Objective: To assess the effect of curcumin on deoxycholic acid (DCA) induced cell proliferation in human HT-29 colon cancer cell line and to discuss its underlying anti-cancer mechanisms.
Methods: The effect of curcumin on cell proliferation was tested in vitro with MTT assay. RT-PCR was applied to measure cyclooxygenase-2 (COX-2) mRNA transcription. Cellular immunochemical stain was applied to label COX-2 protein expression. Radio immunoassay was applied to assess prostaglandin E(2) (PGE(2)) level.
Results: DCA increased cell proliferation, COX-2 mRNA expression and PGE(2) concentration of HT-29 cell line. Curcumin inhibited DCA-induced cell proliferation of HT-29 cell in a dose and time depended manner. Curcumin may inhibit DCA-induced COX-2 mRNA transcription at 6 hour with more than 5 micromol/L and at 12 hour with more than 0.5 micromol/L. However, Curcumin may decrease DCA-induced COX-2 expression and PGE(2) synthesis at 24 - 48 hour with more than 1 micromol/L and at 6-12 hour with more than 5 micromol/L.
Conclusions: Curcumin may inhibit HT-29 cell proliferation, COX-2 mRNA transcription, COX-2 protein expression and PGE(2) synthesis induced by DCA in HT-29 cell line. These data provide new insights into the mechanism of its anti-cancer properties.