Vegetables yield anticancer chemical

Plant chemicals created during the preparation of some vegetables could kill colon cancer cells in a similar way to some cancer drugs.

Scientists at the Institute of Food Research (IFR) have found that natural chemicals sabotage the uncontrolled cell division of colon cancer cells. Cancer cells are immortal because they divide indefinitely, unlike healthy cells which commit suicide at the end of their lifecycle as part of a constant process of renewal.

The plant chemical allyl-isothiocyanate (AITC) is created when some brassica vegetables are chopped, chewed, cooked, processed and digested. AITC is a breakdown product of sinigrin, a chemical compound found in brassica vegetables including mustard, cabbage, horseradish, cauliflower, sprouts, swede, kale and wasabi.

“This is not a miracle cancer cure, but it does show that preventive dietary measures can be discovered and exploited in the same way as drugs”, said Professor Ian Johnson, head of the IFR team. “We have known for many years that sinigrin breakdown products kill cancer cells. But by uncovering a previously unknown part of the process working in a similar way to some anticancer drugs, we hope to show how important diet can be in your personal anticancer armoury”.

The IFR research will be published in Carcinogenesis in July, and is announced at the Science Media Centre in London today, alongside a new report by the World Cancer Research Fund to be published in 2006.

Professor Martin Wiseman, Medical and Scientific Adviser to WCRF said: “This is a valuable piece of research that puts in place another piece of the jigsaw on the way in which foods and nutrition could influence cancer risk. These sorts of studies together with other types of study contribute to a greater understanding of the role lifestyle plays in cancer prevention. Our ’portfolio’ approach allows us to take all different types of study and turn them into real steps that people can take to reduce their own risk of cancer.”

Cell division occurs when a parent cell divides to form two daughter cells during a four-stage process. In the second stage, known as metaphase, pole structures called spindles are created. Anything that disrupts the construction and deconstruction of these spindles halts the process of cell division. Previous studies have shown that damaged cells then commit suicide in a process called apoptosis.

“This is the first time the disruption of metaphase by an isothiocyanate has been explored in detail in relation to colon cancer prevention”, said Professor Johnson. The mechanism is similar to that used by some anticancer drugs. AITC appears to selectively target tumour cells unlike some other chemotherapeutic drugs that also harm healthy cells. However the mechanism needs further investigation.

This research was funded by the IFR’s core strategic grant from the BBSRC. It is part of ongoing work at the IFR to investigate the role of dietary microcomponents as protective factors against cancerous tumours of the colon and other digestive organs.