title: Inhibition of free radical-mediated oxidation of cellular biomolecules by carboxylated chitooligosaccharides.
abstract: The objective of this study was to identify the cellular antioxidant effects of carboxylated chitooligosaccharides (CCOS), a chemically modified derivative of chitooligosaccharides (COS), by assessing oxidation inhibition potential on cellular biomolecules such as lipids, proteins, and direct scavenging of reactive oxygen species (ROS). Radical-mediated oxidation of cell membrane lipids and proteins was dose-dependently inhibited by CCOS, assessed by amount of lipid hydroperoxides and carbonyl carbon content in mouse macrophages, RAW264.7 cells. Further, CCOS inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL60) suggesting indirect possibility of inhibiting generation of reactive oxygen species (ROS) such as superoxide radicals, H(2)O(2) and HOCl. Direct radical scavenging studies carried out with DCFH-DA fluorescence probe concluded that CCOS can act as a potent radical scavenger in cells.
authors.affiliation: Department of Chemistry, Pukyong National University, Busan 608-737, Republic of Korea.
authors.forename: Niranjan
authors.initials: N
authors.lastname: Rajapakse
authors.forename: Moon-Moo
authors.initials: MM
authors.lastname: Kim
authors.forename: Eresha
authors.initials: E
authors.lastname: Mendis
authors.forename: Se-Kwon
authors.initials: SK
authors.lastname: Kim
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000138:chemical synthesis* / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D005456:Fluorescent Dyes; D016166:Free Radical Scavengers / Q000138:chemical synthesis / Q000494:pharmacology; D005609:Free Radicals / Q000737:chemistry*; D018922:HL-60 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007962:Leukocytes / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000494:pharmacology*; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D017392:Thiobarbituric Acid Reactive Substances / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005456:Fluorescent Dyes; D016166:Free Radical Scavengers; D005609:Free Radicals; D009844:Oligosaccharides; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D006861:Hydrogen Peroxide; D009195:Peroxidase