Pulse-modulated extremely high-frequency electromagnetic radiation protects cellular DNA from the damaging effects of physical and chemical factors in vitro

Using an alkaline version of the comet assay, we investigated the protective effects of extremely high-frequency electromagnetic radiation for DNA in mouse peripheral blood leukocytes on the damaging effects of X-ray radiation, hydrogen peroxide, and the alkylating agent methyl methanesulfonate. It was shown that the pre-exposure of cells to pulse-modulated low-intensity electromagnetic radiation (42.2 GHz, 100 µW/cm2, exposure for 20 min, and the modulation frequency of 1 and 16 Hz) exerted a protective effect by reducing the level of DNA damage by 20–45% depending on the type of genotoxic agent. The effectiveness of pulse-modulated radiation increases in the following series: methyl methanesulfonate–X-rays–hydrogen peroxide. Continuous electromagnetic radiation does not have such a protective effect. The mechanisms of the detected protective effects may be associated with the induction of an adaptive response by reactive oxygen species that are formed by the action of pulse-modulated radiation in nanomolar concentrations. © 2015, Pleiades Publishing, Inc.