Previous reports have documented that some isothiocyanates (ITCs) prevent the formation of cancers in animal models.1-4) 6-(Methylsulfinyl)hexyl isothiocyanate (6-MITC) is found in wasabi (Wasabia japonica), a Japanese indigenous herb, and a variety of studies on the anticancer properties of 6-MITC have been described, 5,6) with 6-MITC attracting great attention as a new possible candidate for controlling cancer cell progression and metastasis. Anticancer activity of 6-MITC in vitro was studied with a human cancer cell (HCC) panel and 6-MITC directly affected the cells in the HCC panel.5) A suppression was found in the growth and survival of the cells in culture, and the affected cells were very specific, which included breast cancer and melanoma cell lines. A "COMPARE" analysis using a computerized algorithm, which was based on the HCC database, suggested the suppression mechanism of 6-MITC is unique, involving multiple pathways, and may be different from those of other known chemicals. Another 6-MITC-related anticancer study involves the oral administration of 6-MITC and its effects on the macroscopic pulmonary metastasis. Murine B16-BL6 melanoma cells were injected subcutaneously or intravenously in C57BL/6J mice and the effects of 6-MITC on the metastatic foci formation in the lungs were analyzed.6) The number of metastasized cells in the lungs was significantly reduced by the administration of 6-MITC, and 56% of foci formation was inhibited by the 2 week-prior administration, whereas only 27% inhibition was obtained by the concomitant administration with the cancer cell injection.Anti-cancer activities of ITCs largely involve modulation of metabolism for carcinogens through inhibition of the phase 1 enzymes and/or induction of the phase 2 enzymes, such as glutathione S-transferase and quinone reductase (QR). [7][8][9][10][11][12] In our previous study, we reported that 6-MITC induced QR activity in Hepa1c1c7 cells in a dose-dependent manner.13) However, when the dose level was high at 80 mM, the effect of 6-MITC was nullified and it significantly reduced QR activity. Augmentation of QR activity by 6-MITC seemed to be due to the increase in its mRNA expression, and the inhibition of its activity at 80 mM was ascribed to the reduced gene expression. This negative effect of 6-MITC at 80 mM was overcome by N-acetyl-L-cysteine (NAC) treatment but its mechanism is still unknown.High-performance liquid chromatography (HPLC) combined with mass spectrometry (MS) has been documented as a useful tool for detecting bioactive components, such as flavonoids, puerarin and saponins in herbal medicines, [14][15][16][17] and HPLC with an ultraviolet-ray (UV) detector and MS has been applied for determining some of these components. 18,19) Although HPLC-MS is a more expensive and complex option than other HPLC or TLC detectors, it can greatly simplify sample pre-treatment procedures and shorten separation times in HPLC due to the high selectivity and sensitivity of MS detection. 20) As mentioned earlier, the negative effect o...
