There is increasing interest in how ''natural compounds'' may influence the course of cancer. This is somewhat ironic, as many of the very first anti-cancer drugs were natural products (e.g. vinblastine, which comes from the periwinkle plant, or taxol, which comes from the bark of the pacific yew tree). Overall, something like 75% of our cancer drugs are derived from natural products. Only a minor proportion have been ''synthetic'' – it is only recently that molecular design has allowed us to design more specific, targeted agents.

Nevertheless, many substances that are part of our normal diet may influence our health or the course of a disease, including cancer. We are interested in a group of plant molecules called flavonoids, different forms of which are found in most fruits and vegetables. We are particularly interested in a flavonoid called apigenin that is found in plants such as parsley and chamomile. This has been shown to influence a number of cellular processes that are implicated in the development and course of gastrointestinal cancers.

Of interest to us has been the fact that, beyond the property that most often attracts attention - an ability to kill cancer cells - apigenin affects a protein (CD26) on the surface of colorectal cancer cells that may influence how they spread or metastasize. We are now studying the activities of apigenin and 20 related flavonoids, to see how they affect CD26 as well as other proteins found at the surface of colorectal cancer cells.

Our ultimate goal is to exploit the abundant resources of the natural world to find new ways in which we can interfere with cancer - a disease that after all developed within ourselves and other animals as we became part of that evolving natural world.