Anti-cancerous effects of Wasabia japonica extract in Hep3B liver cancer cells via ROS accumulation, DNA damage and p73-mediated apoptosis

Wasabia japonica (WJ) is widely used as a food spice in Japan and Taiwan. Wasabia isorbiocyanates have effects on detoxification, anti-inflammation, and the induction of cancer cell apoptosis. HPLC and LC-MC/MC analysis of the water extract of WJ (WJE) prepared in this study contained 5-(methylsulfinyl) pentyl ITC, 6-(methylsulfinyl) hexyl ITC and 7-(methylsulfinyl) heptyl ITC. WJE (0.25 to 1 mg/ml) induced a strong cytotoxic effect in Hep3B cells. As evidenced by DNA condensation, flow cytometry and Western blotting, the cytotoxicity of WJE occurred by inducing ROS accumulation, DNA damage and p73-mediated apoptotic death through both intrinsic and extrinsic pathways. The xenograft model demonstrated that WJE was able to suppress tumour growth via a mechanism similar to cellular studies. Our results are the first to demonstrate the anti-cancerous activities of a WJ extract prepared from fresh wasabi rhizomes on liver cancer cells. This investigation supports the future application of WJ in liver cancer therapy.