According to the two-stage cell transformation theory, cancer cells first receive initiation, which is mainly caused by DNA damage and then promotion, which enhance transformation. Since murine Balb/c 3T3 cells lose contact inhibition by cell transformation, the cells have been widely used for transformation experiments. Electrolyzed reduced water (ERW) is a health beneficial alkaline drinking water containing high concentration of dissolved hydrogen, and can scavenge intracellular reactive oxygen species (ROS). ERW contains a small amount of platinum (Pt) nanoparticles as atomic hydrogen donor and ROS-scavenger. Therefore, ERW supplemented with Pt nanoparticles (ERW/Pt) can be considered as a model of strong ERW. Here, we report that ERW/Pt can prevent transformation of Balb/c 3T3 cells. ERW was prepared by electrolysis of 0.002 M NaOH. Balb/c 3T3 cells were treated with 3-methyl cholantrene (MCA) as an initiation compound, followed by the treatment with phorbol-12-myristate-13-acetate (PMA) as a promotion compound. The cell transformation induced by MCA/PMA was strongly suppressed by ERW/Pt treatment, especially at the stage of promotion.
Analysis of intracellular ROS level showed that ERW/Pt could decrease excess intracellular ROS induced by PMA. These results suggested that ERW/Pt suppressed cell transformation at promotion stage by its ROS scavenging effect.