A reduced incidence of different types of
cancer has been linked to consumption of Brassica vegetables, and there is evidence that
glucosinolates (GSLs) and their hydrolysis products play a role in reducing
cancer risk. Wasabi (Wasabia japonica) and horseradish (Armoracia rusticana), both Brassica vegetables, are widely used condiments both in Japanese cuisine and in the United States. Desulfosinigrin (DSS) (1) was isolated from a commercially available wasabi
powder and from fresh wasabi roots.
Sinigrin (2) was isolated from horseradish roots. DSS and
sinigrin were evaluated for their inhibitory effects on
cyclooxygenase-1 (COX-1) and
cyclooxygenase-2 (COX-2)
enzymes, on lipid peroxidation, and on the proliferation of human colon (HCT-116), breast (MCF-7), lung (NCIH460), and central nervous system (CNS, SF-268)
cancer cell lines. DSS did not inhibit COX
enzymes or lipid peroxidation at 250 microg/ml.
Sinigrin inhibited lipid peroxidation by 71% at 250 microg/ml. However, DSS promoted the growth of HCT-116 (colon) and NCI H460 (lung) human
cancer cells as determined by the MTT assay in a concentration-dependent manner. At 3.72 microg/ml, a 27% increase in the number of viable human HCT-116
colon cancer cells was observed; the corresponding increases at 7.50 and 15 microg/ml were 42 and 69%, respectively. At 60 microg/ml, DSS doubled the number of HCT-16
colon cancer cells. For NCI H460 human
lung cancer cells, DSS at 60 microg/ml increased the cell number by 20%.
Sinigrin showed no proliferating effect on the
tumor cells tested. This is the first report of the
tumor cell-proliferating activity by a desulfoglucosinolate, the biosynthetic precursor of GSLs found in Brassica spp.