Antioxidant activity of chitooligosaccharides upon two biological systems: Erythrocytes and bacteriophages

• Published in: Carbohydrate polymers Vol. 79; no. 4; pp. 1101 - 1106
• Main Authors: Fernandes, João C., Eaton, Peter, Nascimento, Henrique, Gião, Maria S., Ramos, Óscar S., Belo, Luís, Santos-Silva, Alice, Pintado, Manuela E., Malcata, F. Xavier
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 17.03.2010; Elsevier
• Subjects: AAPH; Applied sciences; Bacteria; Biological and medical sciences; Chitooligosaccharides; Erythrocytes; Exact sciences and technology; General and cellular metabolism. Vitamins; Hydrogen peroxide; Medical sciences; Natural polymers; Phage P22; Pharmacology. Drug treatments; Physicochemistry of polymers; Starch and polysaccharides; Hydrogen peroxide; DPPH; AAPH; ROS; Erythrocytes; Hb; Phage P22; ATCC; Chitooligosaccharides; PFU; ABTS; Hemolysis; Radical cation; Podoviridae; Red blood cell; Antioxidant; Experimental study; Oligomer; Biological activity; Virus; Radical trapping; Binary mixture; Scavenging efficiency; Oside polymer; Chitosan; Phage
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2009.10.050

Most of the reports to date on the antioxidant capacity of chitosans and chitooligosaccharides (COS) are based on strictly chemical methods. When studying antioxidants with potential in vivo applications, the method used to evaluate the antioxidant activity should be representative of the conditions in which the antioxidant might have a protective effect. In this work we evaluate the antioxidant activity of two COS mixtures and a low MW chitosan (LMWC) upon two biological oxidizable substrates – erythrocytes and phages, subjected to accelerated oxidation conditions. Our results suggest that COS/LMWC can be used as antioxidants in biological systems. All the tested compounds reduced either the hemolytic and DNA damage, by inhibiting H 2O 2- and AAPH-radicals. However, the results obtained for these biological assays did not reveal a dose dependence, contrary to the chemical assay, suggesting that the protective concentrations should be established, in order to prevent enhancement of the oxidative damage – i.e. a prooxidant effect.