Inhibition by berberine of cyclooxygenase-2 transcriptional activity in human colon cancer cells

The enzyme cyclooxpgenase-2 (COX-2) is abundantly expressed in colon cancer dens and plays a key role in colon tumorigenesis. Compounds inhibiting COX -2 transcriptional activity have therefore potentially a chemopreventive pr operty against colon tumor formation. An assay method for estimating COX-2 transcriptional activity in human colon cancer cells was established using a beta-galactosidase reporter gene system, and examination was made of vari ous medicinal herbs and their ingredients for an inhibitory effect on COX-2 transcriptional activity. We found that berberine, an isoquinoline alkaloi d present in plants of the genera Berberis and Coptis, effectively inhibits COX-2 transcriptional activity in colon cancer cells in a dose- and time-d ependent manner at concentrations higher than 0.3 mu M. The present finding s may further explain the mechanism of anti-inflammatory and anti-tumor pro moting effects of berberine. (C) 1999 Elsevier Science Ireland Ltd. All rig hts reserved.