Caffeic acid‐grafted chitooligosaccharides downregulate MAPK and NF‐kB in RAW264.7 cells

Abstract

Chitooligosaccharide (COS) is a derivative of chitosan, which is a natural macromolecular compound. COS has been shown effects in an inflammatory response. Recent reports show that COS derivatives have enhanced anti‐inflammatory activity by inhibiting intracellular signals. Evaluation of the anti‐inflammatory effect of caffeic acid conjugated COS chain (CA‐COS) was performed in this study. The effects of CA‐COS on the inflammatory response were demonstrated in lipopolysaccharide‐stimulated RAW264.7 macrophages. The results showed that CA‐COS inhibited nitric oxide (NO) production and downregulated the gene expression of nitric oxide synthase (iNOS), and cytokines such as tumor necrosis factor‐alpha (TNF‐α), IL‐1β, and IL‐6 without cytotoxic effect. In addition, western blot analysis showed that CA‐COS inhibits the protein expression of iNOS and nuclear factor kappa B (NF‐kB), including p50 and p65, and mitogen‐activated protein kinase (MAPK) signaling pathways. Collectively, these results provide clear evidence for the anti‐inflammatory mechanism of CA‐COS that show great potential as a novel agent for the prevention and therapy of inflammatory diseases.