Anti‐Malarial Activity of Allyl Isothiocyanate and N‐acetyl‐S‐(N‐allylthiocarbamoyl)‐l‐Cysteine

Scope Malaria remains one of the most important infectious diseases in the world. Allyl isothiocyanate (AITC) is a main ingredient of traditional spice Wasabia japonica , which is reported to have anti‐bacterial and antiparasitic activities. However, there is no information on effects of AITC against malaria. The present study investigates the anti‐malarial activity of dietary AITC in vivo and that of AITC metabolites in vitro. Methods and results The ad libitum administration of 35, 175, or 350 µM AITC‐containing drinking water to ICR mice significantly inhibit the parasitemia induced after infection with Plasmodium berghei . On the other hand, after single oral administration of AITC (20 mg kg −1 body weight), N ‐acetyl‐ S ‐( N ‐allylthiocarbamoyl)‐ l ‐cysteine (NAC‐AITC) as one of the AITC metabolites displays a serum C max of 11.4 µM at a T max of 0.5 h, but AITC is not detected at any time point. Moreover, NAC‐AITC shows anti‐malarial activity against Plasmodium falciparum in vitro, and its 50% inhibitory concentration (IC 50 ) against parasitemia is 12.6 µM. Conclusions These results indicate that orally administered AITC is metabolized to NAC‐AITC and exerts anti‐malarial activity against malaria parasites in blood, suggesting that the consumption of AITC‐containing food stuffs such as cruciferous plants may prevent malaria.