Oxygenated water does not induce genotoxic effects in the comet assay.

Drinking of oxygenated water (i.e. water with increased concentration of physically dissolved oxygen) is said to improve oxygen availability of the body and will do the consumer good. However, increased oxygen concentrations can also lead to an increased production of reactive oxygen species (ROS). If antioxidant defences are not completely efficient, ROS can cause cell injury including DNA damage. We therefore investigated whether drinking of oxygenated water can lead to increased DNA damage in peripheral blood cells of test subjects. We also tested whether direct exposure of V79 Chinese hamster cells to oxygenated medium or oxygenated Hank's solution for various time periods induces DNA damage. Induction of DNA damage was measured with the alkaline comet assay (single cell gel electrophoresis). The comet assay, in particular the modification with FPG post-treatment for the determination of oxidative DNA base damage, has been proven to be extremely sensitive for the detection of oxygen-induced DNA damage. However, both the in vivo and the in vitro studies with the comet assay in the absence and presence of FPG post-treatment did not provide evidence for a genotoxic effect of oxygenated water.