Study type: Medical/biological study (experimental study)

Melatonin reduces oxidative stress induced by chronic exposure of microwave radiation from mobile phones in rat brain. med./bio.

Published in: J Radiat Res 2008; 49 (6): 579-586

Aim of study (acc. to author)

To study the intensity of oxidative stress in the brain of animals chronically exposed to cell phones and potential protective effects of melatonin in reducing oxidative stress and brain injury.

Background/further details

Experiments were performed on 84 adult male rats exposed to microwave irradiation during 20, 40 and 60 days (4 hours/day during light period). Four groups (each 21 animals) were formed: 1) control-rats treated daily by saline, 2) rats treated daily with melatonin (2 mg/kg body weight), 3) microwave exposed rats and 4) microwave exposed rats treated with melatonin (2 mg/kg body weight).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: CW
Exposure duration: repeated daily exposure, 4 h/day, for 20, 40, and 60 days

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Charakteristic
Exposure duration repeated daily exposure, 4 h/day, for 20, 40, and 60 days
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber Seven animals were housed and exposed collectively in pure polycarbonate cages of 30 Π40 Π40 cm (W ΠL ΠH).
Setup Every four hours, two cages from the MW and MW+Mel groups were transferred to a wooden desk with rubber surface placed at 5 m from the housed rats, and a mobile test phone was put in a small perforated polycarbonate cell in the center of each cage preventing damage caused by rats.
Sham exposure A sham exposure was conducted.
Additional info Two dummy phones were put in the control and Mel group cages at the same time.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 18.356 V/m - measured - 9.88-18.356 V/m
magnetic flux density 8.69 µT - measured - 4.68-8.69 µT
SAR 0.135 W/kg average over mass calculated whole body 0.043-0.135 W/kg

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

A significant increase in the brain tissue malondialdehyde and carbonyl group concentration was registered during the whole exposure. Decreased enzyme activity of catalase and increased activity of xanthine oxidase remained after 40 and 60 days of exposure to mobile phones. Melatonin treatment significantly prevented the increase in the malondialdehyde content and xantine oxidase activity in the brain after 40 days of exposure while it was unable to prevent the decrease of catalase activity and increase of carbonyl group contents.
Mobile phones caused oxidative damage biochemically by increasing the levels of malondialdehyde, carbonyl groups, xanthine oxidase and decreasing catalase enzyme activity. Treatment with the melatonin significantly prevented oxidative damage in the brain.

Study character:

Study funded by

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