Wasabi: A Traditional Japanese Food That Contains an Exceedingly Potent Glutathione S-Transferase Inducer for RL34 Cells

In the course of our screening of edible plants on the induction of glutathione S-transferase (GST) activity in rat liver epithelial RL34 cells, 6-methylsulfinylhexyl isothiocyanate (MS-1TC) was isolated from wasabi (Wasabia japonica) as a potential inducer of GST. As a result from western blot analyses of GST expression induced by MS-ITC in RL34 cells, increasing of protein levels of both GST-Ya and GST-Yp were detected. And as a result from time dependent GSH level by MS-ITC, the GSH level in RL34 cells was initially decreased, then increased gradually to 1.8 times higher than its basal level after 12 hrs. By adding benzyl isothiocyanate (BITC) isolated from papaya instead of MSITC to the cells, the reactive oxygen intermediates (ROIs) detected by a fluorescence probe were increased immediately. From these data, we discuss the relation between levels of intracellular oxidation and the induction of GST.