Hazardous effects of electromagnetic radiation emitted by mobile phones on the brain and cochlea of albino rats: role of melatonin and vitamin C

ABSTRACT

The wide spread of mobile phone communication raises questions about the effects of electromagnetic fields [EMFs] on the human body. The objective of this study was to examine effects of exposure to radio frequency EMFs emitted by mobile phones on the brain and cochlea, and to investigate the role of melatonin and vitamin C on these effects in adult rats. Forty two adult albino rats were randomly grouped into 7 groups [six rats each]. Group I [Negative control], Group II [Sham-operated without exposure to EMR], Group III [rats treated with melatonin], Group IV [rats treated with vitamin C], Group V [Exposed group, rats were exposed to mobile phone radiation, Group VI [Exposed and treated with melatonin] and Group VII [Exposed and treated with Vit C]. Groups V, VI and VII were exposed to mobile phone radiation for 60 min/day, for 30 days using an experimental exposure device. Glutathione [GSH] level and superoxide dismutase enzyme [SOD] activity in brain tissue and blood, gamma-aminobutyric acid [GABA] and norepinephrine [NE] levels in the brain tissue and serum corticosterone level were estimated in all examined groups. Histopathological examination of brain tissue and cochleae [organ of Corti] by light microscope was also performed for all groups. The results of the study revealed that exposure to mobile phone radiations induced significant decrease in GSH level and SOD enzyme activity in brain tissue and blood, decrease GABA levels and increase NE levels in brain tissue, and significant increase in serum corticosterone level. Brain tissue of exposed rats revealed small dispersed neurons with dark swollen nuclei in undifferentiated layers of the cerebral cortex, deeply stained swollen nuclei of Purkinje cells and hypocelularity of granular layer with disorganization of molecular layer of cerebellum and degenerated neurons with dark pyknotic and swollen nuclei on both sides the dentate gyrus of hippocampus. Complete destruction of all cells of the organ of Corti and neurons of spiral ganglion was noticed in the exposure group. Co-administration of melatonin or Vit. C throughout the exposure period showed significant increase in the levels of GSH, SOD enzyme activity in brain tissue and blood, increase GABA and decrease in NE levels in brain tissue and significant decrease in serum corticosterone level compared to exposed group. Furthermore, brain and organ of Corti of rats exposed to mobile phone and treated with melatonin showed nearly normal structure. While, co-administration of Vit. C throughout the exposure period showed mild protection of brain tissue and organ of Corti. Mobile phone radiations induced both biologically and histopathologically deleterious effects on the brain tissues and organ of Corti, these effects were ignorantly reversed nearly to normal with co-administration of melatonin, while mild reverse was noticed with co-administration of Vit. C. It is recommended to use antioxidants for mobile phone users especially those who use it for long periods, and to decrease the calls period as much as possible