“Inhibitory effects of Delta(9)-tetrahydrocannabinol (Delta(9)-THC), cannabidiol (CBD), and cannabinol (CBN), the three major constituents in marijuana, on catalytic activities of human cytochrome P450 (CYP) 1 enzymes were investigated.

These results indicated that CBD and CBN showed CYP1 isoform-selective direct inhibition and that CBD was characterized as a potent mechanism-based inhibitor of human CYP1 enzymes, especially CYP1A1.”

http://www.ncbi.nlm.nih.gov/pubmed/20117100

“CYP1A1 regulates breast cancer proliferation and survival. This study supports the notion that CYP1A1 promotes breast cancer proliferation and survival… reduction of CYP1A1 levels is a potential strategy for breast cancer therapeutics.”  http://www.ncbi.nlm.nih.gov/pubmed/23576571