title: Quercetin and epigallocatechin gallate induce in vitro a dose-dependent stiffening and hyperpolarizing effect on the cell membrane of human mononuclear blood cells.
abstract: The bioactivity of polyphenols is closely linked to their ability to interact with biological membranes. The study evaluates the in vitro effect of quercetin and epigallocatechin on the membrane anisotropy and transmembrane potential of peripheral blood mononuclear cells (PBMCs) isolated from 26 type 2 diabetes mellitus patients compared to 25 age matched controls. The in vitro assays were analyzed in correlation with the biochemical and inflammatory profile of the subjects and with insulin resistance parameters (HOMA-IR, plasma resistin) as well. For type 2 diabetes patients, the increase of HOMA-IR and resistin concentration was associated with a significant decrease of the PBMCs membrane anisotropy. The two tested polyphenols induced a dose-dependent hyperpolarizing effect and stiffening of the cell membranes for all tested subjects. Physiological levels of quercetin and epigallocatechin gallate had the tendency to normalize the PBMCs membrane anisotropy of the cells isolated from diabetes patients, bringing it to the level of cells isolated from normoglycemic ones. Epigallocatechin gallate induced higher effects compared to quercetin on the membranes isolated from subjects with higher cardiovascular risk. The decrease of membrane fluidity and the hyperpolarizing effect could explain the cardiovascular protective action of the tested compounds.
authors.affiliation: Biochemistry Department, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 6, TraianVuia Street, Bucharest 020956, Romania.
authors.forename: Denisa
authors.identifier: 0000-0003-3289-147X
authors.initials: D
authors.lastname: Margina
authors.affiliation: Toxicology Department, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 6, TraianVuia Street, Bucharest 020956, Romania.
authors.forename: Mihaela
authors.initials: M
authors.lastname: Ilie
authors.affiliation: Biochemistry Department, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 6, TraianVuia Street, Bucharest 020956, Romania.
authors.forename: Daniela
authors.initials: D
authors.lastname: Gradinaru
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D014676:Diet, Vegetarian; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000473:pathology; D007249:Inflammation / Q000097:blood; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D007963:Leukocytes, Mononuclear / Q000166:cytology*; D008297:Male; D008560:Membrane Fluidity / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects*; D008875:Middle Aged; D011794:Quercetin / Q000494:pharmacology*; D052243:Resistin / Q000097:blood
chemical_list: D015415:Biomarkers; D007328:Insulin; D052243:Resistin; D002392:Catechin; D011794:Quercetin; C045651:epigallocatechin gallate