Induction of the anticarcinogenic marker enzyme, quinone reductase, in murine hepatoma cells in vitro by flavonoids

Some flavonoids induce phase II enzymes both in vivo and in vitro. We have determined the structural requirements for this activity by examining the ability of naturally-occurring flavonoids to induce the phase II enzyme, quinone reductase (NAD(P)H:quinone oxidoreductase; EC 1.6.99.2), in murine Hepa1c1c7 cells. Hydroxylation of the B ring is not essential for induction, since galangin and kaempferol (with 0 and 1 hydroxyl in the B ring,...