title: Characteristics of quercetin interactions with liposomal and vacuolar membranes.
abstract: Quercetin (3,3',4',5,7-pentahydroxyflavone) is claimed to exert many beneficial health effects. With application of (1)H NMR (nuclear magnetic resonance) and FTIR (Fourier-transform infrared) techniques, quercetin interaction with liposomes formed with dipalmitoylphosphatidylcholine (DPPC) was analyzed. Patch-clamp technique was employed to study quercetin effects at single channel level of vacuolar membranes in the liverwort Conocephalum conicum. Light and electron microscopy were applied to study quercetin effects on human negroid cervix carcinoma cells (HeLa). Enzymatic measurements along with DPPH (1,1-diphenyl-2-picrylhydrazyl) bioassay were performed to investigate the influence of quercetin on antioxidant enzymes and reactive oxygen species (ROS) production. The inclusion of quercetin to the membrane exerted pronounced ordering effect on the motional freedom of lipids in the head group region as manifested by broadening of the (1)H NMR spectral line representing the choline groups. FTIR analysis revealed quercetin incorporation into DPPC liposomes via hydrogen bonding between its own hydroxyl groups and lipid polar head groups in the C-O-P-O-C segment. Both, FTIR and NMR techniques indicated also quercetin spectral effects in the region corresponding to alkyl chains. Patch-clamp experiments showed that quercetin stabilizes tonoplast and promotes a close state of SV channels. Microscopic observations of HeLa cells revealed characteristic changes in ultrastructure and morphology of the examined cells in comparison to control cells. Pretreatment of HeLa cells with quercetin alleviated H2O2-induced cell injury by improving redox balance as indicated by the increase in glutathione content and SOD (superoxide dismutase) levels as well as by the decrease in ROS level. \In conclusion, the incorporation, distribution and the changes of biophysical properties of the membranes are very important for the effectiveness of phenolic compounds as antioxidant and anticancer factors.
authors.affiliation: Department of Comparative Anatomy and Anthropology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland; Electron Microscopy Laboratory, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland. Electronic address: bozka1996@o2.pl.
authors.forename: Bożena
authors.initials: B
authors.lastname: Pawlikowska-Pawlęga
authors.forename: Halina
authors.initials: H
authors.lastname: Dziubińska
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Król
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Trębacz
authors.forename: Anna
authors.initials: A
authors.lastname: Jarosz-Wilkołazka
authors.forename: Roman
authors.initials: R
authors.lastname: Paduch
authors.forename: Antoni
authors.initials: A
authors.lastname: Gawron
authors.forename: Wieslaw I
authors.initials: WI
authors.lastname: Gruszecki
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000037:antagonists & inhibitors / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D006367:HeLa Cells; D035926:Hepatophyta / Q000737:chemistry; D006801:Humans; D006860:Hydrogen Bonding; D006861:Hydrogen Peroxide / Q000037:antagonists & inhibitors / Q000494:pharmacology; D007425:Intracellular Membranes / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D018408:Patch-Clamp Techniques; D010851:Picrates / Q000037:antagonists & inhibitors / Q000378:metabolism; D011794:Quercetin / Q000737:chemistry* / Q000494:pharmacology; D017550:Spectroscopy, Fourier Transform Infrared; D014617:Vacuoles / Q000737:chemistry*
chemical_list: D001713:Biphenyl Compounds; D008081:Liposomes; D010851:Picrates; D015060:1,2-Dipalmitoylphosphatidylcholine; D011794:Quercetin; D006861:Hydrogen Peroxide; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: 1,1-diphenyl-2-picrylhydrazyl radical; DPPC; DPPC liposomes; DPPH radical; Electron microscopy; FTIR spectroscopy; Flavonoids; Fourier-transform infrared spectroscopy; NMR spectroscopy; Patch-clamp; SV channels; Spectroscopy study; WV; dipalmitoylphosphatidylcholine; nuclear magnetic resonance spectroscopy; slowly-activating vacuolar channels; whole-vacuole