Induction of phase II enzyme, quinone reductase, in murine hepatoma cells in vitro by grape extracts and selected phytochemicals

Consumption of fruits and vegetables has been associated with a lowered risk of developing chronic diseases such as cardiovascular disease and cancer. Grapes are rich in phenolics, flavonoids, and resveratrol, which have been suggested to be responsible for the health functions. Thirteen grape varieties and eighteen common phytochemicals were evaluated for their ability to induce mammalian phase II detoxification enzymes – quinone reductase (QR) in Hepa1c1c7 murine hepatoma cells. Amongst all the grape varieties analyzed, Cabernet Franc showed the highest inducible effect on QR with the lowest induction concentration. Quercetin, genistein, and resveratrol exhibited strong QR induction activity amongst the eighteen phytochemicals. The proliferation of Hepa1c1c7 cells was significantly inhibited in a dose-dependent manner after exposure to all of the grape extracts and some of the phytochemicals. The selective index (SI) of grapes and phytochemicals as anticarcinogenic potency was assessed.