Antioxidant protection of human serum albumin by chitosan.
Inhibition of protein oxidation by reactive oxygen species (ROS) would confer benefit to living organisms exposed to oxidative stress, because oxidized proteins are associated with many diseases and can propagate ROS-induced damage. We measured the ability of 2800Da chitosan, D-glucosamine and N-acetyl glucosamine to protect human serum albumin from oxidation by peroxyl radicals derived from 2,2'-azobis(2-amidinopropane)dihydrochloride and N-centered radicals from 1,1'-diphenyl-2-picrylhydrazyl and from 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid). Comparison with the antioxidant action of vitamin C showed that, on a molar basis, chitosan was equally effective in preventing formation of carbonyl and hydroperoxide groups in human serum albumin exposed to peroxyl radicals. It was also a potent inhibitor of conformational changes in the protein, assessed by absorption spectrum and intrinsic fluorescence. D-glucosamine was much less effective and N-acetyl glucosamine was not a useful antioxidant. Protection of the albumin from peroxyl radicals was achieved by scavenging of peroxyl radical. Chitosan was also a good scavenger of N-centered radicals, with glucosamine and N-acetyl glucosamine much less effective. The results suggest that administration of low molecular weight chitosans may inhibit neutrophil activation and oxidation of serum albumin commonly observed in patients undergoing hemodialysis, resulting in reduction of oxidative stress associated with uremia.
Anraku
Makoto
M
Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Sanzo 1, Gakuen-cho, Fukuyama 729-0292, Japan. anraku@fupharm.fukuyama-u.ac.jp
Kabashima
Mikie
M
Namura
Hitomi
H
Maruyama
Toru
T
Otagiri
Masaki
M
Gebicki
Janusz M
JM
Furutani
Nobuko
N
Tomida
Hisao
H
D001205:Ascorbic Acid / Q000378:metabolism; D048271:Chitosan / Q000378:metabolism* / Q000494:pharmacology; D005470:Fluorometry; D016166:Free Radical Scavengers / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012709:Serum Albumin / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D012709:Serum Albumin; D048271:Chitosan; D001205:Ascorbic Acid