CONSUMPTION OF BRUSSELS-SPROUTS RESULTS IN ELEVATED ALPHA-CLASS GLUTATHIONE-S-TRANSFERASE LEVELS IN HUMAN BLOOD-PLASMA

The effect of consumption of glucosinolate-containing Brussels sprouts on alpha-class glutathione S-transferase levels in human blood plasma was investigated in 10 healthy, male, nonsmoking volunteers. Followin g a 3-week run-in period, five volunteers continued on a glucosinolate -free diet during a subsequent 3-week intervention period (control gro up), while the other five (sprouts group) consumed 300 g of cooked Bru ssels sprouts per day, at the expense of 300 g of a glucosinolate-free vegetable. alpha-Class glutathione S-transferases were measured by ra dioimmunoassay. In the control group, similar alpha-class glutathione S-transferase levels were observed in both periods (P = 0.814), while in the sprouts group the alpha-class glutathione S-transferase levels were elevated by a factor of 1.4 (P = 0.002). We hypothesize that the elevated alpha-class GST levels in plasma reflect GST-alpha induction in tissues such as liver and small intestine under non-toxic condition s. The present findings indicate that alpha-class GST levels in plasma may be used as a biomarker for alpha-class GST levels in tissues. In addition, they support the results of epidemiologic studies that consu mption of cruciferous vegetables may result in a decreased cancer risk .