Antitumor activity of Lepidium latifolium and identification of the epithionitrile 1-cyano-2,3-epithiopropane as its major active component.

Consumption of Brassica (Cruciferae) vegetables is associated with a reduced risk of cancer, but identification of the active components and insights into the underlying molecular events are scarce. Here we found that an extract of Lepidium latifolium, a cruciferous plant native to southern Europe, Mediterranean countries and Asia, showed in vitro cytotoxic activity, inducing caspase-dependent apoptosis, in a variety of human tumor cells, and the plant juice showed in vivo antitumor activity in a HT-29 human colon cancer xenograft mouse model. The epithionitrile 1-cyano-2,3-epithiopropane (CETP) was identified as the major active cancer cell-killing principle of L.