Effect of 4-Methoxyindole-3-carbinol on the Proliferation of Colon Cancer Cells in Vitro, When Treated Alone or in Combination with lndole-3-carbinol

摘要

Consumption of cruciferous vegetables and cancer prevention seem to be positively associated. We present an easy two-step synthesis for 4-methoxyindole-3-carbinol (4MeOI3C), the expected breakdown product of 4-methoxyglucobrassicin during ingestion. 4MeOI3C inhibited the proliferation of human colon cancer cells DLD-1 and HCT 116 with IC_(50) values of 116 μM and 96 μM, respectively, after 48 h in vitro, and is therefore a more potent inhibitor than indole-3-carbinol (I3C). 4MeOI3C and I3C combined in different molar ratios inhibited proliferation in a nearly additive to slightly synergistic manner. Proliferation was inhibited by 100μM 4MeOI3C after 48 h without affecting cell cycle phase distribution, indicating an overall-slowdown effect on the cell cycle. However, 200 μM 4MeOI3C caused a very high level of cell death and an accumulation of living cells in the G_0/G1, phase, indicating a concentration-dependent mode of action. We conclude that 4MeOI3C might play a role in the cancer preventive effect of cruciferous vegetables.