Naslov
Biological activity of flavonoids correlate with the degree of hydroxylation

Autori
Tokalov, Sergei V. ; Rusak, Gordana ; Henker, Yvonne ; Gutzeit, Herwig O.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
5th Conference on Cell Biology

Mjesto i datum
České Budějovice, Češka Republika, 08.09.2003. - 10.09.2003

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
flavones; flavonols; ROS; antioxidative activity; quercetin; myricetin

Sažetak
The biological activity of eleven structurally closely related flavonoids (flavones and flavonols) with different number of hydroxyl groups was analysed and an attempt was made to correlate the observed effects with structural features of the tested flavonoids. Using human myeloid leukemia (HL-60) cells we investigated the toxicity of the flavonoids, their effect on cell proliferation (by metaboilic conversion of Resazurin and by flow cytometry) and their protection against reactive oxygen species (ROS) using fluorescent indicator 2', 7'-dichlorofluorescin-diacetate (quantified by flow cytometry). Among the substances tested 3, 3', 4', 5, 5', 7-hexahydroxyflavone (myricetin) 3, 3', 4', 5, 7-pentahydroxyflavone (quercetin), 3, 3', 4', 7-tetrahydroxyflavone (fisetin) and 3, 4', 5, 7-tetrahydroxyflavone (kaempferol) are characterised by the highest degree of hydroxylation and these compounds induced apoptosis after 48h of culture in a dose dependent manner while flavone, 3-hydroxyflavone (flavonol), 5-hydroxyflavone (primuletin) and 7-hydroxyflavone were ineffective. A similar correlation was apparent when cell proliferation was quantified in the presence of the test compounds (20μM). For example, quercetin increased the percentage of non-cycling cells to 60±3% while the compounds flavone and primuletin did not inhibit cell cycle progression at all. The analysis of the ROS scavenging activity showed a correlation with the degree of hydroxylation. Myricetin, querctin, fisetin and kamepferol lowered the ROS level by a factor of 3-5 while flavone was ineffective. The observation are difficult to interpret at present but altered hydrophobicity by hydroxylation and the possible consequences for the intracellular distribution must be taken into account as well as the different binding propertie of strongly hydroxylated flavonoids with cellular proteins.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA