Asian and western horticultural species of the brassica family with anti-cancer potential

Abstract

Members of the Brassica family include a wide range of horticultural crops (eg. cabbage, mustard, rocket, pak choy, daikon, broccoli) all of which contain compounds known as glucosinolates. Certain glucosinolates and their breakdown products, isothiocyanates, have been linked to a reduction in the prevalence of certain types of cancer (eg. colorectal cancer). One glucosinolate that has recently received much publicity for its anti-cancer action is glucoraphanin, a compound found in high abundance in broccoli, particularly in seed and sprouted-seed. Many other glucosinolates exist with anti-cancer potential, located within different members of the Brassica family. The present investigation identified the glucosinolates present in seed of a range of Asian and Western cultivated species. Based on the known CD values of individual isothiocyanates, the anti-cancer potential of each species was estimated. Seed of species with a similar anticancer-potential to broccoli included red radish and daikon. Seed of species with moderate anti-cancer potential included garden cress, rocket, kale and watercress. The remaining species had moderate to low anti-cancer potential. Other factors that can negatively impact on anti-cancer potential include the ESP-related conversion of glucosinolates to nitriles (rather than isothiocyanates) in some species, and the presence of ‘anti-nutritional’ glucosinolates.