Naslov
Monitoring flavonoid metabolism in human cells by exploiting fluorescence elicited upon quercetin/protein interactions.

Autori
Gutzeit, Herwig O. ; Tokalov, Sergey V. ; Ludwig-Müller, Jutta ; Rusak, Gordana

Izvornik
Croatica chemica acta (0011-1643) 78 (3) (2005); 337-342

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Quercetin; protein targets; flavonoid/protein fluorescence; flavonoid metabolism; leukaemia cells

Sažetak
Despite the wealth of information concerning biological effects of flavonoids, a systematic approach to analyse the molecular targets is still lacking and, for this reason, a rational evaluation of the risks or benefits of flavonoid- containing food or of possible pharmaceutical applications has been 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 visualised 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 quantified using flow cytometry. The 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 metabolised the flavonoid (e.g. by methylation or glycosylation). The biochemical results are consistent with the cytological observations and support the conclusion that quercetin becomes rapidly converted in vital cells to non-fluorogenic metabolites. The loss of fluorescence in vital cells allows to conveniently monitor and quantify the dynamics of quercetin metabolism in human cells.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA