CYP 1B1 (A), 1A (1A1 and 1A2) (B) and 3A4(C) activities of hepatic microsomes isolated from female ACI rats treated with or without a silastic E2 implant along with either two sham polymeric implants (2 cm), or two curcumin implants (2 cm, 20% load) or curcumin diet (1,000 ppm) for over a period of 3 weeks, 3 months and 6 months. CYP1A and 1B1 activities were determined by EROD assay with and without a selective CYP1B1 inhibitor (pyrene). CYP3A4 activity was measured using P450-Glo™ CYP3A4 assay with Luciferin-IPA following manufacturer’s protocol by replacing NADPH regenerating system with NADPH (5 mM). Groups compared are denominated with the same alphabets (* p<0.05, ** p<0.01 and *** p<0.001).