Inhibition of free radical-mediated oxidation of cellular biomolecules by carboxylated chitooligosaccharides

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, H2O2 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.

Chitooligosaccharides (COS) were chemically modified to improve proton donation by introducing –COCH2CH2COO− group to the amino group at C2 position of pyranose unit. The new COS derivative, carboxylated chitooligosaccharides (CCOS), was studied for its effects to inhibit free radical-mediated oxidation of biomolecules in human and mouse leukocytes.Figure optionsDownload as PowerPoint slide