Proteome alterations induced in human white blood cells by consumption of Brussels sprouts: Results of a pilot intervention study.

Epidemiological studies indicate a correlation of cruciferous vegetables consumption with reduced incidence of cancer. This study was designed to investigate molecular mechanisms, which may help to understand the beneficial effects of Brussels sprout consumption. In order to avoid the limitations of in vitro model systems, we performed a dietary intervention study with five participants. We investigated, whether sprout consumption affects the proteome profile of primary white blood cells. In order to achieve maximal sensitivity in detecting specific adaptive proteome alterations, we metabolically labelled freshly isolated cells in the presence of (35) S-methionine/cysteine and performed autoradiographic quantification of protein synthesis. Proteins were separated by 2-DE and spots of interest were cut out, digested and identified by MS. After the intervention, we found a significant up-regulation of the synthesis of manganese superoxide dismutase (1.56-fold) and significant down-regulation of the synthesis of heat shock 70 kDa protein (hsp70; 2.27-fold). Both proteins play a role in malignant transformation of cells. Hsp-70 is involved in the regulation of apoptosis, which leads to elimination of cancer cells, while SOD plays a key role in protection against reactive oxygen species mediated effects. Our findings indicate that the alteration of the synthesis of these proteins may be involved in the anticarcinogenic effects of cruciferous vegetables, which was observed in earlier laboratory studies with animals.