In this study, gallic acid-conjugated chitooligosaccharides (gallate-COS) was evaluated for its enhancing capabilities in free radical scavenging and anti-inflammatory activities in human lung epithelial A549 cells. It was found that gallate-COS possesses significantly high DPPH radical scavenging activity and protective effect against H2O2-induced DNA damage. Likewise, gallate-COS decreased the production of intracellular reactive oxygen species in H2O2-stimulated A549 cells. Moreover, the suppressive effects of gallate-COS on COX-2 expression and PGE(2) production from LPS-stimulated A549 cells were evidenced. Finally, the productions of cytokines including IL-8 and TNF-alpha were also inhibited by gallate-COS in a dose-dependent manner. Collectively, these results suggest that gallate-COS could be used as a functional ingredient with potent antioxidant and anti-inflammatory benefits. (C) 2017 Elsevier Ltd. All rights reserved.