Propyl gallate inhibits TPA-induced inflammation via the nuclear factor-κB pathway in human THP-1 monocytes

Propyl gallate (PG) is an antioxidant that has been used as an additive in several foods to protect against oxidation. The present study examined the anti-inflammatory effect of PG on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in human THP-1 monocytes. Pretreatment with PG markedly inhibited the TPA-induced expression levels of cyclooxygenase-2 and prostaglandin E2. The application of PG significantly inhibited the nuclear translocation of p65, a subunit of nuclear factor-κB (NF-κB) and phosphorylation of p65 (Ser536) in TPA-treated THP-1 cells. PG also inhibited the phosphorylation of IκB and IκB kinase. These results indicate that PG inhibits the inflammatory response by blocking the NF-κB signaling pathway in TPA-induced THP-1 monocytes. Therefore, PG may be useful as a therapeutic agent in inflammatory diseases.