Fig. 7.

Active SREBP2 abrogates the inhibition of NPC1L1 promoter activity by curcumin. Caco-2 cells were transiently cotransfected by electroporation (Amaxa) with human NPC1L1 promoter along with different amounts of empty vector (EV) or mammalian expression vector for active SREBP2 (A) or mammalian expression vector for c-fos (B) with pCMVβ for β-galactosidase to normalize for the transfection efficiency. Cells were then treated with 50 μM curcumin for 24 h and harvested for firefly luciferase and β-glactosidase assays to assess the promoter activity. Results are shown as %control and represent the mean ± SE of 6–9 determinations performed on 3 separate occasions. *P < 0.05 or less compared with respective control. **P < 0.05 or less compared with empty vector.