The Effects of Melatonin on Oxidative Stress Parameters and DNA Fragmentation in Testicular Tissue of Rats Exposed to Microwave Radiation
Sokolovic D, Djordjevic B, Kocic G, Stoimenov TJ, Stanojkovic Z, Sokolovic DM, et al. The Effects of Melatonin on Oxidative Stress Parameters and DNA Fragmentation in Testicular Tissue of Rats Exposed to Microwave Radiation. Adv Clin Exp Med. 2015 May-Jun;24(3):429-36. doi: 10.17219/acem/43888.
BACKGROUND: Microwaves from mobile phones are one of the environmental toxicants that are capable of compromising male fertility by inducing oxidative stress and apoptosis in the testes. Melatonin is a lipophilic tryptophan indole amine and a potent antioxidant.
OBJECTIVES: The aim of the study was to evaluate the effect of melatonin treatment on oxidative stress parameters and DNA fragmentation in the testicular tissue of rats exposed to microwave radiation (4 h/day).
MATERIAL AND METHODS: Adult Wistar rats were divided in 4 groups: I - treated with saline; II - treated with melatonin; III - exposed to microwaves; IV - exposed to microwaves and treated with melatonin. The melatonin (2 mg/kg ip) was administered daily. The animals were sacrificed after 20, 40 and 60 days.
RESULTS: Melatonin treatment prevented previously registered increases in malondialdehyde after only 20 days. Furthermore, it reversed the effects of microwave exposure on xanthine oxidase (after 40 days) and acid-DNase activity (after 20 days). However, neither protein carbonyl content nor catalase and alkaline Dnase activity were changed due to melatonin treatment.
CONCLUSIONS: Melatonin exerts potent antioxidant effects in the testes of rats exposed to microwaves by decreasing the intensity of oxidative stress; it also reduces DNA fragmentation.
The animals were exposed to MWs for 20, 40 and 60 days (4 h per day during the light period). The MWs were produced by a Nokia 3110 mobile test phone (Nokia Mobile Phones Ltd.) .... During MW exposure, 8 rats were able to move freely in a 100% plastic cage without any metallic fittings. A continuous wave near-field electromagnetic signal (900 MHz) for the Global System for Mobile Communication (GSM) was used for the purposes of the experiment ... Electric field intensity (E) ranged from 9.88 V/m to 18.356 V/m, and magnetic field intensity (B) ranged from 4.68 mT to 8.69 mT. The whole-body specific energy absorption rate (SAR) was estimated at 0.043–0.135 W/kg using data for a rotating ellipsoidal rat model.
The animals were divided in 4 experimental groups. Each group consisted of 21 animals housed in 3 cages (7 animals in each). Group I (the control group) consisted of rats treated with 0.9 % saline; Group II (Mel) consisted of rats treated with melatonin (2 mg per kg–1 body weight by IP injection); Group III (MWs) comprised rats exposed to MWs; and Group IV (MWs + Mel) was made up of rats exposed to MWs and treated with melatonin (2 mg per kg–1 body weight by IP injection). The melatonin was administered every morning at . as proposed by Drago et al. . The melatonin was administered intraperitoneally in a single dose of 2 mg/kg–1 in order to avoid the neuromodulatory effect of melatonin. In the control rats, isotonic saline solution (equal to the volume of melatonin) was given intraperitoneally every day during the follow-up.
According to the results of the present study, melatonin caused a significant decrease in oxidative stress intensity, reflected in the decrease in MDA levels. In addition to this, melatonin caused a reversal of the effects of MW radiation on XO activity in the testicular tissue, lowering XO-induced oxidative stress. On the other hand, melatonin showed no significant ability to reverse the effects of MW exposure on catalase levels in testicular tissue. However, melatonin caused a significant decrease in acid DNase activity, reflecting reduced amounts of apoptosis in the testicular tissue exposed to MWs. In conclusion, melatonin exerts potent protective effects in the testes of rats exposed to microwaves by decreasing oxidative stress intensity and DNA fragmentation.
Effect of Mobile Phones on Sperm Quality
Igor Yakymenko, Olexandr Tsybulin, Evgeniy Sidorik, Diane Henshel, Olga Kyrylenko, and Sergiy Kyrylenko, Oxidative mechanisms ofbiological activity of low-intensity radiofrequency radiation. Electromagnetic Biology and Medicine. Posted online on July 7, 2015. doi:10.3109/15368378.2015.
AbstractThis review aims to cover experimental data on oxidative effects of low-intensity radiofrequency radiation (RFR) in living cells.
Analysis of the currently available peer-reviewed scientific literature reveals molecular effects induced by low-intensity RFR in living cells; this includes significant activation of key pathways generating reactive oxygen species (ROS), activation of peroxidation, oxidativedamage of DNA and changes in the activity of antioxidant enzymes. It indicates that among 100 currently available peer-reviewed studies dealing with oxidative effects of low-intensity RFR, in general, 93 confirmed that RFR induces oxidative effects in biologicalsystems. A wide pathogenic potential of the induced ROS and their involvement in cell signaling pathways explains a range ofbiological/health effects of low-intensity RFR, which include both cancer and non-cancer pathologies.
In conclusion, our analysis demonstrates that low-intensity RFR is an expressive oxidative agent for living cells with a high pathogenic potential and that the oxidative stress induced by RFR exposure should be recognized as one of the primary mechanisms of the biological activity of this kind of radiation.
The analysis of modern data on biological effects of lowi-ntensity RFR leads to a firm conclusion that this physical agent is a powerful oxidative stressor for living cell. The oxidative efficiency of RFR can be mediated via changes in activities of key ROS-generating systems, including mitochondria and non-phagocytic NADH oxidases, via direct effects on water molecules, and via induction ofconformation changes in biologically important macromolecules. In turn, a broad biological potential of ROS and other free radicals, including both their mutagenic effects and their signaling regulatory potential, makes RFR a potentially hazardous factor for human health. We suggest minimizing the intensity and time of RFR exposures, and taking a precautionary approach towards wireless technologies in everyday human life.
Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley
Electromagnetic Radiation Safety
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