Anti-inflammatory Activity of n-Propyl Gallate Through Down-regulation of NF-κB and JNK Pathways

The present study aimed to assess anti-inflammatory activity and underlying mechanism of n-propyl gallate, the n-propyl ester of gallic acid. n-Propyl gallate was shown to contain anti-inflammatory activity using two experimental animal models, acetic acid-induced permeability model in mice, and air pouch model in rats. It suppressed production of nitric oxide and induction of inducible nitric oxide synthase and cyclooxygenase-2 in the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. It was able to diminish reactive oxygen species level elevated in the LPS-stimulated RAW264.7 macrophage cells. It also suppressed gelatinolytic activity of matrix metalloproteinase-9 enhanced in the LPS-stimulated RAW264.7 macrophage cells. It inhibited inhibitory κB-α degradation and enhanced NF-κB promoter activity in the stimulated macrophage cells. It was able to suppress phosphorylation of c-Jun NH₂-terminal kinase 1/2 (JNK1/2) and activation of c-Jun promoter activity in the stimulated macrophage cells. In brief, n-propyl gallate possesses anti-inflammatory activity via down-regulation of NF-κB and JNK pathways.