Modification of membranes by quercetin, a naturally occurring flavonoid, via its incorporation in the polar head group

Abstract

Quercetin is a naturally occurring flavonoid that has a lot of beneficial properties to human health. In this report, using the spin label technique, the influence of quercetin on the fluidity of multilamellar DPPC liposomes was studied. The polarity of the environment preferred by quercetin was also examined by determining the dependence of the position of electronic absorption maxima on dielectric properties of different environments. Autofluorescence of quercetin was also used to examine its distribution in cells. An additional aim of the study was to find how quercetin presence affects human skin fibroblasts. The results showed that incorporation of quercetin at physiological pH into DPPC liposomes caused changes in the partition coefficient of the Tempo spin label between water and polar head group phases. By determining the electronic absorption maxima, we observed that the chromophore of quercetin is localized in the polar head region. Fluorescence microscopy of HSF cells showed quercetin presence in the membrane, cytoplasm and inside the nucleus. Ultrastructural observation revealed some changes, especially in membranous structures, after flavonol treatment. From the results we have concluded that quercetin present in the membrane and other structures can cause changes within cells crucial for its pharmacological activity.

Genistein derivatives decrease liposome membrane integrity — Calcein release and molecular modeling study

“…Such effects were found for erythrocyte membrane proteins [12,13] and also for gramicidin ion channels [14].…”

pH dependent antioxidant activity of lettuce ( L. sativa ) and synergism with added phenolic antioxidants

“…They also suggested that flavonoids with more hydroxyl groups have stronger interaction with DPPC membrane interface and that binding of more hydrophilic flavonoids occurs with increasing pH at the membrane surface. Translocation of QC in the polar part of the lipid bilayer, at physiological pH, may be correlated with its protective ability against different deleterious agents including radical scavenging activity (Ollila et al, 2002;Pawlikowska-Pawlega et al, 2007). Deprotonation generally enhances the antioxidant action of the hydroxyflavones due to decrease in IP and BDE upon deprotonation (Peytar-Maillard, Cuvelier, & Berset, 2003;Tyrakowska et al, 1999).…”

Impact of quercetin and fish oil encapsulation on bilayer membrane and oxidation stability of liposomes

“…For stability reasons and low leakage of encapsulates, it is now recommended and approved to use phospholipids with high saturation degree (Pawlikowska et al, 2007) and also by optionally adding cholesterol (Ionescu & Ganea, 2012), which increases membrane stiffness. As application of synthesized phospholipids or cholesterol is not appropriate in food applications, the use of mixed lecithins, e.g., soy lecithin, is cost efficient, unproblematic to food legislation and more nutritionally valuable (Laye, McClements, & Weiss, 2008).…”