Inhibitory Effects of 6-Methylsulfinylhexyl Isothiocyanate on Superoxide Anion Generation from Differentiated HL-60 Human Promyelocytic Leukemia Cells

Abstract

Wasabi is a plant of Japanese origin. It belongs to the Brassicaceae family and produces various isothiocyanates (ITCs). Because 6-methylsulfinylhexyl isothiocyanate (6-MSITC) is particularly stable among wasabi ITCs, it has potential as a functional compound. To clarify the antioxidative activity of 6-MSITC, we investigated its inhibitory effect on superoxide anion (O 2 • −) generation from phorbol 12-myristate 13-acetate (PMA)-stimulated differentiated HL-60 human promyelocytic leukemia cells. Our results showed that 6-MSITC inhibited O 2 • − generation in these cells (IC 50 value: 28.9 μM). 6-MSITC at 0.8, 4, and 20 μM significantly inhibited the consumption of exogenously added NADH compared with the control. On the other hand, < 263 μM 6-MSITC did not scavenge O 2 • − in cell-free experiments. Therefore, we suggest that 6-MSITC inhibited O 2 • − generation by decreasing an enzymatic reaction with NADPH oxidase. Thus, 6-MSITC may be useful as a functional compound.