Melatonin reduces oxidative stress induced by chronic exposure of microwave radiation from mobile phones in rat brain.
OBJECTIVE
The aim of the study was to evaluate the intensity of oxidative stress in the brain of animals chronically exposed to mobile phones and potential protective effects of melatonin in reducing oxidative stress and brain injury.


METHODS
Experiments were performed on Wistar rats exposed to microwave radiation during 20, 40 and 60 days. Four groups were formed: I group (control)- animals treated by saline, intraperitoneally (i.p.) applied daily during follow up, II group (Mel)- rats treated daily with melatonin (2 mg kg(-1) body weight i.p.), III group (MWs)- microwave exposed rats, IV group (MWs + Mel)- MWs exposed rats treated with melatonin (2 mg kg(-1) body weight i.p.). The microwave radiation was produced by a mobile test phone (SAR = 0.043-0.135 W/kg).


RESULTS
A significant increase in the brain tissue malondialdehyde (MDA) and carbonyl group concentration was registered during exposure. Decreased activity of catalase (CAT) and increased activity of xanthine oxidase (XO) remained after 40 and 60 days of exposure to mobile phones. Melatonin treatment significantly prevented the increase in the MDA content and XO activity in the brain tissue after 40 days of exposure while it was unable to prevent the decrease of CAT activity and increase of carbonyl group contents.


CONCLUSIONS
We demonstrated two important findings; that mobile phones caused oxidative damage biochemically by increasing the levels of MDA, carbonyl groups, XO activity and decreasing CAT activity; and that treatment with the melatonin significantly prevented oxidative damage in the brain.
Sokolovic
Dusan
D
Institute of Biochemistry, Medical Faculty in Nis, Serbia. soko@medfak.ni.ac.yu
Djindjic
Boris
B
Nikolic
Jelenka
J
Bjelakovic
Gordana
G
Pavlovic
Dusica
D
Kocic
Gordana
G
Krstic
Dejan
D
Cvetkovic
Tatjana
T
Pavlovic
Voja
V
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects*; D040421:Cell Phone; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004781:Environmental Exposure; D007274:Injections, Intraperitoneal; D008297:Male; D008550:Melatonin / Q000008:administration & dosage*; D008872:Microwaves; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D011837:Radiation-Protective Agents / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*
D011837:Radiation-Protective Agents; D017382:Reactive Oxygen Species; D008550:Melatonin