Inhibition of the enzyme activity of cytochrome P450 1A1, 1A2 and 3A4 by fucoxanthin, a marine carotenoid

Fucoxanthin is a carotenoid that is mainly identified in brown algae and is known to have anticarcinogenic and anti-tumor activities. Carotenoids have generally been shown to induce the expression and enzyme activity of the cytochrome P450s (CYPs). The present study evaluated the effect of fucoxanthin on the expression and enzymatic activity of the major xenobiotic metabolizing enzymes, CYP1A1, CYP1A2 and CYP3A4. Fucoxanthin markedly induced the expression of cyp1a1 mRNA in HepG2 cells, but inhibited its enzyme activity in the cells and in vitro. Fucoxanthin also inhibited the enzyme activity of CYP1A2 and CYP3A4 in a dose-dependent manner in vitro. These results suggest that fucoxanthin may serve as a useful agent in cancer prevention with less adverse effects than β-carotene, including the activation of pro-carcinogens by CYPs.