title: Concentrated green tea supplement: biological activity and molecular mechanisms.
abstract: OBJECTIVE
  This study was undertaken to determine the biological activity of a green tea supplement with respect to cells and erythrocyte membranes and the molecular mechanism of that activity.
  
  
  METHODS
  The extract's activity was evaluated on the basis of its hemolytic, antioxidant and antiinflammatory actions. In addition, the extract's effect on the physical properties of the erythrocyte membrane was examined. We also conducted a detailed analysis of supplement ingredients using high-yield liquid chromatography, supplemented with standard tests of total content of polyphenols and flavonoids in the supplement.
  
  
  RESULTS
  The study showed that green tea extract has a high antioxidant and anti-inflammatory capacity with no deleterious effect on red blood cells. The extract modifies the physical properties of the erythrocyte membrane, apparently by binding to its hydrophilic region, with consequent rigidity of the hydrophobic region, increased hydration and a moderate increase in its resistance to changes in tonicity of the medium. Because the extract's components anchor in the polar region of membrane lipids, they are able to effectively scavenge free radicals in the immediate vicinity of the membrane and hinder their diffusion into its interior.
  
  
  CONCLUSIONS
  Green tea supplement at concentrations markedly exceeding the blood plasma physiological polyphenol concentrations has no destructive effect on the erythrocyte membrane. Due to the high content of flavan-3-ols, the supplement exhibits high biological activity, which makes it an alternative source of those substances to the commonly used infusion of green tea leaves.
authors.affiliation: Department of Physics and Biophysics, Wrocław University of Environmental and Life Sciences, Norwida 25, 50-375 Wrocław, Poland. Electronic address: sylwia.cyboran@up.wroc.pl.
authors.forename: S
authors.initials: S
authors.lastname: Cyboran
authors.affiliation: Department of Physics and Biophysics, Wrocław University of Environmental and Life Sciences, Norwida 25, 50-375 Wrocław, Poland.
authors.forename: P
authors.initials: P
authors.lastname: Strugała
authors.affiliation: Department of Physics and Biophysics, Wrocław University of Environmental and Life Sciences, Norwida 25, 50-375 Wrocław, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Włoch
authors.affiliation: Department of Fruit, Vegetable and Cereal Technology, Wrocław University of Environmental and Life Sciences, Norwida 25, 50-375 Wrocław, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Oszmiański
authors.affiliation: Department of Physics and Biophysics, Wrocław University of Environmental and Life Sciences, Norwida 25, 50-375 Wrocław, Poland.
authors.forename: H
authors.initials: H
authors.lastname: Kleszczyńska
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D028241:Camellia sinensis / Q000737:chemistry*; D004910:Erythrocyte Membrane / Q000737:chemistry* / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D013552:Swine
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D010936:Plant Extracts
keywords: (−) Epigallocatechin gallate (PubChem CID: 65064); Anti-inflammatory activity; Antioxidant activity; Erythrocytes; Gallic acid (PubChem CID: 370); Green tea supplement; Hemolytic activity; Membrane fluidity; Polyphenols; UPLC