Curcumin Inhibits Phorbol Ester-induced Expression of Cyclooxygenase-2 in Mouse Skin through Suppression of Extracellular Signal-Regulated Protein Kinase Activity and NF-$\kappa$B Activation

Recently, there have been considerable efforts to search for naturally occurring substances for the intervention of carcinogenesis. Curcumin, a yellow coloring ingredient of turmeric (Curcuma longa L., Zingiberaceae), has been shown to inhibit experimental carcinogenesis and mutagenesis, but molecular mechanisms underlying its chemopreventive activities remain unclear. In the present work, we found that curcumin inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced expression of CPX-2 in female ICR mouse skin when applied topically 30 min prior to TPA as determined by both immunoblot and immunohistochemical analyses. (omitted)