid-containing foods or of possible pharmaceutical applications is difficult. We have exploited the property of quercetin to elicit fluorescence when bound to specific target proteins and assayed several flavonoids with different modifications (methylation, hydroxylation, glycosylation). Quercetin target proteins can be visualized in living cells, but in vital human leukaemia cells (HL-60) the fluorescence decreases rapidly after labelling, while metabolically inactive apoptotic cells retain the fluorescence. These cytological differences were apparent under the fluorescent microscope and were quantified using flow cytometry. Metabolic conversion of quercetin in vital cells was confirmed and quantified by HPLC analysis. While apoptotic cells still contained considerable amounts of quercetin, vital cells rapidly metabolized the flavonoid (e.g., by methylation or glycosylation). Biochemical results
are consistent with the cytological observations and support the conclusion that quercetin becomes rapidly converted to non-fluorogenic metabolites in vital cells. Loss of fluorescence in vital cells allows convenient monitoring and quantifying of the dynamics of quercetin metabolism in human cells.
Unatoč mnoštvu informacija koje se odnose na biološke učinke flavonoida, sustavni pristup analizi njihovih ciljnih molekula još uvijek nedostaje. Iz toga razloga vrlo je teško racionalno vrednovati opasnosti ili koristi koje donosi hrana koja sadrži flavonoide kao i njihovu moguću farmakološku primjenu. Iskoristili smo svojstvo kvercetina da izazove fluorescenciju kada se veže za specifične ciljne proteine i analizirali nekoliko različito modificiranih flavonoida (metilacija, hidroksilacija, glikozilacija). Ciljni proteini za koje se kvercetin veže u živim stanicama mogu se vizualizirati na temelju fluorescencije. U živim stanicama humane leukemije (HL-60) fluorescencija naglo pada nakon označavanja flavonoidima, dok metabolički inaktivne apoptotične stanice zadržavaju fluorescenciju. Te su citološke razlike jasno zapažene pod fluorescencijskim mikroskopom, a kvantificirane su pomoću protočne citometrije. Metabolička pretvorba kvercetina u živim stanicama potvr|ena je i kvantificirana pomoću HPLC analiza. Dok apoptotične stanice zadržavaju značajnu količinu kvercetina, žive ga stanice brzo metaboliziraju (npr. metilacijom ili glikozilacijom). Ti su biokemijski rezultati u skladu s citološkim promatranjima i podupiru zaključak da se kvercetin u živim stanicama brzo pretvara u nefluorogene metabolite. Gubitak fluorescencije u živim stanicama omogućava praćenje i kvantifikaciju dinamike metabolizma kvercetina u humanim stanicama.
 
Publisher Croatian Chemical Society
 
Date 2005-09-15
 
Type text
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
 
Format application/pdf
 
Identifier http://hrcak.srce.hr/39
http://hrcak.srce.hr/file/39
 
Source Croatica chemica acta; Vol.78 No.3; ISSN 0011-1643 (Print); ISSN 1334-417X (Online)
 
Language en
 
Rights info:eu-repo/semantics/openAccess
Parts of the contents of Croat. Chem. Acta (e. g. figures or tables) may be reproduced without prior permission, provided reference is made to their source.