Curcumin inhibits cyclooxygenase-2 transcription in bile acid- and phorbolester-treated human gastrointestinal epithelial cells

We investigated whether curcumin, a chemopreventive agent, inhibited chenod eoxycholate (CD)- or phorbol ester (PMA)-mediated induction of cyclooxygena se-2 (COX-2) in several gastrointestinal cell lines (SK-GT-4, SCC450, IEC-1 8 and HCA-7). Treatment with curcumin suppressed CD- and PMA-mediated induc tion of COX-2 protein and synthesis of prostaglandin E-2. Curcumin also sup pressed the induction of COX-2 mRNA by CD and PMA. Nuclear run-offs reveale d increased rates of COX-2 transcription after treatment with CD or PMA and these effects were inhibited by curcumin. Treatment with CD or PMA increas ed binding of AP-1 to DNA, This effect was also blocked by curcumin. In add ition to the above effects on gene expression, we found that curcumin direc tly inhibited the activity of COX-2. These data provide new insights into t he anticancer properties of curcumin.