Brassica oilseeds contain a variety of glucosinolates that have traditionally been considered as antinutritional factors with goitrogenic effects (Shahidi et al., 1997). Their breakdown products, upon the action of myrosinase, are nitriles, thiocyanates, isothiocyanates, and possibly oxazolidinethione. Although glucosinolate degradation products are toxic, they are also responsible for the desirable pungent flavor and biting taste of mustard and Wassabi (Japanese horseradish). However, certain glu-cosinolates and their corresponding isothiocyanates have been found to exert potential benefits in inhibiting chemical and other types of carcinogenesis. For example, glucobrassicin and its myrosinase-catalyzed transformation products have been shown to inhibit carcinogenesis induced by polycyclic aromatic hydrocarbons and other initiators (Loft et al., 1992; Talalay and Zhang, 1996). An autolysis product of glucobrassicin, indole-3-carbinol, was found to induce monooxygenase (Loub et al., 1975) and glutathione-S-transferase (Sparnins et al., 1982), and inhibit development of forestomach, mammary, and pulmonary tumors (Wattenberg and Loub, 1978). Thus, potential benefits of certain glucosinolates may require the design of oilseeds where healthful glucosinolates are retained, or perhaps their content increased at the expense of their harmful counterparts.

0 0

Post a comment