Sulforaphane, a primary phytochemical found naturally in broccoli, cauliflower and other cruciferous vegetables, has been shown to selectively target and kill cancer cells while leaving normal prostate cells healthy and unaffected, according to a study published in the journal Molecular Nutrition and Food Research.
It appears that sulforaphane, which is found at fairly high levels in cruciferous vegetables, is an inhibitor of histone deacetylase, or HDAC enzymes. HDAC inhibition is one of the more promising fields of cancer treatment and is being targeted from both a pharmaceutical and dietary approach, scientists say.
“Just because a phytochemical or nutrient is found in food doesn’t always mean its safe, and a lot can also depend on the form or levels consumed. But this does appear to be a phytochemical that can selectively kill cancer cells, and that’s always what you look for in cancer therapies," said Emily Ho, lead author on the study and associate professor in the OSU Department of Nutrition and Exercise Sciences.
Previous studies conducted with mouse models showed prostate tumor growth was slowed by a diet containing sulforaphane. Ho said it is well documented that sulforaphane can target cancer cells through multiple chemopreventive mechanisms, and this study shows sulforaphane selectively targets benign hyperplasia cells and cancerous prostate cells while leaving the normal prostate cells unaffected.
Another study conducted by Cramer and Jeffery found the manner in which broccoli is prepared and consumed, as well as teaming broccoli with broccoli sprouts, may make the vegetable's anti-cancer effect almost twice as powerful.
"Broccoli, prepared correctly, is an extremely potent cancer-fighting agent. To get broccoli's benefits, though, the enzyme myrosinase has to be present; if it's not there, sulforaphane, broccoli's cancer-preventive and anti-inflammatory component, doesn't form," said Elizabeth Jeffery, a University of Illinois professor of nutrition.
John D. Clarke, Anna Hsu, Zhen Yu, Roderick H. Dashwood, Emily Ho. Differential effects of sulforaphane on histone deacetylases, cell cycle arrest and apoptosis in normal prostate cells versus hyperplastic and cancerous prostate cells. Molecular Nutrition & Food Research, published online 4 MAR 2011; DOI: 10.1002/mnfr.201000547Cramer JM, Jeffery EH. Sulforaphane absorption and excretion following ingestion of a semi-purified broccoli powder rich in glucoraphanin and broccoli sprouts in healthy men. Nutr Cancer. 2011; 63(2):196-201.