Investigation of the effects of different frequency radiofrequency radiation emitted from cellular phone on brain tissue dna damage and some oxidant - antioxidant enzymes in rats

Investigation of the Effects of Different Frequency Radiofrequency Radiation Emitted from Cellular Phone on Brain Tissue DNA Damage and Some Oxidant - Antioxidant Enzymes in Rats (ALKIŞ M.E. Doctorate Dissertation, Page: 110, Diyarbakir 2017) The number of users and usage times of mobile phones which are becoming indispensable of modern life are increasing day by day with the development of communication technology. With the latest 4.5G generation mobile phones offering uninterrupted, fast and high quality internet service, more radio frequency radiation is exposed in everyday life. The brain tissue is one of the main tissues which are exposed to radiation emitting from cell phones. Based on both in vitro and in vivo studies, it is claimed that the radio frequency radiation (RFR) may cause DNA damage in tissues. The aim of this study is to investigate the effects of radiations at different radio frequencies (900MHz, 1800MHz and 2100MHz) on brain tissues' DNA damage, some oxidant and antioxidant enzymes. In our study, 28 Sprague dawley male rats were randomly divided into 4 equal groups (n: 7). It is defined as; 1. group: sham-control, 2. group: 900MHz, 3. group: 1800MHz and 4. group: 2100MHz. Experimental group rats were exposed to RF radiation from RF generators each day, 2hours/day for 6 months. The sham-control group rats were subjected to the same experimental procedure except of RF application. The mean ± standard deviation power density and electric field values in plexiglass cages were measured respectively and the results were found as follows: 0.1841±0.078 mW/cm2, 26.42±6V/m at 900 MHz frequency; 0.2392±0.046 mW/cm2, 30.04±2.88 V/m at 1800 MHz frequency and 0.1160±0.046 mW/cm2, 20.95±4.97V/m at 2100 MHz frequency. In the end of the study, we tried to determine the deoxyribonucleic acid (DNA) damage by employing the Comet assay technique to the sections obtained from the brain tissue of the rats. Additionally malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), total antioxidant status (TAS), total oxidant status (TOS) analyses were conducted in the brain tissue samples along with oxidative stress index (OSI) levels and serum nitric oxide (NO) levels for the evaluation of oxidative stress, lipid peroxidation and oxidative DNA damage status. With regard to the biochemical findings it was determined all groups significantly differed (p <0.01) and all TAS levels decreased significantly in all experimental groups but a significant increase was found in TOS, OSI, MDA and 8-OHDG values compared to the sham group. As regards nitric oxide (NO), when the experimental groups were compared to the sham-control group, the nitric oxide levels significantly increased in the three experimental groups. However, while the increase between the 1800 MHz, 2100 MHz groups and sham-control group were significant (p <0.05), the increase between the 900 MHz and the sham-control was found insignificant (p> 0.05). Regarding Comet assay the experimental groups showed an increase in tail moment and tail intensity values compared to the sham group but the increase in tail moment parameter was insignificant (p> 0.05), while the increase in tail intensity parameter was found to be significant only in the 2100 MHz group (p <0.01). It was determined that as the frequency levels increased all parameter values under investigation also increased. In conclusion, the exposure of rats to 900, 1800 and 2100 MHz RF radiation emitting from mobile phones may cause oxidative damage, induce an increase in lipid peroxidation and increase oxidative DNA damage formation in rat brain tissues. Furthermore, 2100 MHz RF radiation may cause formation of DNA single strand breaks. Keywords: Radio frequency radiation, Comet assay, Brain, Oxidative stress, Oxidant-antioxidant level, Lipid Peroxidation, DNA damage, Nitric oxide.