Integration of Quercetin-Iron Complexes into Phosphatidylcholine or Phosphatidylethanolamine Liposomes

Abstract

It is well known that flavonoids can chelate transition metals. Flavonoid-metal complexes exhibit a high antioxidative and therapeutic potential. However, the complexes are frequently hydrophobic ones and low soluble in water, which restricts their medical applications. Integration of these complexes into liposomes may increase their bioavailability and therapeutic effect. Here, we studied the interaction of quercetin-iron complexes with dimyristoylphosphatidylcholine (DMPC) or palmitoyl-oleoyl phosphatidylethanolamine (POPE) multilamellar liposomes. Differential scanning calorimetry (DSC) and freeze-fracture electron microscopy revealed that quercetin-iron complexes did not interact with liposomes. Quercetin however could penetrate lipid bilayers, when added to liposomes at a temperature above lipid melting. Iron cations added later penetrated into the lipid bilayers and produced complexes with quercetin in the liposomes. The quercetin-iron entry in POPE liposomes was improved when the suspension was heated above the temperature of the bilayer-hexagonal HII phase transition of the lipid. The approach proposed facilitates the integration of quercetin-iron complexes into liposomes and may promote their use in medicine.

Spectroscopic determination of intracellular quercetin uptake using erythrocyte model and its implications in human aging

“…Dietary flavonoids have modulatory effect on PMRS activity which is linked to their structural orientation (Singh et al 2016). Quercetin has been reported to interact with phosphatidylcholine and phosphatidylethanolamine head groups in the cell membrane bilayer through hydrogen bonds at low concentrations and hydrophobic tail region at high concentrations (Kim et al 2015). These interactions may induce changes in membrane fluidity of RBCs which are associated with transport system (Kumar et al 2016b;Sanna et al 2015).…”

Iron Complexes of Flavonoids-Antioxidant Capacity and Beyond

“…The lipophilicity of 1:2 and 2:3 complex (metal:ligand) is two and three times higher, respectively [53]. On the other hand, some works implied that quercetin in the membrane system can improve its availability for Fe(II) with subsequent complex formation [54].…”

“…Furthermore, metallocomplexes formed by iron chelation may display their own unique biological activities. Iron complexation affects their biochemical properties such as lipophilicity, membrane transport, or interactions with biomolecules [43][44][45][46][47][48][49][50][51][52][53][54][55][56].…”

Flavonoid Complexes as Promising Anticancer Metallodrugs

“…The interaction study of quercetin-iron complexes with dimyristoylphosphatidylcholine (DMPC) or palmitoyl-oleoyl phosphatidylethanolamine (POPE) multilamellar liposomes revealed that, during preparation, quercetin should be added first to the suspension of liposomes [115]. It was presumed that quercetin can increase the permeability of lipid bilayers to iron cations, showing ionophore activity toward iron cations.…”