Chitosan gallate as potential antioxidant biomaterial.

Chitosan gallate were synthesized using a free radical-induced grafting reaction. Chitosan gallate showed enhanced water-solubility compared to plain chitosan, and exhibited good thermal stability. The IC(50) value of chitosan gallate against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was 17.86 μg/mL. In addition, chitosan gallate effectively inhibited the generation of intracellular reactive oxygen species (ROS), and also suppressed lipid peroxidation in RAW264.7 macrophage cells. Chitosan gallate also exhibited the protection effect on genomic DNA damage by induced hydroxyl radical, and up-regulated the protein expression of antioxidant enzymes including superoxide dismutase-1 and glutathione reductase under H(2)O(2)-mediated oxidative stress in RAW264.7 macrophage cells. These results indicate that chitosan gallate might be potential antioxidant biomaterials.