Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/23/2002
Publication Date: 3/23/2002
Citation: Finley, J.W. 2002. Accumulation of selenium by broccoli: a unique anti-cancer agent [abstract]. 13th Crucifer Genetics Workshop.
Technical Abstract: Selenium (Se) is an essential nutrient that at high levels may be toxic to plants and animals. Clinical trials have demonstrated that supplemental intakes of Se may decrease the risk of prostate, colon and lung cancer. Few foods actively accumulate selenium, but broccoli grown in the presence of Se may increase its Se concentration as much as 10,000 fold. This ability to accumulate Se without impairing plant metabolism is apparently a result of the conversion of Se in the soil to a relatively non-toxic form in the plant (Se methyl selenocysteine, or SeMSC). Because methylated forms of Se appear to be more effective against carcinogenesis than other forms, we have investigated the anti-carcinogenic properties of Se from broccoli in models of colon and mammary cancer. We have used aberrant crypt foci (ACF) as a model of colon cancer, and Se from high-Se broccoli florets or high-Se broccoli sprouts reduced chemically induced ACF to 40-25% of controls. Likewise, Se from broccoli reduced tumor burden in a mouse model of spontaneous mammary cancer. Metabolic studies have demonstrated that Se in broccoli is not as effective as other chemical forms for accumulation in animal tissues (decreased toxicity) and activation of Se enzymes. Therefore, because of its lower toxicity and increased activity against cancer, high-Se broccoli may be an ideal means of providing supplemental Se.